Do I Need a CF for a 65mm f4.5 Caltar?

[747sp]

I just bought one of these as i am in need of something wide for my 4x5 Kit (widest i have is 105mm at the moment). I shoot Landscapes - usually with plenty of light but sometimes dusk and long exposures. Beaches and Mountails etc. Typically I'm going to be f16 and 22 and maybe beyond for the DOF. Do I need a Centre Filter? I did search this subject and it seems a mixed response. Im heading away to NZ for four days in Nov, so i'd rather play safe and get one if its required - i would experiment to see if i really need one if i had time beforehand but its unlikley i will by the time i get the lense get some Sheets shot and get them way and back from Processing. I'm shooting Velvia 50 and 100 mainly. Thanks.

[Bob Salomon]

Most likely you do. It depends on how badly you like the fall-off. Especially if you use displacements and shoot transparencies.

[Cor]

I use a 65mm SA f5.6, and haven't noticed fall of. But I shoot only B&W, and until recently I never used displacements because my old camera did not allow these.

Why is it that light fall off is more apparent on colour material, perhaps because it is less difficult to correct it while printing B&W (and in a way you are helped a bit sometimes by the light fall off of the enlarger lens, both light fall off can cancel each other out)

Best

Cor

[Ivan J. Eberle]

Velvia will be tough or impossible without one. I'd consider changing to or adding C-41 to the workflow instead. Got rid of all the grads when I did. Still shoot E-6, but now only when the light is perfect.

[Bob Salomon]

"only when the light is perfect"

Perfect for what?

[Ivan J. Eberle]

Perfectly within the 6 stop dynamic range of Astia 100F, Bob.

At the beach here (e.g. Big Sur/Carmel/Pt Lobos) it takes a bank of clouds overhead being illuminated by the setting sun to even come close to that. Otherwise it's silhouette time, which gets stale pretty quickly. C-41 solves a host of problems. Even a stack of Grad ND filters (and a center filter) are a poor substitute for in-film masking.