very bad purple fringing with 50D how about 7D?

<p>Okay, some of you might be aware, but the 50D has a serious problem! I would like to pop a question to all you happy 7D owners. The question concerns non repearable purple fringing from 50D. I do waterports photography and found the 50D to be absolute rubbish in this case. In very backlit situations the 50D would color the water in the picture entirely purple. You do not believe? well I will post a picture to proof what I am saying. In fact 15% of all my watersport photographs are distroyed by this phenomenon. I have never seen this problem with the previously owned 20D! And so in complete dispair I have sold the 50D and bought one of the last remaining 40D's and guess what.... everything is back to perfect again. So this step up in 50% more pixels has some serious downsides, if you ask me. So you can guess my question, does the 7D display the same problem? I Really would like to buy that camera but offcourse only if its usefull. And oh yes, if I look at the 50D pictures and compare them to my 40D pictures, I find the 50D so soft that I do not see any gain in I Q in the real world over my 40D's. Maybe I am crazy but printed big size the 40D looks sharper, huhh how is that possible. And so for me the 5D markii is back in the picture.. here you can see an example, I know its not art but you'll see what I mean <a rel="nofollow" href="http://www.photo.net/photodb/member-photos?user_id=5738984">http://www.photo.net/photodb/member-photos?user_id=5738984</a></p><div></div>

<p> </p>

<p>Try hue/saturation > magentas > saturation -100<br>

I would buy a camera with great care and consideration, they will usually stay with you a long time. If there isn't anything 'major' you 'need' just be happy with what you have. Regarding print sizes... well, I sore a fantastic print from a 5MP camera earlier in the week, in a gallery. It must have been atleast A3 size.<br>

Take care, Richard</p>

<p>Hard to see with this little information what is going on. The area in question is the brightest in the image. Are your highlights blown? Lots of things other than the camera body can contribute to purple fringing. I have been shooting with a 50D for 6 months and haven't had any substantial problem with purple fringing. then again, off the top of my head, my water shots have been in brighter light.</p>

<p>Were you using the same lens in all pictures? This is usually a lens issue. But I suppose cramming too many pixels too close together could have a price. </p>

<p>Do you use a polarizer? For the type of shooting you do I would always carry one to control the extreme highlights which is what causes CAs in the first place.</p>

<p>This is essentially an exposure problem, and it does not affect only your camera. The backlit water is extremely bright, and the brightest portions are small spots of light reflected directly from the sun. Unless you drop the exposure level so that these sources don't blow out you will get this effect. Of course, this creates another problem if you are trying to retain any detail in the shadowed areas of your intensely backlit subject.</p>

<p>You can often reduce (or sometimes eliminate) this in post using a variety of techniques. The recovery slider in ACR (or similar in other RAW converters) can sometimes recover some of the blown highlights. In ACR you can also use the defringe setting diminish this. The tools for adjusting CA can also help.</p>

<p>Once you are in Photoshop in may be possible to do some work with masks and selections and saturation to help out. Finally, do check to see if the effect is really visible in the final print - not everything visible at 100% on the screen will have an effect on the final result.</p>

<p>None of this is to say that this isn't an issue, but I find that it is not a factor with one particular camera.</p>

<p>Dan</p>

<p>Purple fringing is a lens problem. What lens are you using?</p>

<p>"Purple fringing" is not purely a lens problem. It can happen with some very fine lenses in challenging exposure situations, particularly when very bright (e.g. - blown out) areas or highlights are juxtaposed with darker areas.</p>

<p>Dan</p>

<p>That's easy to fix</p><div></div>

<p>I've never seen purple fringing from my 50D. I've shot a lot of strongly backlit subjects with my 7D and even the blown HLs aren't purple.</p>

<p>What lens were you using? I've seen this effect with cheaper lenses, but never with L's.</p>

<p>The 35L and 85L will produce purple fringing under certain conditions.</p>

<p>Len,</p>

<p>They are two of the very few Canon L lenses that do not have Flourite elements, that is they are not Apochromatic and corrected for three different light wavelengths.</p>

<p>Nice observation, Scott.</p>

<p>Another look with magenta desaturation.</p><div></div>

<p>Lenses may cause purple fringing but camera bodies and sensors do not. I just checked several water and backlit images from my 50D and there is no purple fringing at all, nada, zip, none.<br>

My 40D does not have purple fringing when shooting backlit subjects either.</p>

 

<p>I don't think most people here understand your question, Douwe. You have discovered a clear difference between cameras. This has nothing to do with how to repair the photos. I think you are asking whether 7D owners have experienced this anomaly. In my experience, some lenses work better with some cameras, so it might be helpful (or confusing) to identify which lens you are using. </p>

<p>This guy claims he sold his 50d and bought the 40 so why is he whinning about the 50d now. I smell troll here. He posts one crappy picture and were all supposed to beiieve he's on the level yeah right</p>

<p>Wikipedia, for what it is worth, claims the sensor may be part of the problem in purple fringing. http://en.wikipedia.org/wiki/Chromatic_aberration#Photography and http://en.wikipedia.org/wiki/Purple_fringing .<br>

That fits my experience with Nikon cameras. I had it quite a lot with a D40X but hardly ever with a D300 using exactly the same lens.<br>

With a Canon 20D and a 135mm f/2.0 Canon lens I managed to get chromatic aberration with two colours at the same time. I assume newer Canon cameras would not have that problem. See samples here: http://photophindings.blogspot.com/2009/04/chromatic-aberration.html</p>

<p>I'm sure this guy has better things to do then waste his time here it's obvious he was a problem and he's not the only one to experience this with a 50d. So I have heard purple fringing is a lens problem like CA's but a sensor can exaggerate this problem especially when it has got tightly packed pixels<br>

<a href="http://www.fredmiranda.com/forum/topic/831605">http://www.fredmiranda.com/forum/topic/831605</a><br>

<a href="http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/Blooming_01.htm">http://www.dpreview.com/learn/?/Glossary/Digital_Imaging/Blooming_01.htm</a></p>

<p>I took this yesterday, I was testing out a 5dMK2 and a 7d, I know it's not water but it's the best high contrast shot I could get in a shop. They are 100% crops both shot at 160th,5.6,iso 640, on a canon 24-70 2.8 L.<br>

<a href="http://www.photo.net/photodb/folder?folder_id=942184">http://www.photo.net/photodb/folder?folder_id=942184</a></p>

<p>Lets stick to the question, I posted a question wich was, does the 7D have the same problem as the 50D?<br>

Offcourse they are blown highlights, but believe me or not the lenses I use are the same (canon L) I allways use The 20D and the 40D clearly do not! have this problem... Offcourse you can repair it in p.s., I have succeeded doing just that. But that is not what you want is it? In the mean time I found this review and what do you know... his findings are the same as mine http://www.luminous-landscape.com/reviews/cameras/50d.shtml<br>

And thank you people that take this question serious, well appreciated, I am not trying to put anybody's camera down, I am just looking for an answer.</p>

<p>The OP has a legitimate question. My D80 has CA problems, though not as bad. Using the same lens on a D300 almost eliminates the problem. Of course the D300 has built in CA correction, which manages to make shots useable, which with the D80 were not salvageable even using CA corrections in CS2. It is largely a lens issue, but the camera can make a huge difference in my case.</p>

<p>Here is the answer to your question. No canon cameras do not have purple finging problems. and yes you do have issues. you have been bashing this brand for almost a year now under various names. Get a life</p>

<blockquote>

<p>Try hue/saturation > magentas > saturation -100</p>

</blockquote>

<p>I would strongly advise against this approach. The saturation adjustment in Photoshop should never be used on a narrow hue range with that much strength, as there is no blending or fall off, but rather a completely abrupt, harsh transition. If these are the only magenta tones in the entire image, the effect will be less destructive, but in general this type of saturation adjustment is almost always quite destructive and is usually a very bad idea.</p>

<p>Douwe,</p>

<p>Your point was "The question concerns non repearable (sic) purple fringing from 50D". You have not shown an image that has that so there is not an issue as far as I can see.</p>

<p>I was on topic, I took your point seriously and, from the image you posted, you do not have a problem. Does anybody want to do PP to every shot? Not really, but are we prepared to work on worthwhile images, and, how many of them require no post? None of mine that is for sure, and I come from a slide background.</p>

<p>The main thing I get from these threads is that there seems to be a huge difference in peoples cameras and the quality of the images they get out of them, all across the camera models. Some people swear there is a major issue and others just can't replicate it. I recently did tests on my camera to see if it has an issue that a knowledgeable pro who uses the same model says his body exhibits, mine does not. There seems to be a huge variance in how well people take the images that exhibit problems but even when you level the playing field with abilities or methodology different bodies of the same model show different results.</p>

<p>It seems to me some people just don't know what they are doing and there are just as many quality control issues at Canon. It seems as simple as that, just don't ask me to work out what to do about it! Very careful examination and hands on testing with money back warranties seems the only way to get a good body, secondhand or new. Sending things back to Canon seems a pointless waste of time half the time, it seems the body is almost mostly within spec. Very very frustrating if you get a bad one.</p>