Should I get a center filter for my 65mm Nikon-SW f/4 & 90mm Sinaron-W f/6.8?

So I have three wide angle lenses - a 65mm Nikon Nikkor-SW f/4, a 75mm Nikon Nikkor-SW f/4.5, and a 90mm Sinar Sinaron-W f/6.8. (I think all have a 67mm front attachment filter thread.)

Should I spend an extra $400 to get a center filter to help with vignetting, or can I take care of said vignetting with Photoshop?

If you guys do recommend a center filter, which one(s) would you recommend?

Many thanks!

Only you can answer this. Do you shoot negs or chromes? Do you see the falloff? If so, does it bother you? Do you mind spending time correcting falloff in PS?

Check this site.
https://galerie-photo.com/center_fil...mat_lenses.pdf

According to the site, +1.5 stop center filter could be used for your all three lenses.

BTW, I use the Schneider IIIc center filter for apo grandagon 55mm and for super angulon 47mm xl.
It works very well on both lenses.

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Originally Posted by Bob Salomon

Only you can answer this. Do you shoot negs or chromes? Do you see the falloff? If so, does it bother you? Do you mind spending time correcting falloff in PS?

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Hi Bob,

I shoot both color negative and color transparency (Ektar, Portra 160/400, Provia, and Velvia, specifically).

I definitely see falloff with my 65mm Nikon Nikkor-SW f/4, especially when I’m shooting transparency. With my 90mm Sinar Sinaron-W f/6.8, the falloff is very slight, but still there. It’s bothersome, for sure.

I wouldn’t mind spending the time correcting the falloff on Photoshop, but I’m not sure what the best way is to this, or if editing on Photoshop would even look good.

I guess the real question is would spending $300+ on a center filter be worth it if I can solve it with Photoshop? Is it even possible to fix in Photoshop?

It’s posible to fix in photoshop, easy to do it in camera raw filter but it’s not trivial to do it accurately. Mind you you can’t even create a standard fix (like by recording an action) because the effect will shift following your movements for a given shot.

To learn the best correction in a neutral state (no movements), you can take a shot of a white wall or equivalent uniformly illuminated surface and play with it on photoshop to remove the fall off the best you can — that will tell you the radius of the radial vignette to apply and also how strong. Then you can do the same for any other shot, and if you use movements I would record on paper approximately what and by how much so that you can use it as a starting point in photoshop to move the circle.

Note all this works assuming that with the fall off around edges you still are in the linear region of the exposure. Otherwise if you’re close to the toe, the amount will not be constant, or worse, it’s not recoverable. With slides it gets tricky quickly because the dynamic range is so limited to start with (for example you would need to check that the exposure will work around the edges given the known fall off, but then again is only really easy in a neutral state — no movements).

It’s definitely easier to have the filter on the lens for sure. Whether it’s worth that much, depends on your wallet and how much you care/want to correct it. If you can afford it and use these lenses often, then you probably will be better off biting the bullet.

Quote:

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Originally Posted by manfrominternet

So I have three wide angle lenses - a 65mm Nikon Nikkor-SW f/4, a 75mm Nikon Nikkor-SW f/4.5, and a 90mm Sinar Sinaron-W f/6.8. (I think all have a 67mm front attachment filter thread.)

Should I spend an extra $400 to get a center filter to help with vignetting, or can I take care of said vignetting with Photoshop?

If you guys do recommend a center filter, which one(s) would you recommend?

Many thanks!

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I don't think you need complexity and expense of photoshop, during printing just burn the center with some cardboard.

Hmm. I wrote the article referred to in post #3 above.

OP, there's no fixed rule about which focal lengths absolutely need a CF and which can be used without one. The choice depends on the user's preferences. To find out what you can stand, shoot a distant landscape with each lens on reversal film. Color, b/w, makes no difference but it has to be reversal. Use no movements. This will tell you whether you can tolerate the lens' cos^4 falloff. Stop the lenses down at least 2 stops to eliminate mechanical vignetting. A CF won't reduce mechanical vignetting.

That said, the generally accepted nearly fixed rule for 4x5 is that 90 mm is the shortest focal length that can be used without a CF. Decentering movements increase the need for a CF.

Oh, yeah, about how bad cos^4 is, with no movements on 4x5 a 65 will give corners 2.44 stops down from the center; 75, 2.0; 90, 1.5.

Short answer: If you shoot transparencies, definitely yes. It'll save a lot of headaches, time and probably money down the road.

If you're shooting negative film, well, then, maybe. With color neg and then scanning for printing, I would likely spring for the center filter. With black-and-white and wet printing, I'd likely not (I've always been able to adjust for the falloff when printing as long as I allow for additional exposure when the image is made).

As mentioned, you can likely get one filter that works with all the lenses (largest size, step up rings, etc.)

Best,

Doremus

Quote:

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Originally Posted by manfrominternet

Hi Bob,

I shoot both color negative and color transparency (Ektar, Portra 160/400, Provia, and Velvia, specifically).

I definitely see falloff with my 65mm Nikon Nikkor-SW f/4, especially when I’m shooting transparency. With my 90mm Sinar Sinaron-W f/6.8, the falloff is very slight, but still there. It’s bothersome, for sure.

I wouldn’t mind spending the time correcting the falloff on Photoshop, but I’m not sure what the best way is to this, or if editing on Photoshop would even look good.

I guess the real question is would spending $300+ on a center filter be worth it if I can solve it with Photoshop? Is it even possible to fix in Photoshop?

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A cf is your answer.

You can't post-correct something that's not there to begin with. With even color neg film, falloff is related to not only a density difference, but potentially a hue shift toward the corners due to dye curve crossover. That can hypothetically be used for artificial creative effect, or it might constitute a visual annoyance and distraction. It's possible, with enough time and mental torture, to dub or paint or dither or fake in something missing using PS, but I wouldn't personally term that a correction. Things are so much easier with a filter on hand to begin with. In black and white imagery, some people like strong falloff toward the corners, some don't.