Thursday, 11 April 2013

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 fact 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

6 comments:

Jao van de Lagemaat said...

Wow, that is an enormous distance. Neat trick with the coins.

obakesan said...

Hi Jao

thanks for the comment. I normally use microscope slides with permanent marker on it, but guessed that coins would be more available.

I had posted similar to this on forums before but thought that since my blog gets more traffic I may actually help more people this way.

The distance is rather large, its larger than that on my 4870. Makes me wonder if its a larger to enable them to make the scanner a few mm smaller (noone told engineering so they didn't compensate) and chalk up a win for the marketing department ...

:-)

Noons said...

My 4990 Epson was exactly the opposite: it focused too far into the glass! Never managed to get perfect focus out of it.
It's gone now, after a violent encounter with the floor boards...

Wonder if this problem was fixed in all new ones or it's something we can take it back to Epson to get fixed if it happens again?

obakesan said...

Well I reckon it should be a warranty issue. Perhaps a quick test like this can save a lot of frustration.

chuck94022 said...

Though I already dialed in my Betterscanning holder, I thought I'd try this during my last scanning run. The problem I found in doing it is getting sufficient light underneath the coins to make the details visible. How did you accomplish this? A flashlight to the side? That didn't work well for me.

I tried scanning in document mode (so it is lit from underneath), but I don't trust that the focus area is the same (I highly doubt it, though I don't know how they would accomplish this mechanically unless the scanning CCD is physically shifted lower by the machine.

obakesan said...

Chuck

Use silver coins and pull the curves up to see it more clearly.

Definitely don't do this in reflective setting as the scanner changes focus

:-)