tuning focus on an Epson Perfection scanner

For people who like to tune their flatbed scanners with some 'adjustment' one of the things people most commonly do is adjust the height of their film holders to get the film in the place where its focused.

This is because Epson Perfection scanners are not really calibrated in the factory (well come on, they only cost $700). So for those seeking the best out of their scanner dollar (and lets face it, you can't buy the Nikons anymore) we try to make the tools we have just that bit sharper than they are 'out of the box'

I thought I'd share with you the little shortcut I use to find the sweet spot. Its a stack of coins. In this case its the 5c coin.

Sticking them on the glass so that they hang over each other one can see pretty quickly where the focus point is.

Obviously coin 1 is on the glass ...

 

Its at coin 4 through to 5 that things appear their sharpest. So, now by measuring the coin thickness you can quickly set up your Better Scanning holders to get the best out of your film scans.

How much better?

Well about like this:

and this is a 100% crop of a 1200dpi scan of a slide which I wasn't really that happy with (crummy lens). Chalk and Cheese isn't it ...

Hmmm ... speaking of which, its time for some cheese to go with my red wine I think...

Happy Adjusting

the colour version

Hi

in my blog post "standing on a bridge that's gone" I mentioned that I was doing a colour negative 6x12 of the following digital





well here it is ...




I think its more natural (and doesn't blow out the sky). With the digital, I could have metered to prevent hi-light blowout, but I always meter for film to get the mids and shadows looking good on the digital ... the Negative has more headroom (and natural compression) than the digital. If I had chosen to expose more carefully for that on the digital I know from experience that it would be quite noisy in the shadows.

In some ways its of course a similar sort of look and feel the the black and white ... (here is an ADOX sheet of 4x5)

but with (in my view) better colours than the digital. To be honest I reckon I'd need to have gone down the HDR path (and hope to shit nothing moved) to get a better rendering than the Negative ... which btw was 400 ISO.


In case you're wondering how much detail was on the negative, well here is a 100% section from down the bottom ... and this is only a 1200 DPI scan with my Epson


not bad ... sometimes the big camera is worth the struggle

Epson 4990 response testing

Some time ago I tested my Epson 3200 scanner for its ability to plumb the depths of a Stouffer wedge. The reason is to understand (not guess at) how much density the scanner can cope with (meaning how much shadow detail can be recovered from slide scanning).

I scanned the wedge as a linear full range positive and then input the median values obtained from each 'patch'. That's the blue line is the scan value (255 - 0) returned, the red line is the Log₁₀ of that.

Looking at the straight numerical levels shows that it really starts to plateau out at about 17 on the step wedge. It seems like a good result, but when compared to the much older 3200 its not that much different.


Since it is the log difference between the values that is important in film scanning I've placed them in the graph. Interestingly the 3200 actually remains linear in the log responce longer than the 4990.

I don't know if this is a good or a bad thing as film already has non-linear responses in the shoulder of the curve anyway.

Well, anyway it seems that the 4990 goes into the shadows a little better than the 3200, but despite how it seems on scanning film its not screamingly better when measured.