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View Full Version : Super-Symmar XL 150 needs center filter?



Uri A
1-Sep-2009, 23:31
Hi all,

Hypothetical question for anyone who uses this lens:
If you were to shoot an image with the SSXL150 onto 8x10 using NO camera movements, using a middling aperture, say f22, and focussing for 6m-infinity (a typical landscape), would you get falloff at the corners of your negative?

In other words, is the center filter just for tricky movements or shooting wide open where you use the outer portions of the image circle, or is it an everyday requirement?

Thanks for reading! :)

Bob Salomon
2-Sep-2009, 02:45
Yes it has fall off. That is why they made the filter. On 810 you will see more of it.

Peter K
2-Sep-2009, 05:10
If you were to shoot an image with the SSXL150 onto 8x10 using NO camera movements, using a middling aperture, say f22, and focussing for 6m-infinity (a typical landscape), would you get falloff at the corners of your negative?

In other words, is the center filter just for tricky movements or shooting wide open where you use the outer portions of the image circle, or is it an everyday requirement?
Every lens has falloff from the center to the edges. But the Super-Symmar XL Aspheric has less falloff as a lens without an aspherical element. So one needs only a center filter with very critcal subjects like an even illuminated wall. Also the center filter needs at least f16, so wide open is no option.

BTW I've never used a center filter with my "long" SA's, the SA 165mm has the same image circle as the Super-Symmar XL Aspheric 150mm. Of course, the SA has a little bit smaller angele of view.

Peter

Peter De Smidt
2-Sep-2009, 05:52
Lots of subjects look good with a little fall off. I used a 47mm lens on a 4x5 without a center filter. Before using it, I was worried about fall off. It didn't bother me a bit on the slides.

percepts
2-Sep-2009, 05:58
That lens has masses of available shift even on 8x10. I would be surprised if you needed a centre filter at infinity with f22 and no tilts or shifts.

But you should remember that all lenses have falloff from the centre outwards. But when you put neg in the enlarger the enlarger lens has falloff too. So with a negative, the enlarger lens cancels out the taking lens falloff to a certain extent. But if you are scanning to print digitally, then....

Ron Marshall
2-Sep-2009, 06:10
With a 75mm on 4x5 (21% extra coverage versus 19% extra with the 150 on 8x10) I only feel the need for a CF with transparency film, with neg, the amount of falloff doesn't bother me. But I always use one on my 55mm.

Try a test sheet before you buy!

CG
2-Sep-2009, 08:34
If you shoot a higher contrast film / N++ development etc, you may find you want a center filter if fall off bothers you. If you like fall off, you may not mind the 150 w/o filter.

Bob Salomon
2-Sep-2009, 09:05
There is no hypothetical answer. It depends on you, what you will shoot and what you will do after you shoot.
If you are shooting negatives you can burn and dodge to even it out. If you are shooting chromes then you can't.
If you are shooting indoors you can overlight the edge and corners, if you are shooting outside then you probably can't, unless you are on a movie set.
If you are shooting scenes with expanses of open sky or sand that go across the scene then you might find the fall-off noticeable. If you are shooting scenes with forests on the edges then you may never see the fall off.
Some people prefer the fall off as they feel that it pulls the eye into the scene, others feel that it gives a wide angle look to the image. Many can't stand the fall off. Maybe you will do architecture and shoot the front of a glass or steel building that goes from the bottom to the top of the film. Then you very may see fall off in the building's glass or aluminum surface.
In order for a center filter to work the lens must be stopped down at least two stops as was noted earlier. That means that using a center filter wide open won't do anything.
Lastly, my hypothetical question, how do you know that you will NEVER use ANY movements? You will certainly at some time use tilts or swings to control the plane of focus in your scene, won't you? Using a typical folding camera you may have base tilts. These will make your image shift on the ground glass and make the fall off assymetrical - making the need for a center filter more obvious.

So the only answer is yours. Go out a shoot with the lens under the conditions that you normally shoot and with the film that you normally use and see what you get. Like it without? Don't get the filter. Don't like it? Get the filter. But bear in mind, the lens manufacturer won't not offer the filter unless there was a need for it. They don't want a filter lying in inventory because there is no need for it and no market for it.

Eric Leppanen
2-Sep-2009, 09:52
The following comments of course reflect my personal taste only...

When the SS150XL is centered on its image circle, I do not use the CF when shooting B&W or color neg film. The falloff is not noticeable with real-world subjects.

When shooting chrome film, or using significant movements, I always use the CF.

Depending on your shooting style and choice of subjects, there are cases where the falloff can be your friend. If you shoot from the bottom of a canyon, for example, apply some front rise, and need to hold back the sky and brightly lit top of the frame, then the falloff by itself might be enough to do the trick, without resorting to a yellow/orange or ND grad filter.

Uri A
3-Sep-2009, 06:27
Thanks for your comments everyone!! About to start shooting on this lens .. hate to waste film :)

Your help is much appreciated.

Uri A
3-Sep-2009, 06:32
One more question: what does it mean that the filter 'wont work' wide open (that's what it says on the Schneider site too), but only with the lens stopped down a few stops?

In the words of Pauline Hanson: "please explain"

Mike1234
3-Sep-2009, 09:42
It's been years since I've shot LF but I shot lots of it way-back-when. I'm just now re-enterring the LF arena.

That said, I didn't own CF's before because I couldn't afford them. Considerably more than half of the images I shot with WA really needed a CF. Darkroom manipulation can only do so much... film does not respond linearly to exposure variations... and my experience was with B&W with a long gamma curve. Color neg and especially color slide film just exacerbate the problem. My new WA lenses will ALL have CF's. I won't "always" use them but will much, if not most, of the time.

But this is just my opinion... as influenced by the subjects I like to shoot, my shooting style, and my personal preferences.

Bob Salomon
3-Sep-2009, 10:07
One more question: what does it mean that the filter 'wont work' wide open (that's what it says on the Schneider site too), but only with the lens stopped down a few stops?

In the words of Pauline Hanson: "please explain"

A lens must be stopped down at least 2 stops for the CF's effect to work. Doesn't matter whose lens or CF is used. CFs are of no use wide open.

Bob Salomon
3-Sep-2009, 10:09
Thanks for your comments everyone!! About to start shooting on this lens .. hate to waste film :)

Your help is much appreciated.

Waste is the wrong word. You do have to test to find what works best for you.

Mike1234
3-Sep-2009, 10:12
^^^ It's a DOF issue. CF's are made to work at average working apertures. Large apertures simply cannot "see" the concentration of ND at the lens' center... it's simply "too" blurred. CF's could probably be made to work at wider apertures (to some degree) or smaller ones but then we'd have to buy 3 or 4 CF for every lens. It's not a viable marketing tactic. Not enough of each type would sell to make it profitable.

percepts
3-Sep-2009, 10:29
^^^ It's a DOF issue. CF's are made to work at average working apertures. Large apertures simply cannot "see" the concentration of ND at the lens' center... it's simply "too" blurred. CF's could probably be made to work at wider apertures (to some degree) or smaller ones but then we'd have to buy 3 or 4 CF for every lens. It's not a viable marketing tactic. Not enough of each type would sell to make it profitable.

Ahem...

I think its because any small point in the subject sends a cone of light which covers the whole surface of the lens. The lens does its stuff and focuses the whole of the cone into a single circle of confusion on the film.

If you use a wide aperture, that means some of that cone of light is given max filtration and some is given minimum filtration and that ain't gonna work as it should. It will lighten the central area and you'll get light falloff on film because the center will be too light. A smaller aperture will reduce the variable filtration for a single point in the subject and be closer to correct.

Whats that's go to do wif DOF I have no idea. How you are going to correct that with a different center filter I have no idea.

Mike1234
3-Sep-2009, 10:52
^^^ I believe I just said that, albeit in different terms. :)

It has nothing to do with the DOF of the subject but rather the relationship of the CF and image hitting the film plane. These are two completely independant working DOF issues. Simply put, the CF has to be (not blurred) enough to function as designed.

Uri A
3-Sep-2009, 17:46
Thanks Mike and percepts! I think I get it...