Flare normally comes from your tubes or bellows
2
SigmaTog wrote:
I have just purchased a vintage Canon 20mm f3.5 Macro Bellow Lens.
Congratulations. I've used those before: they're sharp, low distortion, flat field, and have excellent contrast.
It is pristine, but it has a terrible flare.
Is there a way to deal with this please ?
That lens is not known for flare. If it's truly pristine, but there's a lot of flare, check your tubes or bellows. Remember, most lenses will happily spray light at least 45° off axis (some might go past 60°) so if it's in a relatively shiny tube, you will get a ton of flare.
Are you on a Canon bellows with the huge, flat Canon FD adapter? Generally, that combo pretty much won’t flare. The stray light doesn’t even hit the first 40-50mm of the bellows, and bellows accordion pleats are pretty good light absorbers.
Now, my conical RMS adapter flared like crazy when I got it. It was fine with microscope objectives, which only illuminate like a +/- 15° cone, but turned to crud with my 25mm Leitz Photar, which sprays light far and wide, like your Canon. I ended up having to really carefully cut flock paper to fit. Wasted three or four pieces before I got it right.
Tubes are easier to add flock paper to, because they’re wider than a conical adapter, and you can baffle them by cutting discs to fit, then cutting appropriate holes in the discs. That's provided you haven’t got flare starting in your RMS adapter.
-- hide signature --
The term "mirrorless" is totally obsolete. It's time we call out EVIL for what it is. (Or, if you can't handle "Electronic Viewfinder Interchangeable Lens" then Frenchify it and call it "LIVE" for "Lens Interchangeable, Viewfinder Electronic" or "Viseur électronique").
-----
Stanley Joseph Wisniewski 1932-2019.
Dad, so much of you is in me.
-----
Christine Fleischer 1947-2014.
My soulmate. There are no other words.
-----
Rahon Klavanian 1912-2008.
Armenian genocide survivor, amazing cook, scrabble master, and loving grandmother. You will be missed.
----
Ciao! Joseph
www.swissarmyfork.com