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View Full Version : Circle of coverage for Ilex Paragon Anastigmat 12"/305mm f4.5 ?



svarzaru
7-Apr-2017, 07:08
Anyone know how much this lens cover? Searched everywhere and I cannot find a thing. Thanks!

Dan Fromm
7-Apr-2017, 13:59
I b'lieve it is an f/4.5 tessar type. The f/4.5 tessar type coverage rule of thumb is that the lens will cover 115% of its focal length.

On another topic, I recall seeing posts by you, possibly on photo.net, up to perhaps a decade ago. Where have you been, are you well?

Dave Wooten
8-Apr-2017, 13:47
I have a 215 mm that covers 8x10

Dan Fromm
9-Apr-2017, 07:51
f/4.5, Dave?

Dave Wooten
9-Apr-2017, 14:31
Yes

John Jarosz
9-Apr-2017, 15:01
I have a Paragon Anastigmat 12" but it's f 6.3. It covers 8x10. If anyone is interested I can mount it on the 8x20 and measure the image circle.

They made 2 versions? One was f 6.3 and the other was f 4.5?

Dan Fromm
9-Apr-2017, 17:01
John, they made an f/6.3 Commercial Ektar clone usually sold as Acutar and an f/4.5 jes' plain f/4.5 tessar type usually sold as Paragon. Also a 215/4.8 convertible Plasmat that was sold under many names including Acuton, Ilex Caltar, ...

Usually doesn't mean always. There were no rules in Rochester and no one followed them.

Mark Sampson
9-Apr-2017, 17:52
"There were no rules in Rochester and no one followed them."
To an old Rochesterian that's the best laugh today!
See also Kodak's use of the word 'Polymax'.

JWN
23-Sep-2017, 20:13
I have a Paragon Anastigmat 12" but it's f 6.3. It covers 8x10. If anyone is interested I can mount it on the 8x20 and measure the image circle.

They made 2 versions? One was f 6.3 and the other was f 4.5?


I'd appreciate it if you would mount it and let me know the diameter of the image circle. I have seen it mounted to a 7x17 banquet and wanted to confirm the circle would cover. My point being that when I obtain a 7x17 that can be mounted horizontally and vertically, I'll want a suitable lens for it. Thanks! John

Dan Fromm
24-Sep-2017, 07:04
Lessee now. 7 x 17's diagonal is around 467 mm. A 305 mm lens that covers 467 mm covers an angle of a bit over 74. You're asking a lot of an f/6.3 Tessar, if that's what you meant.

Michael Graves
24-Sep-2017, 08:15
I used to have one of these, and my example just barely covered 8x10 with any degree of sharpness. The circle of illumination was fairly wide and lit up an image closer to 10x12, but the corners were quite mushy beyond 8x10.

Mark Sawyer
24-Sep-2017, 09:12
I have a 215 mm that covers 8x10

I'd wager that's the f/4.8 Acuton, a Plasmat design. The 12-inch f/4.5 is a Tessar, a completely different beast.

JWN
24-Sep-2017, 17:49
I know! I was looking for (and appreciate) the answer. I found it strange that the seller of the banquet camera was convinced that this lens was normally used on a 7x17.

JWN
24-Sep-2017, 17:51
Thanks for the confirmation of its unsuitability!