Some mysterious softness on Voigtländer Ultron 28mm f1.9 LTM

calbunker · Feb 5, 2026

Hey y’all,

I picked up a neat Voigtländer Ultron 28mm f1.9 LTM a few months ago. Test results from reviews I read looked wicked sharp and very nice. I’ve found the lens to be awesome… but pretty damn soft wide open. A lot softer than the reviews show (and say)

My standards aren’t super high, I’ve got some other vintage lenses (Summitar 5cm f2, Summaron 3.5cm f3.5, Canon 35mm f2.8, Voigtländer 75mm f2.5) and all of them are considerably sharper, especially wide open.

Any ideas on why my copy seems to be softer than usual? I can share some example photos if that’s useful.

nikomax · Feb 6, 2026

Could it have some haze? Apparently older Voigtlander lenses are prone to getting it.

Richard G · Feb 6, 2026

When I bought my Zeiss 35 C Biogon, second hand, I was puzzled at its softness. A large fingerprint on the rear element. I had to look for it.

Nitroplait · Feb 6, 2026

Check for haze. I had to give up my LTM 12mm f5.6 because of that. Hope it won’t happen to my LTM 50/1.5 and LTM 21/4

Slumgullion · Feb 6, 2026

calbunker said:
Hey y’all,

I picked up a neat Voigtländer Ultron 28mm f1.9 LTM a few months ago. Test results from reviews I read looked wicked sharp and very nice. I’ve found the lens to be awesome… but pretty damn soft wide open. A lot softer than the reviews show (and say)

My standards aren’t super high, I’ve got some other vintage lenses (Summitar 5cm f2, Summaron 3.5cm f3.5, Canon 35mm f2.8, Voigtländer 75mm f2.5) and all of them are considerably sharper, especially wide open.

Any ideas on why my copy seems to be softer than usual? I can share some example photos if that’s useful.

Can you show us an example?

As said above, the lens is prone to haze forming inside. Shine a bright light through it to see if it appears foggy.

I have a non-fogged copy. It is sharp wide-open, but I wouldn't necessarily describe it as being a class leader in resolution or contrast. In fact, it's the pleasant softness that makes its images so lovely, imo.

Some mysterious softness on Voigtländer Ultron 28mm f1.9 LTM

calbunker

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nikomax

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Richard G

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Nitroplait

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Slumgullion

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