Vignetting so soon?

[NoBob]

Hi,

With a 150mm Fuji lens (224mm IC), how much front rise should I be getting before there's any vignetting?

Thanks.

[Chauncey Walden]

The 224mm IC is for the Fujinon-W 150mm f/5.6 (the 150mm f/6.3 has 198mm IC.) Without resorting to math, you could just draw a 224mm diameter circle and move a 4x5 (assuming you are using it on a 4x5!) rectangle around in it until you lose a corner to answer your question.

[Sal Santamaura]

This is the second time in as many days that I've mentioned how valuable it is to visit this site's home page and the links on it, one of which is


http://www.largeformatphotography.info/lenses/LF4x5in.html.

That chart includes the 150mm Fujinon CM-W, whose image circle (223mm) is within 1mm of the OP's question, and is probably the lens being asked about. Shown, along with other useful information, is maximum rise in both horizontal and vertical film orientations.

[NoBob]

Thanks, am going to check again tomorrow, because I'm getting a lot less than the movement indicated in the table.

[Dan Fromm]

Filter? Lens hood? Hole centered on board?

[Mick Fagan]

I have two of these lenses, one is in a Razzle, which is a converted Polaroid, the other runs between various cameras. On my Calumet 400, with straight bellows it does have vignetting if I pull the bellows out for closeish stuff. On my Shen Hao I sort of run out of movement, but it has tapered bellows, on My Toyo G45 monorail with straight bellows at infinity about 43mm maybe a smidge more on the vertical rise is about where I start to see some bellows shadowing, but I think there is a very slight bellows sag there.

I have just picked up the Toyo, so I was interested to see where coverage started and ended with the huge movements this camera is capable of. That's how I know. :D

All coverage I've mentioned is at f22.

Mick.

[NoBob]

I'm getting 35mm front rise with the Fuji 150mm f5.6 (checked the corners through the lens and on the ground glass) on a Technikardan 45.

[Chauncey Walden]

I would have guessed just from visualizing it and using a 5x7 as an anchor that you would get about an inch and a quarter or about 32mm.

[Sal Santamaura]

I'm getting 35mm front rise with the Fuji 150mm f5.6 (checked the corners through the lens and on the ground glass) on a Technikardan 45.


Filter? Lens hood? Hole centered on board?Answers to Dan's questions? To which I'd add: aperture setting? Vertical or horizontal back orientation?

According to the home page link I included in post #3, you should be getting about 46mm or 41mm rise (horizontal and vertical back positions respectively) at the specified image circle, which is determined at f/22, so you're not too far off. Without answers to the above questions, it's entirely possible that one or more factors they address could reduce available rise by 10mm.

[Vaughn]

Filter? Lens hood? Hole centered on board?

Obvious, but I'll mention it anyway -- any front tilt used? That changes things quickly!

[NoBob]

Hi,

No tilts, filter or hood.

Lens is centred on board, give or take a millimetre.

Will post some pictures to see if anyone can see something I don't.

[Sal Santamaura]

...No tilts, filter or hood.

Lens is centred on board, give or take a millimetre...That leaves one question unanswered and prompts one new question. First, are you checking available rise with the lens wide open or at f/22? Second, with a Technika-type board that centers your lens in the light trap circle, does the Technikardan 45 put the lens axis in the center of the film? I don't know how that camera is designed; Technikas (Master, 2000, 3000) would probably be exhibiting around 7mm of rise with such a board, since, as best I can determine, they're designed to be in a neutral configuration using Linhof boards with downward-offset holes. Bob Soloman -- please jump in here. :)

[NoBob]

Some rough phone shots. Front rise is set to zero in the first shot, looking between the standards. Anyone spot anything?

131823131824131825131826

[Sal Santamaura]

Some rough phone shots. Front rise is set to zero in the first shot, looking between the standards...That looks like the lens is centered on the film, but it's tough to tell with complete certainty.

Again, at what aperture setting did you examine available rise? I'd expect a lot more (right around the table's 46mm with horizontal film orientation as shown in post #13) at f/22 than at f/5.6.

[NoBob]

I checked at both f5.6 and f22. There wasn't much difference. In fact when I stopped down and checked on the ground glass, it was 34mm, but that could be because I was a bit stricter about what counted as an acceptable amount of darkening in the corner.

[Sal Santamaura]

Uncle! I give up. There must be something wrong with the lens or, alternatively, perhaps the image circle you originally quoted is for a different 150mm Fujinon version.

[NoBob]

Yeah, I don't know what's going on. I'll just use it. Maybe I'll figure out what's going on some time later.

[Bob Salomon]

That leaves one question unanswered and prompts one new question. First, are you checking available rise with the lens wide open or at f/22? Second, with a Technika-type board that centers your lens in the light trap circle, does the Technikardan 45 put the lens axis in the center of the film? I don't know how that camera is designed; Technikas (Master, 2000, 3000) would probably be exhibiting around 7mm of rise with such a board, since, as best I can determine, they're designed to be in a neutral configuration using Linhof boards with downward-offset holes. Bob Soloman -- please jump in here. :)

Yes, especially with Linhof manufactured boards. Then you know that the lens is properly positioned on the film.

[NoBob]

The lens has a 52mm filter thread, and it says Fujinon W 1:5.6/150 on the outside of the barrel, so the IC should be 224mm.

[Sal Santamaura]

...with a Technika-type board that centers your lens in the light trap circle, does the Technikardan 45 put the lens axis in the center of the film?...


Yes, especially with Linhof manufactured boards. Then you know that the lens is properly positioned on the film.I'm still not clear on this Bob. Other than those for Compur/Copal 3 shutters, do any Linhof-manufactured Technika boards center their holes on the light trap? I thought all those pre-bored for 0 (like the OP's 150mm Fujinon) and 1 shutters were offset down around 7mm.

With which boards is the Technikardan configured to place a lens axis on the film's center, those that are offset down or ones with centered holes?

[Bob Salomon]

I'm still not clear on this Bob. Other than those for Compur/Copal 3 shutters, do any Linhof-manufactured Technika boards center their holes on the light trap? I thought all those pre-bored for 0 (like the OP's 150mm Fujinon) and 1 shutters were offset down around 7mm.

With which boards is the Technikardan configured to place a lens axis on the film's center, those that are offset down or ones with centered holes?

All Linhof made Technika 45 boards, regardless of shutter size, have the hole centered in the same spot on the board except for a special z marked number 3 size board which has the hole raised in the board for 3 or 4 larger modern lenses in a 3 shutter that require extra clearance for the rear lens group to clear the edge of the hole in both the Technika 45 and the TK models to allow them to seat and latch onto the front standard. Otherwise these larger lenses will hit the back edge of the hole on the front standard and not allow the board to properly seat on the camera. This z board is a special order item only from the factory.
Since Linhof never offered Fuji lenses they have never published lens board recommendations for those lenses. However, since the Fuji lenses use common shutters they would use standard Linhof boards for that focal length in that size shutter. The proper Linhof lens board for a Technika for that lens would be the 001016 Comfort recessed board.

[Colin Graham]

I'm getting 35mm front rise with the Fuji 150mm f5.6 (checked the corners through the lens and on the ground glass) on a Technikardan 45.

Maybe I'm missing something, but 35mm of rise looks pretty consistent with the stated coverage of that lens, especially with V rise or H shift.

[Colin Graham]

Forgot to mention-- if you need more coverage, look for the W 5.6 version with the inside lettering, which has roughly a 245mm circle. I use mine on 5x7.

http://www.subclub.org/fujinon/150w56.jpg

[Jason Greenberg Motamedi]

Maybe I'm missing something, but 35mm of rise looks pretty consistent with the stated coverage of that lens, especially with V rise or H shift.

Yes, 35mm is just about right for this lens...

A rough calculation: 224mm (expected IC of lens) - 150mm (approximate 4x5 coverage) = 74 / 2 = 37mm

[Sal Santamaura]

Maybe I'm missing something...Yes, you are. Your drawing isn't correct. Given that the horizontal image size of a 4x5 frame is 120mm, you've drawn a circle of 208mm diameter, not 224mm. The graphical approach works well, but only if dimensions are right.

[Sal Santamaura]

Yes, 35mm is just about right for this lens...

A rough calculation: 224mm (expected IC of lens) - 150mm (approximate 4x5 coverage) = 74 / 2 = 37mmThat's not a valid approach; one must use geometry, not simple subtraction. Or, rely on the table I linked to in post #3. I recently obtained a used lens and physically compared its available rise to what that table claimed. The two numbers were within 1mm of each other.

[Colin Graham]

It was just a rough sketch to confirm the results the OP was getting, but I should have clarified that I used 100mmx130mm for the size, which is the viewable area on my 4x5's ground glass. Attached are the complete dimensions for that sketch, as well as an updated one with one closer to film size. So, depending on the camera model, I suppose there can be quite a bit of different between WYSIWIG and WFSIWFG, ha.


Yes, you are. Your drawing isn't correct. Given that the horizontal image size of a 4x5 frame is 120mm, you've drawn a circle of 208mm diameter, not 224mm. The graphical approach works well, but only if dimensions are right.

[Dan Fromm]

How much darkening are you seeing? Cos^4 says that at 224 mm a 150 mm lens should be down not quite 1.5 stops from the center.

[Bob Salomon]

How much darkening are you seeing? Cos^4 says that at 224 mm a 150 mm lens should be down not quite 1.5 stops from the center.

That also depends on the coverage of the lens, An Apo Sironar S is 75°, an Apo Sironar W was 80° and an Apo Sironar N was 72°. Older lenses of similar design could be down to about 68° and process lenses could be as narrow as 40°. So a general statement like yours needs clairification as to what the lens covers at infinity at f22.

[Sal Santamaura]

...when I stopped down and checked on the ground glass, it was 34mm, but that could be because I was a bit stricter about what counted as an acceptable amount of darkening in the corner.


How much darkening are you seeing?...


That also depends on the coverage of the lens...a general statement like yours needs clairification as to what the lens covers at infinity at f22.In my opinion, reliance on "ground glass darkening" is not the way to make this determination. First, at infinity focus, stop down to shooting aperture, typically f/22. Then, since it appears from the images you posted that the Technikardan's focus screen does not have clipped corners, look at the screen's corners through the lens (i.e. from the camera's front). Next, increase front rise until just before the screen's corners are obscured by the lens or, if you're using one, filter. Note how many millimeters of rise it took to do that. Finally, without changing anything, expose some film. Only when you have processed film in hand will the real answer be determined.

This is based on your lens being a modern design with hard circle cutoff, usually manifest by front or rear cell intrusion into the ray path. Many older lenses did not include hard stops and could illuminate far further off axis than they were capable of rendering with acceptable resolution. Contemporary designs typically resolve well right out to the edge of their circles of illumination.

[Dan Fromm]

That also depends on the coverage of the lens, An Apo Sironar S is 75°, an Apo Sironar W was 80° and an Apo Sironar N was 72°. Older lenses of similar design could be down to about 68° and process lenses could be as narrow as 40°. So a general statement like yours needs clairification as to what the lens covers at infinity at f22.

Bob, the lens the OP asked about covers 224 mm. That's why I used 224 mm in my calculation.

You're absolutely right, I did my little calculation for the special case "150 mm lens covers at least 224 mm." Whether a narrow angle 150 mm process lens will illuminate 112 mm off axis but not cover in the sense of putting good image out there is an interesting question but I'm not sure its relevant to the OP's question.

[NoBob]

For an image circle of 224mm, the equation in Fig. 2 on this Photo.net page gives 41.5mm rise

http://photo.net/large-format-photography-forum/00aMke?start=10

Using paper, pencil and a compass, I get the same figure, give or take a millimetre.

[Sal Santamaura]

For an image circle of 224mm, the equation in Fig. 2 on this Photo.net page gives 41.5mm rise

http://photo.net/large-format-photography-forum/00aMke?start=10

Using paper, pencil and a compass, I get the same figure, give or take a millimetre.Getting closer, but, in that treatise, Jim Momary makes the following working assumption:


"The film is truly 4X5. (I made no provision for film holder masking, so my figures are slightly erring on the positive/safe side.)"


Since four inches is 101.6mm, five inches is 127.0mm and the actual image area of concern for 4x5 film is 95mm x 120mm, results with Jim's approach do indeed give a smaller result for maximum rise than what's really available. Working through the equation using 95mm x 120mm would undoubtedly give an answer that comports with the approximately 46mm found on this site's table.

[Chauncey Walden]

It seems to me that Bob has said that the OP's camera is designed to have the typical Linhof board with the 7mm offset down lens centered on the film. I think the OP said his lens board was hole centered. Unless he has moved his board down 7mm after he mounted it to center the lens on the film he would be losing 7mm of rise. No?

[NoBob]

That would make sense, but I also checked the amount of rise with a Fuji 125mm f5.6. It has a 52mm thread so should have an IC of 198mm. http://www.subclub.org/fujinon/byfl.htm

If using the Fig. 2 calculation on the photo.net page, front rise is 25.15mm. In practice, I get 25mm. And the lens is centred on the board.

[NoBob]

So I bought an off-centre lens board for the 150mm. What I found is that although you apparently gain in front rise, which is proportional to the amount by which the hole is off centred, what you see in the ground glass (before vignetting starts to show up) is the same as when the lens is mounted on the board with the hole in the centre.