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02-28-2009, 06:54 AM   #1
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Bubble in Voigtländer glass?

I just noticed that there seems to be something that looks like a bubble in the front glass of my Voigtländer Ultron lens. I got this one as a replacement for a copy that was soft at infinity (ironically, this one seems at least as soft as the first copy).

It's hard for me to estimate the size of the bubble since I am looking at it through a lens (d'oh) but I'd say around a millimeter in diameter. Should this be a reason for me to send it back again? Are bubbles in glass a common phenomenon/problem?

02-28-2009, 07:39 AM   #2
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Can you send any pic of your lens with bubbles, in which you can see them?

It should be very usefull. Thanks.
02-28-2009, 10:14 AM   #3
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Here's a picture of it.
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02-28-2009, 10:31 AM   #4
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I have read about bubbles in older Zeiss lenses. They are supposed to be accepted as normal and not have any substantial impact on image quality. This is possibly true, and probably acceptable in vintage glass that can't be returned. But every other glass surface is coated, so I have always taken the "no effect" line with some doubt. I don't think I would be thrilled with a bubble in a newly purchased lens that I could return. Maybe the actual effect is small but if bubbles were really nothing to worry about, there would be more bubbles in our lenses.

02-28-2009, 11:27 AM   #5
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That's a pretty sizable bubble. I'd send it back if I could.
02-28-2009, 11:59 AM   #6
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Re the bubble:
I would expect it to have a small effect on image contrast (the cross-section of the bubble is small compared to the cross-section of the front element).

I'd send the lens back anyway. If you ever decide to sell the lens the bubble will scare away buyers and invite lowball offers.

Re softness at infinity:
My Voigtlander SLs (125 and 180) both focus very slightly past infinity -- wide open shots of distant objects become sharper if the focus is set a tiny bit short of the infinity stop. Perhaps your Ultrons also focus past infinity?

I don't think focusing-past-infinity is a significant defect.


Welcome to the forum, and good luck with getting an Ultron you like.
02-28-2009, 03:02 PM   #7
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Thanks, guys. I think I will send it back...

troyz, that's exactly what I meant. To be honest, if I was to make the decision again, I probably wouldn't have sent it back again. Still, this Ultron focuses waaay past infinity and I think that just doesn't seem/feel right with such a lovely overall lens (possibly my favourite, even).

Last edited by amaurosis; 02-28-2009 at 03:16 PM.
01-09-2010, 12:05 AM   #8
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Old thread to life...

I noticed the same thing on my Ultron, but it's not as bad as this... you can only see it when looking through the lens and only at a certain angle.

01-09-2010, 02:52 AM   #9
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QuoteOriginally posted by amaurosis Quote
Still, this Ultron focuses waaay past infinity and I think that just doesn't seem/feel right with such a lovely overall lens (possibly my favourite, even).
Why doesn't it seem right? Some lenses (mirror lenses, for example) are designed to allow focusing past infinity, so under temperature changes they continue to work. I'm not sure if this is the case with the Ultron, but I've got plenty of lenses that won't focus properly when set at infinity and will only do that if you set the ring somewhat shorter of the infinity marker.

As for bubbles, they're not common and if you can return the lens for peace of mind, you can just do that. But small bubbles are probably nothing to worry about and they'll have no effect on your images.
01-09-2010, 03:05 AM   #10
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QuoteOriginally posted by Laurentiu Cristofor Quote
But small bubbles are probably nothing to worry about and they'll have no effect on your images.
There may be no effect on images but there would be an effect on resale value.
01-09-2010, 11:40 AM   #11
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QuoteOriginally posted by Damn Brit Quote
There may be no effect on images but there would be an effect on resale value.
Yes, you can get an excellent lens cheaper
01-09-2010, 01:14 PM   #12
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Ultimate example of bubbles and bugs in a lens:

Vintage Folding Cameras
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