mjh Posted July 3, 2018 Share #41 Â Posted July 3, 2018 Advertisement (gone after registration) Since it is so symmetrical, my guess is that it is coming from sensor. It most certainly is. Reflections off a CD or DVD can show similar patterns, btw. 2 Link to post Share on other sites More sharing options...
Advertisement Posted July 3, 2018 Posted July 3, 2018 Hi mjh, Take a look here Ugly lens flare!. I'm sure you'll find what you were looking for!
AlanD Posted July 4, 2018 Share #42  Posted July 4, 2018 Interesting link According to the author the whole issue has nothing to do with camera, lens or brand, but with the flange distance. Which should mean that M, or, even better, R lenses show the issue to a lesser extent. Combination of lens design (distance of rear most element to sensor) and the sensor design (Sony glass.). I don’t think that is seen on any M camera while M adapted to Sony (same flange distance once adapted) can show the problem. Link to post Share on other sites More sharing options...
wlaidlaw Posted July 4, 2018 Share #43  Posted July 4, 2018 It most certainly is. Reflections off a CD or DVD can show similar patterns, btw.  Surely that is a diffraction effect off the "grooves" or circular lines of pits, like a diffraction grating which many modern spectrometers use rather than a prism. 1 Link to post Share on other sites More sharing options...
jaapv Posted July 4, 2018 Share #44 Â Posted July 4, 2018 Exactly. The structure of the microlenses is the cause of this effect. If you look carefully you'll sometimes see that the flare is contained in a rectangular "box". On a DVD it is the 3D structure of the stamper. 1 Link to post Share on other sites More sharing options...
pgk Posted July 4, 2018 Share #45 Â Posted July 4, 2018 My guess is that there is some 'additive' effect between the reflections of the sensor array and the lens - it will be some lens surface being of appropriate size/placement/position to reflect the lens array image highly magnified. Irritating, but I have seen this off other lenses/cameras somewhere before. Link to post Share on other sites More sharing options...
jaapv Posted July 4, 2018 Share #46 Â Posted July 4, 2018 It is not a guess - it is a diffracted reflection off the microlens layer of the sensor. The shorter the register distance and the distance between the rear lens element and the sensor the more pronounced it will be. I guess that a sensor without AA filter will be more affected. (a piece of matte glass does wonders against reflections ) 1 Link to post Share on other sites More sharing options...
pgk Posted July 4, 2018 Share #47 Â Posted July 4, 2018 (edited) Advertisement (gone after registration) Thanks. I also think that the curvature of an (the rear?) element will be an exacerbating factor. I don't know the lens but I'd guess that the rearmost glass to air surface is of curvature such that it can reflect the specific few microlenses imaged back onto the sensor as the array seen? If so then the further that the point source of light is off-axis then the less evident the reflections might be? Edited July 4, 2018 by pgk Link to post Share on other sites More sharing options...
jaapv Posted July 4, 2018 Share #48 Â Posted July 4, 2018 According to the article linked to, it is the other way around. Avoid the flare by positioning the sun exactly in the middle: Â Â Probably has to do with microlenses on the surface of the sensor that are very prone to reflections. Since the light is falling at extreme angles to the surface of the sensor when it passes through a small aperture opening, the angle of light is most likely the cause of such microlens reflections. Interestingly, this effect is minimized when the sun is in the center of the frame, as demonstrated below (shot with the Fuji 27mm f/2.8 lens at f/11): Link to post Share on other sites More sharing options...
pgk Posted July 4, 2018 Share #49 Â Posted July 4, 2018 According to the article linked to, it is the other way around. Avoid the flare by positioning the sun exactly in the middle: Â Safari won't open the page, but I'd doubt it. If its a reflection from a curved surface the ideal would be to angle it so that it is projected outside the sensor area. I can't see that central placement would potentially reduce it but off axis placement eventually should. Link to post Share on other sites More sharing options...
jaapv Posted July 4, 2018 Share #50 Â Posted July 4, 2018 Yes, that would be true if the sensor behaved like a flat mirror, but the microlenses are curved three-dimensional surfaces. I guess it is more of a fresnel-like interference pattern reflected onto the rear lens and back again onto the sensor, making the shape of the rear element a factor as well. 1 Link to post Share on other sites More sharing options...
Boojay Posted July 5, 2018 Share #51  Posted July 5, 2018 Interesting discussion.  Now I was really expecting to see some severe flare from this grab shot - 55-135 - no hood, B+W UV haze filter.   Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/282940-ugly-lens-flare/?do=findComment&comment=3549901'>More sharing options...
jaapv Posted July 5, 2018 Share #52 Â Posted July 5, 2018 The 55-135 has a small rear lens that is situated far from the sensor. At least 5 cm beyond the flange. I would be surprised if it were very susceptible to this kind of flare. Â Edit: As Ian mentions in a subsequent post, it is present in a limited amount, so even now. 1 Link to post Share on other sites More sharing options...
wattsy Posted July 5, 2018 Share #53 Â Posted July 5, 2018 It is not a guess - it is a diffracted reflection off the microlens layer of the sensor. The shorter the register distance and the distance between the rear lens element and the sensor the more pronounced it will be. I guess that a sensor without AA filter will be more affected. (a piece of matte glass does wonders against reflections ) Â Â You seemed quite certain earlier on in the thread that the effect was caused by the filter. Link to post Share on other sites More sharing options...
wattsy Posted July 5, 2018 Share #54  Posted July 5, 2018 (edited) Interesting discussion.  Now I was really expecting to see some severe flare from this grab shot - 55-135 - no hood, B+W UV haze filter.   No flare.jpg   I'm not sure what point you are making but I see the same "interference pattern" type "flare" in your photo. A pattern of large and regularly spaced pink dots with the sun at the centre. Edited July 5, 2018 by wattsy 1 Link to post Share on other sites More sharing options...
jaapv Posted July 5, 2018 Share #55 Â Posted July 5, 2018 You seemed quite certain earlier on in the thread that the effect was caused by the filter. Correct. I changed my mind after studying the effect. 1 Link to post Share on other sites More sharing options...
JTLeica Posted July 5, 2018 Share #56  Posted July 5, 2018 Interesting discussion.  Now I was really expecting to see some severe flare from this grab shot - 55-135 - no hood, B+W UV haze filter.   No flare.jpg  I do see severe flare... Link to post Share on other sites More sharing options...
Boojay Posted July 5, 2018 Share #57 Â Posted July 5, 2018 I'm not sure what point you are making but I see the same "interference pattern" type "flare" in your photo. A pattern of large and regularly spaced pink dots with the sun at the centre. Â Â I do see severe flare... Â Yes, me too, but I was expecting to see it, type of shot, no hood, hard for this not to occur in such shooting conditions. Link to post Share on other sites More sharing options...
lct Posted July 5, 2018 Share #58 Â Posted July 5, 2018 I do see severe flare... Â I would not say severe but i see some sensor flare at f/8 here as you do. Would be worse at f/11 and f/16 most probably. See my pics below. 1 Link to post Share on other sites More sharing options...
lct Posted July 5, 2018 Share #59 Â Posted July 5, 2018 Test with a flare free lens at f/8, f/11 and f/16. (Digital CL, Biogon-C 35/2.8 with hood, OoC jpegs) Â f/8: https://photos.smugmug.com/photos/i-W6WxWKD/0/afff181d/L/i-W6WxWKD-L.jpg f/11: https://photos.smugmug.com/photos/i-DzRrG9g/0/34e84554/L/i-DzRrG9g-L.jpg f/16: https://photos.smugmug.com/photos/i-cPSCGpC/0/41464fa4/L/i-cPSCGpC-L.jpg Link to post Share on other sites More sharing options...
PDP Posted July 5, 2018 Share #60 Â Posted July 5, 2018 @Ict, I did the same yesterday: CL lens (11-23 TL) - wide open, fine; at f16, ugly Link to post Share on other sites More sharing options...
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