Long lens for 12X20: an epiphany!

On a recent trip with my 12X20 to Machu Picchu, I realized that the

600 mm lens I use as my normal for the format (a Fujinon) is just not

quite long enough for some shots I'd like to take. I've looked over

various recommendations (Apo Artar 30 or 35 in, Apo Germinar 750 or

1000), and then ran across one post claiming that the Nikkor 1200 Tele

ED covers 12X20 at infinity. This seemed HIGHLY unlikely to me, as

Nikon lists the IC as 316 mm, and generally does not underestimate IC

for their lenses. It would take something like 590 mm to cover 12X20:

quite a difference! Still, I happen to own a Nikkor 1200, and what

does it cost to try it out (besides a couple of sheets of 12X20

film?!) Well, the results surprised me: the 1200 Tele lens DOES in

fact cover 12X20 at infinity (well, a church that's about 1/2 mile

from my house, anyway!) It seemed that coverage wide open (f18!) was

a bit fiddly at the corners, but it was easy to get coverage at f32.

Interestingly, I couldn't get the corners to cover at f45 or f64! I

would probably shoot at f32 if I was going to use this lens at 12X20.

 

So, what advantages of this lens as a long lens for 12X20?

 

1. Readily available new.

2. Fits in a modern shutter (Copal 3)

3. Multi-coated

4. The 1200 mm focal length is quite distictly different from the 600

mm normal lens (I was having a hard time convincing myself a 30 in/750

mm lens would be worth it...)

5. Tele design means that, with a flange distance of 750 mm, on my

Wisner (max bellows draw of 48 inches) I can focus to 2 meters. Not

bad! A Docter (Apo Germinar) 1000 would have only allowed me to focus

to 18 feet, and still not given me as large a magnification as the

1200 Tele.

 

Well, this was a shocker to me! Will the lens be sharp enough for

your uses at 12X20? Hard to say, but assuming you're contact

printing, it would have to be pretty bad to be noticeable. I expect

to start carrying this lens with me as part of my 12X20 lens kit,

starting tomorrow at my nephew's soccer game! 12X20 sports

journalism, here I come!

 

BTW, no idea if the 800/600 versions of this lens wil cover 12X20. I

own the 800, but haven't bothered to check...

 

 

Nathan

Nathan, that's good news to hear. I hope the f32 proves to be a reliable aperture for you at 12x20 with further testing/printing.

 

I like how your ultra large formatters "take whatever you can get" approach.

Damn, I'm confused. How are you getting coverage at f/32 but not at 45 or 64? I keep rereading, hoping that I'm missing something, but I don't get it. Is this a diffraction problem specifically related to the tele? I would think that a "standard" 1200 would stop WAY DOWN to like 128 or 256 with pretty good results.

Good question, Chad! Is this a weird artifact of the tele design? Maybe experimental error on my part, though it was pretty reproduceable. What I think you can take to the bank is that the lens is usable at infinity on 12X20: best check the corners, using whatever approach you use, at the specific aperture at which you intend to shoot...

 

Nathan

Nathan, I have other old teles that do the same thing. Incidentally, it's very nice to have a physician whose professional expertise is vision, take such an interest in photography and optics.