Rodenstock Grandagon 90mm 6.8

[miesnert]

Hello,

I have tried searching the forum and the internet, altough a lot of information can be found about the Grandagon-N it is hard to find information about the plain Grandagon (non-N).
When shooting 4x5 I close the lens down to f22. But, I want to start using the lens with a 6x9 back to hopefully be able to shorten my exposure times. I shoot most of my work at night and run exposure times from 30 to 60 minutes most of the time, sometimes this is still not long enough so I am hoping to be able to use f16 on 6x9 and shorten my exposures in some situations a bit.
I have seen on the Rodenstock site that the working aperture for the Grandagon-N 90mm 6.8 is stated at f22-f32, but I assume that this is to make sure the coverage is adequate. If I were to shoot for 6x9 at f16 the coverage would be more than okay, my question is: would the sharpness at this aperture be okay, or is this lens sharpest at f22-f32 and is f16 to soft to use the 6x9 negatives? I want to make analogue c-prints, approx 100cm wide with the negatives, I know 4x5 will be sharper and finer grained, but this is just for those cases where the exposure times end up being way to long.

Thank you for you answers in advance.

[vinny]

f16 will be fine, maybe even sharper.

[mark.s]

i do not own a 90 6.8 grandagon but with most lenses f16 should be even sharper than f22. I only use f32 if it is really necessary in terms of depth of field. With all of my lenses f32 is softer than f16 and f22 because of defraction.
In your case i think i would use f16 and portra 400.

[mark.s]

maybe it helps: check out the work "paradise now" by peter bialobrzeski- all shot at night.
he shoots 4x5 and as far as i know he used f11 a lot for this project, to avoid very long exposure times.
(he said that at some kind of presentation...)
http://www.bialobrzeski.de/work/paradise_now/ParadiseNow-18.html

[miesnert]

Thanks a lot for the quick responses guys.
Portra 400 is a good idea as well (I tend to use fuji 160ns mostly). It and shooting at f16 will give me a lot more speed. (I also understand that portra 400 can be pushed to 800 quiet well so this might be an option as well). I will give it a try.

[miesnert]

maybe it helps: check out the work "paradise now" by peter bialobrzeski- all shot at night.
he shoots 4x5 and as far as i know he used f11 a lot for this project.
(he said that at some kind of presentation...)
http://www.bialobrzeski.de/work/paradise_now/ParadiseNow-18.html

I have this book, love it. I somehow never consider apertures that small when shooting 4x5, I am afraid I will not get everything sharp in the frame, f16 seems to be to big to me already, but maybe this is a misunderstanding on my part. I will try and experiment a bit with opening up a bit more with 4x5 (altough I think he uses a lot wider lenses than I mostly use, most of my work is shot with 125 or 180mm lenses on 4x5.)

[Kodachrome25]

I shot the lens wide open for an IR film focus test once and it was tack sharp. I have had no issues with using that lens as wide as F8 and getting more than adequate coverage...

[miesnert]

Thank you, good to know.

[Bernice Loui]

+1

Don't be afraid to use this lens at f8, the results may surprise you. Alternatively, consider one of the 90mm f4.5 wide angles (Grandagon, SW Nikkor...) using it at f5.6 or larger aperture to gain more light gathering ability on to the film and lowering exposure time.

The other consideration is light fall off towards the edges of the film. To correct this using a center filter cost light loss.. There is always a trade off.


Bernice


I shot the lens wide open for an IR film focus test once and it was tack sharp. I have had no issues with using that lens as wide as F8 and getting more than adequate coverage...

[Jim Noel]

The indication by the manufacturer of f-22 has nothing in particular to do with sharpness or a recommended setting. It is the standard at which the angle of coverage is calculated. The lens will cover 4x5 adequately at any aperture unless you are using some extreme movement. In fact, I use mine on the 5x7 occasionally.

[Bob Salomon]

The indication by the manufacturer of f-22 has nothing in particular to do with sharpness or a recommended setting. It is the standard at which the angle of coverage is calculated. The lens will cover 4x5 adequately at any aperture unless you are using some extreme movement. In fact, I use mine on the 5x7 occasionally.

f22 is the diffraction limited stop. Beyond that on 45 and smaller you will start to degrade the image from diffraction.

[miesnert]

Thank you all for your answers, you have been very helpful.
I am wondering, why does Rodenstock mean on their website when they state: "working aperture f22-f32" ? If it is not for sharpness (because this is better at larger apertures and not for the image circle which is adequate at larger apertures as well?

[Bob Salomon]

Thank you all for your answers, you have been very helpful.
I am wondering, why does Rodenstock mean on their website when they state: "working aperture f22-f32" ? If it is not for sharpness (because this is better at larger apertures and not for the image circle which is adequate at larger apertures as well?

f22 is the diffraction limited stop. Beyond that on 45 and smaller you will start to degrade the image from diffraction.

[Bernice Loui]

Note what Bob replied regarding f22 and diffraction limit. Beyond this, The image is truly in focus only where the lens is focused, closing down the aperture ("stopping down") results in the other image areas coming into apparent focus.

Using the view camera movements can be used to enhance the areas that are in focus. With a wide angle lens, it does not take much tilt/swing to alter the plane of focus.

It pretty much comes down to what the image maker wants to be in focus in the image.. this is the degree of image focus control easily available on a view camera.

There can also be a significant reduction in exposure times due to reciprocity..

Suggest some experimentation to determine if using significantly larger apertures and reduction in exposure times and film speed results in meeting your image making needs. There are no fixed rules , it depends pretty much on what the image making hardware is capable of -vs- the needs of the image maker to achieve the image in mind.


Bernice




Thank you all for your answers, you have been very helpful.
I am wondering, why does Rodenstock mean on their website when they state: "working aperture f22-f32" ? If it is not for sharpness (because this is better at larger apertures and not for the image circle which is adequate at larger apertures as well?

[8x10 user]

I have actually used a 75mm Grandagon N F4.5 along side the Sironar Digital line with 22 MP phase one back. Both lenses were tack sharp at 100% (note, a higher resolution back would show a difference). The 9um pixel is very close to the grain structure size of slide film. The 9um ccd size roughly equates to a 10x enlargement by drum scan. Like others have said, you should be fine using it up to F/11. In general wider apertures are used with smaller formats and some of the aperture recommendations are based (in part) on the depth of field/coverage in a given format. Some of the longer Rodenstocks have F/33-F/45 down as a recommend aperture. Now is a 360mm Sironar S softer at F/16 then a 150mm? No, it just has lower DOF.

These were done somewhere around F/16, or maybe a little wider.

The first one is the whole image

108028

And these are 100% view crops from the above image.

108029108030

[8x10 user]

Hmm, I'm looking on Prograf (http://www.prograf.ru/rodenstock/largeformat_en.html) and it looks like they have F/16 down for the F/4.5 version and F/22 for the F/5.6 version. So YMMV from my experiences with the F4.5.

[miesnert]

I have done some tests with the lens at f16 with Portra 400, they look nice and sharp, however the first one does seem to lose a bit off sharpness at the point deepest into the frame. In the second dof would never be a problem anyway.

108202
Wista VX
Horseman 6x9 back
Rodenstock Grandagon 90mm 6.8 MC
f16
Kodak Portra 400

108203
Wista VX
Horseman 6x9 back
Rodenstock Grandagon 90mm 6.8 MC
f16
Kodak Portra 400