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#1
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emulsion side down and histograms
Hello,
I have two questions. When scanning 35mm or 4x5s does the emulsion side go down? Is there a rule for this? I thought it went down but my scans are mirrored and I get different results when emulsion is up or down. Is it better to adjust the levels (histogram) with the scanning software or in Photoshop? I don't want to lose information when scanning. I've read scantips.com, searched this group and googled. I have alot of slides of artwork to scan. I don't want the fastest way, I'd like to do it the best way. I'm using Silverfast SE (came with the scanner) and an Epson 4870. I don't know if it's relevant but I'm on a Mac with system 9.2.2 I've become a bit scrambled over this and any help will be so appreciated. Thanks, Linda -- remove invalid to reply |
#2
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Scan so the image comes out with correct orientation (however whichever way
yields best results for you is all that counts). There are two schools of thought about image tuning: adjust extensively prescan, adjust minimally prescan. Again whatever works for you works best for you. My personal preference is to make minimal adjustments prescan that yield uncompromised/unclipped images and adjust later in Photoshop. Severely underexposed or overexposed images may require extensive prescan adjustment to get any kind of usable image. You have to experiment and learn what you are doing. It is more important to understand what the adjustments actually are doing to the image data then to worry about whether or not to make adjustments pre or post scan. |
#3
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When scanning 35mm or 4x5s does the emulsion side go down? Is there a
rule for this? I thought it went down but my scans are mirrored and I get different results when emulsion is up or down. You don't explain what you find "different?" Which produces better results for you? That is the best answer. If you want to know what Epson recommends, look at the letter graphic/decal on the holder. That shows how the lettering on your film should read when you look at the film after it is placed in the holder. Doug -- Doug's "MF Film Holder" for batch scanning "strips" of 120/220 medium format film: http://home.earthlink.net/~dougfishe...mainintro.html |
#4
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Emulsion Down, and 'flip' the image either in the scanning program or in
PhotoShop. Just ask yourself ... just exactly WHY should I scan *through* the film base? "Linda" wrote in message . com... Hello, I have two questions. When scanning 35mm or 4x5s does the emulsion side go down? Is there a rule for this? I thought it went down but my scans are mirrored and I get different results when emulsion is up or down. Is it better to adjust the levels (histogram) with the scanning software or in Photoshop? I don't want to lose information when scanning. I've read scantips.com, searched this group and googled. I have alot of slides of artwork to scan. I don't want the fastest way, I'd like to do it the best way. I'm using Silverfast SE (came with the scanner) and an Epson 4870. I don't know if it's relevant but I'm on a Mac with system 9.2.2 I've become a bit scrambled over this and any help will be so appreciated. Thanks, Linda -- remove invalid to reply |
#5
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"RSD99" wrote in message
news:lc%ue.902$Uc2.403@trnddc03... Emulsion Down, and 'flip' the image either in the scanning program or in PhotoShop. Just ask yourself ... just exactly WHY should I scan *through* the film base? Maybe because the light travels through the film base to produce the image on the sensor. Either way you turn the film, the light has to travel through the film to get to the sensor. That is why it is called a transparency, light passes through the film. You turn the film the way that when scanned produces a right side up or correct left to right image. Sometimes with some scanners the image maybe correct left to right but upside down. My Canon CanoScan 8400F scans 120 negatives shot with a twin lens reflex camera are upside down when scanned with the correct left to right orientation. A simple matter to turn all the images in the image editor at the same time. (The scanner driver can also rotate the image, one at a time). And yes, you can flip or rotate the image in a photo editor, no matter which way you scanned it. -- CSM1 http://www.carlmcmillan.com -- "Linda" wrote in message . com... Hello, I have two questions. When scanning 35mm or 4x5s does the emulsion side go down? Is there a rule for this? I thought it went down but my scans are mirrored and I get different results when emulsion is up or down. Is it better to adjust the levels (histogram) with the scanning software or in Photoshop? I don't want to lose information when scanning. I've read scantips.com, searched this group and googled. I have alot of slides of artwork to scan. I don't want the fastest way, I'd like to do it the best way. I'm using Silverfast SE (came with the scanner) and an Epson 4870. I don't know if it's relevant but I'm on a Mac with system 9.2.2 I've become a bit scrambled over this and any help will be so appreciated. Thanks, Linda -- remove invalid to reply |
#6
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But one way ... with the emulsion side of the film *down* ... the *image*
does *not* have to travel through the dirt, distortion and contamination(s) of the film base. The film base is, was, and always will be manufactured to simply be a support for the emulsion. The film base was *never* designed to be part of the optical path, and is not manufactured to the parameters that would be required for that usage. . Don't you think that just might be the reason why *all* optical enlargers and projection systems place the emulsion side of the image towards the final projected image? "CSM1" wrote in message ... Maybe because the light travels through the film base to produce the image on the sensor. Either way you turn the film, the light has to travel through the film to get to the sensor. That is why it is called a transparency, light passes through the film. You turn the film the way that when scanned produces a right side up or correct left to right image. Sometimes with some scanners the image maybe correct left to right but upside down. My Canon CanoScan 8400F scans 120 negatives shot with a twin lens reflex camera are upside down when scanned with the correct left to right orientation. A simple matter to turn all the images in the image editor at the same time. (The scanner driver can also rotate the image, one at a time). And yes, you can flip or rotate the image in a photo editor, no matter which way you scanned it. -- CSM1 http://www.carlmcmillan.com -- "Linda" wrote in message . com... Hello, I have two questions. When scanning 35mm or 4x5s does the emulsion side go down? Is there a rule for this? I thought it went down but my scans are mirrored and I get different results when emulsion is up or down. Is it better to adjust the levels (histogram) with the scanning software or in Photoshop? I don't want to lose information when scanning. I've read scantips.com, searched this group and googled. I have alot of slides of artwork to scan. I don't want the fastest way, I'd like to do it the best way. I'm using Silverfast SE (came with the scanner) and an Epson 4870. I don't know if it's relevant but I'm on a Mac with system 9.2.2 I've become a bit scrambled over this and any help will be so appreciated. Thanks, Linda -- remove invalid to reply |
#8
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"RSD99" wrote in message
newsHhve.1096$4M1.772@trnddc07... But one way ... with the emulsion side of the film *down* ... the *image* does *not* have to travel through the dirt, distortion and contamination(s) of the film base. The film base is, was, and always will be manufactured to simply be a support for the emulsion. The film base was *never* designed to be part of the optical path, and is not manufactured to the parameters that would be required for that usage. . The film base is a part of the optical path. The orange base color of Color Negative film is an very important part of the film/print process. Slides which have a clear film base still used the film base as a part of the optical path, especially if projecting in a Slide projector. The image is made from the light and the density of the emulsion of the film. The film base can not be removed from the equation. You can not separate the image from the film base. Don't you think that just might be the reason why *all* optical enlargers and projection systems place the emulsion side of the image towards the final projected image? The emulsion side is toward the paper because that is the correct orientation of the image as photographed by the camera. A optical enlarger such as used in a darkroom to make photographic prints on photographic paper (The standard Film camera, develop the film, print the picture kind) transmits the light source through the film through a lens onto the paper, thereby making an image on the paper which is then developed in chemicals. The film is between the light source and the lens of the enlarger. The same as in a scanner, the film is between the light and the sensor. Any dirt, dust or crap on either surface of the film will make a white spot on the print. That is why film must be clean to make spot free prints or images of any kind, digital or optical. It is simple physics, when light passes through an object, it passes through both surfaces. -- CSM1 http://www.carlmcmillan.com -- |
#9
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"CSM1" posted:
"... It is simple physics, when light passes through an object, it passes through both surfaces. ...." That is true ... but there is a significant difference between "transmitting light" through a semi-transparent (and also distorting) substrate and "transmitting an image" through the same substrate. Would you, for instance, prefer to take a picture through a (dirty) window or mirror, or would you move the camera slightly to view the same scene directly ... without "looking through the window?" Correspondingly, the *image* on a piece of film does not need to be "read" through the additional distortions of the film base simply because that gives the proper "orientation." That's what the 'Invert' function of the scanner software (and PhotoShop) are for. As I posted, the film base is designed and manufactured simply to hold the emulsion. It is *not* designed to be part of an optical (or image) "chain," and the material used is not designed to, nor does it have, the suitable optical properties. Otherwise we would all be still be taking our photographs on glass plates .... and *optical* grade glass plates at that! I stand by my previous advice that film is best scanned with the emulsion side towards the sensor. Historically (traditionally) for several reasons this is the method used. Only *one* of those reasons is that it provides the proper image orientation with the optical system(s) used. You, of course, are free to scan your images through the distortion(s) that might be caused by the film base. "CSM1" wrote in message m... "RSD99" wrote in message newsHhve.1096$4M1.772@trnddc07... But one way ... with the emulsion side of the film *down* ... the *image* does *not* have to travel through the dirt, distortion and contamination(s) of the film base. The film base is, was, and always will be manufactured to simply be a support for the emulsion. The film base was *never* designed to be part of the optical path, and is not manufactured to the parameters that would be required for that usage. . The film base is a part of the optical path. The orange base color of Color Negative film is an very important part of the film/print process. Slides which have a clear film base still used the film base as a part of the optical path, especially if projecting in a Slide projector. The image is made from the light and the density of the emulsion of the film. The film base can not be removed from the equation. You can not separate the image from the film base. Don't you think that just might be the reason why *all* optical enlargers and projection systems place the emulsion side of the image towards the final projected image? The emulsion side is toward the paper because that is the correct orientation of the image as photographed by the camera. A optical enlarger such as used in a darkroom to make photographic prints on photographic paper (The standard Film camera, develop the film, print the picture kind) transmits the light source through the film through a lens onto the paper, thereby making an image on the paper which is then developed in chemicals. The film is between the light source and the lens of the enlarger. The same as in a scanner, the film is between the light and the sensor. Any dirt, dust or crap on either surface of the film will make a white spot on the print. That is why film must be clean to make spot free prints or images of any kind, digital or optical. It is simple physics, when light passes through an object, it passes through both surfaces. -- CSM1 http://www.carlmcmillan.com -- |
#10
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In article , CSM1
writes "RSD99" wrote in message news:lc%ue.902$Uc2.403@trnddc03... Emulsion Down, and 'flip' the image either in the scanning program or in PhotoShop. Just ask yourself ... just exactly WHY should I scan *through* the film base? Maybe because the light travels through the film base to produce the image on the sensor. It certainly does, but after the light has been spatially modulated by the image it only passes through the film base *if* the film is oriented the wrong way. Consequently, the optical loss on the *image* only occurs if the film is oriented with the emulsion on the side of the light source - which *is* the wrong way. Put it another way. The film base is not perfect - it scatters and distorts the light to a certain degree. If the base is on the illumination side then that scattering and distortion of the light only serves as a diffuser. Even if the film base scattered significantly, all that would happen would be that the light reaching the emulsion (and hence the image) would be more diffuse. The image would still be perfectly formed on the CCD by the scanner's primary lens. Indeed, certain scanners have specific diffusers designed into them because there are advantages of a diffuse source. Mount the film the wrong way round and that built in mild diffusion on the film base affects the *image* as well as the illumination. Mount it the correct way and only the image is not affected. Either way you turn the film, the light has to travel through the film to get to the sensor. In an enlarger, light has to travel through the condenser lens or the diffuser to get to the sensor too - and the same thing happens in scanners. In neither enlarger nor scanner does the condenser or diffuser have the same image forming capabilities as the primary lens - they don't need to because the light passes through them before it picks up the image. The same is true of the film base - if it is oriented correctly. Conduct a simple experiment. Make a synthetically bad film base by taping a sheet of tracing paper to one side of the slide. Hold it up to a light source and look through it in each orientation - with the tracing paper on the illumination side and then again with the tracing paper on the sensor side (ie. towards your eye). In which orientation do you see the cleanest sharpest image? Well, to a much lesser degree, that same light scattering of the tracing paper occurs in the film base itself. As a result of conducting that experiment, come back and tell us which side the non-optical graded film base should be on! The image losses introduced by scanning the film in the wrong orientation are minimal and in almost all cases (unless you happen to get a rogue batch of film) there are other more significant loss mechanisms, but they are never zero. Since they are unspecified and variable they are best avoided by adopting the correct orientation as the default. Only flip the film if there is no alternative. -- Kennedy Yes, Socrates himself is particularly missed; A lovely little thinker, but a bugger when he's ****ed. Python Philosophers (replace 'nospam' with 'kennedym' when replying) |
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