90mm for 6x17

[SMBooth]

Looking around for a 90mm to fit to a 6x17. I have narrow down the choice to either the Rodenstock Grandagon 90mm f6.8 (or Caltar -N) or the Fujinon 90mmf8. The Nikon f8 is a little out of the budget. Both will cover quite OK but Ive read the Grandagon is designed for less light fall off at the edges. Is this true, and is it worth the extra dollars to pick up the Grandagon over the Fujinon.
If any one has either for sale quite welcome to PM me.

Thanks Shane

[Bob Salomon]

For 617 you should use the faster lenses with their greater coverage. But they still may need the center filter if you want more even coverage.

[Phil Hudson]

I wonder if there is a real difference between comparable (say 100/102 degree) Rodenstock and Schneider wide angle designs and the way that they deal with light fall-off, or whether Rodenstock market the effectiveness of a common design feature more effectively:

"With the Grandagon-N, all the problems which occur in connection with large image angles have been ideally taken care of: The distortion has been reduced to a small residual value; the light fall-off towards the edges has been greatly reduced thanks to an optical trick (“pupil distortion” = the entrance pupil diameter increases when viewing at an angle); the sharpness sets standards for this class of lenses.

I wonder if this "optical trick" is also inherent in the Super-Angulon design?

[engl]

I wonder if there is a real difference between comparable (say 100/102 degree) Rodenstock and Schneider wide angle designs and the way that they deal with light fall-off, or whether Rodenstock market the effectiveness of a common design feature more effectively:

"With the Grandagon-N, all the problems which occur in connection with large image angles have been ideally taken care of: The distortion has been reduced to a small residual value; the light fall-off towards the edges has been greatly reduced thanks to an optical trick (“pupil distortion” = the entrance pupil diameter increases when viewing at an angle); the sharpness sets standards for this class of lenses.

I wonder if this "optical trick" is also inherent in the Super-Angulon design?

The "optical trick" is a tilting exit pupil, several of the wide-angle designs have this. The Super Angulon, Grandagon, Nikon SW, Fuji SW/SWD, perhaps some more. These lenses have close to cos^3 theta falloff (where theta is angle from optical axis).

Most lenses do not have this property and instead have cos^4 theta falloff. This includes some wide angles lenses, like the Super-Symmar XL.

[Phil Hudson]

Most lenses do not have this property and instead have cos^4 theta falloff. This includes some wide angles lenses, Schneider XL is one of them. The Schneider XL lenses are commonly used with a center filter to even out falloff.

Is this true for Schneider Super-Angulon XL or Super-Symmar XL, or both?

[SMBooth]

Thanks so far, Engl, you seem to be saying that any (Super Angulon, Grandagon, Nikon SW, Fuji SW/SWD) would do the trick.

[engl]

Sorry, my first message was a bit inaccurate and I edited it. The Super-Angulon XL seems to be cos^3 (tilting pupil) and the Super-Symmar XL is cos^4 (not tilting, more falloff).

[Steve Goldstein]

You need to be careful about flange focal length unless your 6x17 has a bellows. There's several mm of variation between the various brands; you can run into trouble with a camera having fixed cone.

[Phil Hudson]

Sorry, my first message was a bit inaccurate and I edited it. The Super-Angulon XL seems to be cos^3 (tilting pupil) and the Super-Symmar XL is cos^4 (not tilting, more falloff).

I think I get it now - many thanks for your input!

[Gem Singer]

Take a look at the previously owned f6.8 90 CaltarII-N MC lenses that are listed here---

www.keh.com

[SMBooth]

Take a look at the previously owned f6.8 90 CaltarII-N MC lenses that are listed here---

www.keh.com

Yes, seen those, but can get a EX+ Fuji same price as a Bargain Caltar. So which is the better way to go is the essence of the thread. I don't mind paying more if the light falloff is better controlled on the Grandagon/Caltar, but not if Im only paying for 1/2 stop in speed

[Gem Singer]

You are not only getting an extra 1/2 stop speed, but also a larger image circle with the 90 Caltar (Rodenstock Grandagon). The most bang for the buck.

The Nikon/Nikkor f8 90SW has the largest image circle (235). As you state, it is out of your price range.

The Nikkor is a great lens for 6x17. I have never found the need for a center filter with mine.

I did not use my Fujinon f8 90SW for 6x17. However, if that's the lens you finally select, it should work just fine.

[SMBooth]

You are not only getting an extra 1/2 stop speed, but also a larger image circle with the 90 Caltar (Rodenstock Grandagon). The most bang for the buck.

The Nikon/Nikkor f8 90SW has the largest image circle (235). As you state, it is out of your price range.

The Nikkor is a great lens for 6x17. I have never found the need for a center filter with mine.

I did not use my Fujinon f8 90SW for 6x17. However, if that's the lens you finally select, it should work just fine.

I thought that 5mm image circle gain was more buck than bang, but then I suppose more is better. I think your right, the fujinon, or a SA will be OK for my use. I can always use PS to tickle the edges if/when required. Thanks

[Lachlan 717]

For what it's worth, I use a Schneider SA f5.6 on my 617.

Never had any issues, either in use or in image.

[SMBooth]

I would I be right in saying that just because a faster lens has a greater image circle, the vignetting or edge falloff start around the same distanse from the centre of the lens, or does a F4.5 with a 235mm IC show less fall off on a 6x17 image then a f8 with 216mm IC because the IC is bigger and the falloff is further out. I should say at the same f stop of f22

[Bob Salomon]

I would I be right in saying that just because a faster lens has a greater image circle, the vignetting or edge falloff start around the same distanse from the centre of the lens, or does a F4.5 with a 235mm IC show less fall off on a 6x17 image then a f8 with 216mm IC because the IC is bigger and the falloff is further out. I should say at the same f stop of f22

The fall off starts after about 70% of the field, so a lens with a larger circle will exhibit less fall off at a given spot compared to the slower lens that has less coverage.

[SMBooth]

Thanks Bob, looks like I'll push the hand deeper into the pocket and get something with a larger IC.

[Ole Tjugen]

The fall off starts after about 70% of the field, so a lens with a larger circle will exhibit less fall off at a given spot compared to the slower lens that has less coverage.

I would love to see documentation of this, as it goes against all optical laws.

A case in point - the largest image circle, or more correctly angle of coverage, is that if the ancient and iconic Goerz Hypergon. Which has cos^4 falloff, more than e.g. a Schneider Super Angulon XL.

The falloff starts immediately. Only the optical axis has full illumination, but the drop in illumination only becomes apparent as the angle from the axis increases.

[SMBooth]

Problem solved, I brought a Nikon 90mm f8. Thanks all for help.

[Bob Salomon]

I would love to see documentation of this, as it goes against all optical laws.

A case in point - the largest image circle, or more correctly angle of coverage, is that if the ancient and iconic Goerz Hypergon. Which has cos^4 falloff, more than e.g. a Schneider Super Angulon XL.

The falloff starts immediately. Only the optical axis has full illumination, but the drop in illumination only becomes apparent as the angle from the axis increases.

The fall off is after 70% of the circle so a lens with a larger circle will exhibt less fall off on the same format as a lens with a smaller circle.

[Ole Tjugen]

The fall off is after 70% of the circle so a lens with a larger circle will exhibt less fall off on the same format as a lens with a smaller circle.

No, not if the two lenses have the same focal length. What you are saying is that a 600mm Nikkor T-ED will have virtually identical falloff to a 120mm Nikkor SW, since both have about the same image circle (310 vs 312mm). That is demonstrably false.

Comparing two directly comparable modern lenses - Schneider Super Angulon classic and Super Angulon XL, both 90mm focal length, shows that it isn't even correct for THOSE lenses, from the same manufacturer.

https://www.schneideroptics.com/pdfs/photo/datasheets/super-angulon/super-angulon_xl_56_90_1.pdf

http://www.schneiderkreuznach.com/foto_e/an_su_classic/pdf/AN_SU_68_90_R44907_1AE.PDF

Neither does the fall-off start at 70% of the image circle, nor does the one with the larger image circle show less fall-off at a given distance from the center - neither expressed as a measured distance in mm, nor in % of the total image circle.

So again, I would dearly like to see some documentation on the effect you describe.

[Bob Salomon]

No, not if the two lenses have the same focal length. What you are saying is that a 600mm Nikkor T-ED will have virtually identical falloff to a 120mm Nikkor SW, since both have about the same image circle (310 vs 312mm). That is demonstrably false.

Comparing two directly comparable modern lenses - Schneider Super Angulon classic and Super Angulon XL, both 90mm focal length, shows that it isn't even correct for THOSE lenses, from the same manufacturer.

https://www.schneideroptics.com/pdfs/photo/datasheets/super-angulon/super-angulon_xl_56_90_1.pdf

http://www.schneiderkreuznach.com/foto_e/an_su_classic/pdf/AN_SU_68_90_R44907_1AE.PDF

Neither does the fall-off start at 70% of the image circle, nor does the one with the larger image circle show less fall-off at a given distance from the center - neither expressed as a measured distance in mm, nor in % of the total image circle.

So again, I would dearly like to see some documentation on the effect you describe.

No I'm not. I am saying that a 90mm 4.5 will start the fall off further out from the center then a 90mm 6.8 from the same manufacturer. Same for a 90mm 5.6 vs the f8. The SA and the SA XL are different designs. Try the 90mm 5.6 vs the 90mm f8 SA and leave out variations like the XL.

[Ole Tjugen]

Bob - the SA f:8 is 6 elements in 4 groups, the SA f:5.6 is 8 elements in 6 groups. So you might just as well say that THOSE are different designs?
Note that all three - f:8, f:6.8 and f:5.6 XL take exactly the same strength center filter, only the diameter is different due to the different size of the front element.

http://www.schneiderkreuznach.com/archiv/pdf/an_su_1995.pdf


You can't make a general statement like that and then say that it doesn't apply to lenses of different design - how could the angle of coverage be different if the design were identical?

I don't have the relative illumination data for the F:8 or the f:5.6 non-XL, but the ones I do have contradict your statement.

[Bob Salomon]

Bob - the SA f:8 is 6 elements in 4 groups, the SA f:5.6 is 8 elements in 6 groups. So you might just as well say that THOSE are different designs?
Note that all three - f:8, f:6.8 and f:5.6 XL take exactly the same strength center filter, only the diameter is different due to the different size of the front element.

http://www.schneiderkreuznach.com/archiv/pdf/an_su_1995.pdf


You can't make a general statement like that and then say that it doesn't apply to lenses of different design - how could the angle of coverage be different if the design were identical?

I don't have the relative illumination data for the F:8 or the f:5.6 non-XL, but the ones I do have contradict your statement.
Then go to the Linos site and download the Grandagon-N curves.

[Ole Tjugen]

Then go to the Linos site and download the Grandagon-N curves.

Which show that both the f:4.5 and the f:6.8 version of the Grandagon-N reach 1 stop fall-off at about 67mm from the lens axis. These too are of "different construction", did you notice? The f:6.8 is six elements/four groups, the f:4.5 is eight elements/four groups. Both give slightly less than cos^4 fall-off, but slightly more than the Schneider Super-Angulon f:6.8 "Classic". Even comparing a 6in4 to another very similar one from a different manufacturer shows that the rule doesn't hold...

[engl]

There is no such thing as falloff beginning at 70% of the field, it begins as soon a you go off the center axis. How rapidly it falls off depends on the design of the lens, and not how big the image circle is. This is easily checked in lens data sheets, as Ole points out.

A Super Symmar XL 80mm has greater falloff in the corners of a 4x5 frame (no movements) than a Grandagon-N 75mm, even if the Super Symmar has a slightly longer focal length and a much bigger image circle. Using image circle to estimate falloff is misleading.

[richard brown]

Back to the original poster.... so glad to hear you bought the nikon f8 90mm.... i have a couple of 617 cameras and the fuji 90 had the optical characteristics of toilet paper out at the edges and some fall off. the older super angulon 90 f8 wasn't much better. But the nikon is great. I know nothing of the scientific stuff, just the negatives and what they can resolve and how the print looks which is ultimately, what I hope is our goal.
Happy shooting with your new glass!!!