Re: Film/slide scanning
so if a sensor is right where two film grains meet with very different colors or values, what does the pixel do? Does it choose one color or the other, or does it appear as an everage between the two? rg2 On 9/19/07, Doug Franklin [EMAIL PROTECTED] wrote: Rebekah wrote: Thanks Doug, I think you've made me even more nervous about having my slides scanned now! No really, that was all good to know. I'm going to read about GA like you suggested. Maybe I'll just have them scanned at 3000dpi, or better yet, just wait until I get my own scanner :-) Well, I didn't intend to scare you off. I intended something more along the lines of letting you know what /could/ happen ... not leave you with the impression that it would or probably would happen. I'm sorry for doing that. It occasionally happens, and when it does, it's almost always on a photo you really want to salvage. But it's not all that common, viewed in the large. It happens mostly with particular films scanned with particular scanners. Avoid those combinations, and your pretty much golden. GA also seems to be more common with consumer grade equipment. I haven't heard much in the way of whining about GA happening on professionally done scans. Maybe it happens but they've got more adjustments or better technology to take care of it when it does, so the customer never sees it. The rest of this is just sort of FYI explaining what causes it ... GA is a fact of life at certain resolutions. Basically, if the average size of a film grain (actually dye cloud on color films and chromogenic B+W films) is similar to the size of the sensor's pixels, things can get colorifically strange when the grains and the pixel wells overlap each other in some ways. Actually, it's when the size of the image of the dye cloud projected onto the sensor is similar in size to the sensor's pixel. Similar in this case seems to be somewhere around plus/minus half an order of magnitude. You can get similar issues when making any medium transfer, including copying film to film. It's just that on both films, the grains are more or less randomly distributed, both spatially and in size. Which means that the erroneous grains are also more or less randomly distributed. This takes the sting out of it for the human visual system, and it's much less noticeable. OTOH, the pixels on a sensor are rigidly and regularly distributed and sized. The erroneous pixels are still more or less randomly distributed, but somewhat less randomly than above. And they're less randomly distributed by being on a harshly rectilinear grid of fixed size features. That makes the effects stand out to human eyes when it does occur. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Rebekah wrote: so if a sensor is right where two film grains meet with very different colors or values, what does the pixel do? Does it choose one color or the other, or does it appear as an everage between the two? Well, it averages. But the thing doing the averaging isn't the pixel or the sensor, it's the optical path between the film and the sensor. The light arriving at that sensor pixel is some sort of average (geometric? quantum? something) of all of the grains that were in between the light source and the sensor pixel in question. That's why the colors change and the pixels look like speckles. There can also (in some emulsions) be spaces in between the grains that can affect the averaging and the resulting color. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
wait, if you could decrease the distance between the sensor and the film, would the average be more accurate? What if pixels were a different shape, like hexagons? Would it look better? rg2 On 9/21/07, Rebekah [EMAIL PROTECTED] wrote: so digital pixels suck in comparison to film grain ;) gotcha. rg2 PS thanks for taking the time to explain all that to me :) On 9/21/07, Doug Franklin [EMAIL PROTECTED] wrote: Rebekah wrote: so if a sensor is right where two film grains meet with very different colors or values, what does the pixel do? Does it choose one color or the other, or does it appear as an everage between the two? Well, it averages. But the thing doing the averaging isn't the pixel or the sensor, it's the optical path between the film and the sensor. The light arriving at that sensor pixel is some sort of average (geometric? quantum? something) of all of the grains that were in between the light source and the sensor pixel in question. That's why the colors change and the pixels look like speckles. There can also (in some emulsions) be spaces in between the grains that can affect the averaging and the resulting color. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
so digital pixels suck in comparison to film grain ;) gotcha. rg2 PS thanks for taking the time to explain all that to me :) On 9/21/07, Doug Franklin [EMAIL PROTECTED] wrote: Rebekah wrote: so if a sensor is right where two film grains meet with very different colors or values, what does the pixel do? Does it choose one color or the other, or does it appear as an everage between the two? Well, it averages. But the thing doing the averaging isn't the pixel or the sensor, it's the optical path between the film and the sensor. The light arriving at that sensor pixel is some sort of average (geometric? quantum? something) of all of the grains that were in between the light source and the sensor pixel in question. That's why the colors change and the pixels look like speckles. There can also (in some emulsions) be spaces in between the grains that can affect the averaging and the resulting color. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Rebekah wrote: so if a sensor is right where two film grains meet with very different colors or values, what does the pixel do? Does it choose one color or the other, or does it appear as an everage between the two? An average between the two. This issue is fundamental to all digital sampling and it's called aliasing. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On 21/09/2007, Rebekah [EMAIL PROTECTED] wrote: wait, if you could decrease the distance between the sensor and the film, would the average be more accurate? What if pixels were a different shape, like hexagons? Would it look better? The little device bellow may ease the grain pain: http://www.scanhancer.com/ I'm having one customized for my LS-8000 -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
have you had a chance to try that on someone else's scanner? That looks interesting rg2 On 9/21/07, Digital Image Studio [EMAIL PROTECTED] wrote: On 21/09/2007, Rebekah [EMAIL PROTECTED] wrote: wait, if you could decrease the distance between the sensor and the film, would the average be more accurate? What if pixels were a different shape, like hexagons? Would it look better? The little device bellow may ease the grain pain: http://www.scanhancer.com/ I'm having one customized for my LS-8000 -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Rebekah wrote: wait, if you could decrease the distance between the sensor and the film, would the average be more accurate? What if pixels were a different shape, like hexagons? Would it look better? It's not about digital versus analog, aliasing happens in both cases. It's just that aliasing errors in the analog world are more randomly distributed and harder to detect for the human visual system. The only way to eliminate it in the general case is to have an infinite number of inifintely small sensors. In the specific case of scanners and film, just avoid the bad combinations. Different film emulsions have different characteristics for the size and shape and distribution of grains just as different scanners have different sensor characteristics. Some combinations lead to strong GA, many don't. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: have you had a chance to try that on someone else's scanner? That looks interesting No, only on my scanners to date. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
No, only on my scanners to date. oh I didn't realize you had more than one...hmm Doug, thanks again for your answer. :) You have great explanations. rg2 On 9/21/07, Digital Image Studio [EMAIL PROTECTED] wrote: On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: have you had a chance to try that on someone else's scanner? That looks interesting No, only on my scanners to date. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: No, only on my scanners to date. oh I didn't realize you had more than one...hmm I have three currently in fact, I'm just not strong willed enough to actually hook them up and start ploughing though my film backlog. Apart from a distinct lack of contiguous free time there always seems to be one or two little issues to contend with that allow me to say oh well not just yet. Though once I have a Scanhancer for each of my scanners I can then calibrate them, after that I've pretty much run out of excuses. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
LOL!! Procrastinating can be fun. Why do you have three scanners? Are they each for different things, or are they different models as you've accumulated them? rg2 On 9/21/07, Digital Image Studio [EMAIL PROTECTED] wrote: On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: No, only on my scanners to date. oh I didn't realize you had more than one...hmm I have three currently in fact, I'm just not strong willed enough to actually hook them up and start ploughing though my film backlog. Apart from a distinct lack of contiguous free time there always seems to be one or two little issues to contend with that allow me to say oh well not just yet. Though once I have a Scanhancer for each of my scanners I can then calibrate them, after that I've pretty much run out of excuses. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
You know how it is, once you buy one it's so much easier to buy the next... Rebekah wrote: LOL!! Procrastinating can be fun. Why do you have three scanners? Are they each for different things, or are they different models as you've accumulated them? rg2 On 9/21/07, Digital Image Studio [EMAIL PROTECTED] wrote: On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: No, only on my scanners to date. oh I didn't realize you had more than one...hmm I have three currently in fact, I'm just not strong willed enough to actually hook them up and start ploughing though my film backlog. Apart from a distinct lack of contiguous free time there always seems to be one or two little issues to contend with that allow me to say oh well not just yet. Though once I have a Scanhancer for each of my scanners I can then calibrate them, after that I've pretty much run out of excuses. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- Remember, it’s pillage then burn. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On Sep 21, 2007, at 5:41 PM, Rebekah wrote: ...Why do you have three scanners? Are they each for different things, or are they different models as you've accumulated them? Don't know about Rob. I have four scanners: film - Minolta Scan Dual II, purchased in 2000. Simple, cheap (new), does a great job when used with VueScan. Minolta software was awful. Cost me about $350 then. film - Nikon Coolscan IV ED (aka LS-40) purchased used last year. One of the best film scanners in the 3000 ppi class. Excellent carriers (35mm and APS), dust and scratch removal ICE, fast. Cost me $235 last year, perfect condition. flatbed - Epson 2450, purchased in 2002 so I could work with Medium Format negatives. Not the greatest film scanner but acceptable for a 13x19 inch print with 645 or 6x6 film. Nothing else that did medium format film scanning was in an approachable price range in 2002. Does a great job on paper originals. flatbed - Epson V700, purchased late last year ... because if I'm going to do any work at all with the P645 camera that doesn't immediately look like crap compared to what comes out of the K10D, I needed a better quality scanner. This is the best I can justify for the amount of use I'll get out of it, and even that was more rationalization than justification. If I need better quality scans, I'll rent time on the Imacon at the pro shop nearby where I can get about 10 scans done in an hour's rental at $50/hour. G -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On 22/09/2007, Rebekah [EMAIL PROTECTED] wrote: LOL!! Procrastinating can be fun. Why do you have three scanners? Are they each for different things, or are they different models as you've accumulated them? They are all for different purposes, it's no accumulation over time, I've already owned and sold a Polaroid Sprintscan 35+ and 4000 and an Agfa DuoScan film scanners. Like Godfrey each of my current units have fairly specific uses. I have a Konica Minolta AF-5400 II for 35mm film scanning, a Nikon LS-8000 ED for medium format film scanning up to 6x9cm and like Godfrey an Epson Perfection V700 Photo flatbed with which I hope to scan some larger transparencies. What I want to do however is scan my neg sheets to generate rough positive digital proofs using the V700, that's primarily why I bought it. -- Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://picasaweb.google.com/distudio/PESO http://home.swiftdsl.com.au/~distudio//publications/ Pentax user since 1986, PDMLer since 1998 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Rebekah wrote: Thanks Doug, I think you've made me even more nervous about having my slides scanned now! No really, that was all good to know. I'm going to read about GA like you suggested. Maybe I'll just have them scanned at 3000dpi, or better yet, just wait until I get my own scanner :-) Well, I didn't intend to scare you off. I intended something more along the lines of letting you know what /could/ happen ... not leave you with the impression that it would or probably would happen. I'm sorry for doing that. It occasionally happens, and when it does, it's almost always on a photo you really want to salvage. But it's not all that common, viewed in the large. It happens mostly with particular films scanned with particular scanners. Avoid those combinations, and your pretty much golden. GA also seems to be more common with consumer grade equipment. I haven't heard much in the way of whining about GA happening on professionally done scans. Maybe it happens but they've got more adjustments or better technology to take care of it when it does, so the customer never sees it. The rest of this is just sort of FYI explaining what causes it ... GA is a fact of life at certain resolutions. Basically, if the average size of a film grain (actually dye cloud on color films and chromogenic B+W films) is similar to the size of the sensor's pixels, things can get colorifically strange when the grains and the pixel wells overlap each other in some ways. Actually, it's when the size of the image of the dye cloud projected onto the sensor is similar in size to the sensor's pixel. Similar in this case seems to be somewhere around plus/minus half an order of magnitude. You can get similar issues when making any medium transfer, including copying film to film. It's just that on both films, the grains are more or less randomly distributed, both spatially and in size. Which means that the erroneous grains are also more or less randomly distributed. This takes the sting out of it for the human visual system, and it's much less noticeable. OTOH, the pixels on a sensor are rigidly and regularly distributed and sized. The erroneous pixels are still more or less randomly distributed, but somewhat less randomly than above. And they're less randomly distributed by being on a harshly rectilinear grid of fixed size features. That makes the effects stand out to human eyes when it does occur. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Thanks Doug, I think you've made me even more nervous about having my slides scanned now! No really, that was all good to know. I'm going to read about GA like you suggested. Maybe I'll just have them scanned at 3000dpi, or better yet, just wait until I get my own scanner :-) If you just want to see the sort of thing you'll get, look at http://www.panix.com/~johnf/digital/zoom3.html The last image is a detail from a Pro Photo CD scan. The images are part of my FA* 250-600 shakedown test: http://www.panix.com/~johnf/digital/250-600.html Thanks John, that's exactly what I was looking for. Good examples! rg2 On 9/19/07, John Francis [EMAIL PROTECTED] wrote: On Tue, Sep 18, 2007 at 08:23:31PM -0400, Doug Franklin wrote: Rebekah wrote: By the way, does anyone have a picture scanned at 4000dpi that I could look at? I've got tons. It'll take me a couple of days to track them down. I've got a Pro Photo CD lying around somewhere - that's 4000dpi. If you just want to see the sort of thing you'll get, look at http://www.panix.com/~johnf/digital/zoom3.html The last image is a detail from a Pro Photo CD scan. The images are part of my FA* 250-600 shakedown test: http://www.panix.com/~johnf/digital/250-600.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Film/slide scanning
I'm going to send away a few slides and some film for scanning. What's the best resolution out there that I should be looking for? I see 3000dpi and 4000dpi, is there a larger number that I'm likely to find? If I have a good, sharp photograph scanned at 4000dpi, how big can I make it before it starts to look bad? Thanks in advance guys :) rg2 P.S. Does anyone personally recommend any scanning companies that you send your film to or do you all just have your own scanners...? -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
I do my own scanning. I have two film scanners (Minolta Scan Dual II and Nikon Coolscan IV ED), both in the 3000 ppi class, for 35mm work. I've used 4000 and 5400 ppi film scanners ... there are gains, particularly with respect to grain aliasing, but I found the improvements insignificant for my print needs (up to 13x19 inch). Like with all 35mm film, enlargement to more than 16x is iffy at best. A full 35mm frame scanned at 2900 ppi and printed at 220 ppi nets a 12.5x18.7 inch image area, generally about as big as I'd want to make a 35mm film image print. The output density is a little low for exhibition quality prints, but how good it looks depends on your skill in processing and printing it. If you go to 4000 ppi scan density, the output density at that size goes up to about 300 ppi, often considered the standard for film image prints. Most of my 35mm film image prints I make to A3 paper at about 10x15 inch image area, which nets an output density of 260 ppi with a 2900 ppi scan. This overall looks quite good. Godfrey On Sep 18, 2007, at 7:10 AM, Rebekah wrote: I'm going to send away a few slides and some film for scanning. What's the best resolution out there that I should be looking for? I see 3000dpi and 4000dpi, is there a larger number that I'm likely to find? If I have a good, sharp photograph scanned at 4000dpi, how big can I make it before it starts to look bad? Thanks in advance guys :) P.S. Does anyone personally recommend any scanning companies that you send your film to or do you all just have your own scanners...? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
How much do you want to spend. You can get upwards to 100,000ppi scans but they cost a small fortune. Of the run of the mill film scanners I believe the Minoltas at 5200ppi were the highest. However a well done 4000ppi scan should allow fine prints up to about any size you would want. Somewhere about 14-15k ppi is about the limit of normal film as you are actually recording the grain structure. Rebekah wrote: I'm going to send away a few slides and some film for scanning. What's the best resolution out there that I should be looking for? I see 3000dpi and 4000dpi, is there a larger number that I'm likely to find? If I have a good, sharp photograph scanned at 4000dpi, how big can I make it before it starts to look bad? Thanks in advance guys :) rg2 P.S. Does anyone personally recommend any scanning companies that you send your film to or do you all just have your own scanners...? -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
4000 dpi should easily be good for prints up to 16 on the longest side. I have a nikon coolscan 4000 and i've done 16 x 20 prints of excellent quality. You have to start with a good slide / negative though since at those enlargement ratios the smallest flaws are going to become visible... e.g. if your focusing is slightly off its going to show up. Also I usually find i get better results with slide film as opposed to negatives. Somehow the scans end up being cleaner (less grainy) and the colours more accurate. Maybe that's just me coz I shoot much more slide film than negative film. On 9/18/07, Rebekah [EMAIL PROTECTED] wrote: I'm going to send away a few slides and some film for scanning. What's the best resolution out there that I should be looking for? I see 3000dpi and 4000dpi, is there a larger number that I'm likely to find? If I have a good, sharp photograph scanned at 4000dpi, how big can I make it before it starts to look bad? Thanks in advance guys :) rg2 P.S. Does anyone personally recommend any scanning companies that you send your film to or do you all just have your own scanners...? -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- Regards Patrick Genovese -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Thanks guys. I had no idea if 4000dpi was good enough or not, I had nothing to compare it to. Looks like scans cost around a dollar, give or take, for that quality. Other than scanning 8-10 of my best, I'll probably save up for a scanner. By time I have enough for one the quality will be ridiculous ;) Maybe I'll even be able to scan all my kodachrome. By the way, does anyone have a picture scanned at 4000dpi that I could look at? rg2 On 9/18/07, Patrick Genovese [EMAIL PROTECTED] wrote: 4000 dpi should easily be good for prints up to 16 on the longest side. I have a nikon coolscan 4000 and i've done 16 x 20 prints of excellent quality. You have to start with a good slide / negative though since at those enlargement ratios the smallest flaws are going to become visible... e.g. if your focusing is slightly off its going to show up. Also I usually find i get better results with slide film as opposed to negatives. Somehow the scans end up being cleaner (less grainy) and the colours more accurate. Maybe that's just me coz I shoot much more slide film than negative film. On 9/18/07, Rebekah [EMAIL PROTECTED] wrote: I'm going to send away a few slides and some film for scanning. What's the best resolution out there that I should be looking for? I see 3000dpi and 4000dpi, is there a larger number that I'm likely to find? If I have a good, sharp photograph scanned at 4000dpi, how big can I make it before it starts to look bad? Thanks in advance guys :) rg2 P.S. Does anyone personally recommend any scanning companies that you send your film to or do you all just have your own scanners...? -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- Regards Patrick Genovese -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net -- the subject of a photograph is far less important than its composition -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
Rebekah wrote: By the way, does anyone have a picture scanned at 4000dpi that I could look at? I've got tons. It'll take me a couple of days to track them down. A 4000 ppi scan of a 35mm frame at sixteen bits per color is about 125 MB. Even at eight bits per color, it's still over 60 MB. Remember, that's ~24 MP (~6,000 by ~4,000). The issue with 4000 ppi scans is that they can exhibit grain aliasing (GA). Lots of caveats here, of course: a) some photos b) scanned with some scanning technologies c) lit with some lighting technologies d) at some resolutions e) from some films/emulsions For example, some of my images show terrible GA on my Canon CanoScan FS4000US at 4000 ppi. Those same images look just fine scanned on a friend's Minolta at 2700 ppi. They also look fine scanned on my FS4000US at 2000 ppi or less. Negative films seem to show the problem more than slide films in my experience. It's caused by the physics of the interaction between the film realization of the image and the sensing of that image. The film realization is in the analog domain. It represents the image as randomly distributed clouds of color information. The sensing occurs in the digital domain. Individual pixel receivers on the sensor. These pixel receivers are *not* *at* *all* randomly distributed. Search the web for the term grain aliasing and you'll find plenty of stuff out there. You can believe some of it. :-) You can also try the PDML archives. Search for the same thing. We had some pretty long and detailed discussions about it back around 1999 or 2000 or 2001. Back then, I had some shots on my web site that showed bad cases of GA. It showed up worst in the sky areas of those photos. Cotty will probably remember the shots of the '69 Plymouth Superbird at Road Atlanta. In general, it will show up worst in areas that are a uniform color, as little colored speckles. If any of your scans exhibit GA, you can often eliminate it by rescanning at 3000 ppi or lower, or 5000 ppi or higher. The problem seems to be most pronounced for most 35mm films at around 4000 ppi (and presumably any integer multiple of 4000 ppi). Failing that, bring the 4000 ppi image into your photo editing software. Apply a little Gaussian Blur followed by a bit of Unsharp Mask. It won't be as good as if you could've avoided the GA in the first place. It'll be better than it started out, though, with judicious selection of parameters for GB and USM. They're different for every image, of course. :-) There are also software denoisers, either standalone programs or plug ins for Photoshop, etc. They'll attempt to get rid of noise. Unfortunately, GA isn't exactly noise. It's pretty close, though, so sometimes the denoisers can really help; other times, not. -- Thanks, DougF (KG4LMZ) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
Re: Film/slide scanning
On Tue, Sep 18, 2007 at 08:23:31PM -0400, Doug Franklin wrote: Rebekah wrote: By the way, does anyone have a picture scanned at 4000dpi that I could look at? I've got tons. It'll take me a couple of days to track them down. I've got a Pro Photo CD lying around somewhere - that's 4000dpi. If you just want to see the sort of thing you'll get, look at http://www.panix.com/~johnf/digital/zoom3.html The last image is a detail from a Pro Photo CD scan. The images are part of my FA* 250-600 shakedown test: http://www.panix.com/~johnf/digital/250-600.html -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
