[Guest]

I've heard from some that banding in 7d and 5d might be caused by IF and therefore while it might partly be attributed to QC it is also attributed to primary location of the photographer. If in fact IF is the (partial) cause then perhaps the cameras could use better shielding but I'm unsure how much can be done here after all the sensor needs to be exposed when you take the picture.



[quote name='thw' date='08 June 2010 - 06:23 AM' timestamp='1275974620' post='330']

Low ISO noise and banding is not apparent on every 7D sensor. It varies from one copy to another, thanks to Canon QC. I have pixel peeped images from a few copies and they are all free from low ISO noise and banding. Also, I am very confident the 550D sensor will be free from such problems simply because it has two channel output (lower frame rate) instead of four.



If you want to compare RAW images from 10D, 20D... to 70D including D100, D200 and D300, take a look at [url="http://pixinfo.com/cikkek/dslr_evolution.3"]this Hungarian site[/url]. It contains the most comprehensive results. At the pixel level, the 7D is NOT in anyway inferior to the 20D. At the image level, it beats out everything else.



The remaining complaints come from (i) people who believe in the megapixel myth without any real experience whatsoever with the cameras (ii) trolls and green-eyed monsters. Wait till Nikon update their D90 and D5000 sensors with more pixels... these myths will die quickly and silently.

[/quote]

[Guest]

[quote name='you2' date='09 June 2010 - 12:19 PM' timestamp='1276078758' post='380']

I've heard from some that banding in 7d and 5d might be caused by IF and therefore while it might partly be attributed to QC it is also attributed to primary location of the photographer. If in fact IF is the (partial) cause then perhaps the cameras could use better shielding but I'm unsure how much can be done here after all the sensor needs to be exposed when you take the picture.

[/quote]



IF == Internal Focusing? Increased Frequency? Intermediate Failures? Intelligent Forking? Instant Fetch? Increased Features? Immediate Failures? Incongruous Fares? Innocent Fires? Intolerable Fishing?



I am confused.



-Lars

[Guest]

infrared interference I think; basically micro-waves or external electronic signals, magnets, cell phones and similar.



[quote name='larsrc' date='09 June 2010 - 02:57 PM' timestamp='1276091846' post='387']

IF == Internal Focusing? Increased Frequency? Intermediate Failures? Intelligent Forking? Instant Fetch? Increased Features? Immediate Failures? Incongruous Fares? Innocent Fires? Intolerable Fishing?



I am confused.



-Lars

[/quote]

[wim]

[quote name='Pinhole' date='09 June 2010 - 01:49 AM' timestamp='1276040965' post='355']

I second that! A very informative post - thanks, Wim!





I don't want to hijack the thread either, but ... I have only ever used the centre focus point and recomposed on (analogue + digital) SLRs. It's probably due to me starting off with rangefinders that I never got into all that - and I've gradually switched to an almost totally manual-focus lens range on my DSLR.



Is there any real advantage to using the multiple focus points except the convenience of not having to re-frame the shot? Would it be beneficial to 'learn' to use this feature?

[/quote]

Thank you for your kind words!



Officially, focusing and recomposing is not a good idea, certainly not from a theoretical POV. With dslrs the effect is worse too, because effectively dslrs have less DoF than analog cameras have (0-sensor thickness vs 0.2 mm film thickness).



However, I must admit I do this all the time, although I often either use MF after AF, or use a point that is as far from the camera as my subject. And if you actually use small apertures, it generally doesn't matter all that much anyway. Don't forget that AF with fast lenses is only specced to be within 1/3 of DoF, and slower lenses only within DoF. I used to do centre MF with MF analog cameras, because it was more convenient to use the centre wedge for focusing than anything else, except fro macro of course: it would eb too dark. For macro I used a very finely ground matte focusing screen, for accurate MF. In a way you can compare that to the -S type of focusing screens (EE-S, Ef-S, Eg-S) for Canon bodies.



It certainly is useful to learn other ways of using AF IMO, for the simple reason that one should know its tools well, to use them optimally. I often find that when I learn something new about a subject, and practice with it, it means I can use it, and it extends my arsenal of tricks.



HTH, kind regards, Wim

[wim]

[quote name='you2' date='09 June 2010 - 12:17 PM' timestamp='1276078636' post='379']

If you track objects then I believe multiple focus points is a real winner. I personally do not do much BIF (bird in flight) or sports but I have seen detail descriptions of how those folks expect cameras to behave. I personally tend to focus on more static or slow moving objects and in those cases use center point only. I did once shoot a soccer game and at that time wished I had better tracking.

[/quote]

Yes, I know the feeling. I recently shot a fast sport with the wrong body (few AF points, relatively slow AF and tracking) and the wrong lens (slow AF too). It was a real pain, felt like a throwback to the (not so) good old days where all we had was trying to apply fast MF <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.



Kind regards, Wim

[backcountryskier]

My ideal camera would have 4 AF points. Located at 1/3rds. There would be 4 little buttons where I could select directly.



FWIW, my 7D is my first camera where I do not center, focus, and recompose. I've got the joystick mapped directly to AF point. No other buttons need to be pressed.