Re: [pinhole-discussion] zone plate
If it's down, you can get to much of the information mirrored on my site at http://mywebpages.comcast.net/hmpi/Pinhole/Articles/PinholeArticles.htm. Cheers - george --- John Fisher photobu...@hotmail.com wrote: Would you check the URL? I have tried to open the site.But haven't had any luck. thank you From: Paul Prober pro...@silcom.com Reply-To: pinhole-discussion@p at ??? To: pinhole-discussion@p at ??? Subject: [pinhole-discussion] zone plate Date: Fri, 25 Oct 2002 15:34:34 -0700 Hi, Chris Patton at Pinhole and beyond has a zone plate area. The site address is www.standford.edu/~cpatton/zp.html There is many zone plate lens, plus formulas for focusing the lens to subject. Paul Prober ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ _ Unlimited Internet access -- and 2 months free! Try MSN. http://resourcecenter.msn.com/access/plans/2monthsfree.asp ___ Post to the list as PLAIN TEXT only - no HTML Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ = Handmade Photographic Images - http://GLSmyth.com DRiP Investing - http://DRiPInvesting.org __ Do you Yahoo!? Y! Web Hosting - Let the expert host your web site http://webhosting.yahoo.com/
Re: [pinhole-discussion] zone plate
Stanford is incorrectly spelled, it should be STANFORD not STANDFORD. Guillermo - Original Message - From: John Fisher photobu...@hotmail.com Would you check the URL? I have tried to open the site.But haven't had any luck. thank you From: Paul Prober pro...@silcom.com Reply-To: pinhole-discussion@p at ??? Chris Patton at Pinhole and beyond has a zone plate area. The site address is www.standford.edu/~cpatton/zp.html There is many zone plate lens, plus formulas for focusing the lens to subject. Paul Prober
[pinhole-discussion] zone plate
Hi, Chris Patton at Pinhole and beyond has a zone plate area. The site address is www.standford.edu/~cpatton/zp.html There is many zone plate lens, plus formulas for focusing the lens to subject. Paul Prober
Re: [pinhole-discussion] zone plate question
- Original Message - From: Richard M. Koolish kool...@bbn.com I'm not sure I would describe the workings of a zone plate this way. It doesn't matter where in the zone plate (or pinhole) the light passes through. It doesn't bend at one place and not in another. The way you think about a zone plate or pinhole is that every clear point acts like a spherical wave is generated there. Then from any point in the image plane, you add up all the contributions to the intensity at that position from all the individual contributing points of the zone plate or pinhole. Some waves will be in phase and reinforce each other, and some waves will be out of phase and destructively interfere. In the simple case of a pinhole, you discover, that a point source of light in a subject does not generate a true point of light at the film or even a simple disk, as if a beam of light came through. Instead, you get the clasic diffraction pattern of a point, i.e. a central disk (the Airy disk) surrounded by diffraction rings. Note that every aperture produces diffraction. Even the most perfect lens can't focus a point source into an image point. Normally you don't see this because the diffraction pattern is so small. An f/10 lens produces an Airy disk of only .0134 mm for green light. On the other hand, if you place a very small pinhole, say 50 microns (.05 mm) 100 mm away from the film and shine a red laser pointer at it, you will get a diffraction disk of about 3 mm in diameter. The zone plate has a lot of chromatic aberration. That is, it can't focus different colors of light at the same place. That's what causes the characteristic glow around bright objects in a zone plate photograph. One color may get focussed sharply and the others will get spread out into disks of various sizes around the sharp point. I can't speak to the issue of how much this changes with the number of rings in the zone plate since I haven't done any research on this. It would be an interesting and fairly easy experiment to try. Dick Koolish (kool...@bbn.com) ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
Re: [pinhole-discussion] zone plate question
Kate, I don't think I mentioned distortion in my post. A faster ZP has more clear rings, but that causes no distortion, the ZP camera still is free of linear distortion (at least). The increased number of clear rings increase the ratio noise/signal, tho. Noise is the light that reaches the film without having suffered diffraction, therefore do not contribute to the sharpness of the image, this is the light mostly responsible for the characteristic glow of a ZP image. Signal is the light that grazes the edges of the rings, suffer diffraction and is focused on the film plane, this light is the one resposible for the sharpness of the image. Guillermo I'm not sure I would describe the workings of a zone plate this way. It doesn't matter where in the zone plate (or pinhole) the light passes through. It doesn't bend at one place and not in another. The way you think about a zone plate or pinhole is that every clear point acts like a spherical wave is generated there. Then from any point in the image plane, you add up all the contributions to the intensity at that position from all the individual contributing points of the zone plate or pinhole. Some waves will be in phase and reinforce each other, and some waves will be out of phase and destructively interfere. In the simple case of a pinhole, you discover, that a point source of light in a subject does not generate a true point of light at the film or even a simple disk, as if a beam of light came through. Instead, you get the clasic diffraction pattern of a point, i.e. a central disk (the Airy disk) surrounded by diffraction rings. Note that every aperture produces diffraction. Even the most perfect lens can't focus a point source into an image point. Normally you don't see this because the diffraction pattern is so small. An f/10 lens produces an Airy disk of only .0134 mm for green light. On the other hand, if you place a very small pinhole, say 50 microns (.05 mm) 100 mm away from the film and shine a red laser pointer at it, you will get a diffraction disk of about 3 mm in diameter. The zone plate has a lot of chromatic aberration. That is, it can't focus different colors of light at the same place. That's what causes the characteristic glow around bright objects in a zone plate photograph. One color may get focussed sharply and the others will get spread out into disks of various sizes around the sharp point. I can't speak to the issue of how much this changes with the number of rings in the zone plate since I haven't done any research on this. It would be an interesting and fairly easy experiment to try. Dick Koolish (kool...@bbn.com)
Re: [pinhole-discussion] zone plate question
- Original Message - From: Kate Hudec hu...@rcn.com I was interested in Guillermo's recent post about the relationship between number of rings and zone plate image sharpness. I have a converted Lubitel with 75mm focal length. If I wanted a camera with MORE distortion (which I understand from Guillermo's post would also be a faster camera), would I need a camera with a longer or shorter focal length? Thanks in advance. Kate, I don't think I mentioned distortion in my post. A faster ZP has more clear rings, but that causes no distortion, the ZP camera still is free of linear distortion (at least). The increased number of clear rings increase the ratio noise/signal, tho. Noise is the light that reaches the film without having suffered diffraction, therefore do not contribute to the sharpness of the image, this is the light mostly responsible for the characteristic glow of a ZP image. Signal is the light that grazes the edges of the rings, suffer diffraction and is focused on the film plane, this light is the one resposible for the sharpness of the image. As far as getting distortion using longer or shorter focal length: Very wide angles of view are considered distorting because of the radically altered perspective compared to what we are used to see with our own eyes. If this is the kind of distortion you refer to, then, with a 6x6 film format Lubitel, you would need to have (IMO) the lens (pinhole or ZP) as least as close as 30mm from the film plane (closer would be better). I too have a modified Lubitel and I believe that even carving the front of the camera and recessing the lens, it'd be impossible to install the lens 30mm or less from the film plane w/o having vignetting caused by the viewing lens. If you want to sacrifice the composing help the viewing lens afford, then I think it may be doable but it'd easier if you get a cheaper 6x6 folder camera remove the bellows and modify it as pinhole/ZP. Something like this one I made: ftp://penate:athx2...@members.home.com/penate/cameras/12.jpg or this ftp://penate:athx2...@members.home.com/penate/cameras/6x6.jpg Hope it answers your questions. Guillermo
[pinhole-discussion] zone plate question
I was interested in Guillermo's recent post about the relationship between number of rings and zone plate image sharpness. I have a converted Lubitel with 75mm focal length. If I wanted a camera with MORE distortion (which I understand from Guillermo's post would also be a faster camera), would I need a camera with a longer or shorter focal length? Thanks in advance. Kate
Re: [pinhole-discussion] Zone Plate Focus stringency
Re: [pinhole-discussion] Zone Plate Focus stringency
Re: [pinhole-discussion] Zone Plate Focus stringency
Just as a point of reference, if you're going for this look Well, this is my first time attempting something like this. I suspect they will all look the same pretty quickly and get boring. I can't see this one hanging on the wall very long. But, I'm usually heavy into composition, so its nice to have something that took off on its own. I'm trying to figure out how to incorporate a mirror into the image plane to get the image into a mirror-image Rorschach sort of format. you can also get it with a Lomo LC1 - it's a 35mm, with a lens with pinhole-like falloff, and it has an exposure meter that will keep the shutter open until it thinks it's received I just ordered a couple of fully manual Lomos from Free Style Camera. I'll see what it takes to convert those. $12 each, so not a huge investment. I did a search for the LC-1 online, but kept getting the LC-A. Is that the same? Looks like the one Free Style sells for $149. enough light - I've had it stay open 5 minutes. I have photos from halloween in Greenwich Village a few years ago that look very much like this one. I would suspect there is not much variability between photos taken while driving in traffic at night. ;-) Thanks for the info. Dwight
Re: [pinhole-discussion] Zone Plate Focus stringency
Just as a point of reference, if you're going for this look you can also get it with a Lomo LC1 - it's a 35mm, with a lens with pinhole-like falloff, and it has an exposure meter that will keep the shutter open until it thinks it's received enough light - I've had it stay open 5 minutes. I have photos from halloween in Greenwich Village a few years ago that look very much like this one. At 4:52 PM -0800 10/29/01, TSHACK wrote: - Original Message - From: Chris Peregoy pere...@gl.umbc.edu To: pinhole-discussion@p at ??? Sent: Monday, October 29, 2001 4:19 PM Subject: Re: [pinhole-discussion] Zone Plate Focus stringency [...] OK, I just got back a test roll from my hacked TLR zone plate camera. This is the only one worth reporting on. Its taken in traffic at night, but I flipped the image because it works better like that. Unfortunately, this doesn't really showcase the zoneplate qualities, unless its to give the lights a softer glow. But it certainly has a lot more life than the other shots on the roll. http://groups.yahoo.com/group/pinholegallery/files/DSZP/zpdashboard.jpg Focal length, 90mm, ASA 100, exposure 4 blocks at 25mph. I'm about to build a rig to use as a mount for the cameras that will fit in my moonroof opening and allow me to also reach up and trigger the shutter open and closed. ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/ --
Re: [pinhole-discussion] Zone Plate Focus stringency
- Original Message - From: Chris Peregoy pere...@gl.umbc.edu To: pinhole-discussion@p at ??? Sent: Monday, October 29, 2001 4:19 PM Subject: Re: [pinhole-discussion] Zone Plate Focus stringency TSHACK wrote: very good. thanks. That was going to be my reply Mom, Chris is making fun of me. OK, I just got back a test roll from my hacked TLR zone plate camera. This is the only one worth reporting on. Its taken in traffic at night, but I flipped the image because it works better like that. Unfortunately, this doesn't really showcase the zoneplate qualities, unless its to give the lights a softer glow. But it certainly has a lot more life than the other shots on the roll. http://groups.yahoo.com/group/pinholegallery/files/DSZP/zpdashboard.jpg Focal length, 90mm, ASA 100, exposure 4 blocks at 25mph. I'm about to build a rig to use as a mount for the cameras that will fit in my moonroof opening and allow me to also reach up and trigger the shutter open and closed.
Re: [pinhole-discussion] Zone Plate Focus stringency
TSHACK wrote: very good. thanks. That was going to be my reply -- HTML HEAD TITLE/TITLE /HEAD BODY BR Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/ /BODY /HTML
Re: [pinhole-discussion] Zone Plate Focus stringency
very good. thanks. - Original Message - From: Guillermo pen...@home.com To: pinhole-discussion@p at ??? Sent: Monday, October 29, 2001 2:34 PM Subject: Re: [pinhole-discussion] Zone Plate Focus stringency - Original Message - From: TSHACK tsh...@silver-bayou.com That was going to be my question. When you focus a lens using a ground glass, you are just making coincide the -ideally- flat image the lens is projecting with the surface of the ground glass, if you remove the ground glass, your eyes can't see the image, but the image is still there focused in the air. If you take a loupe and make its base coincide with that image in the air, in other words, with the Aerial Image, you will then see the the exact same image your film will see. This is best seen in axis with the lens. If your camera has GG, remove it an install a piece of clear glass, this will allow you to rest the loupe steady, otherwise, you will have to rely on your steady hand. Again, you will probably be surpriced of what you see. Guillermo ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.???/discussion/
Re: [pinhole-discussion] Zone Plate Focus stringency
- Original Message - From: TSHACK tsh...@silver-bayou.com That was going to be my question. When you focus a lens using a ground glass, you are just making coincide the -ideally- flat image the lens is projecting with the surface of the ground glass, if you remove the ground glass, your eyes can't see the image, but the image is still there focused in the air. If you take a loupe and make its base coincide with that image in the air, in other words, with the Aerial Image, you will then see the the exact same image your film will see. This is best seen in axis with the lens. If your camera has GG, remove it an install a piece of clear glass, this will allow you to rest the loupe steady, otherwise, you will have to rely on your steady hand. Again, you will probably be surpriced of what you see. Guillermo
Re: [pinhole-discussion] Zone Plate Focus stringency
- Original Message - From: Chris Peregoy pere...@gl.umbc.edu To: pinhole-discussion@p at ??? Sent: Monday, October 29, 2001 12:14 PM Subject: Re: [pinhole-discussion] Zone Plate Focus stringency Guillermo wrote: Although I do not recommend focusing of the zoneplate every time you make an exposure, I do recommend you focus it ONCE so you find out (if you wish) the actual focal length of it. To do it, aim your camera to a light source (light bulb for instance) or well illuminated object and focus on the aerial image, rather than on the ground glass. You will be surprised how good is the image a ZP produces. And yes, use a loupe. Guillermo What do you mean by aerial image That was going to be my question.
Re: [pinhole-discussion] Zone Plate Focus stringency
Guillermo wrote: Although I do not recommend focusing of the zoneplate every time you make an exposure, I do recommend you focus it ONCE so you find out (if you wish) the actual focal length of it. To do it, aim your camera to a light source (light bulb for instance) or well illuminated object and focus on the aerial image, rather than on the ground glass. You will be surprised how good is the image a ZP produces. And yes, use a loupe. Guillermo What do you mean by aerial image -- Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/
Re: [pinhole-discussion] Zone Plate Focus stringency
- Original Message - From: TSHACK tsh...@silver-bayou.com I congratulate you folks who can focus one of these things through the viewfinder. I pulled out my Crown Graphic, slapped on the reflex viewer, tried focusing on a light source, tried focusing on a subject outside, and I really couldn't tell any difference except at the extremes. Maybe if I use a loupe. Maybe not. Although I do not recommend focusing of the zoneplate every time you make an exposure, I do recommend you focus it ONCE so you find out (if you wish) the actual focal length of it. To do it, aim your camera to a light source (light bulb for instance) or well illuminated object and focus on the aerial image, rather than on the ground glass. You will be surprised how good is the image a ZP produces. And yes, use a loupe. Guillermo
Re: [pinhole-discussion] Zone Plate Focus stringency
A zone plate focusses like a lens so you should adjust the focus for objects at different distances. On the other hand, they tend to have large f numbers (like f/32) so they have large depth of field. They are also hard to focus because they are so dim. I congratulate you folks who can focus one of these things through the viewfinder. I pulled out my Crown Graphic, slapped on the reflex viewer, tried focusing on a light source, tried focusing on a subject outside, and I really couldn't tell any difference except at the extremes. Maybe if I use a loupe. Maybe not.
Re: [pinhole-discussion] Zone Plate Focus stringency
- Original Message - From: Richard M. Koolish kool...@bbn.com A zone plate focusses like a lens so you should adjust the focus for objects at different distances. On the other hand, they tend to have large f numbers (like f/32) so they have large depth of field. They are also hard to focus because they are so dim. Right. And if you ever decide to focus them, it is best to do it on the aerial image. My suggestion: don't bother focusing, mount it at a distance from the fillm plane equal or as close to the focal length it was made for and that should be sufficient to get good results. BTW, I don't think making ZP faster than f/64 is a good thing. A f/32 ZP would require a large number of rings/zones and that augments the noise/signal ratio considerably. For instance, a 90mm ZP f/32 would need 79 rings/zones (total), f/64 would just need 19. Guillermo
Re: [pinhole-discussion] Zone Plate Focus stringency
I think technically they should be refocused (anyone, please correct me if I'm wrong).but in practical terms my experience is, they needn't be. Try simply setting it to it's designed focal length and shootingIMHO little out of focus softness is often a plus. Mike In a message dated 10/28/01 5:02:21 PM, tsh...@silver-bayou.com writes: Once you have the zone plate focused for one object, will it be focused for any other objects closer or further away, or do I need to refocus according to the distance of my subject? dwight A zone plate focusses like a lens so you should adjust the focus for objects at different distances. On the other hand, they tend to have large f numbers (like f/32) so they have large depth of field. They are also hard to focus because they are so dim.
Re: [pinhole-discussion] Zone Plate Focus stringency
If it needs to refocused, my hacked TLR job is not going to work. I'll either need an SLR, or my Crown Graphic. I hope not. We'll see what happens. Tonight I took my Zero Image 6x9, gripped it in place on the top of my car by closing the moonroof on it, then drove around in traffic. I'll see what comes out of it. I've come up with a new exposure measurement system: f/90, 100 asa, exposed 4 blocks @25mph. I took the ZP TLR out and took some shots of neon lights reflected into the bay water, so I had the long, wide streaks extending down into the water. I sort of half-assed guessed at the exposure of 5 minutes. It might have needed to be more, but I can always go back. - Original Message - From: neuhausph...@aol.com To: pinhole-discussion@p at ??? Sent: Sunday, October 28, 2001 5:13 PM Subject: Re: [pinhole-discussion] Zone Plate Focus stringency I think technically they should be refocused (anyone, please correct me if I'm wrong).but in practical terms my experience is, they needn't be. Try simply setting it to it's designed focal length and shootingIMHO little out of focus softness is often a plus.
Re: [pinhole-discussion] Zone Plate Focus stringency
I think technically they should be refocused (anyone, please correct me if I'm wrong).but in practical terms my experience is, they needn't be. Try simply setting it to it's designed focal length and shootingIMHO little out of focus softness is often a plus. Mike In a message dated 10/28/01 5:02:21 PM, tsh...@silver-bayou.com writes: Once you have the zone plate focused for one object, will it be focused for any other objects closer or further away, or do I need to refocus according to the distance of my subject? dwight
Re: [pinhole-discussion] Zone Plate Focus stringency
In a message dated 10/26/01 0:45:31 PM, tsh...@silver-bayou.com writes: Anyone know of some cheap SLR's that I can remove the lens but keep a functioning shutter? Like toy level prices Dwight Dwight, Try ebay for an old argus model aor check flea markets for old folding cameras with small shuttered lenses...some model shutters have lots of timed speeds, some don't so you'll have to look. When you find a good one remove the lens/shutter assembly, remove the lens cells, set the diaphram to a medium aperture and tape your zone plate directly to the diaphram. If you tape the zone plate very well, the diaphram blades are quite secure, but it does help to pin the diaphram adjustment lever in some way. Here's my zone plate argus A HREF=http://members.aol.com/neuhausphoto/arguszpcam.jpg;arguszpcam.jpg /A or http://members.aol.com/neuhausphoto/arguszpcam.jpg I discarded the lens cells but used the barrel as a hood for added protection to the mechanism. I adapted prontor II shutter to the camera too...this shutter has many more speeds than the original argus item. Good luck Mike
[pinhole-discussion] Zone Plate Focus stringency
I'm hacking up an old TLR right now to put another shutter on it for zone plate work, and I'm wondering, how critical is the focal length for focusing. If I'm putting a 90mm zone plate on, but due to mechanical impediments it has to mount at 95 mm, how much of a difference will this make in the image. Anyone know of some cheap SLR's that I can remove the lens but keep a functioning shutter? Like toy level prices? The Holga doesn't have the shutter speed range I'm looking for. Dwight
[pinhole-discussion] zone plate
hello everyone. I have a stupid question--what exactly is zone plate photography and what is the process?? I see a lot of images on the web sites here that I find really interesting and I would like to know more about it. thanks! meg
Re: [pinhole-discussion] zone plate
Hi, Tati. Do you know João Ribeiro, here from the group? He is also brazilian (as I am), and do beautifull zone plates. Perhaps you can write him directly in portughese, for better understanding. Hello all! I'm brazilian and I have just started to try pinhole and I can't understand what is zone plate,I've read about this in English but I didn't understand what's this! Can anybody help me?! Thanks regards from Brazil Ana Maria Schultze Sao Paulo - SP - Brasil - arte-educar-ow...@egroups.com arteeducad...@hotmail.com uin 1457876 Conheça a lista de discussão sobre arte-educação: http://www.egroups.com/group/arte-educar Veja as mensagens já postadas em: http://www.eScribe.com/art/arte-educar/
Re: [pinhole-discussion] zone plate
- Original Message - From: tatico...@starmedia.com Hello all! I'm brazilian and I have just started to try pinhole and I can't understand what is zone plate,I've read about this in English but I didn't understand what's this! Can anybody help me?! Thanks Check Joao Riveiro's article written in Portuguese: http://www.alaz.f2s.com/tec/tec1.html Guillermo
[pinhole-discussion] zone plate
Hello all! I'm brazilian and I have just started to try pinhole and I can't understand what is zone plate,I've read about this in English but I didn't understand what's this! Can anybody help me?! Thanks -- Abra grátis sua conta no StarMedia Email. Inscreva-se agora mesmo! http://www.br.starmedia.com --
[pinhole-discussion] Zone Plate design
I've read a number of papers explaining the physics of a Zone Plate. However, I haven't seen anything that deals with the number of Zones that comprise the Zone Plate. Is there an optimum number of zones? Does it change with the focal length? What is the effect on resolution depth of field? Thanks, Eric Kees Medford OR
[pinhole-discussion] Zone Plate Generator
I have just added the ability to specify the inner ring size so that you can print to paper and photograph it. I didn't know if this was a good way but it was relatively easy to do. I will be looking at John Yeo's program to see how he did it. Larry
Re: [pinhole-discussion] Zone Plate Image Generator
Ok, I just cleaned it up a bit and compiled it. You can download it from my local machine at ftp://pinhole:pinh...@cosmic9.dyn.dhs.org:21. Zone.exe is the program itself, and zone prog source.zip is the source code. I'm 56k so it might go pretty slow, but they're small files so it doesn't matter. George expressed interest in posting my program on his website, http://members.home.net/hmpi/, so you can probably get it there also. I'm taking a more advanced visual basic class next semester, so i might improve on it. You will probably need the visual basic run time file to run it, you can get that at ftp://ftp.simtel.net/pub/simtelnet/win95/dll/simvb6-6.zip. John - Original Message - From: Larry Fratkin To: pinhole-discussion@p at ??? Sent: Thursday, December 28, 2006 6:28 AM Subject: Re: [pinhole-discussion] Zone Plate Image Generator John and folks, If people would like one for photographing I would be happy to do it. Just let me know if there's interest. The calculators on my site were usually made because I thought I needed them and then thought that maybe others need them too. I would be interested in seeing the source code to see how you did it. I'm also curious what format you generated. My web host only allows Perl, so I'd have to translate it. Larry -Original Message- From: John Yeo jonn...@thegrid.net To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Wednesday, December 27, 2000 9:54 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Hi Larry, Nevermind that. For some reason, microsoft paint displayed nothing, while photoshop displayed it properly. I was expecting an output that one would photograph from a distance like what they have at http://members.home.net/hmpi/Pinhole/Articles/ZonePlate/Zone_Plate.htm. Is that how it is supposed to work, or does it give one the actual size? I made a zone plate calculator a while ago in visual basic. It calculated ring sizes, magnified sizes (for photographing from a distance) and also calculated the true f stop (just the area of the clear rings). If anyone wants it, I can compile it and send it out. If you want to add to it, let me know and i'll give you the source code. I don't really care what you do with it, post it on the web, whatever. John - Original Message - From: Larry Fratkin To: pinhole-discussion@p at ??? Sent: Wednesday, December 27, 2006 6:47 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator john, Yes, I did put a few hours into this, but it was fun. Thanks for appreciating that. What were the settings you typed in? I'd like to repeat them to see what I get. Also, sometimes you really have to look for the zone plate in the middle of the image. Larry -Original Message- From: John Yeo jonn...@thegrid.net To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Wednesday, December 27, 2000 4:48 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all. John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] Zone Plate Image Generator
Guy, Yup, it makes perfect sense. You're right, mounting usually involves cutting away most of the film. I'll look into generating multiple zone plates per image. It should be relatively simple. Then, if Eric wants to make zone plates to sell, he can do it economically by having many images in one frame. I also thought about contact printing the image after I get the first one back. Larry -Original Message- From: Guy Glorieux guy.glori...@sympatico.ca To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Thursday, December 28, 2000 9:08 AM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Larry, Many thanks for this great little tool! I needed a 30mm zone plate for one of my short focal cameras but the last I knew from Eric Renner when I was looking for that short focal length is that he did'nt have any. It occured to me that this is very tiny little spot on a 35mm film size (24x26mm), with a lot of wasted film around it that has to be cut out anyway to fit on the hole of the camera. So what I want to do is to place several zone plates on the same 24x36mm space. I could do this by generating several zone plate files and then cutting and pasting them with Photoshop on one single sheet of film. Or, if you have friends who want zone plates as well, you could share the cost of the lab by placing perhaps 4 zone plates on the same sheet of film. Seems to make sense. Does it? Larry Fratkin wrote: Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] Zone Plate Image Generator
Larry, Many thanks for this great little tool! I needed a 30mm zone plate for one of my short focal cameras but the last I knew from Eric Renner when I was looking for that short focal length is that he did'nt have any. It occured to me that this is very tiny little spot on a 35mm film size (24x26mm), with a lot of wasted film around it that has to be cut out anyway to fit on the hole of the camera. So what I want to do is to place several zone plates on the same 24x36mm space. I could do this by generating several zone plate files and then cutting and pasting them with Photoshop on one single sheet of film. Or, if you have friends who want zone plates as well, you could share the cost of the lab by placing perhaps 4 zone plates on the same sheet of film. Seems to make sense. Does it? Larry Fratkin wrote: Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] Zone Plate Image Generator
Hi Larry, Nevermind that. For some reason, microsoft paint displayed nothing, while photoshop displayed it properly. I was expecting an output that one would photograph from a distance like what they have at http://members.home.net/hmpi/Pinhole/Articles/ZonePlate/Zone_Plate.htm. Is that how it is supposed to work, or does it give one the actual size? I made a zone plate calculator a while ago in visual basic. It calculated ring sizes, magnified sizes (for photographing from a distance) and also calculated the true f stop (just the area of the clear rings). If anyone wants it, I can compile it and send it out. If you want to add to it, let me know and i'll give you the source code. I don't really care what you do with it, post it on the web, whatever. John - Original Message - From: Larry Fratkin To: pinhole-discussion@p at ??? Sent: Wednesday, December 27, 2006 6:47 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator john, Yes, I did put a few hours into this, but it was fun. Thanks for appreciating that. What were the settings you typed in? I'd like to repeat them to see what I get. Also, sometimes you really have to look for the zone plate in the middle of the image. Larry -Original Message- From: John Yeo jonn...@thegrid.net To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Wednesday, December 27, 2000 4:48 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all. John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] Zone Plate Image Generator
Benno, I guess it needs more instructions. I'll put some together and put them on the page. Basically, the width and the height are MM and tell what size film you're going to. Then the focal length is the distance between the zone plate and the film. The number of rings is up to the user. The resolution, DPMM, should be around 100 to get a good image. That translates to roughly 2500 DPI. Are these good enough instructions? Anyone want to add or comment on them? Larry -Original Message- From: Benno Jones ben...@jps.net To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Wednesday, December 27, 2000 5:58 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Worked for me I just don't know all the proper numbers to put in for a real zone plate. But with guess work I got an image of a zone plate when I opened the file in Photoshop. Benno Jones John Yeo wrote: Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all. John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com -- See my homepage at http://www.jps.net/benshan It's a well-known fact that although the public is fine when taken individually, when it forms itself into large groups, it tends to act as though it has one partially consumed Pez tablet for a brain. - Dave Barry ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.p at ???/discussion/
Re: [pinhole-discussion] Zone Plate Image Generator
john, Yes, I did put a few hours into this, but it was fun. Thanks for appreciating that. What were the settings you typed in? I'd like to repeat them to see what I get. Also, sometimes you really have to look for the zone plate in the middle of the image. Larry -Original Message- From: John Yeo jonn...@thegrid.net To: pinhole-discussion@p at ??? pinhole-discussion@p at ??? Date: Wednesday, December 27, 2000 4:48 PM Subject: Re: [pinhole-discussion] Zone Plate Image Generator Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all. John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] Zone Plate Image Generator
Worked for me I just don't know all the proper numbers to put in for a real zone plate. But with guess work I got an image of a zone plate when I opened the file in Photoshop. Benno Jones John Yeo wrote: Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all.John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks,I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then.The calculator/generator is at http://www.MrPinhole.com/zp.htmlla...@mrpinhole.com -- See my homepage at http://www.jps.net/benshan It's a well-known fact that although the public is fine when taken individually, when it forms itself into large groups, it tends to act as though it has one partially consumed Pez tablet for a brain. - Dave Barry
Re: [pinhole-discussion] Zone Plate Image Generator
Larry, Thanks for making this. I'm sure you have already put a lot of work into it... but i get nothing but a blank bitmap. No rings at all. John - Original Message - From: Larry Fratkin To: pinhole list Sent: Wednesday, December 27, 2006 3:52 PM Subject: [pinhole-discussion] Zone Plate Image Generator Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
[pinhole-discussion] Zone Plate Image Generator
Folks, I have created a zone plate image generator so that I could make my own zone plates. The program downloads a .BMP so it's PC centric, I think. The idea was to use the program to generate a zone plate image and then take it to the bureau to have it put to film. They charge about $15.00 for this. I haven't tried it out yet so I don't know how well it works. I'll be visiting them on Friday and I'll drop it off then. The calculator/generator is at http://www.MrPinhole.com/zp.html la...@mrpinhole.com
Re: [pinhole-discussion] zone plate image quality
You could find out a lot by reading Chris Pattons page at http://www.stanford.edu/~cpatton/zp.html or reading his zoneplate math at http://www.stanford.edu/~cpatton/zoneplatemath.htm, maybe he would even answer a question. -- Chris Peregoy | http://www.gl.umbc.edu/~peregoy | http://imda.umbc.edu/
Re: [pinhole-discussion] zone plate image quality
I have not done any experiments, but I am very interested in this topic. Ideally, a physics person should be contacted for numerical answers (perhaps someone on this list is a professor at a university and knows someone in the physics department?). Unfortunately, one of the qualities of zone plates and pinholes is that they always have a single optimum wavelength of light, depending upon their configuration. Focus would not be perfect with that wavelength, but focus decreases with wavelengths farther from the optimal. It would be interesting to see the difference in focus between a pinhole or zone plate used with full spectrum light versus using a filter to create monochromatic light of the optimum wavelength. The difference would likely be noticeable, perhaps remarkable (or perhaps not : ) ). Jarred Richard M. Koolish wrote: I can think of a few things that might affect zone plate image quality, the number of zones, the density of the dark and light zones, the thickness or characteristics of the zone plate film. Has anybody done some experiments? ___ Pinhole-Discussion mailing list Pinhole-Discussion@p at ??? unsubscribe or change your account at http://www.p at ???/discussion/
[pinhole-discussion] zone plate image quality
I can think of a few things that might affect zone plate image quality, the number of zones, the density of the dark and light zones, the thickness or characteristics of the zone plate film. Has anybody done some experiments?
