View previous topic :: View next topic |
Author |
Message |
Alfie
Joined: 13 Oct 2002 Posts: 15 Location: Massachusetts, USA
|
Posted: Sat Nov 29, 2003 5:27 am Post subject: |
|
|
Hello all,
Does anyone know if the Wollensak 90mm f12.5 Extreme Wide Angle Raptar is of a different formula, and has different coverage, than the f6.8 Wide Angle Raptars? In "Photographic Lenses" by C.B. Neblette the f6.8 WA Raptar is shown as being the same 4-element formula as the Wide Field Ektar and a host of other WA lenses, while the 159mm f9.5 WA Raptar is shown as an 8-element 4-group lens, like a dialyte composed of cemented doublets (I'm not too up on lens lingo, but I think this is a more-or-less correct explanation). The f12.5 Extreme WA isn't in the book. Basically, I'm wondering if the 90mm f12.5 EWA has greater coverage than the 90mm f6.8 WA Raptar. Does anyone know? Is it suitable for 5x7?
Thanks! |
|
Back to top |
|
 |
RichS
Joined: 18 Oct 2001 Posts: 1468 Location: South of Rochester, NY
|
Posted: Sat Nov 29, 2003 5:41 am Post subject: |
|
|
My book doesn't give the construction details for the 90 EWA f/12.5 but it does state that it was made for 5x7 coverage if that helps...
The 90mm f/6.8 WA Raptar is listed for 4x5 coverage only. And that may help answer your question.
_________________ ----------------------------------------
"Ya just can't have too many GVIIs"
---------------------------------------- |
|
Back to top |
|
 |
Alfie
Joined: 13 Oct 2002 Posts: 15 Location: Massachusetts, USA
|
Posted: Sun Nov 30, 2003 7:02 am Post subject: |
|
|
Thanks!
Despite my longwinded question, the 5x7 coverage issue was basicaly all I wanted to know.
Now if I can only find a nice one for a reasonable price...
_________________ My wife asked me what I gave the urchin begging in the street. "f8 at 1/125th," I replied. |
|
Back to top |
|
 |
rwarhover
Joined: 11 Aug 2002 Posts: 8 Location: New York City
|
Posted: Sat Dec 13, 2003 12:49 pm Post subject: |
|
|
I recently bought a Wollensak 159mm f/9.5 which will cover 8x10.The trouble with a lot of these lenses (mine included) is that they were cemented with Canadian Balsom and element separation is common. When I got my lens (eBay) it looked fine at first glance but with magnification you could see hundreds of tiny "bubbles" inside. These are tiny air spaces caused by the separation. The end result is extreme diffusion/halation/softness (obvious on the ground glass). If you buy an old Wollensak, look at it with a loupe or view it on a camera first if you can.
Good luck, Bob |
|
Back to top |
|
 |
|