Of filters, step up rings, and flare

[quokka]

Hello all,

I have an R3A with a Nokton 40/1.4, and a Mamiya 6 with a 75/3.5. I need to get some filters.

I would like to avoid buying two sets of filters if possible. As the 150mm lens for the Mamiya (which I may soon buy) takes 67mm filters I would like to buy filters in that size and use step up rings for my smaller lenses.

My question is this: what is the effect on lens flare of using a 67mm filter on a lens (such as the Nokton or the Mamiya 75mm) in place of a lens shade?

Cheers,
Rory

 

[pvdhaar]

My question is this: what is the effect on lens flare of using a 67mm filter on a lens (such as the Nokton or the Mamiya 75mm) in place of a lens shade?

You'll be bitten twice, I guess. Although most front elements are somewhat recessed in the lens mount, a lens shade is intended to keep stray light away from it, increasing contrast. You're now taking that away, and replacing it with a non-recessed glass surface which introduces additional internal reflections, potentially causing ghosts.

Using a large filter with stepup rings is doable with SLRs where you can evaluate the effects (ghosts/flare/contrast) through the lens, and use your hand to provide shade. But personnally I'm not fond of filters for RFs where I can't see what happens.

At the very least, I'd fit a screw in shade on the filter front thread to keep light away from the filter..