DSLR Scanner: Scans and Comparisons

[Daniel Moore]

I had a look at your 3D file and it looks very interesting. The butt joints on the upper carriage rails leaves me wondering how well machined those ends will be but you won't know until you try it, as I did with my approach. I'm not clear on whether the belt is direct drive or motors are mounted at 90 degrees (gear driven). The pulleys look like they are not GT2 type. The precision of GT2 is much finer than other types which I attribute to obtaining an insane level of repeatability with my system. This can greatly impact the ability to use templates to stitch featureless areas. The fewer the teeth the higher the torque I've read. I'm using 20 tpi pulleys with Nema 17 motors rated at 60 oz/in.

If you haven't already, here's a great quick read on the subject of belts/pulleys pertinent to our application:
http://reprap.org/wiki/Choosing_Belts_and_Pulleys

[rbultman]

I'm moving the conversation to the negative stage thread.

[colorfulbliss]

Hi all! I have spent the last month and a half experimenting with DSLR scanning and have some samples to show. I currently own a PrimeFilm 7200 for 35mm, and an HP G4050 for 6x7 and 4x5. I am fairly satisfied with the results from the PF7200, but the G4050 is pretty disappointing from a sharpness standpoint (not to mention the frequent battles with streaks). So the goal was to get a scanner that could match the output of the PF7200 with the larger formats. They aren't many choices at a price level that a (non-wealthy) hobbyist photographer can afford. I considered a dedicated medium format scanner, but they are fairly expensive and would orphan the 4x5. I tossed around the idea of getting a v700, but I've read so many mixed opinions on its performance that I hesitated to shell out the cash for it. Then I stumbled upon the DSLR scanning threads here on LFF and thought I might give it a whirl. So far I only have a cobbled together proof-of-concept rig, but after some agonizing hours playing with it I do believe it is a worthwhile project.

Here's what I'm working with so far: Samsung NX100 (14.6MP APS-C), 55/3.5 Micro-Nikkor-P, Porta-Trace box with original lamps removed and replaced with RGB LED ribbon light strips, camera and light source stationary, hand panning the film holders out of my two current scanners (not very accurately, I might add).

Workflow: Raw > MakeTiff > Microsoft ICE > ColorPerfect > Lightroom. sRGB colorspace maintained throughout processing.

This sample is Ektar 35mm shot with a Maxxum 35-105 3.5-4.5 and self-developed. Scan is at 1:1, 3-shot stitch



Comparison. DSLR on the left PF7200 on the right



I have a sample from the G4050 if anyone really wants to see it. It's a blurry mess as you might imagine.

I haven't yet sorted out how I am going to approach building a negative stage, but I probably will stick with something manual as I don't scan a large volume of films. That could all change though!

Thanks for looking!

[Peter De Smidt]

Nice job! Thank you for posting.