Update to Epson scanning article: how to bypass all tonal adjustments

[Ken Lee]

Epson Scan settings:

VueScan settings:

[Pere Casals]

Also this link has the DR results for v700 and 4990

http://www.silverfast.com/PDF/TestRe...E_DWueller.pdf

It puts it as 3.1 for a single pass. That is quite a lot when you adjust the time, to zero out the film base.

And 3.4D with multiexposure it is a pretty competent job !

[Ted Baker]

Quick review,

Vuescan exposure is much better, very close to perfect (what is the density of number 1 supposed to be?). From the example I assume you just used auto and slide film, vuescan does a good job in that mode.

Epson scan not so good, but it is also possible to make mistakes in the analysis, especially with Epsonscan can you post the original vuescan file, without any changes? Working from that you should be able to work out what epsonscan does.

When you did your cropping in preview for both programs, did you make sure that there was no clearer areas than step 1?

Then of course you need to it for all three colors with a filter if you want to check that aspect of it as well.

[Ken Lee]

Quick review,

Vuescan exposure is much better, very close to perfect (what is the density of number 1 supposed to be?). From the example I assume you just used auto and slide film, vuescan does a good job in that mode.

Epson scan not so good, but it is also possible to make mistakes in the analysis, especially with Epsonscan can you post the original vuescan file, without any changes? Working from that you should be able to work out what epsonscan does.

Then of course you need to it for all three colors with a filter if you want to check that aspect of it as well.

I have added a link the original raw VueScan scan file with no gamma adjustment to the same post where I posted the others.

All those files are down-sized to a width of 1200 pixels.

[IanBarber]

Ken, just remind me why you chose Slide Film as the Media in Vuescan

[Ted Baker]

Thanks,

Will take a look and do a proper analysis over the next few, days. (my own step wedge was old and only went to 2.1)

If you have a chance to do it again, with vuescan do the preview, put a crop around step 3 or step 6 (roughly the density of BW film base). Hit preview again, the click on lock exposure, then crop the entire step wedge. (note the exposure time for reference)

Steps below your reference will be blown out, but it will be interesting to check for any improvement in SnR in darker steps.

Actually this last test is quite important, as it should show if there is any meaningful difference for BW negative scanning.

[Pere Casals]

Here's a quick test of EpsonScan with no adjustments

Nice test !

By adjusting the curve it is made clear that the Epson reaches well 3.05D, that this wedge reaches, but with some noise in the higher, IMHO if using multiexposure noise would impreve a lot and a denser wedge would be needed to see the scanner limit.

By inspecting the values (F8, information dialog, 16 bits value) the expected value for step 4 should be 1/2 if the step 1, it goes close but with some discrepance... perhaps actual densities shpuld be checked or taken from a calibration...

[Ken Lee]

Ken, just remind me why you chose Slide Film as the Media in Vuescan

I guessed that scanning it as a slide, IE a positive, would be simpler and therefore better, since no reversal step is included in the process.

[Ted Baker]

I guessed that scanning it as a slide, IE a positive, would be simpler and therefore better, since no reversal step is included in the process.

Ken, you made the best choice for the test. When using auto exposure, which is the default, unless you go looking for manual exposure. the auto exposure algorithm is different. When you choose negative it will adjust all three channels, but this is "ISO" change not a time change and actual exposure time it calculates is different. (Its shorter, probably because shorter is faster). With Raw you still get a negative regardless.

[chassis]

Ken, thanks for this, it is a big service to the community here.