Drum scans vs Epson 4990

[Roger Cole]

I took the liberty of increasing contrast just a bit in the 4990 scan and applying just a bit of unsharp mask. Let's see how this compares.

Here's your drum scan:

And here's the 4990 with a bit more contrast and just a touch of unsharp masking:



Note: I will gladly delete this from my personal web space after some discussion or at the request of the OP, whichever comes first. Image is the property of the original poster.

[Zaitz]

Not a problem and that shows a good comparison. What I am wondering, I guess, is the small difference (I consider it a fairly small difference) in quality between the scanners what one should expect?

[Roger Cole]

Not a problem and that shows a good comparison. What I am wondering, I guess, is the small difference (I consider it a fairly small difference) in quality between the scanners what one should expect?

I think the real lesson is that it's really pretty much impossible to see the difference (given some adjustments in post processing) at these resolutions. Doesn't mean there wouldn't be at higher resolutions or when printed.

And of course I just did a quick and dirty few clicks, and it's obvious I slightly over did it, exceeded the contrast of the drum scan and probably sharpened a tad too much too.

The key I think will be in the printing, especially at large print sizes. From 4x5 I doubt most would see any difference (if carefully post processed to match) at anything smaller than 4x, 16x20, but I admit that's a WAG.

[photobymike]

I did the same test 3 years ago, Drum vs Epson v750... The problem i ran into was consistency in quality of the drum scans.... v750 was not as good but in the long run with many scans to do it was cheaper. I scan anything from 35mm to 4x5 BW, color neg, and positives. Just recently i got my epson v750 to do a 12,800 highest resolution on 35mm film.it is like 200 mega pixels .... cool very cool...... and the Digital Ice is a dream come true. Its just like my scanner has taken the place of my Omega D2 enlarger. In the last three years i have scanned thousands of pictures with my trusty 750. It is given me constancy in quality output on my schedule... late at night. I make prints on an Epson 4800 printer.....

The the bottom line is the print.

Viewing prints from both (same image) I am absolutely sure you could not tell the drum scan from the v750 flat bed scan. (My wallet could feel the difference.) I have tried and challenged other photographers to tell the difference in the prints.... heck they cant tell the difference between my digital and my film pictures.....

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[timparkin]

I've done a couple of side by side comparisons on these and here are a few comments

1) it looks like the drum scanner operator hasn't focussed correctly and they haven't used a large enough aperture for the scan. The noise levels in the image when sharpened to match the 4990 demonstarte this

2) The drum scan has had some shadow/highlight applied or some excessive medium radius sharpening by the looks of it - there is a lot less large scale contrast in the drum scans than the epson scan (particularly in the forest shot)

3) The drum scan will demonstrate it's difference in the handling of highlights. This is born out in the shot of the chandelier which shows a lot better handling of the parts of the lampshade overlapping the left hand bulb.

4) The 4990 shot of the chandelier looks like it has had some strong noise reduction applied? The difference in the noise within the light area of the chandelier goes from hardly any noise to nasty digital noise

Finally, I wouldn't expect a huge amount of difference between a drum scan and the 4990 for 8x10 neg. Yes you will get a better tonality if you choose the right aperture and you should get a more representative gradation if the scanner has been profiled properly. However the 4990 resolves about 1600-2000dpi which is probably as much detail as you have in your image. The only area that would be obvious is in highlight handling and tonality (although the latter presumes the scanner operator knew what they were doing)

[Ari]

There's a noticeable difference in sharpness or acuity; what size enlargements do you typically make?

[Ken Lee]

A more rigorous and profusely documented comparison of scanners appears on this forum already: see http://www.largeformatphotography.info/scan-comparison/.

When making comparisons, it's important to explain the details: size of sample, resolution, degree of enlargement, etc. Otherwise, it's all just speculation. For example, see this page, also a scan from 8x10. There's no ambiguity about sample size.

[Brian Ellis]

The drum-scanned images look better to me.

The second image (drum) on my monitor is so soft in some areas, mainly the fabric in the upper left corner and the wood, that it appears to be out of focus. It looks much worse than the first (4990) to me in those areas. However the large area to the right has slightly more detail with the drum scan than the 4990. I agree that with the second set he drum looks better. However, a lot of the difference appears to be a matter of better contrast, something that could be adjusted easily in post processing.

It's been said here many times that there's nothing magic about just getting a drum scan. Some operators are more talented than others, some know what they're doing and others don't (or don't care enough to take the necessary time to do it right).

And even with a good operator the degree of noticeable difference between a prosumer scanner like the 4990 and a drum scan seems to depend to some extent on the image. In my admittedly limited experience with having drum scans made, the main difference has been better detail in shadow areas. If an image doesn't have important detail in those areas then the differences have been pretty hard to see.

And of course print size is also relevant. The largest prints I make with my 3800 are about 16x20. I suspect (or hope) that with larger prints the differences would be more apparent.

[Noah A]

There are so many variables here so it's somewhat hard to make any conclusions from the samples you've posted. Overall I think the drum scans are quite far ahead of the Epson scans. They're sharper and have more contrast without losing detail in the highlights and shadows.

What are the scan resolutions? What aperture was used on the drum scan? What have you posted here? Are they 100% crops? (I doubt it, unless the scans are on the small side.)

Roger's adjustments definitely improve the Epson scan, but he posted it next to a raw drum scan, which could also be improved by some adjustments.

The same thing happened to me when I posted a similar comparison on a different forum. Someone sharpened the heck out of the Epson scan, boosted the contrast and then compared it to the raw drum scan. Clearly both scans can benefit from some post processing, and I'd argue that since it needs less sharpening and less contrast adjustment, the drum scan will likely make a better print in the end. At least it will if you're picky about your work and know what you're doing on the print end of things.

Also, if you're making 11x14in. prints from 8x10, you won't see as much difference between the scans as if you're making 48x60in. prints from 4x5.

Assuming that prints are your final desired output, I would suggest that you optimize both scans and make good prints of each.

[Nathan Potter]

Comparisons between scanners can be difficult. The fact is, what are you comparing? What precisely is the objective of the comparison? A comparison of resolution is common, but that cannot be reasonably decoupled from contrast. The story can only be told accurately by quantitative data take under a set of known conditions.

In some sense you hardly need to do a comparison. The published specs and a few tests will indicate the capabilities of drum vs flatbed.

If you scan a high resolution target of increasing spacial frequencies you'll find one set where the clear space between lines no longer shows a minimum density (256). At this spacial frequency the spot (or aperture) is about the size of the space. I've done this recently for the V750 and found this size to be close to 1 mil (25 um). This size is a result of limitations inherent in the lens and detector. It's consistently different by a bit in the X and Y scan direction. It simply says that each pixel of digital information represents the average color and grayscale within that 25 um diameter area. No detail can be recovered smaller than a nominally 25 um area.

Now in fact the best drum scanners are capable of far smaller apertures, ideally down to less than 5 um diameters coupled with higher Dmax capabilities due to PMT technology.

Of course this assumes that the instruments are adjusted properly and operating properly.

In order to capture detail in the original film accurately we assume that the 25 um aperture is the Nyquist frequency (20 lp/mm), so by D =Nq X (2), we really can only replicate detail at a level of 10 lp/mm (50um features). This would be of course at 100% contrast or so - a very tough standard. Reducing the contrast increases the apparent resolution and is a very reasonable thing to do - say in the 10 to 50% range.

A drum scanner with a 5 um aperture very clearly has capability that greatly exceeds that of an Epson V750.

If you don't see a difference then the detail wasn't in the scanned film to start with or the machines were not adjusted to optimum performance prior to scan.

It's probably best not to obsess over this since Photoshop manipulations will largely corrupt the original film image and transpose it from reality through the artists license to his/her personal vision.