35mm vs MF: file size and output quality

Hello,

I'm certain this has been asked before somewhere in the forums, but

I just can't find it. Forgive me.

If the scanning service I use scans 35mm at 4000dpi, creating a

roughly 60mb file, and scans 6x7 at 2000dpi, creating a roughly 60mb

file, how does the output quality of those two scans compare? Have I

given up the advantage of the larger negative, or will the medium

format neg still give a superior output?

Thanks for any help you can give. . .

There should be much less film grain visible in the MF scan. as a result the image quality should be better.

I agree too. Taking it a bit further; a 4x5" scanned so its file size is 60 Megs would be even better.

File size doesn't affect actual image composition, only how much of it you have recorded. So a 4000dpi scan pulls out all the useful information from 35mm and some fluff (sometimes not, depends on your opinion) and you have a 60mb file that may or may not be all actual useful image data. A 60mb scan from 6x7 contains much more useful data, and depending on print size will appear much crisper with better color, etc, yadda yadda.

 

If you scan a 4x5 to 60mb, you may or may not see a difference over the medium format depending on what you do with it. 4x5 is incredible for the amount of information that can be pulled out of it, but a 60mb scan from 4x5 is relatively small, but if you're only printing 16x20s for example, it'll only be a little better than a 6x7 scanned to 60mb. Surface area is always better, the more the merrier, but obviously there are certain areas where it'll all basically look the same because you simply are not enlarging it as much.

 

With that said, a 20x24 of 35mm looks better when done well digitally than it ever did when made with analog methods in my opinion. It seems to allow more enlargement in my opinion. My comparison for this is limited to only a few personal examples and a number of other people's prints, but it's largely proved to be accurate.

I agree with the other posters. I'm of the opinion that there isn't much useful

information about the subject to be pulled from a piece of film beyond about

2000 dpi. After that, you are mostly sharpening grain (but many disagree with

this, and they may be right). So the bigger the film, the better. I much prefer

scans of medium format on my Epson GT-9700F (same as the 2450) flatbed to

scans of 35mm on my dedicated film scanner. No doubt the film scanner is

sharper, but the larger negatives make the results from the flatbed look

better.

 

To give a different example, when Canon's D30 came out, people were

surprised that it was only 3.4 or so megapixels but could deliver images much

better than smaller P&S digital cameras with more pixels. The key is that the

sensor in the D30 was much bigger. The size of the sensor is very important,

whether it's a chip or a piece of film.

<I>how does the output quality of those two scans compare</i><P>You have the comparisons in front of you. Why are you asking us?<P>Yes, I'm with the skeptics who think scanning film above 2,000dpi is a complete waste of time. I'd almost rather scan 35mm at 2,000 dpi, rescale to 4,000, and add digital noise. Doub't if you could tell the difference.<P>I just sold some 16x20 LightJet prints scanned from Ektar 25 at 4,000dpi. They are significantly more grainy than my 20x24 MF work at 2,000dpi scanned from 100speed film.

When I got my 4000dpi film scanner; I started to rescan some favorite negatives; that were previously scanned with a 2720 dpi film scanner. With the old Ektar 25; some of the sharper negatives are much better. With most all of my asa 800 available light sports shots; there is little or no improvement. The above is for color negatives<BR><BR>With B&W; there is a much better improvement in the 4000 dpi versus 2720 dpi scans. This is because B&W negatives have a higher resolving power than many color films.