Sony A33 samples, with and without ghosting

After some discussions in Chinese with the folks at sonydslr.com.tw, they produced some 100% crops from the A33, some of which had the ghosting from the semi-reflective mirror, while some didn't. According to the photo-taker, there was no ghosting with these images even under 100% inspection: View: original size View: original size View: original size View: original size He commented that he never saw these ghosts in any daylight shots. The following shots had ghosts (100% crops follow each image): View: original size View: original size View: original size View: original size View: original size View: original size so the problem can definitely be seen in the A33 as well, but seems to be even less noticeable than on the A55. For those who can read Chinese, here is the original thread: http://www.sonydslr.com.tw/alpha/viewtopic.php?f=9&t=41257&start=75 From my discussions with them, it seems they are just regular forum folks like you and I who got to try out these cameras by merit of being high-ranking members of a prominent Sony-exclusive camera forum. After I presented our theory of what's going on at the mirror they were quite open to the possibility that this is a real (albeit small) flaw of these cameras.

View: original size This image came up in the previous thread, IIRC with people pointing to the ghosts on lights to the right. But I read the Chinese description and the photo-taker says this was taken using 6-shot Multi-shot NR mode on a moving vehicle , so this image can definitely be disregarded as an example of ghosting. We can instead marvel at the auto image-alignment prowness of this camera

Definitely there is a some kind of problem with bright objects.

Well the person who shot these images didn't buy the ghost theory you can read that here in english http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&eotf=1&u=http%3A%2F%2Fwww.sonydslr.com.tw%2Falpha%2Fviewtopic.php%3Ff%3D9%26t%3D41257%26sid%3D53abf794c501ee39e8f157d068cb03c2%26start%3D90&sl=auto&tl=en And you can see the same effect in every other camera like the below A550 View: original size ;. View: original size

from A550 View: original size

You will only see it in water reflections in normal cameras. The lights under that moon shot may have also had water reflections, but there are plenty of unambiguous examples (most of all this test shot) in this and the previous thread. View: original size
aim120 wrote: from A550 View: original size

aim120 wrote: Well the person who shot these images didn't buy the ghost theory you can read that here in english http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&eotf=1&u=http%3A%2F%2Fwww.sonydslr.com.tw%2Falpha%2Fviewtopic.php%3Ff%3D9%26t%3D41257%26sid%3D53abf794c501ee39e8f157d068cb03c2%26start%3D90&sl=auto&tl=en
Unlike google, I can actually read and write Chinese, and I have explained the phenomenon to them and they have accepted it is real. On page 6, he didn't buy the "ghost theory" (there was nothing to buy, since they were not aware of the possibility of double-reflection in the mirror), and yes, he theorized that the moon was obscured for part of the shot, creating the double image. I pointed out the double images of the lights under the horizon: View: original size "that may be reflection from the water, but this test shot tells the story" View: original size to which he responded ":eek: for reference, the shot was taken using the 16-80mm ZA. Now we can have a long discussion on whether this was caused by lens characteristics or some bug with the camera body, or some other factor... unfortunately, I have returned the A55 so there's no way I can continue testing for this anymore View: original size " The post that followed was me explaining the double reflection theory to them. His next post was "if that's true, then that's another flaw with this camera View: original size " His next post, first post of page 7 which you linked to, says "yep, these ghosts appear under overexposed light sources in night scenes. But you won't notice them unless you go looking for them at 1:1 for every shot" (he used the term "flare" to refer to the phenomenon I explained to him in the previous page, which is technically correct. Lens flare, after all, also result from multiple reflections between lens elements.

Time for Dpreview.com to write a "ghost story". I don't know what to believe from all these samples. Long exposure, multi exposure, lens flare etc. The last bridge shoot also has some small "lights" to the right sometimes, not just under always. We need some clear talkers here. First, is it a real issue with A33/A55? Second, how big an issue and when to be aware of it? Some of the night shoots even looks cooler with some added "sparkles"

This is an issue which could be out to bed by properly controlled testing using bright lights in a dark studio. This issue will test the sincerity & integrity of Review Sites & if none of them tackle this issue then we can draw our own conclusions -- Keith-C

Imaging Resource did it here: When additional surfaces are added to an optical path, especially ones not perpendicular with the image plane, there is always a chance that light will travel an unintended path. In the case of the A55V and A33, it appears that the rear surface of the translucent mirror film can reflect light back to the front surface of the film, which reflects it back to the rear, causing a "ghost" reflection or multiple reflections to appear in the final image under certain conditions. The above left crop shows this phenomenon in one of our Sony A55V flash test shots, where a very strong reflection from the plastic edging of our flash-range/uniformity target also has a small ghost image in the form of a horizontal white line below it. (Thanks to IR reader Erick E for pointing this out in one of our flash range images!) The crop on the right is from a similar flash shot, taken with the same lens, but using the Sony A560 which is a traditional SLR without a translucent mirror in the optical path. As you can see, under nearly identical conditions (the A560's flash is a bit stronger), no ghosting is present. http://www.imaging-resource.com/PRODS/AA55/AA55A4.HTM

Thanks! The best part was the last section. Here it is, from http://www.imaging-resource.com/PRODS/AA55/AA55A4.HTM "We only found ghosting in a small subset of our test images, as it seems to require fairly specific conditions to be noticeable. Ghosts only appeare in a couple of our flash shots similar to the one shown above, as it appears that camera/subject angle needed to be just right, to reflect enough light from the flash head back into the lens to show the ghost. Dave also saw this phenomenon in some night shots he has taken with the Sony A55V, which we hope to share some crops from shortly. From Dave's experience, the ghosting seems to require a very concentrated light source, sharply focused, and ideally a relatively small light source with darker areas surrounding it. The ghosting did not appear with larger, less sharply-defined light sources, or when light spilled from the source on surrounding areas (thereby making the lighting broader and more diffuse). Under conditions of really severe light overloads ghosts seem to be masked by lens flare. Based on our tests, we can confirm that this is a genuine phenomena with the Sony A33/55. Should you be concerned about it? Perhaps. Some people would certainly find it objectionable, especially if they did a lot of night photography of things like cityscapes. Personally, it wouldn't deter us from buying a Sony A55V, because we don't do much cityscape-type photography: Our night shots tend to be ones where the subjects are people or areas lit by nearby light sources. With these sorts of shots, ghosting of the type shown above wouldn't be an issue. Bottom line, you'll need to decide for yourself if this would impact your personal style of shooting enough to outweigh the benefits of the Sony A55's pellicle mirror design."

thanks for pointing this out and the link. This flaw, while not insignificant, does not shadow over the greatness of A55 and A33. They are perhaps among the best for the market they target.

... that these two new SLTs have propensity to ghost under extreme highlight conditions (such as a night city scapes). This is not a myth or theory, it's a propensity. So I'd say if your taking a lot of urban night shots, this is not the best camera to buy. Whoever specializes in urban night shots, please raise your hand. Now, for the rest of us, this unique camera could be very promising. Cheers, Seth

Well two of the DPR sample images that showed ghosting were normal daylight shots with shiny chrome elements. I guess if it only pops up sometimes in conditions without lights it's excusable. The double moon howerever... View: original size (from http://www.sonydslr.com.tw/alpha/viewtopic.php?f=9&t=41257&start=75 linked in original post) This ghost issue, and the behaviour of the EVF at 6 & 10 fps (it freezes up) hurt these cameras. They should have sealed the sensor behind the mirror too, and had a good system for exchanging them. Thanks to Joe for doing the research.

The double moon, according to the person who posted the photograph, was a result of a 122 second exposure.

The double moon, according to the person who posted the photograph, was a result of a 122 second exposure.
Yeah the guy reckons the clouds mostly obscured the moon, so it may be the case. Personally I don't think so. For interests' sake the moon will move its own width in about 2 mins.

Hynee wrote: Well two of the DPR sample images that showed ghosting were normal daylight shots with shiny chrome elements. I guess if it only pops up sometimes in conditions without lights it's excusable. The double moon howerever...
... would also count as a nightscape.

Joe0Bloggs wrote: For those who can read Chinese, here is the original thread: http://www.sonydslr.com.tw/alpha/viewtopic.php?f=9&t=41257&start=75
Hmm Google translate says "Indeed, the theme of the night had taken exposure light source below there will be the existence of such flare, Unless analities to each photo to view a 1:1 go out, or really have not to notice"/ http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&u=http%3A%2F%2Fwww.sonydslr.com.tw%2Falpha%2Fviewtopic.php%3Ff%3D9%26t%3D41257%26sid%3D53abf794c501ee39e8f157d068cb03c2%26start%3D90&sl=auto&tl=en Does this mean something like "Only anal retentive [pixel peepers] who view these at 1:1 would really notice" ? - if so, that's the best description I've read of some of what has been going on in these "ghosting" threads.
  • C

CFynn wrote:
Joe0Bloggs wrote: For those who can read Chinese, here is the original thread: http://www.sonydslr.com.tw/alpha/viewtopic.php?f=9&t=41257&start=75
Hmm Google translate says "Indeed, the theme of the night had taken exposure light source below there will be the existence of such flare, Unless analities to each photo to view a 1:1 go out, or really have not to notice"/ http://translate.google.com/translate?js=y&prev=_t&hl=en&ie=UTF-8&layout=1&u=http%3A%2F%2Fwww.sonydslr.com.tw%2Falpha%2Fviewtopic.php%3Ff%3D9%26t%3D41257%26sid%3D53abf794c501ee39e8f157d068cb03c2%26start%3D90&sl=auto&tl=en Does this mean something like "Only anal retentive [pixel peepers] who view these at 1:1 would really notice" ? - if so, that's the best description I've read of some of what has been going on in these "ghosting" threads.
Well since you ask - No it probably doesn't but why do you & some others on these forums always see these issues in terms of Anal matters ? -- Keith-C

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