DSLR Scanner: Lenses

[Oren Grad]

What about using an eyepiece magnifier?

In general, DSLR focusing screens are not designed for manual focus acuity, so magnifying the screen may not help much. In a 5DII you could swap the stock screen for an Eg-S, but if you intend to use a macro lens with a smallish maximum aperture, the extra snap may be lost. Critical focus through the finder also depends on precise alignment of the mirror and focusing screen with the sensor, and that can't be assumed. Despite all that, it might still help you get better results in your particular situation - your camera, your eyes, the particular originals you're trying to copy. The only way find out is to try it.

[rdenney]

The answer then is to have enough resolution to use a cluster of pixels to represent each grain. Yes, focus will still be an issue, but at least you might see it well enough with live view.

I might try it with the 645z when it comes. At 1:1, the sensor resolution is 4800--at 2:1 it would be 9600, and grains might be 2x2 or 3x3 pixel clusters, visible in live view. The macro lens, reversed, might get that job done--most macro lenses are optimized for 1:2ish and reversed would be optimized for 2:1. Also, no AA filter. A small enough aperture to account for minor misalignments might have the same effect as the AA filter, though.

Ultimately, though, I suspect a perfect representation of grain is going too far, unless we are making billboards that will be viewed up close. I'm pretty sure my enlarger lenses weren't able to pull that off, either, although I know there some now that will. And right now I'm scanning my 4x5's in an Epson flatbed--maybe 2000 spi usable. With only four images from the Pentax, I could nearly double that. As you say, we set our own requirements based on our own needs, and for me I don't print bigger than 16x20.

For making my Kodachrome dupes, though, I do not have to have it grain sharp. My lenses weren't that good back in the day, and I won't be printing these large. Projected, they'll be fine. But I don't want obvious grain aliasing, either.

Rick "needing orthographic projection here, too" Denney

[Ted Baker]

I would like use my Nikon DSLR to test some scanning software I am working on.

I don't own any macros lens I was going to get 60mm 2.8 Autofocus of ebay, hopping that I autofocus might actually be useful for roll film. Sort of like pakon for medium format. Am I just kidding myself with the autofocus? i.e. should I just get much cheaper old 55mm micro.

[Peter De Smidt]

Hi Ted, I only use manual lenses. The 55 micro is a very good lens.

[mdarnton]

I have an old pre-AI 55/3.5, an AI one, and the 60/2.8 AF-D. They are all equal for the task. All three are better than any mainstream enlarging lens I tested, except, strangely enough, the EL-Nikkor 75/4, which I had read was a stand-out for macro work, and the 63mm/2.8, which is a fine lens. Autofocus does work well for me for larger film. It's a bit tricky for copying 35mm.

[MAubrey]

In general, DSLR focusing screens are not designed for manual focus acuity, so magnifying the screen may not help much. In a 5DII you could swap the stock screen for an Eg-S, but if you intend to use a macro lens with a smallish maximum aperture, the extra snap may be lost. Critical focus through the finder also depends on precise alignment of the mirror and focusing screen with the sensor, and that can't be assumed. Despite all that, it might still help you get better results in your particular situation - your camera, your eyes, the particular originals you're trying to copy. The only way find out is to try it.

This is actually something that makes mirrorless bodies better, pixel level zooming for critical focus can't be beat by any SLR focusing screen.

[mdarnton]

I use live view focus on my Nikon D7200, and it's adequate.

[Ted Baker]

I have an old pre-AI 55/3.5, an AI one, and the 60/2.8 AF-D. They are all equal for the task. All three are better than any mainstream enlarging lens I tested, except, strangely enough, the EL-Nikkor 75/4, which I had read was a stand-out for macro work, and the 63mm/2.8, which is a fine lens. Autofocus does work well for me for larger film. It's a bit tricky for copying 35mm.

Thanks that's good to know. I am going to bid for a 55mm 3.5 Nikkor to start with. I can't go wrong with that. I mainly want to improve my software first.

I will probably get one of 60mm af lenses at some point to see if I can make it work for faster pakon/fuji/noritsu style scanning of roll and 35 film.

[Megapixel]

While looking for macrophotography lenses I came across these nicely done tests of optics on the Close-Up Photography website. Some of these optics may also be suitable for a DSLR/mirrorless film scanning setup. He uses an integrated circuit silicon wafer for a high resolution target and compares film scanner objectives, microscope objectives such as Mitutoyo's, macro lenses such as Canon's MP-E 65mm and Voightlander's APO-Lanthar 125mm, enlarging lenses, stacked lenses, industrial lenses, close-up lenses, etc.

Well worth a look if you are considering these types of optics.

[Megapixel]

If you are considering reverse-mounting a Canon EOS-type lens for scanning, the Vello / Mieke Macrofier Reverse Mount Adapter and Extension Tube may be of interest.

Its unique feature is the ability to reverse-mount a Canon EOS (Electro-Optical System) type lens and maintain electronic control of the aperture (EXIF data also, and maybe autofocus but safest to focus manually). B&H and Amazon sell it for $100, but you can also purchase it more directly online for around $60 on eBay or the Mieke Online Store. You should consider what sizes of adapter rings you will need. B&H includes 6 sizes versus the Mieke Online Store includes only 4 sizes.

For some macrophotography examples of this in use with the inexpensive Canon EF 40mm f/2.8 STM lens, see the Google translation of makrofokus nonaC 40mm f/2.8 and on YouTube, How I Built My Own Super Macro Rig for $250.