EOS 7D Mark II User experience Thread

Karl Günter Wünsch wrote:

rnclark wrote:If there is a high contrast edge a little outside the AF rectangle, the AF system will still be detecting that signal.  If you have more than one AF point enabled, the system will lock onto the brightest high contrast object near any AF point.  For example, a bird flying at an angle toward you: the wings flapping may go through an AF sensitive zone.  Will the camera lock on to the eye, or the wingtip?

I would suggest you give the 7DII a chance to work it's magic and give it a spin in all focusing points enabled with iTR tracking enabled too. It may not quite get to the advertised 10 fps in that mode (Canon says you lose about 0.5 frames/second to the calculations necessary for the iTR) but it may well surprise you how well it does and how it avoids just that kind of mishap you described...

rnclark wrote:

E.J. Peiker wrote:Ah I missed that statement but suspected it from his review.  It doesn't explain multiple shots of a static subject taken in a burst where some are sharp and some are not though - I think that goes to the AI Servo hunting that others have commented on in this thread.

There are several factors in any phase detect AF system.  First is to remember that phase detect AF works on the out-of-focus light cone.  That means that the edges of sensitivity are soft.  It also means the sensitive area is larger than the AF rectangles one sees in the viewfinder.  When we are tracking a moving subject, or even hand holding on a static subject the AF area is moving around on the subject.  If there is a high contrast edge a little outside the AF rectangle, the AF system will still be detecting that signal.  If you have more than one AF point enabled, the system will lock onto the brightest high contrast object near any AF point.  For example, a bird flying at an angle toward you: the wings flapping may go through an AF sensitive zone.  Will the camera lock on to the eye, or the wingtip?  For this reason I first go out at night with a new camera and test the AF sensitive regions using a single bright light (distant street light) or the Moon high in a clear sky.  I see how far away from a single AF point I can get the camera to still achieve focus.  You'll be surprised how far it is.

Because the AF zone is large and fuzzy, and larger and fuzzier the faster the f/ratio, I pretty much use only one AF point with no expansion.  I have gotten more consistent results with a single AF point than any other mode.  This is the way I set up my 7D2.

Wandering of the AF point can even happen on a static subject with the camera on a tripod, especially a long telephoto.  Small vibrations move the field of view and if there is a bright high contrast edge near the edge of the AF sensitive zone, it can influence the AF position.  This is more of a problem if multiple AF points are enabled, even enabled as "assist" AF points.  The more AF points, the more the chance of a signal near the edge of an AF zone  that will change as small vibrations change the signals to the AF modules.

I have more info on how AF systems work and their fuzzy nature at http://www.clarkvision.com/articles/und ... autofocus/

And remember, microadjustment is a function of temperature.  The smaller pixels in the 7D2 will be more sensitive to temperature effects.  Thus, if you go out on a cold morning that then warms up, the microadjustment of big telephotos will change as the day warms up.

There is a saying in science: every precision instrument is a thermometer.  Digital cameras are precision instruments.

Roger

...unless it is featureless like a clear sky.

OntPhoto wrote:
Great review.  I forget exactly where the more powerful battery of the 1D X comes into play.  Only the initial drive of the lens?

Lensmaster wrote:Unfortunately camera's aren't perfect yet, I don't know why anyone would think they are .

Rob

Scott Fairbairn wrote:Personally, for what I photograph, I have never found any of these zone/auto point switching and so on to work very well. They all seem to pick up the background unless it is featureless like a clear sky.

Who said they were supposed to be? I'd just like to see them work as advertised.

Karl Günter Wünsch wrote:

I forget exactly where the more powerful battery of the 1D X comes into play.  Only the initial drive of the lens?

Only there for about the 1st second... See Chuck Westfall on the 7DII autofocus http://www.the-digital-picture.com/Comp ... rison.aspx

Scott Fairbairn wrote:

Lensmaster wrote:Unfortunately camera's aren't perfect yet, I don't know why anyone would think they are .

Rob

Who said they were supposed to be? I'd just like to see them work as advertised. 

OntPhoto wrote:The complete 7D MK2 review has been posted by the Digital Picture.
http://www.the-digital-picture.com/Reviews/Canon-EOS-7D-Mark-II.aspx

Compare the above detailed review about the 7D MK2 versus 7D and 70D image quality/noise versus the Ken Newcombe quick review someone posted a link to here awhile back where he (Ken) claims to see no difference in image quality/noise.

Neilyb wrote:So between the 70D, 7D and 7DII nothing has really changed up to about ISo3200. At ISO 12800 the 7DII is much better than the old model but still I wouldn't use it. Maybe, as Roger says, it is a much better camera for very low light but I hardly shoot in the dark and never do Astro. I am still holding off buying one as much as I would like the crop, until I really need it maybe.