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Film vs Digital - Color Rendition


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Also, to Stuart & anyone else suggesting MF:

 

I realize that MF & LF are the way to go for pixel peepers & landscape photographers, but man I have a lot of respect

for anyone that can tame these beasts for the often time-critical type of sunrise & sunset photography I'm a fan of. B/c

I feel that these instruments will try to do anything & everything to mess up your shot (from what I've read, not from my

own experience). From rangefinder focus calibration errors, to difficulty of framing with a rangefinder given different focal lengths, to

1-stop accuracy in metered manual mode for the M7 (a nightmare for Velvia), to manual focus for the Pentax 67II & also mirror/shutter

vibration, to film flatness problems with the Pentax 645N... with 10-15 shots a roll (or 3-5 b/c of bracketing with slides),

how much time to you spend just fiddling with the darn system & changing film vs. actually composing & shooting the

fleeting sunset?

 

I want to try MF, I really do; it's just that older (film) systems seem unnecessarily prohibitive from what I've read so far. Granted I'm spoiled coming from

Canon EOS. Perhaps the Mamiya 645 AFDIII is more what I should be looking at... Nice hefty $$ tag tho!

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<p>Regarding your question about real life contrast, in general for landscapes you can have it all depending on the light. Much higher than resolution charts (like trees against the sky) and much lower (shadowed areas).<br>

Medium format (as well as 35mm) are great, but you need to be prepared to invest on a scanner. Up until the time the Coolscan was sold, a one time scanner purchase that would last a lifetime cost the same as a DSLR which would be replaced sooner or later. Now it is more difficult.</p>

<p>Those who purchased a Coolscan 9000 invested the least money for the obtainable quality.</p>

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<p>I think we measured around 150 lines/mm (which corresponded to 4.25 on your chart) for 35mm Velvia 50.</p>

<p>Any idea why <a href="http://www.hevanet.com/cperez/MF_testing.html">this</a> site rates the highest resolution MF combo (Mamiya 7 | 80mm f/4) at only 120 lines/mm?</p>

<p>Are they just being really conservative (e.g. looking at where the response of the film drops to 50%) or are MF lenses just much worse than Canon EOS lenses?</p>

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<p>Right, I believe you :)</p>

<p>I'm just wondering if medium format lenses are worse or something, since I keep hearing 'MF lenses don't have to be as good as 35mm lenses b/c MF is more forgiving since the magnification factor going to print is less... yada yada'.</p>

<p>Over the next few weeks I'll do the tests myself with resolution charts of varying contrast ratios (I want to go down to a 1:2 chart), & will rent a Mamiya 645 to try the same test on 120 Velvia 50 (yes, I realize that will be a test of the Mamiya lens; the film's the same as the 35mm film!).</p>

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<p>To put it in perspective, the Epson printers (nominal native resolution of 360 or 720) can only resolve between 240 and 300 lines per inch.<br>

A shot with the Mamiya 7 and Techpan captures more detail than the Epson 60" wide printer can output. </p>

<p>Film and camera are not the bottleneck. The bottleneck is either the scanner or the printer (or both).</p>

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<p><em>"Right, I believe you :)"</em></p>

<p>I don't. That would put Mauro as the only person in the world to get close to those figures. Most testers get 110-140 center, holding well to the middle then dropping off to 60-80 corner at the best apertures.<em> </em></p>

<p>It is commonly accepted that the larger the lenses designed image circle the lower the lpmm figure is. The reason they render such sharp images is that to make the same size print you enlarge so much less than a sharper lensed but smaller format print.<em><br /></em></p>

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I could rent the Mamiya 7II, but I tried it out the other day & I'm afraid to say I absolutely hated it. Not being able to

see my composition is just unacceptable to me growing up on Canon EOS systems. The possibility of the rangefinder

focus calibration being off introduces another huge variable (not user adjustable AFAIK). Metered manual only giving

you information in 1-stop intervals with Velvia film? Good luck!

 

I realize some people love this system. 20 minutes in my hands & I never want to pick one up ever again. Just my

personal opinion, of course!

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Unless, Mauro, you think I should test the Mamiya rangefinder lenses separately from the 645AFD lenses... Let me

know.

 

Scott, the outer edge numbers are no longer measuring the resolution of the film, but more optical defects of the lens.

Of course, all together we're measuring the resolution of the system, not just the film, etc.

 

The test chart WAS in the center in Mauro's shots. He sent me the film. I get about 150 lines/mm, though the contrast

at that point is well below 1:2. See for yourself the contrast of the lines at 4.25 in that Imacon scan I posted a while

back...

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<p>Oh sorry, so if I don't use a camera, just contact sheet my film behind very small drawn lines I can get a higher figure than any camera system can deliver? Bit too theoretical for me.</p>

<p>How exactly was the 350lpm figure achieved? With a contact exposure?</p>

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<p>Since we were talking about resolution of digital sensors vs. film, or at least that's where I kinda side-tracked the discussion to (sorry Mauro), yeah, we're getting theoretical here.</p>

<p>But anyway, if I'm trying to measure the resolution of a sensor or film, obviously I'd draw my conclusions from the center of the frame since I'm not trying to bring optical defects into the equation. You answer one question at a time.</p>

<p>As for the 350 l/mm, I'm not surprised. Kodak's own <a href="http://www.kodak.com/global/en/professional/support/techPubs/p255/p255.pdf">tech sheet</a> for technical pan lists 200 lines/mm showing a 30% response. Maybe by 350 l/mm there's only a 10% response which some testers may still be able to discern? What do you think the response of the Velvia 50 in the Imacon scan is at 4.25 (corresponding to 150 lines/mm) below?</p>

<p><img src="http://rishisanyalphotography.com/ForumPostFiles/photo.net/MinoltaDSE5400vsImacon848.jpg" alt="" width="800" /><br>

<a href="http://rishisanyalphotography.com/ForumPostFiles/photo.net/MinoltaDSE5400vsImacon848.jpg">Full-Resolution Image</a></p>

<p>Probably pretty low... If anyone wants to do the math:</p>

<ul>

<li>Whitest white of the chart on the Imacon scan of Velvia 50 is 30% K (Grayscale in Photoshop)</li>

<li>Blackest black of chart is 88% K</li>

<li>Black line @4.25 is ~70% K (100% yield would yield 88%)</li>

<li>White line @4.25 is ~65% K (100% response would yield 30%)</li>

</ul>

<p>Honestly, I'm not sure of the best way to calculate the response from that information, but I'm sure someone else here can help me out? Either way, 65% vs 70% between the white & black lines, respectively, at 150 l/mm is obviously a very low response. Still discernible on this test chart though.</p>

<p>Furthermore, Scott, take a look at <a href="http://www.imx.nl/photo/Film/page169/page169.html">this comparison</a> of 35mm orthopan vs. a Leica M9 (18MP). The guy used an enlarger to make a large print of an enlarged portion of the negative (much like you yourself suggest), then scanned that in... effectively removing poor scanners from the equation. It blows away the 18MP full frame capture. Of course I think that orthopan film has 2x the resolution of more 'normal' films like Velvia 50, so, again: I'm not surprised.</p>

<p>Cheers,<br />Rishi </p>

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<p>Mauro can one still buy the techpan or Spur Orthopan films? I'd love to try to make high-resolution 35mm color images from them using filters... just for fun! Well I guess first I'd have to find a way to scan all the detail out of them ;)</p>

<p>Guess I could try this with Tmax 100, but that orthopan film seems out of this world...</p>

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<p>Rishi,</p>

<p>That is yet another fatally flawed comparison, if you are trying to maximise the two then that is what you have to do. You have to interpolate the digital capture, it works very well. Showing a digital file at 400% without work is pointless.</p>

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<p>You know Scott, I was actually thinking the same thing last night. And was wondering if you should do bicubic upsampling on the digital file.</p>

<p>But then that got me to thinking what goes on optically during enlargement. Does bicubic upsampling better mimic what goes on optically (which probably actually averages contrast from a significant surrounding area for any given spot that is being enlarged)?</p>

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<p>Man, Mauro, I'm having some real problems with that 150 lines/mm number we came up with. Because if you take the formula:</p>

<p>1/Rsystem = 1/Rlens + 1/Rfilm</p>

<p>And if the film is 160 lines/mm (it's probably lower than that since your chart is not 1:1000 contrast), then a system resolution of 150 lines/mm would require the lens to resolve <strong>2400 lines/mm</strong>.</p>

<p><em>Something's very wrong here...</em></p>

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<p>Rishi,</p>

<p>This very evening I have just been doing some up-sampling tests. Obviously you could argue that the scan could be upsampled, and so on and on.</p>

<p>The key to all this, other than academic interest, is to work out what you want to print and at what sizes. I am vilified for saying that very good 36x24 prints can be made from 135 format digital.</p>

<p>Here is a 100% crop from a 135 format digital enlarged 400%, but interpolated. This gives a good file 7488x11232 pixels, or a 31"X47" print at 240ppi. It has had minor sharpening and noise reduction but is not optimised, it shows zero pixilation unlike the linked to comparison.</p>

<p>I am not saying digital is "better" than film, I never have, I am just pointing out that if you wanted to you could make pretty good huge prints with small digital cameras.</p><div>00YUzE-344511584.jpg.d31983bf7f5b1790112d69872e01dbb7.jpg</div>

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<p>I've also printed a 24"x36" on an Epson 9900 from a Canon 5D (12MP) file, and actually sold it. I myself wasn't too pleased without stepping a couple feet back from the print (which is ok given its size), but here's what the full-size print looks like:<br>

<img src="http://rishisanyalphotography.com/Singles/10-1005_SeattleRizalBridge/10-1005_SeattleRizalBridge-HDR_v5.0.jpg" alt="" width="800" /><br>

... and here's what the 10.5x upsampled 1:1 crop looked like at 360ppi (so keep in mind, naturally it'll look worse than yours at 4x upsampled 240ppi... also I used Genuine Fractals): <em>[hint: crop was made from somewhat above center of image]</em><br>

<img src="http://rishisanyalphotography.com/ForumPostFiles/photo.net/Seattle-RizalBridge_24x36-100PercentCrop.jpg" alt="" /><br>

I was honestly much happier with my 16x24 135 Velvia 50 print, which I also sold. But for a fair comparison I should blow that up to 24x36 @360ppi and show it here for comparison... a little too tired to right now going on 3 am on a Friday night :)</p>

<p>Scott -- do you agree with my 2400 lines/mm figure? And do you at least see response in the film at the 150 lines/mm mark (4.25)?</p>

<p>Also, Scott, I agree that upsampled crop looks great... I'd be more than confident to send that data straight to the printer!</p>

<p>Cheers,<br />Rishi </p>

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<p>OK what the heck I went ahead & upscaled one of my 35mm Velvia 50 Imacon scans to 24x36 at 360ppi (same as the above example). But I'm choosing not to post the image visually here, because a comparison is so subjective. However, if you're really curious, you can find the 100% crop <a href="http://rishisanyalphotography.com/ForumPostFiles/photo.net/LewisRiverFalls_Velvia50_24x36_100PercentCrop.jpg">here</a>. Obviously there's small scale detail that the 5D missed on this scale... but I don't think that's really surprising. For reference, here's the full image it came from:<br>

<img src="http://staff.washington.edu/rjsanyal/photoblog/wp-content/gallery/trabantshowing/trabantshowing-17.jpg" alt="" width="800" /></p>

<p>My biggest problem with this particular scan was the pepper grain. Which is why I don't like any Imacons below the latest ones, on which I haven't even run any tests to see how well they suppress pepper grain... just taking their word for it. Nothing like cloning out hundreds of little air bubbles from your scan [Enter Erik de G's Scanhancer]!</p>

<p>-Rishi</p>

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<p>Rishi, I'm not sure about the resolution of the Mamiya lenses (7IIs and RZs) but it is very very high.<br>

In my regular workflow (7II or RZ67, lenses: 50-80-110-180, usually TMAX on Xtol, Coolscan 9000, Epson 7880 24x32), the bottleneck of detail work in this order:</p>

<p>1- Printer. Cannot output the detail that gets to it. <br>

2- Scanner. Cannot retrieve all the detail from film.<br>

3- Film. Cannot retrieve all the detail the lens provides.<br>

4- Camera+lens. </p>

<p>That said, it is great for the workflow to work like that because of the smooth extinction. e.g. the fact that the scan has more detail than the printer can output ensure natural vs abrupt extensions.</p>

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