Nikkor 800mm f12 T-ED Covers 7x17?

[Kerry L. Thalmann]

I know the "official" spec on this lens lists the image circle as a paltry 310mm (barely hits the corners of 8x10), but have heard it may actually cover considerably more. I have read anecdotal reports that the 1200mm T-ED nearly covers 12x20, and there is one thread where a poster claims the 800mm and 120mm cover 11x14 (http://largeformatphotography.info/lfforum/topic/500928.html). I also know from expereince with the smaller Nikkor T-ED series that the 500mm and 720mm T-ED cover considerably more than the 360. In all the specs for the Nikon teles, they list the same image circle for all focal lengths within a given set. This doesn't make a lot of sense to me as intuitively I would think the image circle would increase with focal length (barring mechanical vignetting).

So, does anyone have any experience using the 800mm Nikkor T-ED on 7x17 (or even 11x14). If so, did it cover? Any left over for movements? What was the performance like in the corners?

Thanks,
Kerry

[Donald Hutton]

C'mon Kerry - a few more days and you will have it in your hands! (I saw you get one for a steal on the big site a few days ago.... )

[Kerry L. Thalmann]

Don,

Yes, it has arrived. The problem is my 7x17 camera won't be done for a couple months to test it. While I have pretty much settled on the design of the camera, IF the 800mm T-ED would cover 7x17, it would eliminate the necessity of an additional extension rail, intermediate standard and second bellows to go longer than 600mm. As the 800mm T-ED needs less than 21" of extension, I can easily use it on my 4x10 and 8x10. It would be nice to be able to use it on the 7x17 as well, but that may be asking too much.

Kerry

[Donald Hutton]

I'd be very interested to know too - my 11x14 has only got 30 inches of bellows (which is probably just fine for most of what I do); but an 800mm....!

[Eric Woodbury]

Kerry

I have the 800mm Nikkor T, but no camera larger than 8x10. I just mounted it on the 810 and focused at infinity. At f/32 I can barely move the front up or down from center without obscuring the iris. I believe that the 310mm IC is probably correct and that it will never cover 717. Looks like the limiter is the rear exit node.

[John Z.]

I was the original poster of the thread, and yes the 800 T truly does cover 11x14, as well as the interchangable 1200mm T Nikkor rear lens element (have not tried the 600 T). It makes a great combo of long lenses for my 11x14, with only needing one shutter. Even of far greater importance, the telephoto aspect of the lenses means I can use my Wisner without bellows extension (since the Telephoto needs only about 2/3 the bellows draw of an equivalent focal length lens). Prior to discovering this combo, I had been looking at Red Dot Artar 30 inch and 40 inch lenses, and considering a bellows extension through Wisner. Adding a longer bellows, however, creates a whole new set of problems (compression), not to mention expense.

I did come across an old thread on Photonet.com where another large format user also has stated the same facts about coverage of the Nikkkor Telephoto lenses. One caveat someone mentioned is that it is always possible that different production runs of the Nikkor lenses could be different, and have different coverages, so you just have to try it and see, but I will be interested to hear of your results. Given that the Nikkor 450 M has a huge coverage, beyond its published range, it certainly is reasonable to expect that other Nikon lenses may do the same.

[Jerry Fusselman]

John, is that coverage even when focused at infinity? Can the corners handle enlargement?

[John Z.]

I cannot say if enlargement would affect the results, since I am making 11x14 contact prints only. I have made some excellent photos of distant objects, and not seen any problems in the corners of the contact prints. It occurs to me that I have not photographed a far distant mountain range or similar subject to test the coverage at 'true' infinity. Still, I have photographed scenes that were 60 to 80 feet away, which for all practical purposes are distant scenes.

[bglick]

Kerry, what film will you be using in this camera?

[Kerry L. Thalmann]

Kerry, what film will you be using in this camera?

Mostly TMAX 400 and probably a some FP4+ and PL100.

Kerry

[Paul Schilliger]

A quick try onto the wall show an image circle of at least 40cm for the 800 and 1200. If you are shooting color, you might run into color fringing though beyond the specified image circle. However, with the small enlargement factor that this format will require, it should remain unnoticed on the print. Good luck!

[Kerry L. Thalmann]

There seems to be some difference of opinion on this matter. And while I find it a bit hard to believe that Nikon made more than a couple production runs of this lens, I'm wondering if there are indeed differences in the construction of some 800mm T-ED Nikkors.

Specifically, the rear cell of my 800mm lens has a black circular disk with a round opening that looks like some sort of field stop. I'm wondering if everyone else's 800mm has this same disc. I didn't actually attempt to stick my calipers down inside the lens (didn't want to risk damaging anything), but on my lens the disk is located approximately 1¼" from the front of the rear barrel and the opening in the disk is approximately 1½". So, do all 800mm T-EDs have this disk/field stop? If not, I'm wondering if it's possible to have it removed to increase the coverage of the lens (not that I intend to attempt to remove it myself).

Kerry

[Eric Leppanen]

Kerry,

While I no longer own my Nikkor 800T, my recollection was that, when applying front rise and staring through the front of the lens to see if I could still make out the edges of the ground glass, my 800T seemed to have a similar circle of illumination to my 800mm APO Tele Xenar convertible (which has a 480mm rated image circle). I did a few test shots for edge sharpness with movements, but alas, I cannot find them nor can reliably recollect the results. I'm sure the lens is good for at least some movement, as I used to apply some rise/fall to compensate for pressing a long lens support arm up against the underside of the front standard (to stabilize the camera, which I found absolutely necessary when using this lens).

Looking at my Ebay sale photographs of my 800mm rear element, I don't see any black circular disk. It looks like clear glass extended all the way to the barrel. I will separately email you a photograph of the rear element for comparison.

I'm 99.9% sure you've long ago thought of this, but how much shift capability do you have with your existing 4x10 or 8x10 cameras? Can you achieve 2" or more of shift so you can take a test shot of what would be the edge of an 11x14 negative?

[mohan]

hello Kerry and all!

So, what is the final word on the lens... Does it cover the 7x17? And what is the "real" image circle spec. of this lens?

Thanks

Mohan

[Tom Duffy]

For what it's worth, I use the 600T, which is supposed to have the same image circle as the 800 and 1200 Nikkor. It barely covers 8x10. I use it with the 5x7 format, primarily.

[asnapper]

Kerry,

I purchased a 600/800 T-ED off eBay here in England a few months ago at a bargain price. I use the lens on my 10x8 but I have put it on my 14x17 camera & it looks to cover okay. If the wind is not to strong at the weekend I will expose some 14x17 film & report back with my findings.

Andy