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
