Since starting to scan my negatives using a digicam I've learnt a few things and have changed my setup quite a bit so though an update might be in order. I also thought having a dedicated thread on the subject might be useful so anyone else can add to it.
There's been a few posts previously in the 'I just made/fixed ...' thread:
http://www.filmwasters.com/forum/index.php?topic=8655.msg121179#msg121179http://www.filmwasters.com/forum/index.php?topic=8655.msg123458#msg123458http://www.filmwasters.com/forum/index.php?topic=8655.msg127540#msg127540The last one is my original setup.
The main issue I had was with the lens I was using (Tamron 90mm). One known problem with using that lens on digital is the reflection you can get from the back element causing a light spot in the middle of the image. Sometimes it seemed to work, others not. I also had a problem with flatness of field. So I experimented with various other lenses I have. The results ranged from pretty good to terrible. All good lenses if used normally but reproducing at 1:1 was a different matter. The best I had was the Zeiss/Contax 85mm f/2.8 but, again, flatness of field wasn't quite good enough. I thought an enlarger lens might do better so I bought a Schneider Componon-S 80mm to try. It's the best of what I've tried so far. The maximum aperture is f/5.6 and, at that, it's very sharp but the corners are showing softness. Again, it's a flatness of field issue. At any aperture below maximum, sharpness starts to fall off, presumably due to refraction. At f/22 it's not acceptable. At f/11 the sharpness degradation is barely noticeable but the corners are now a lot better so that's what I'm using it at.
The problem with using the enlarger lens is the range of extension needed and this necessitated a change from extension tubes to a bellows. So the setup is now like this.
The extra weight and the fact the weight was now further away from the support meant the carriage I was using to move the rig up and down the rack was allowing the whole lot to sag causing problems keeping the lens axis perpendicular to the negative. So I bolted another carriage to the first to make the whole thing more stable.
This now works fine and I can copy 35mm up to 6x9 without any problem. 6x12 or 5x4 would mean a bit of a change of setup but I rarely need that.
I also changed my light source to a small MedaLight I've had knocking around for years. It has an illuminated area which will cover up to 5x4 and it's very even. It's not too bright and exposures are usually around 2 seconds. But that's not a problem if I use a delayed release or tether the camera to the PC and fire it from the PC to prevent any movement. Tethering to the PC has the added advantage of not having to remove the flash card from the camera to transfer the images and you can do an immediate check on the scan to see if it's OK.
Here's the full setup along with the masks I found necessary to prevent stray light causing a problem.
Feel free to add your experiences if you scan using a digicam and maybe this will be a useful resource for anyone thinking of doing the same.