Enlarging lens onto a Canon EF body

[markbau]

My friend has a Canon body with an EF mount. He has been unhappy with the results when using it to copy objects using a copy stand with the 50mm lens that his camera came with. I suggested that using an enlarging lens may result in better quality, I have spare 50 and 80mm Companion S enlarging lenses I could loan him. I've searched but so far cannot find an adapter to put an enlarging lens onto his camera body, does anyone know if such a thing exists?

Thanks for any help.

 

[Nicholas Lindan]

Usually enlarging lenses are used with a bellows. I don't know of a way to mount a 39mm enlarging lens onto a Canon EF mount but you might consider mounting the lens on a body cap. The lens would be secured to the body cap in the same manner it would be mounted to an enlarger's lens board.

 

[AnselMortensen]

A focusing helical or a bellows would be necessary.

 

[Oren Grad]

M39-to-EF adapters exist, but you need a way to focus the lens.

I've put M39-mount repro lenses (Apo-Rodagon-D) on an EF-mount camera using an M42-mount bellows adapted to the body with an M42-to-EF adapter and an M39-to-M42 adapter on the other end. An alternative is to use an M39-to-M42 adapter to attach the lens to an M42 helical mount and then adapt the latter to the EF-mount body. In general, helicals are easier if you need short extensions, bellows if you need longer. So think about the size of the objects being photographed and the magnifications (and thus focus extensions) required.

You can find such adapters and helicals on eBay.

 

[koraks]

He has been unhappy with the results

In what way? What kind of objects is he/she trying to reproduce? Is this a digital or a film-based EF camera?
I'd suggest getting the problem definition straight first before jumping into solution mode. It's of course technically possible to adapt an enlarging lens to an EF camera body, but it's questionable whether this is the most straightforward or best solution.

 

[markbau]

He is using a digital body. I'll ask him for more details as to why he is unhappy with the 50mm lens he has, all I know is he was considering buying an astronomically priced 50mm Canon lens. He is copying very large plans/tech drawings from about 500mm - 2 meters away. Most of the stuff is too big, or expensive, to get scanned.

 

[xkaes]

I'd suggest getting the problem definition straight first before jumping into solution mode. It's of course technically possible to adapt an enlarging lens to an EF camera body, but it's questionable whether this is the most straightforward or best solution.

But we love to leap before we look -- or hadn't you noticed.

P.S., adapting an enlarging lens to anything is easy, but you have to know the rear thread on the enlarging lens first -- or you could just run out an buy a 39mm adapter, and discover later that your enlarging lens doesn't have a 39mm thread.

 

[Chan Tran]

Get a Canon Bellow EF and a 39mm to EF mount adapter. I don't have Canon but I have Nikon and I use the Nikon Bellow with a 39mm to Nikon F mount adapter. I used the setup for 50mm, 80mm, 105mm and 135mm lenses. They all work fine. The picture was taken with the EL Nikkor 50mm f/2.8. Magniication is about 2.5:1. The numbers are 1/10 inch. The division on the bottom scale is 0.5mm per divisison

 

[koraks]

He is copying very large plans/tech drawings from about 500mm - 2 meters away

The cheapest 50/1.8 Canon EF lens would be fine for this purpose. I doubt you'll get much more real-world quality by adapting a repro lens, which would be working at or beyond the limits of its optimization at such magnification scales.

To add: the astronomically priced 50's tend to be the larger aperture ones; 1.4, 1.2 and 1.0. Optically, these aren't any better (and often worse) than the plain-Jane 50/1.8 under the conditions you'd be using them for repro work. The exception is a 50mm macro, which should be suitable, but AFAIK it's not astronomically priced.

If more resolution and/or even less distortion is required, and he has the space, I'd suggest looking out for a second-hand EF 85/1.8 or 100/2, both of which are top-notch optics, available for a friendly price.

 

[xkaes]

Tell him to use f8 and a cable release. If he's still unhappy, maybe the problem is how the lens is being focused -- Manually??? Automatically???

 

[koraks]

@xkaes solid advice; I agree.

 

[grain elevator]

Possibly he has other issues like flatness, alignment, lighting, distortion, or, if he's not really a photographer, exposure and post processing - one might underexpose predominantly white subject matter such as drawings and be frustrated about the grey mess. Best to look at his results to determine what he needs.

 

[Dan Fromm]

He is using a digital body. I'll ask him for more details as to why he is unhappy with the 50mm lens he has, all I know is he was considering buying an astronomically priced 50mm Canon lens. He is copying very large plans/tech drawings from about 500mm - 2 meters away. Most of the stuff is too big, or expensive, to get scanned.

Hmm. 50mm lens. Sensor-to-subject distance 0.5 - 2m. Magnification on the order, if my arithmetic is correct, of 1:10 to 1:20. How fine is the fine detail in the drawings? Even shooting from tripod with cable release, possibly electronic, and careful focusing and the sensor perfectly parallel to the subject he's probably at or over the edge of what can be done.

IIRC, my beloved 55/2.8 MicroNikkor AI is diffraction-limited over a 7mm circle (on film or sensor) at f/4. This from Brian Caldwell many years ago. Stopping down will increase the diffraction-limited circle's diameter, reduce the diffraction limit. The diffraction limit is ~ 1500/f#. Again, how fine is the detail in the subject?

 

[Oren Grad]

I'll second Dan's point about getting to the nub of the matter; how much fine detail is your friend trying to record from such large originals? Without knowing that, it's impossible to tell whether he needs a different lens, a sensor with more pixels, different technique, some combination of the above - or even whether the task is doable at all within whatever his budget is. Some samples of captures that he thinks are unsatisfactory may help in sorting this out, even just small crops.

 

[Focomatter]

Canon made a 50mm f/2.5 EF macro lens that should have a flat enough field for copying.

 

[wiltw]

He is copying very large plans/tech drawings from about 500mm - 2 meters away.

The cheapest 50/1.8 Canon EF lens would be fine for this purpose. I doubt you'll get much more real-world quality by adapting a repro lens, which would be working at or beyond the limits of its optimization at such magnification scales.

Even the usual normal lens is optimized even for 18" distance, so no need for enlarging lens which is usually optimized for 4:1 - 8:1 enlargement on enlargers.

As already identified, the nature of the dissatisfaction needs to be better understood to address that specific issue...

• better 'flat field' to allow larger aperture, rather than diffraction-limited smaller apertures?
• evenness of illumination field ?
• insufficient resolution?

what aperture is he using currently? which Canon body?