And a 90mm probly not do a 6x17 as that would need a Image Circle Diameter
of about 180mm +++ if that back is offset back any the 90mm would never go back in far enoght to work!!!!

this is the thread i made for the backs

http://graflex.org/helpboard/viewtopic.php?t=6296

thanks again guys!

setback the film plane is set back to get a bigger Image Circle Diameter
or to make the film size bigger as a 4x5 is 127mm long where as a 6x17 is 170mm long!!

a Super-Angulon 8/90mm has a Image Circle Diameter @ f16 of 216mm
so it would work!! like wise a Angulon 6.8/90mm Image Circle Diameter at f/16
154mm AND that would not work on a 6x17 back
so most fo the other 90mm will not work on a 6x17!!

Lens are designed by the manufacturer to cover a given format so focal length will not determine if it will cover or not.
This chart will help some:
http://graflex.org/lenses/lens-spec.html

Image coverage required for 4x5 is:
(4*25.4)² + (5*25.4)²=format diagonal²
101.6² + 127²
10322.56 + 16129=
26451.56
square root=
162.64 mm

Because the actual image size on the negative is smaller a 158 mm or 159 mm image circle may work.

thank you again for answering my newbie questions

you guys are very helpful!

45PSS wrote:

Quote: i didn't knew you can restore graflex I just repair them. I've mentioned this in several of my post. Quote: there are a lot of versions of angulon. There is one Angulon. Those badged Linhof or other camera manufacturer name are hand picked cells matched by that camera manufacturer from the production run by the lens company. Quote: another thing is i'm planning to put a 6x12 or 6x17 back for panoramic shots A Graphic has a 4x5 fixed film plane opening. 1 inch = 2.54 cm; 1 inch = 25.4 mm. 5*2.54= 12.7 cm. A 6x12 will work on the Graphic, a 6x17 would not. Quote: was watching a 127 commercial ektar a few days ago then last night it was sold for $45 too bad! i should bought it. i was hesitation because i thought it was for smaller graphics. A 135mm will cover 4x5 with some movements. The 127 is for 3x4 with movements, It just covers 4x5 without movements but may be soft in the corners to slight vignetting depending on the production tolerance of the lens.

banjo and 45pss

thank you again..

so a 90mm would work for a 6x12 back on a pacemaker speed graphic?

those formulas, computations are giving me a headache

pardon my newbieness

If it was designed to cover that format or larger. You have to check the manufacturers data sheet or a table such as the one I previously posted to find out.

ok thanks! i will try to understand those you posted.

45PSS wrote:

If it was designed to cover that format or larger. You have to check the manufacturers data sheet or a table such as the one I previously posted to find out.

As far as an economical portrait lens goes I've been happy with the 10" (250mm) f/5.6-32 Tele-Optar made by Wollensak. I don't know if this lens comes in a shutter. Mine is a barrel lens, used with the back shutter. $65 including lens board after a little bargaining.

hey the 10" (250mm) f/5.6-32 Tele-Optar that I got for less then $100.
has a shutter and I do like it on my Crown

Hi all...this recent discussion just has me wondering...is the 10" (250mm) f/5.6-32 Tele-Optar a reasonably sharp lens? It can be used hand-held on a Pacemaker 4x5 Speed, correct? Can any of you good people post any photos taken with this lens? Thanks much in advance for any responses!!!

it can be used hand by some & using a storb flash would help
BUT I dont like using a 4x5 hand held any more
so as much as I can for hand held work I us a Century 23
as using a 4x5 & that 250 lens & a strob 5 to 7 lbs that you are holding

Cheat
http://www.bhphotovideo.com/c/product/5478-REG/Manfrotto_679B_679B_3216_3_Section.html

interesting.. would you share some photos?

thanks!

Billy Canuck wrote:

As far as an economical portrait lens goes I've been happy with the 10" (250mm) f/5.6-32 Tele-Optar made by Wollensak. I don't know if this lens comes in a shutter. Mine is a barrel lens, used with the back shutter. $65 including lens board after a little bargaining.