7x17 coverage

[ronald lamarsh]

I am considering building a 7x17 rear standard for my 5x7. I've read that one should use a lens that is appropriate for the 5x7 format(210mm240mm) to maintain the panoramic qualities of the format. So what lenses does everyone out there use that have that kind of coverage?

[Ernest Purdum]

If I did the math right, you need something over 467mm coverage. This means a lens suitable for the 11" X 14" fomat. The Schneider Super-Angulon 210mm f8 and the Rodenstock 200mm f6.8 Grsandagon-N are two possibilities. I hope your 5" X 7" camera has a sturdy front standard. These are big and heavy lenses.

[sanking]

There are really very few good choices in the 210mm to 240mm range for the 7X17, at least not in the area of bargains. Ernest is right in that you need a lens that will cover a circle of about 467mm.

Here are some of your choices, and the negatives.

1. The 210mm Super Angulon and 200mm Grandagon-N will certainly cover but they are really huge. I used the big Super Angulon on my 7X17 for a couple of years but eventually got rid of it because it was just too big for my style.

2. The new 210mm Schneider SSXL is slightly smaller than the 210 Super Angulon, but is not cheap. Good choice if money is no object but stll very big.

3. 210 f/6.8 Schneider Angulon. This lens is small and has a circle of illumination that covers the 7X17 format easily, but it is very soft at the corners, even when stopped down to f/32 or f/45. Overrated and overpriced in IMO.

4. 183 f/18 Series V Protar. Very small lens and some specimens will *just* cover the 7X17 format. Mine vignettes every so slightly.

5. 210mm f/9 Computar. Very small lens with huge coverage and will cover the format sharply all the way to the corners. This would be my first choice in this focal length for a really wide-angle lens for the 7X17 because of the combination of coverage and small size. But very hard to find!! I have a 300mm version of this lens and it covers 12X20 with about three inches of movement.

5. 240mm Goerz Dagor will cover 7X17 but the corners will be very soft. A better lens would be the Zeiss Dagor of the same focal length, but these are hard to find. Offers a good compromise of performance and price while still being fairly wide ange.

6. 270mm Goerz Dagor. This lens would cover 7X17 nicely, allowing a bit of movement, and is still very wide for the format.

[tim atherton]

"5. 210mm f/9 Computar. Very small lens with huge coverage and will cover the format sharply all the way to the corners. This would be my first choice in this focal length for a really wide-angle lens for the 7X17 because of the combination of coverage and small size. But very hard to find!! I have a 300mm version of this lens and it covers 12X20 with about three inches of movement."

Sandy,

this would be the same as the Kowa/Kyvytar 210 f9/6.8 I think (there was one just on ebay).

Have you actually tried it? @f22 some say it covers 460mm, but that seems over optimistic imo based on the Kowa. I'd say around 380mm @f22. I think Jim Galli may have tested the Computar.

It may cover that at around f45?

tim

[Michael Jones]

Sorry Tim, the f6.8 is not the same construction as the f9 Kowas. It has about the same coverage as any other plasmat, maybe 250mm of coverage on a good day.

Mike

[Jim Galli]

Michael, I think you're confusing the 6.3 Symmetrigon with the 6.8 lens. The f9 Computar is limited by the barrel mount. There's actually f6.8 available when mounted in Copal 1 shutter. When Kyvyx inherited and sold them they changed the wording on the front and it actually says f6.8. I've got both; a f6.8 Kyvytar and an f9 Computar and also an f9 Graphic Kowa and the parts are interchangeable. That said though i couldn't get more than about 380mm circle out of any of them. 10X12 maybe but not 1114. So maybe there are some differences I don't know about.

To answer the original question though, a 305 G-Claron is a great choice and so is the Konica 260mm GRII. (Won't go in a shutter) I just got a Graphic Kowa 240 f9 and it looks promising but doesn't go in a shutter easily. All of these are relatively light and inexpensive and excellent for sharpness.

[tim atherton]

Mike my Kowa 210 f9 actually opens to 6.8 now it's in a shutter, and does give me about 380mm coverage @f22

[Michael Jones]

I agree, I thought Tim was referring to the Symmetrigon. My confusion rests with the atual marking on the lens. Sorry.

Mike

[sanking]

The 210mm Computar Symmetrigon, which I think is a f/6.8 lens, is not the one that covers 7X17.

I don't know the history of the 210mm f/9 Computar but there may have been more than one design marketed under this name and aperture. In any event the 210mm f/9 Computar I mentioned in the first post is definitely not the same lens as 210mm Kowa Graphic. The 210 Kowa Graphic does not come even close to covering 7X17.

[tim atherton]

Sandy,

any idea if this is the type of Computar you are referring to?:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2950592709&category=30076

I'm interested if you have measured the iamge circle on one so we can get some actual figures?

thanks

tim