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#1
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Medium format versus digital sharpness
How many megapixels would a digital camera image file need to equal the
sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? Robert |
#2
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Medium format versus digital sharpness
"Robert Montgomery" wrote: How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? The short answer is that there are no affordable digital systems that compete with 6x7 and 4x5. Your mileage will vary, but my experience is that for practical purposes, 12.7MP (the Canon 5D) acts very much like 645. But 6x7 scanned on a Nikon 8000 is noticeably better than the 5D. So the new 21MP Canon 1DsIII should give 6x7 a run for its money. (Although the only Canon wide angle lens up to that is probably the new 14/2.8 II L. And maybe the new 16-35/2.8 when stopped way down. Maybe.) I'd guess the 39MP digital backs would be encroaching on 4x5 territory. David J. Littleboy Tokyo, Japan |
#3
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Medium format versus digital sharpness
Robert Montgomery wrote:
How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? 6x7 cm: about 112 MP 4x5": about 352 MP Please don't believe reports that suggest that 21 MP even comes close to 6x7 quality. |
#4
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Medium format versus digital sharpness
Q.G. de Bakker wrote:
Robert Montgomery wrote: How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? 6x7 cm: about 112 MP 4x5": about 352 MP Please don't believe reports that suggest that 21 MP even comes close to 6x7 quality. Doesn't it really come down to print size? :-) Dana |
#5
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Medium format versus digital sharpness
Recently, Dana Myers posted:
Q.G. de Bakker wrote: Robert Montgomery wrote: How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? 6x7 cm: about 112 MP 4x5": about 352 MP Please don't believe reports that suggest that 21 MP even comes close to 6x7 quality. Doesn't it really come down to print size? :-) Some people think so, others (including me) don't think that's the whole picture. ;-) Compare a 4x5" contact print with a 4x5" enlargement from whatever source you want, and see if they look the same. To me, they do not. The same can be said for other format comparisons, and the larger the print, the more obvious the differences. Neil |
#6
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Medium format versus digital sharpness
Dana Myers wrote:
Doesn't it really come down to print size? :-) Not at all. If about print sizes at all, it is about (not comes down to) the maximum print size you can get out of each. |
#7
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Medium format versus digital sharpness
"Robert Montgomery" wrote in message news:NZgNi.145964$bO6.50583@edtnps89... How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? Robert There are a Lot of variables involved: the lens used to make the original image, the method used to make the print (lens or printer) and the type of film you are using for comparison. You could make the assumption that to record equivalent detail, the digital imager would need to have the same number of pixels as the film has grains. A high speed film has larger grains and fewer of them per area, a fine grain film has smaller grains and more of them. A source that I trust (but no longer remember who!) claims that 36Mpixels equals average consumer 35mm film. A 35mm negative is 24x36mm, so if my math is right (!), a 6x7 neg would be equal to 175Mpixels. But you asked for file size-- that brings in more variables if that is really what you want. Some file types compress the image so that it fits in a smaller size. For example, an outdoor picture may include an area of sky of a certain solid color. The file storage won't store individual pixels, but rather an indication that a certain area is to be a certain solid color. A photograph of a white sand beach (very little detail) may make a smaller size file than a close-up of an elderly face (wrinkles, hair, etc.). |
#8
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Medium format versus digital sharpness
On Oct 4, 10:05 pm, Robert Montgomery
wrote: How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? Robert I put up a page that discusses this for 6x7 along with a sample 6x7 slide scanned at 4000 DPI. The link is http://chasfs.com/mega.py The sharpness is affected by the lens, the film, the scanner and any post processing. The sample referred to above is about 90 megapixels, and is unsharpened. You can play around with it in Photoshop, but may not use it for commercial purposes. You might try downrezzing it by various amounts and then uprezzing it to see if you can tell when the amount of detail is noticeably affected. Peace, -chasfs |
#9
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Medium format versus digital sharpness
Ken Hart wrote:
"Robert Montgomery" wrote in message news:NZgNi.145964$bO6.50583@edtnps89... How many megapixels would a digital camera image file [..] [...] But you asked for file size-- [...] No, he didn't. He asked about how many megapixels there would need to be in that file. Why keep people confusing matters by bringing in megabytes? The number of those does not tell us a single thing. |
#10
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Medium format versus digital sharpness
"Scott W" wrote in message ... Q.G. de Bakker wrote: Robert Montgomery wrote: How many megapixels would a digital camera image file need to equal the sharpness of a six-by-seven centimeter or a four-by-five-inch transparency? 6x7 cm: about 112 MP 4x5": about 352 MP Please don't believe reports that suggest that 21 MP even comes close to 6x7 quality. Hmmm, 112MP from 6x7, that is pretty impressive and far past anything I have seen, you go a scan that shows that? Scott I'm not sure how Q.G. came up with the 112 MP figure but it's not implausible. You figure desktop film scanners such as those from Nikon and Minolta can do 4000 DPI. Taking a 6x7CM transparancy and converting to inches 2 1/4x4000=9000 2 3/4x4000=11000 9000x11000=99MP Now when you get into drum scan terrority the resolutions get much higher. |
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