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Ektar 100 versus Alpha 900, Velvia 100, Portra 160VC and TMax 100


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The scanned images are not contrasty even for the low resolution chart. Based on my experience with velvia 50 and 100 and the USAF test chart, the line pairs on the slides are very contrasty when viewed under a 30X microscope with a proper light source. The detection limit of the 30X microscope is 80-90 lps/mm.

 

Richard

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<p>Daniel,<br>

<br /> We know resolving power goes down with contrast on films.<br>

<br /> "Pretty much any full frame body will produce higher IQ on real photographs than 35mm film."<br>

We are trying to discuss based on actual results.  Do you have any side by side tests to support your claim?<br>

Say like a tree shot with 35mm film and any full frame body?</p>

<p>"This A900 comparison, on a target which lends itself to film, just shows how big the gap is with current 20+ MP bodies."<br>

If it makes you happy to believe that no one will stop you.  Not sure what was wrong with the OP's test, my resolution results are drastically better than his.<br>

 </p>

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<p>Newton,<br>

<br /> Yes, resolution wise the A900 is very good and can make prints comparable to 35mm film.<br>

No, it won't be comparable to medium format film - especially detail wise for landscape prints 16x20 and 20x24. <br>

<br /> I shoot 6x7 and get around 98 true megapixels of data with velvia (high contrast).  The A900 gets about only 12 true megapixels of data (high contrast).  Also my system (RZ67II) just captures more information all together through the lens onto the film plane than possible on a FF(35mm) system.</p>

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<p>Mauro:</p>

<blockquote>

<p>The A900 gets about only 12 true megapixels of data (high contrast)</p>

</blockquote>

<p>Says who? Any data to back this up?</p>

<p>As for your 800% comparison of Marco's results vs. yours: you're right, there's something terribly wrong with Marco's results. I'm inclined to believe your results, Mauro, as your explanation of 8.93x100 to calculate LPPH all seems reasonable & correct to me.</p>

<p>As for an 8000ppi scan -- do you have an extra frame of film to send me? I can scan on an Imacon 848. Or, I could just repeat the test myself :)</p>

<p>What size would you suggest I print Stephen Westin's resolution chart at so I can repeat the test myself, then compare a LS-9000 vs. Imacon 848 scan?</p>

<p>Thanks,<br /> Rishi</p>

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<p>Mauro, I have to say going through your smugmug stuff: nice methodology.</p>

<p>Couple of questions for you:</p>

<ol>

<li>In your 'Color Comp' image comparing TMX to Provia to Velvia -- did you use individual color profiles for each film when scanning, to make sure you're truly representing what's on the film?</li>

<li>You list the 40D's 'True Resolution' as 5.6 MP. How did you arrive at this?</li>

</ol>

<p>Thanks in advance,<br /> Rishi</p>

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<p>Rishi,<br>

"The A900 gets about only 12 true megapixels of data (high contrast)"<br>

 - at 2700 lpph -->  Resolution = 2700 * 2700 / 24 *36 = 11 megapixels</p>

<p>"As for an 8000ppi scan -- do you have an extra frame of film to send me? I can scan on an Imacon 848. Or, I could just repeat the test myself :)"<br>

- I have lent the shot I scanned to someone else but I have the one next to it which is one stop under exposed.  It should work about the same.   Can I cut just that frame for you or you need a strip to feed in the scanner?</p>

<p>"What size would you suggest I print Stephen Westin's resolution chart at so I can repeat the test myself, then compare a LS-9000 vs. Imacon 848 scan?"<br>

- It doesn't matter.  The larger and highest resolution the better of course.</p>

<p>"In your 'Color Comp' image comparing TMX to Provia to Velvia -- did you use individual color profiles for each film when scanning, to make sure you're truly representing what's on the film?"<br>

- No same standard setting for all.</p>

<p>"You list the 40D's 'True Resolution' as 5.6 MP. How did you arrive at this?"<br>

- From my own test.  Roughly at 2000 lpph -->  Resolution = 2000 * 2000 / 24 *36 = 6 megapixels</p>

<p> </p>

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<p>I scan Ektar on a Nikon Coolscan V, which has a true dpi of 4,000.  If the Ektar is underexposed then a small amount of grain shows up.  With normal exposure there is no grain at all.  It's the only color reversal film for which I don't have to use the scanner's digital GEM grain removal.  I am MUCH more impressed by it than I expected to be.<br>

Is it totally sharp at 4,000 dpi?  No.  I have to reduce it to 3200 dpi for that.  That's using a Nikkor 35/1.4 AIS lens, one of the sharpest lenses they make.  Is it very sharp?  Yes!<br>

Also, I wasn't doing wet scanning.  It's possible that a wet scan would sharpen it up more.  Of course, it's also possible that a wet scan would reveal grain.<br>

My two cents.</p>

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<p>Mauro, I don't understand your calculation.</p>

<p>Let's assume that for each line pair, you need 2 pixels to represent the line pair (one black, one white). If you can resolve 2700 line pairs per height, then essentially you need 5400 (2700 x 2) pixels along the y-axis (height) to resolve those 2700 line pairs.</p>

<p>For the horizontal axis, if we assume equal resolving ability, we'd be able to resolve 2700 x (36/24) = 4050 line pairs per width. Again, if we assume you need 2 pixels to represent each line pair, that means we have 8100 pixels across the width of the sensor.</p>

<p>Now, if we multiply 5400 x 8100, we get 43.74 megapixels.</p>

<p>Which also doesn't seem right, but for the opposite problem of yours (i.e. it seems too high).</p>

<p>Help me out here,<br>

Rishi</p>

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<p><em>We are trying to discuss based on actual results.  Do you have any side by side tests to support your claim?<br /> Say like a tree shot with 35mm film and any full frame body?</em> <br /> <br /> Google is your friend ;-)<br /> <br /> http://www.sphoto.com/techinfo/dslrvsfilm.htm<br /> <br /> http://www.ales.litomisky.com/projects/Analog%20versus%20Digital%20Shootout%20(Hasselblad,%2035mm,%20Canon%205D).htm<br /> <br /> http://www.luminous-landscape.com/reviews/shootout.shtml<br /> <br /> http://www.photographical.net/canon_1ds_35mm.html<br /> <br /> You can argue line pairs all day long. As I said, seeing and seeing clearly are two different things. Even if the A900 ultimately resolved fewer line pairs on some chart than a particular film (I'm sure you could soup some B&W emulsions to beat it here), it will produce the superior print with the higher overall IQ.<br /> <br /> People have been producing fantastic prints with lesser DSLRs for a long time now, regardless of line pairs on a chart. Image quality is not just about high contrast line pair resolution.</p>
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<p>Mauro,</p>

<p>Sorry but I'm going to have to slightly counter your conclusion, but let me start off by saying that, to me, your results show that the Ektar 100/Coolscan 9000 combo show that, for black & white resolution test charts, the resolving power of Ektar100/LS-9000 seem to be on par with that of the Sony A900. This says nothing, of course, about lower contrast scenes and/or 'cleanliness' or 'perceived sharpness' of the two formats.</p>

<p>Now, the folks over at dpreview.com gave the Sony A900 a conservative rating of 2700 LPPH. I'm going to compare your image & their image blown up to 800%, to compare what their line pattern looks like @2700 LPPH and what your line pattern looks like at ~2700 LPPH. Here we are:<br>

<img src="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_vs_SonyA900-1.jpg" alt="" width="800" /><br>

<a href="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_vs_SonyA900-1.jpg">Link to Full-Size Image</a></p>

<p>I'd say, in all fairness, your pattern at 2670 LPPH looks like their Sony A900 representation of the pattern at 2700 LPPH.</p>

<p>If we look at your Ektar 100 image at the region pertaining to 3700 LPPH, which you claim to be the resolution limit, I'd have to say that the analogous region on the Sony A900 pattern is somewhere around 3800 LPPH. Actually, that's me being very generous to the film scan. More like the region in your image pertaining to 3560 LPPH (4, on your chart) corresponds to the area pertaining to 3800 LPPH on the Sony image. I still think that's me being overly generous. Evidence presented below:<br>

<img src="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_vs_SonyA900-2.jpg" alt="" width="800" /><br>

<a href="http://staff.washington.edu/rjsanyal/Photography/FilmVsDigital/Ektar100_vs_SonyA900-2.jpg">Link to Full-Size Image</a></p>

<p>So... I don't think you can say that the Ektar 100/Coolscan 9000 combo outresolves the Sony A900. They're about on par with another, comparing these two tests, for black & white (high contrast) regions. I think resolution will fall off faster for film at lower and lower contrast due to a formidable portion of film being needed to represent many tones... but I could be wrong. Let's save that discussion for somewhere else and focus on what's at hand :)</p>

<p>Rishi</p>

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<p>That being said, Mauro, I would like to make an 8000ppi scan to make sure we extract all the detail out of the Ektar 100. I'll also place it under my 'scope to see what I can resolve by eye.</p>

<p>I'll PM you my address.</p>

<p>Cheers,<br>

Rishi</p>

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<p>Rishi,  "So... I don't think you can say that the Ektar 100/Coolscan 9000 combo outresolves the Sony A900. They're about on par with another, comparing these two tests, for black & white (high contrast) regions."</p>

<p>The criteria for the chart is "Can you count the lines?".  So this is your comparison:</p>

<p>http://shutterclick.smugmug.com/gallery/6616619_YJEwK#433420448_yQERk-X2-LB</p>

<p>Give it to an unbias person and ask him/her to count the lines on both charts.  Then tell us the results (answer is 5 and 9).</p>

<p> </p>

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<p>Mauro, if you look at the images I posted above, at 2800 LPPH for the Sony, I count 9 lines. For 2670 LPPH in your example, I count 5 lines.</p>

<p>Any further down the chart, I can't say for certain that there are 5 lines. For the Sony, a little further down the chart I can still guess 9 lines, but certainly by 3800 LPPH, I cannot discern 9 lines. Nor can I discern 5 lines at your 3700 LPPH mark. I can discern like 2 or 3, but to be fair to the Sony, I can also discern 5 or 6 lines at 3800 LPPH.</p>

<p>So I still think it's fair to say that the Ektar/Coolscan 9000 combo did not outresolve the Sony. Feel free to challenge.</p>

<p>Great, I'm even more curious to check out the Velvia 50 results, as that's what I shoot. I'll scan them this weekend if I receive 'em by then!</p>

<p>Cheers,<br>

Rishi</p>

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<p>Mauro,</p>

<p>Scanning any negatives on the Imacons is an exercise in futility. At least, prior to the 949, which I hear has a softer light source. Any little defects picked up by the Imacon are, of course, magnified upon processing the negative (the 'stretching of the rubber band' explanation that Marco provided on his website), which is NOT the case with slide film.</p>

<p>Therefore, scans just look like they have holes all over them. I never scan negatives on the Imacon because of this... IR dust removal and/or the softer light source of the LS-9000 are essential to me when scanning negatives.</p>

<p>Additionally, you can't do the cool 'super advanced erik krause workflow' with the Imacons to subtract film base color :)</p>

<p>-Rishi</p>

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<p>ha ha, well don't worry about cleaning the films or exagerated grain.    We are just benchmarking resolution not framing them for posterity. </p>

<p>To clear grain quicky and sharpen for resolution evaluation try this -> 1- Sharpen (150, 1.5,0) 2- Neat Image 3- Sharpen (50,1,0)</p>

<p>As you will see, my development process for TMX takes resolution pass the 200 lines/mm from the TMX specs.</p>

<p>It'd be nice if you could add a crop of each film next to your collage above.</p>

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<p>Of course, I'll do a nice comparison of the Coolscan vs. the Imacon scan vs. the Sony.</p>

<p>Also, I find it interesting that you sharpen, then apply NR, then sharpen again... typically I apply NR and then sharpen... why do you add in the first sharpening step? Additionally, my final round of sharpening (no not output sharpening) is typically done with a mask, a la Bruce Fraser, but thank heavens for the kind souls over on the Lightroom dev team that built this functionality into LR.</p>

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<p>A presharpen (with no other edits to avoid modifying the noise pattern) often/always increases N.I. efficiency.</p>

<p>The last sharpen I do after all edits are done and it is sized for print.</p>

<p>Try it both ways sharpen-NE and NE-sharpen, and let me know your observations.</p>

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