Making a scanner with a DSLR

[Peter De Smidt]

Hi Jim. Nice test. Dslr scanning does seem to have a lot going for it.

[SURF]

Jim,
With a sharp applied to the Epson scan and balancing the sizes Pentax still feels like a better scanner than Epson.

[buggz]

This is an awesome thread w/ GREAT information!
I will have to try to rig up some things w/ my 5DMkII and bellows w/ the different macro lenses I have.
I have purchased the Epson V750M Pro as yet, but am still planning to do so.

[buggz]

Can one use a cheap Gagne Porta-Trace light box for this?
5K bulbs is what is wanted?
Yes, I am a newbie in this area, but really wanting to learn and experiment also.
Thanks!

[Peter De Smidt]

Sure, you can use a Porta-trace box. That's what I did some initial tests with. Mine is visually uneven, though. If you have a styrofoam box, take the top off. Put the box top down the on the light box, such that the open top of the box is sitting on the light box. Get a piece of diffusion material, I use rigid plastic, a little bigger than your negative. Cut a whole in the bottom of the box, which is now on top, a little smaller than your diffusion material. Tape diffusion material over hole. Turn on light box and see how even the source is. (You don't have to use a box. You could make one out of foam core, styrofoam sheets... It doesn't have to be very thick. 2 to 3 " should be enough.

[rdenney]

I don't think this will replace an Epson scanner, which is worth owning just for sheer convenience. The effort required to make this scan should be reserved for those negatives needing more enlargement than the Epson supports, or that benefit in some other way from using this method. The level of effort will be closer to what it takes to make a scan using a drum scanner. We won't achieve that quality, but it will be cheaper and it will be a usable method for much longer than drum scanners will be available and operational.

Summary: Even if my setup works as well as I hope it will, I'm not reserving the portion of my work area currently devoted to my Epson V750.

Rick "but the light table may have to find a new spot" Denney

[Peter De Smidt]

How long does it take to do a high resolution scan of a 4x5" negative on an Epson V750?

[rdenney]

How long does it take to do a high resolution scan of a 4x5" negative on an Epson V750?

I haven't timed it, but it's "a few minutes" rather than "nearly an hour". I don't know where this process will end up, but I suspect it will depend on the stitching software. Even then, I bet it's closer to the "nearly an hour" than the "few minutes". It would be less fiddly, I'm thinking, than a drum scan, but definitely more fiddly than an Epson.

Rick "who got redirected mid-project and now it may be a while" Denney

[Peter De Smidt]

Here's a test image that is much more challenging to stitch:



Again, it's a 6x7 Acros negative. It took 25 frames to cover it at 1:1 with my 55mm Micro Nikkor-P F3.5 reversed. This would make a print roughly 26 inches by 32 inches at 300 dpi.

Clearly, there are some stitching flaws, and there's a repetitive luminosity "motif" in the sky.

Here's a detail:



If you'd like to work with the 8-bit tiff source images, you can download and extract the folder at:
http://dl.dropbox.com/u/3595413/Ligh...%208%20bit.rar

Feel free to post versions here.

[rdenney]

Could the luminosity motif be a function of vignetting in the reversed lens?

Rick "thinking this might be a more common problem with shorter lenses" Denney