7D focusing question??

[Admin US West]

It was invigorating to get your prompt response
Having photographic experience since 1964(that was when Kodak Type3 ortho film was around) look it up
I tried 1)Center pin focus
2)Mirror lock
3)Shutter 2000+
4)Max light
5)Weighted down Tripod out of the wind( we don't have earth tremors here)
6)Lowest ISO
7)External shutter release
8)Manual and auto focus
I felt the problem not auto focus or the non Pro lenses. Through the eye piece the image is outstanding.
Help me if I am wrong The problem is between capturing and storing the info. May be a fine adjustment.
I am pleased to hear that the density on a sensor is greater than a transparency. That is a great plus for HDR
I on my 7D Color gradation delicate.... shadow to three quarter tone smooth.... quarter tone to hi-lite...catch light snappy.
a bit disappointed with the soft shades around the molding of face and skin tones. any help. besides portraiture mode.
Please give your input I enjoyed your constructive criticism Now your superior advice.
A new body for me end, mid 2012? The new 5D or Eos1D When the new models come out.
low light wild life..........sports including fast martial art movements.
I am re inspired with MY 7D. maybe it can sleep on the pillow with me again and not go to the display cabinet
Will let you know what results when it gets back
thanx
pax

Are you able to post some images so we can see what the issues are? Unfortunately, its is not easy for most of us to see well enough thru the eyepiece to determine if the focus is right on.

As far as Digital being better than slide film, its not that simple. Digital has many strong points, and so does film. There is always a tradeoff of some sort. Which ever looks better to you is the correct choice for you, but I might like something else better. Its not a matter of right or wrong, just of personal choice.


Did you try manual focusing using liveview? Using the same settings, while on a tripod, turn on live view, and use the magnification control to view the image at 5X or even 10X. Then, see if you can manually focus the image to be sharper. If you can make a improvement, then by adjusting the AF microadjust forward or backwards, you can improve focus for that distance to subject, and likely at all distances. When using live view, you are seeing the image right off the camera sensor, while thru the eyepiece, it can be focused differently, but that is unusual. Camera makers sometimes use small shims under or above the focus screen to correct this.

As far as skin tones, that can be caused by the lightinng, cameras are often not as good at guessing colors as we would like. A camera photosite only sees black and white, so there is a complex algorythm in the processor that constructs the colors to be like the original, or sometimes not.

If the photo was taken using raw, then there is leeway for quite a bit of adjustment in processing to get the look you want. Some processing software will remember this and import your images with the same adjustments every time, but you do have to turn that setting on.

 

[justsomedude]

I dont know what happened since we last posted, however if you need to send equipment in to make sure it's fully up to par with Canon, great... however after that point, it may not be an equipment problem but a user problem if it still exists. ...As i've said in other posts, if you or anyone have questions, feel free to ask and or email me before giving up on a camera which may or may not be the problem.

Thanks for the detailed response Awin. If my post seemed to be exuding frustration, it's because it was. I've just seen enough of the "you-just-don't-understand-the-ultra-advanced-7D-to-use-it-properly" comments strewn about the internet on this issue, and I have little to no patience for them; regardless of how "helpful" the poster's intent may be. With respect to additional details, I've sent the body back twice now. The first service resulted in no change, while the second trip proved to establish consistent and tack sharp focus with my 2 kit lenses (28-135 and 18-55) and my L series 70-200 f/2.8 II.

Curiously, the problems remain with my 50mm. MF adjustments fix the problem, but, and this is where it gets really weird, for only a short period of time. After a random time period (sometimes a few minutes, a few hours, or even a few days), the focus goes bonkers again. I explained this to the Canon service tech., and he was baffled. Now, both my 50mm and the 7D are at Canon Irvine (at this very moment) to try to get to the bottom of this.

The saddest situation, however, is my Tokina 11-16mm. No type of MF adjustments can fix this baby. When paired with the 7D it is just a total nightmare. Focus is sometimes spot on, and then sometimes totally out the window. There appears to be no rhyme or reason as to if/when/where it will focus, and it's driven me to madness. Selected points will "lock" focus with 100% consistency, it's just that the resultant photo is rarely actually "focused" (a total mish-mash of front/back focus). After a visit to THK service in California, the lens returned with a note saying "no work required - meets all manufacturer specifications." I even called and got to speak with a Tokina tech. directly who said the 11-16mm should have no issue pairing with the 7D. I've sent this letter/info on to Canon with its latest service, but not the lens, since I'm sure they won't touch non-Canon lenses. This is the same 11-16 that performed flawlessly on my 40D. So, to me, this seems very very bizarre.

Anyway - that's where I'm at. 3 of 5 lenses are now great. 50mm is so-so, but unreliable enough to be useless on paid gigs. Tokina 11-16mm is totally useless, and will probably be sold if there are no improvements after the latest 7D service visit.

However, I am more hopeful now than I have been regarding my future with this body. A recent shoot at a nearby racetrack with my 70-200 has really boosted my spirits. Even at 160th with AIservo and panning, she grabbed focus superbly. >> http://www.akphotodenver.com/client/mra711/download/7Dhope.jpg

Hopefully, all gets corrected in time. I'm not bailing on Canon, or this body, just yet. I'll keep you posted.

 

[maharzan]

Whatever great 7D is on paper, it shouldn't be so tedious to get that sharp focus while other cameras seems to do it in instant. Afterall, so many people in so many forums cannot be wrong, you know. If they get sharp pictures easily on 40D,Xsi etc, it shouldn't be so hard on the great 7D. I just feel something is wrong. I never had any experience on other DSLRs but even cameras I used back then (analog) was easy to focus, even if it was manual. I just hate having to spend 30 secs trying to get a sharp focus or 4-5 shots to get 1 good shot. With technology, things should be easier and faster not the other way around. I am definitely going to consider another body in near future. Life should be easy you know.

 

[awinphoto]

justmedude, thanks for your response regarding your camera situation. While I have used the 28-135 and have my preconceived notions on that lens, I'm glad the camera was repaired to work well with that lens. Regarding the 50mm... which 50mm is it? The 50mm 1.2 was very shaky on my camera with a low keeper rate when I tested it through CPS, however on my 1.4, while plagued with the crappy micro motor, is more consistent. The 1.8, while I honestly cant say I've used that lens, it is what it is... The 1.2 i've heard lots of complaints about the focus issue so i'm sure it's the lens, however it cannot confirm or deny if it is a lens defect or not.

Regarding the 11-16 tokina... dont get me wrong, i used to love tokina's... That was one of my favorite lenses out of college because they offered lenses I could afford on ebay with a small budget, especially on the wide end. I haven't played with the lens you got so i cant speak for it, however you said you had great photos with it with the 40D and now you cant with the 7D? While I doubt canon would be willing to adjust the tokina to meet the cameras sensor for optimum focus, that's a tough one. If MA doesn't work for you... well lets put a hypothetical out there... is the OOF consistant... Lets say you shot a similar scene over and over and over with that lens, is the area in focus (that you were intending to be OOF) is that scene consistantly in focus meaning the AF is working properly however with the combination of the sensor and the lens, it is outside the range of MA allotment? Or is it sometimes front focusing, sometimes backfocusing, just all over the place? I guess that would be the first place I'd check is the see the consistency of the focus issue. In that case, i would have to say perhaps there is a possible fix... If not and it's all over the place, I would have to say it's a compatibility issue.

I have heard hints through the intrawebs that some lenses have certain issues with compatibility with newer bodies, for evidence of that see the issues about some of the older canon lenses and tamron lenses not seeing the correct ID's of the lenses in the metadata... Without being there and seeing the situation myself it's pure speculation on my part so dont get me wrong.

I dont mean to come off on a "its the operators problem, stupid" attitude, sometimes we all get lemon equipment, however I also came from humble beginnings during and out of college with little money to start my gear, using my first credit card to buy my 10D and shopping for lenses on ebay because that's all i had to start with. I had lenses and equipment that had issues and I couldn't afford to fix them so i had to learn to overcome it... Sometimes I feel people give up too quickly without putting in the time to learn to overcome obstacles. Then when people start blanket stating their in the heat emotions on the internet about equipment that may or may not be true and or thought out, I think it does the internet community a dis-service in that regards. I hope to hear back from you regarding your issues.

 

[awinphoto]

Whatever great 7D is on paper, it shouldn't be so tedious to get that sharp focus while other cameras seems to do it in instant. Afterall, so many people in so many forums cannot be wrong, you know. If they get sharp pictures easily on 40D,Xsi etc, it shouldn't be so hard on the great 7D. I just feel something is wrong. I never had any experience on other DSLRs but even cameras I used back then (analog) was easy to focus, even if it was manual. I just hate having to spend 30 secs trying to get a sharp focus or 4-5 shots to get 1 good shot. With technology, things should be easier and faster not the other way around. I am definitely going to consider another body in near future. Life should be easy you know.

I understand where your coming from, however hindsight is always 20/20 in regards to photography and camera gear. With the 7D it magnifies so much more due to all the extra MP that any and every little flaw in focus and or lens will be that much more magnified. I had the pleasure a few months ago to run into a CF card with pictures I didn't delete yet which were from my old 30D and sigma tele lens... During the time when I had that camera, it seemed to constantly pop out amazing photos one after another, however looking back at that card and photos, now with my increased expectations, I would be ashamed to show any of those photos on my portfolio due to stuff I may not have noticed during my time using that camera. It doesn't mean the camera was bad, but my increased expectations of me, of my current gear, of my skill set has changed. Comparing different, especially older generations of cameras is apples to oranges due to that same reason. 7D is a beast of a camera, but on the same note, any slight issue will be that much more magnified.

 

[bvukich]

I understand where your coming from, however hindsight is always 20/20 in regards to photography and camera gear. With the 7D it magnifies so much more due to all the extra MP that any and every little flaw in focus and or lens will be that much more magnified. I had the pleasure a few months ago to run into a CF card with pictures I didn't delete yet which were from my old 30D and sigma tele lens... During the time when I had that camera, it seemed to constantly pop out amazing photos one after another, however looking back at that card and photos, now with my increased expectations, I would be ashamed to show any of those photos on my portfolio due to stuff I may not have noticed during my time using that camera. It doesn't mean the camera was bad, but my increased expectations of me, of my current gear, of my skill set has changed. Comparing different, especially older generations of cameras is apples to oranges due to that same reason. 7D is a beast of a camera, but on the same note, any slight issue will be that much more magnified.

Nail, head, hit.

 

[maharzan]

Do you guys have sample photos so I can check how sharp you guys can get and what you did to take those photos? That might help.

 

[justsomedude]

Regarding the 11-16 tokina... dont get me wrong, i used to love tokina's... That was one of my favorite lenses out of college because they offered lenses I could afford on ebay with a small budget, especially on the wide end. I haven't played with the lens you got so i cant speak for it, however you said you had great photos with it with the 40D and now you cant with the 7D? While I doubt canon would be willing to adjust the tokina to meet the cameras sensor for optimum focus, that's a tough one. If MA doesn't work for you... well lets put a hypothetical out there... is the OOF consistant... Lets say you shot a similar scene over and over and over with that lens, is the area in focus (that you were intending to be OOF) is that scene consistantly in focus meaning the AF is working properly however with the combination of the sensor and the lens, it is outside the range of MA allotment? Or is it sometimes front focusing, sometimes backfocusing, just all over the place? I guess that would be the first place I'd check is the see the consistency of the focus issue. In that case, i would have to say perhaps there is a possible fix... If not and it's all over the place, I would have to say it's a compatibility issue.

I hope to hear back from you regarding your issues.

Awin, thanks again for the detailed reply - your patience and help is MUCH appreciated.

So, some more detail... the 50mm is the cheapie 1.8 (yes, I'm on a budget). But even with that said, I really wouldn't expect such glaring inconsistencies in sequential photos. Check the following full resolution samples (and note, all three are sequence photos, with a good pause between shots for reacquiring focus)...

http://www.akphotodenver.com/images/7D

These are all handheld images, One Shot focus, single shot "sequence" mode, with manually selected single point of focus (center point). On the microwave images, the vertical black/white edge of the clock/panel was used as contrast line for focusing. One could argue the slow-shutter speed was the problem, but the exact same issue appeared moments later when I took photos of a pay phone outside my window at blazing fast shutter speeds. On the pay phone images, the text of the word "phone" in the pay phone booth was the area used for focus. The lens is wide open on all shots where (yes, I know) the 1.8 performs poorest with "sharpness." Still, this level of inconsistency seems outside the realm of "normal performance" for me. Heck, if this IS indeed "normal" for the cheapie 1.8, please let me know, and maybe I just need to drop the dollar on the 1.4. Thoughts? Metadata is unedited and available if you choose to download the images. Also - these exact images were sent to Canon on CD with the current service visit.

Now, on to the Tokina. The performance actually IS somewhat front-focus consistent. At 0-MF, the lens bumps infinity up a little bit, throwing everything beyond 4'-5' out of focus. Everything within that distance is tack sharp. Manual focus at infinity allows proper focus to be achieved. Furthermore, adjusting MF to +20 seems to help... somewhat. Performance is vastly improved with center-point focus, but the outer points are still bonkers. Infinity focus is achieved for that center point (somewhat) consistently, which leads me to believe the Tokina is possibly outside the MF range. Is this fixable? Yet, the issue with the outer points leads me to believe a possible lens ID issue might also be at play. Tokina samples are available at the same link above.

 

[motorhead]

Justsomedude,

I've carefully examined all your examples and apart from random sharpness variations which I'd suggest are caused by hand holding the camera, they all seem reasonable. Certainly I have worse examples shot using Canon "L" glass handheld. It does not take much to just take that edge off. The only one I'd have reshot immediately would be the gym shot.

Remember none of us stand still when we shoot. We might think we do, but in reality we all sway slightly.

To fully test for front/back focusing issues try shooting using a tripod, so that camera movement is completely ruled out as a possible cause. Apart from my motorsport images I use a tripod for everything, and for the bikes/cars I use a monopod! I've had too many otherwise good compositions lost due to camera movement.

 

[justsomedude]

Justsomedude,

I've carefully examined all your examples and apart from random sharpness variations which I'd suggest are caused by hand holding the camera, they all seem reasonable. Certainly I have worse examples shot using Canon "L" glass handheld. It does not take much to just take that edge off. The only one I'd have reshot immediately would be the gym shot.

Thanks for the critique, motorhead - it is much appreciated. Although how can camera shake be entering in as a factor at 1/6400 of a second shutter speed (as was used in the pay phone photos)? Also, every Tokina image was with a tripod - and the interior ones all used a remote shutter release cable. You really would not have re-shot this one - where the focus point was the microwave clock? > http://www.akphotodenver.com/images/7D/Tokina_no_focus-8280.jpg To me that seems unacceptably blurred. Sh*t, I can't even read the time on the clock. But maybe my expectations of sharpness are too high?

The bulk of my frustration is mainly coming from the change in performance from 40D to the 7D. I even went back to my older Lightroom imports and found that I had far better consistency with focus shot-to-shot on the 40D with the same lenses than the 7D. Perhaps I'm just seeing more "faults" due to the pixel density of the 7D? If that's the case, I guess I can learn to live with it.

 

[Loswr]

You really would not have re-shot this one - where the focus point was the microwave clock? > http://www.akphotodenver.com/images/7D/Tokina_no_focus-8280.jpg To me that seems unacceptably blurred. Sh*t, I can't even read the time on the clock. But maybe my expectations of sharpness are too high?

I sure would have... The shot linked above looks severely front-focused. The cabinetry to the right of the dishwasher and the left edge of the fridge actually look in focus, and when I look at the EXIF, a Subject Distance of 1.13 is reported (in meters, I believe), consistent with extreme front focus. That's even more evident in shot -8283, where the clock is unreadable, but the words on the ice maker in the left door of the fridge are legible. THe AFMA of +20 is also consietent, and as you say, not enough - the lens and body need to be calibrated together (which Canon won't do for a 3rd party lens, and Tokina might not be able to adjust the lens enough (and I don't think they'd touch the body).

 

[awinphoto]

Awin, thanks again for the detailed reply - your patience and help is MUCH appreciated.

So, some more detail... the 50mm is the cheapie 1.8 (yes, I'm on a budget). But even with that said, I really wouldn't expect such glaring inconsistencies in sequential photos. Check the following full resolution samples (and note, all three are sequence photos, with a good pause between shots for reacquiring focus)...

http://www.akphotodenver.com/images/7D

justsomedude,

thanks for sharing your photos... as neuro mentioned, it does appear to be severely front focused however i'm not sure about your options regarding the tokina lens. If there is any consolation prize, you can live with it, call it art, and charge 3x the price =). I used to have quite a selection of sigma lenses once I started upgrading my gear from the 10D to 30D... Once I moved to the 50D I joined CPS and still am with CPS. Ever since then I only have 1 sigma lens left (10-20mm) which I will keep until I make the leap into full frame completely. The reason I did that was in the long run, if i needed anything fixed within canon, it's just one company to deal with than sigma (and or tokina, tamron, etc)... If you have a full MA and you still cant get + or - 20 something doesn't seem right. IF and that's a big IF it is the case and there is a severe incompatibility, I would ask if you still have your 40D and if it still works great with the 40D. If you got rid of the 40D, just asking, but is there a chance it was dropped or something happened to maybe loosen an element to cause it to be so far off? Just trying to rule that situation out.

Regarding the 50mm 1.8, I cant say I've used that lens so I cant speak for that lens... From what reviews i read, it was a good bang for your buck lens with the 1.4 and 1.2 being just a tad sharper overall which speaks a lot for a lens averaging just about $100. The 1.4 is a good lens, however in another forum post, i gave my 2 cents on that lens... It's sharp from 1.8 and up... however the crappy micro usm causes me to almost wait a second or two to allow the lens to fully catch up to me shooting which is ok for portraits, so-so for event photography, however for fast shooting, is a nightmare. It's a lens issue for that lens. Also the focus mech for the 1.2 I tested left me wanting a lot (A LOT) more. I dont know if the 1.8 issue is because you're shooting to fast (not fully waiting on the focus beep) like my 1.4 has or if it is a MA issue. That's one of those hands on things I couldn't tell ya unless i'm there. As far as upgrading, i would wait and see if and when the 1.4 gets replaced. Then I'd buy one once they are out and reviews come back glowing.

You mentioned you sent in your camera again... I hope you sent all your lenses in because I would hate for the adjustments they made last time to make the 28-135 and the other lens to get screwed up just to make the 50mm up to par. As always, if you have any more questions or concerns, feel free to email me or post a message for me.

 

[awinphoto]

justsomedude... Just thinking about your tokina situation... The general rule of thumb has been, with 3rd party lenses, to go to camera stores and test several versions of the lens to get the sharpest because QC and repairs would be so troublesome, however in the terms of camera upgrade that gets thrown out of the water since it's pairing with a new camera. When I moved to the 7D, my sigma 135-400mm lens, while having sharp images, especially on continuous focus, just couldn't keep up with the 7D... it was always half a second (or longer) behind and couldn't catch up when I needed the shot, it wasn't there... So it gave me the excuse to upgrade to the 70-200 L... it doesn't have the extra 200mm which i only used once in a blue moon to be honest with myself but was faster, lighter, and an L lens in quality, construction and optics. I understand the tokina is a nice lens, and given the product production, perhaps that could give you an excuse for another lens? If not anything but selling that lens for full market price on craigslist (there's always suckers) and buying a brand new lens in which you can test at the camera store. I know that's not the suggestion you're hoping for but for what it's worth. If not, try sending to a local camera store that does repairs... see what they offer since they aren't necessarily brand exclusive. Maybe it could be something simple we aren't noticing.

 

[justsomedude]

justsomedude... Just thinking about your tokina situation... The general rule of thumb has been, with 3rd party lenses, to go to camera stores and test several versions of the lens to get the sharpest because QC and repairs would be so troublesome, however in the terms of camera upgrade that gets thrown out of the water since it's pairing with a new camera.

Awin and Neuro - thanks for the responses. I don't think I'm going to kill myself over the Tokina clarity, it's just not worth it. Once I get the 7D back and (hopefully) all my lenses check out OK, I'll give the Tokina one more visit to THK service. If that doesn't fix it, off to the auction block she goes... maybe for a canon 17-55 EF-S, we'll see.

But one last item of concern: what are your thoughts on the vertical "light" band I've been finding in some of my images (I forgot to mention it before)?

http://www.akphotodenver.com/images/7D/band1.tif (warning - 51 MB file!)
http://www.akphotodenver.com/images/7D/band2.tif (warning - 51 MB file!)

This is almost more troublesome than the damn focus issues!

 

[awinphoto]

justsomedude... Just thinking about your tokina situation... The general rule of thumb has been, with 3rd party lenses, to go to camera stores and test several versions of the lens to get the sharpest because QC and repairs would be so troublesome, however in the terms of camera upgrade that gets thrown out of the water since it's pairing with a new camera.

Awin and Neuro - thanks for the responses. I don't think I'm going to kill myself over the Tokina clarity, it's just not worth it. Once I get the 7D back and (hopefully) all my lenses check out OK, I'll give the Tokina one more visit to THK service. If that doesn't fix it, off to the auction block she goes... maybe for a canon 17-55 EF-S, we'll see.

But one last item of concern: what are your thoughts on the vertical "light" band I've been finding in some of my images (I forgot to mention it before)?

http://www.akphotodenver.com/images/7D/band1.tif (warning - 51 MB file!)
http://www.akphotodenver.com/images/7D/band2.tif (warning - 51 MB file!)

This is almost more troublesome than the damn focus issues!

I see that the 2 images were taken with the 70-200 2.8... Does this banding show up in every picture with every lens in the same location? OR, does it come up in a certain lens combination? That's an interesting phenomenon.

 

[justsomedude]

I see that the 2 images were taken with the 70-200 2.8... Does this banding show up in every picture with every lens in the same location? OR, does it come up in a certain lens combination? That's an interesting phenomenon.

So far I've only seen it with the 70-200, but then again, I haven't looked through enough photos yet to be sure. Also, it's inconsistent even with the 70-200, and only appears with certain types of lighting. Odd. I'll dig some more into my archives and see what I can find.

 

[awinphoto]

I see that the 2 images were taken with the 70-200 2.8... Does this banding show up in every picture with every lens in the same location? OR, does it come up in a certain lens combination? That's an interesting phenomenon.

So far I've only seen it with the 70-200, but then again, I haven't looked through enough photos yet to be sure. Also, it's inconsistent even with the 70-200, and only appears with certain types of lighting. Odd. I'll dig some more into my archives and see what I can find.

Take a look to see if you can see it on any other images on other lenses... perhaps it could be a light leak with the lens but if it is with other lenses, then it could be with the sensor...

 

[justsomedude]

I see that the 2 images were taken with the 70-200 2.8... Does this banding show up in every picture with every lens in the same location? OR, does it come up in a certain lens combination? That's an interesting phenomenon.

So far I've only seen it with the 70-200, but then again, I haven't looked through enough photos yet to be sure. Also, it's inconsistent even with the 70-200, and only appears with certain types of lighting. Odd. I'll dig some more into my archives and see what I can find.

Take a look to see if you can see it on any other images on other lenses... perhaps it could be a light leak with the lens but if it is with other lenses, then it could be with the sensor...

Boom... there it is with the 50mm. Didn't take much searching in my 7D test archive to find one either. Note, exposure and contrast have been modified to make the "band" stand out more. http://www.akphotodenver.com/images/7D/50mm_band.jpg

I'm finding that it's most obvious in any image that has consistent exposure (meaning little detail) along the right side of the frame. So anything with sky, clouds, or as in this case a uniform wall, it becomes very apparent.

Man, I just have to laugh at this point. I really have no idea WTF is going on with Canon QC. At this point I'm ready to just dropkick this 7D out the window, take the insurance money, and get a 5D. This is getting f*cking ridiculous. Although if I were smart, I'd learn my lesson and go to Nikon. Maybe I'm just a glutton for punishment.

 

[justsomedude]

Update...

Canon has had my 7D exactly one week, and I have not yet received a service update from them. I actually see this as a good sign, because when they did their (in)famous "electrical adjustments to the AF assembly", the entire process - door to door - was ten days. The fact that they've had it a week already indicates to me that they must be doing some serious work and/or investigating. In my past dealings with their Irvine service facility, this is the longest I've gone without getting some type of automatic email update.

Fingers crossed that they are working to get her in tip top shape!

 

[awinphoto]

Update...

Canon has had my 7D exactly one week, and I have not yet received a service update from them. I actually see this as a good sign, because when they did their (in)famous "electrical adjustments to the AF assembly", the entire process - door to door - was ten days. The fact that they've had it a week already indicates to me that they must be doing some serious work and/or investigating. In my past dealings with their Irvine service facility, this is the longest I've gone without getting some type of automatic email update.

Fingers crossed that they are working to get her in tip top shape!

I'm glad they are taking their time with the camera rather than doing a rush job. I've spent time thinking about your striping issue (banding) and since it's in a particular area, I would hate to think it's a bad sensor... I know they issued (a while ago) a firmware update that dealed with some banding issues, however if you have a fully up to date firmware, then I dont want to do the disservice and make suggestions without really looking at the camera and knowing the situation first hand.

Fingers crossed and give us updates as you get your camera back.