Reverse Vignetting with 21mm F2.8 Biogon

[foggie]

Hi Guys,

I noticed some lightened corners on shots taken with my 21mm Zeiss ZM Biogon f2.8. Any idea what's going on? It looks just like reverse vignetting! I am using a silver-coloured UV filter on it -- could this be causing the problem?

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/321392_10150357951011416_656341415_10103987_431468 1_n.jpg


https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/299033_10150357950611416_656341415_10103971_547055 _n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/299402_10150357950671416_656341415_10103973_387653 0_n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/302568_10150357950851416_656341415_10103981_606397 _n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/302062_10150357950961416_656341415_10103985_409562 _n.jpg

[mooge]

those last two are very nice.


uhh, and a silver filter sounds plausible... it seems like the light corner is opposite the light source. maybe. I dunno.

[charjohncarter]

I've tried to create the opposite with hoods, and I've a couple of lenses that darken the corners which I covet. But I don't know what is going on here. Maybe do an extreme shade to correct or make a slight vignette.

Or take the filter off and try. The silver may be causing internal reflection in the corners. But I bet it is the filter doing something. The lens is wide so the filter could be causing some reflection.

[Phil_F_NM]

When I had my ZM 21mm/2.8 I used it on my M8 and had a silver Leica UV/IR filter on it. I noticed similar flare in the images of my M8 and then used some flat black paint to blacken the inner threads of the filter and the problem went away. It happened on the M9 when I got it and used a silver rim filter so I took the filter off and just shot it bare. Didn't have a problem then. One thing I noticed is the filters by Leica have a really good amount of thread in them so they might be a bit deeper than others. After that, I begen to prefer the BW slimline filters.

Phil Forrest

[foggie]

Thanks, guys. I'll try using it without the UV filter for a while and see what happens. Finding a better replacement is impossible since I had enough trouble getting that one crappy 46mm that's causing flaring.

[foggie]

When I had my ZM 21mm/2.8 I used it on my M8 and had a silver Leica UV/IR filter on it. I noticed similar flare in the images of my M8 and then used some flat black paint to blacken the inner threads of the filter and the problem went away. It happened on the M9 when I got it and used a silver rim filter so I took the filter off and just shot it bare. Didn't have a problem then. One thing I noticed is the filters by Leica have a really good amount of thread in them so they might be a bit deeper than others. After that, I begen to prefer the BW slimline filters.

Phil Forrest

Updating this old post to confirm that the problem was indeed the silver filter reflecting light and it went away when I used some dark blue nail polish to paint the inside threading.

[semilog]

Never seen this type of flare, but I use UV or 81A filters (B+W or Hoya HMC) with black rings and blackened filter edges on my ZM lenses. That includes the ZM 21/2.8. Great lens.