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04-04-2009, 02:31 PM   #1
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What are those red dots?

Pictures from my Helios-44M-4 lens sometimes show some red (and green) dots. I'm wondering what is this, ghosting maybe? Also, does it have something to do with the small chip on the edge of the back element? Or it's just coating issue?

at F5.6


at F2 (was checking infinity focus)


at F5.6 or 8, shot through bus window


04-04-2009, 04:07 PM   #2
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They look like out of focus traffic lights and car tail lights to me.
04-04-2009, 07:03 PM   #3
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It looks like the green circle, in the 2nd shot, is the green go signal of the traffic light to me. I am not so sure about the red circles.
04-04-2009, 07:15 PM   #4
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The tail lights and signal lights are only showing this phenomenon. It looks like a harsh color attribute reaction to me.

04-05-2009, 01:34 AM   #5
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Thanks for the all answer. So I guess it's not related to optical quality, I thought it was one of those optical flaws like CA.

The other possible reason is the coating on the Helios, since I never get similar phenomenon with my other lenses with multicoatings. I have another lens with simple coating, my vivitar series 1, but it never shows similar thing, but then again I dont use it a lot, which I should for now.

I remember I read somewhere that *istDS is very sensitive to infra red, maybe the combination of DS IR sensitivity and Helios poor coating cause this phenomenon? Just now I've tried to reproduce the thing but I failed, have to try more I suppose.

One more thing, when I open the image in photoshop, I notice that the red spots have almost white color in red channel and absolutely black in the green and red channel. Thoughts?

04-05-2009, 02:20 AM   #6
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It's interesting that they're all from lensed light sources, and are so thoroughly saturated. I'd be interested to know what causes this effect too; based on the scene it doesn't look like the relative amount of visible light should be that high.

Out of pure curiosity, do you happen to know if the traffic signal lights are of the old incandescent-bulb-behind-a-lens type that looks lit only in the center, or the newer type that's lit evenly across the entire lens? (It's a different light source in the newer type, I just can't remember what it's called.)

If they're incandescent, I would think that lends more weight to the IR theory.
04-05-2009, 06:15 AM   #7
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Sorry I dont know which kind of light the traffic signal is. I might be able to go there and check again tomorrow and I'll get back to you.
04-05-2009, 12:24 PM   #8
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I've also seen similar effects with my K100D using both a Vivitar-A 28mm f2.8 & Pentax-A 135mm f2.8, both constant apature at f2.8. I've noticed this after Pennsylvania started changing over to LED traffic lights.

I think they give a different wavelength - they're more noticeable at night at longer distances.

04-05-2009, 01:15 PM   #9
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QuoteOriginally posted by sajah Quote
One more thing, when I open the image in photoshop, I notice that the red spots have almost white color in red channel and absolutely black in the green and red channel. Thoughts?

That is simply telling you that the spot is completely blown out in the red channel, and there are no other colors in the light. Pretty much to be expected from a red light source like a tail light or red stop light.
04-07-2009, 06:30 PM   #10
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Do you have a UV or other type of filter on the lens?
04-07-2009, 08:32 PM   #11
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Nope I dont use any filters since the front element is already deep inside, so it's unlikely for my fingers to end up there. Besides, I'm running out of good filter lol

here's a pic of my helios
04-07-2009, 08:35 PM   #12
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QuoteOriginally posted by sajah Quote
One more thing, when I open the image in photoshop, I notice that the red spots have almost white color in red channel and absolutely black in the green and red channel. Thoughts?

The hexagonal shape is interesting. I assume you have a six-bladed aperture ring? If so, it could be lens flare, but I've never seen a case with such saturated color before.
04-07-2009, 08:42 PM   #13
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Yeah you are right, my helios has 6 blades. That's why I thought it was ghosting, because I read it looks like aperture shape and I never really see ghosting before.
04-07-2009, 08:42 PM   #14
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I have shot + 1000 shots

with my two helios and never saw any thing like it... But neither of mine are multicoated so who knows. I do know that folks who have the 44M-4 say it is one of the best versions.

You might ask over at mflenses.com There are a lot of folks who have a lot of russian lens experience, so if it is a multicoating issue, someone may have seen it before

The red is 'so' over saturated that I just dont see how the lens does that.

What are your camera settings?
04-07-2009, 09:04 PM   #15
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Good idea, thanks, I better ask there also

I use Jpeg with 3 stars quality, vivid Image Tone, and Saturation, Sharpness and Constrast all set to default middle position
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