Another thread about copying negatives

[KevinDks]

Dear all

I have quite a large collection of medium format negatives, all black and white, quite a few thousand images in total.

There are just too many to scan every one, but I need to start digitising them somehow, because a few of the oldest ones are starting to deteriorate with evidence of acid corrosion and bubbling which is found in some acetate films of their age. I've ordered an Epson V700 which I will use for the very best images, but for the rest and for proofing I want to use a dSLR on a copy stand, so I can photograph the negs on a lightbox.

I've done this with a compact digital camera and it was OK, but with a dSLR and a copy stand I think I can get files good enough to print to 8 x 10 or so. The question that I have is about lenses - assuming a Nikon DX camera, what focal length of macro lens should I be looking for? The negs are almost all 6x6cm. Has anyone got actual experience of doing this with a macro lens (or even with macro filters, although I doubt I could get the quality that a sharp 6x6 deserves)?

Any other ideas on the copying process would be appreciated too.

Many thanks

Kevin

 

[Dwig]

What you need is a lens that delivers a flat field and minimal rectilinear distortion. Closeup lenses will not do an acceptable job and neither with the macro function of any zoom lens. These are fine for 3d subjects of the "macro wildlife" and "macro landscape" sort, but will not deliver good images for copy work.

Focal length is not much of an issue when copying flat originals with no texture. Any of the commonly available "macro" lenses, like Nikon's 60mm Micro Nikkor and 105 Micro Nikkor offerings, will do.

I've done a great deal of copywork over the last 45+ years, both film and digital. I've also done some film to digital copying with digital cameras and a lot of film scanning (I currently use an EPSON v700). I'm not sure that you'll find copying negatives this way any real advantage over using the v700. While any one image can be copied somewhat faster than the v700's scans, the difference is small. If you are copying a large number at one time it may be practical to consider the copy setup. If you will be doing small batches, the setup time would likely be long enough to make using the v700 faster.

Whatever you do, the v700 will yield better results. The v700's dynamic range is greater than a DSLR's resulting in better highlight and shadow detail. The only way to accomplish similar dynamic range with DSLR copies is to employ HDR techniques which would totally eliminate any speed advantage to the copy stand approach.

 

[KevinDks]

Hi Dwig

I was hoping you would reply .

The V700 should be here tomorrow, so it will be interesting to see how quick it is. I've scanned many 35mm slides with a Nikon Coolscan V and that is really the only speed benchmark I have, and the reason why I thought that scanning 10,000 + negatives wasn't going to be practical. I'm buying a second, even bigger archive as well, so I'm just making the problem worse for myself...

Someone on another forum has also pointed me towards the Nikon 60mm, and it sounds like it would allow me to work at a reasonable distance from the negative. The 60mm AF-D has been discontinued, but still seems to be available at a reasonable price.

I have a supplementary question. When I tried this with my compact digital, a Canon G7, I just put a negative on my lightbox, set the exposure mode to manual and adjusted the settings so the "needle" was in the middle. Looking at the histogram of the resulting jpeg showed a big space at both the highlight and shadow end, which obviously can be corrected with Levels, but I wonder why I'm getting that. The negatives I tried it with were all taken with flash, and I think that may be the reason - no extreme highlights or shadows, just average tones across the whole image.

Cheers

Kevin

 

[Dwig]

The images from digital cameras have a very straight "curve", shadow to highlight. Film, on the other hand, has a distinct "toe" (flatter curve in the shadow area) and "knee" (a gradual flattening of the curve toward horizontal in the highlights). As a result, when you use a digital camera to copy negatives the shadow detail in the toe and highlight detail in the knee get compressed into a narrow range and don't reproduce with significant separation.

The greater bit depth of premium scanners (typically 16bit/pixel) and the corrections built in to the scanning software handle this much better than trying to correct the image from a digital camera. This is most pronounced when the digital camera is producing JPEG files, which are only 8bit/pixel. The only real hope of approaching the results from a premium scanner is to shoot RAW and converting the 12bit/pixel (or 14bit/pixel with some high end DSLRs) into 16bit/pixel work files.

BTW, the 60mm Micro-Nikkor, either version, would be an excellent lens for this use. For that matter, if your body will meter with older AI lenses, a 55mm f/2.8 or, better yet, an AI version (native or converted) of the 55mm f/3.5 Micro-Nikkor would also be an excellent choice. Autofocus is of little value in this situation. At these magnifications, you need to manually focus by adjusting the body to subject distance while the lens is preset to the correct magnification. Any focusing done with the lens will change the magnification. AF's only use is as a fine focus correction for subsequent images after you've manually focused the first of the series. Also, I highly recommend that you setup the lightbox and negative carrier so that the surface of the light box is an inch or so away from the film. That way any dust or scratches on the surface of the light box will not be in focus and won't show in the image.

 

[KevinDks]

Thanks Dwig, that makes sense regarding the curve on digital cameras.

That's a great tip about keeping the negative above the surface of the lightbox. I think I'm going to rig something up with piece of plywood, a sheet of black foam material and the 6x6 negative carrier from my enlarger. I'm watching a 60mm macro on eBay, but I'll have a look for those others you mention and check whether my camera can meter with them.

The V700 came yesterday, but I was in London collecting another 25,000 negatives from the '60s, so I'm about to set it up now and give it a try.

Thanks again for all your help.

Kevin