Chris T Loc: from England across the pond to New England

Yes, Richard … what else could AE possibly mean - in reference to AF on modern DSLRs/MILCs ????

Chris T Loc: from England across the pond to New England

Gene - how could the amount of focus points be unrelated to AF Performance???

You just indicated a Sony 1" bridge w/ 315 was better than your D810 w/ only 45 ….

If I read that right - the greater amount you have - DICTATES how good your AF is ….

Architect1776 Loc: In my mind

Anything over 1

Chris T Loc: from England across the pond to New England

Yes, John … I think it's also the same with the D7100 … but the D5000 series - don't think has that …

RichardTaylor Loc: Sydney, Australia

So why would the number of focus points affect the Auto Exposure?
Wouldn't that be a function of the metering mode, exposure compensation, ISO, and the amount of light in the scene?

Chris T Loc: from England across the pond to New England

I don't know, Richard … I first read about this occurrence in a review of the Canon EOS 80D, and it's bothered me, ever since - thus, I've avoided it like the plague!!! … But, I've now read about this potential problem - in reviews of OTHER cameras, too - both DSLRs and MILCs. I'm just trying to get to the bottom of it - that's all. If posting this Topic - elicits other responses, in agreement - then, it's brought the problem to the fore, and perhaps - something could be done about it. So far, only OleMikey - has agreed to the Potentiality of the problem. I'm just trying to find out if other UHHers have also experienced this ….

Chris T Loc: from England across the pond to New England

I don't have any idea why someone would do that, DS … but, I think - if you use Matrix - or Multi-Spot AF - you are engaging as many Focus Points - as the camera makes available - be it 600 or 6000. And, it's occurred to me - when you allow that many focus points to activate - there's a distinct possibility - AE can be affected. This is only a theory - mind. I don't KNOW if there's a correlation, but, there could be ….

Chris T Loc: from England across the pond to New England

So, Charlie - you HAVE had problems attaining focus, when too many were in play … which camera's this?

But, do you think that complication - of having TOO many focus points to deal with - has affected AE?

JCam Loc: MD Eastern Shore

The consistency may be ok, but having all the multiple points "talk" to one another and then chose an Average setting for f-stop or focus points may be costing you time between shots, not much but for multiple action shots the delay may cost you the perfect once in a lifetime opportunity especially of kids playing or fast moving sports. I use the center spot only for 95% of my photography.

RichardTaylor Loc: Sydney, Australia

Just looking through the Canon EOS 80D manual there is no reference to a corrrelation betweeen auto focus points and exposure, except in very low light/contrast where autofocus may not work (see page 136). I have not had this problem with my Canon or Olympus bodies.

Could you please provide links to these reviews?

RichardTaylor Loc: Sydney, Australia

What do your own tests show?

Chris T Loc: from England across the pond to New England

Thanks, CO … I think you've made my point, here. When the CPU is overloaded with info - which can come from employment of TOO MANY focal points - there's a tendency for AE to be affected …. right, CO?

Chris T Loc: from England across the pond to New England

Well, Richard - the camera I own with the greatest amount of focal points - is the a77 II (79) and after that would probably be the D7100 with just 51. I don't really see either one as relevant here. What I'm making reference to - is these newer designs - with DPAF, and 45 or more, and then - the current crop - which have as many as 633, or even more - close to 6000 - someone mentioned - I guess that was the EOS R. Don't think I'll ever be testing something with that kind of magnitude. And, since none of mine have DPAF - I really don't worry about it, for myself. But, I suspect - these new advances - may well be gumming up the works. CO put up that thing about the D5, D500 and D850 - all having separate CPUs to handle the AF chores, just IN ORDER - NOT - to gum up the works!!! … So, I think there's something to this - hey?

Chris T Loc: from England across the pond to New England

Richard - if you are dealing with just ONE Processor - to handle ALL AF and AE functions, isn't it possible - all of this can confuse the CPU? …

Now, bear in mind - the most advanced PCs - now separate Video chores from all other functions - either, by the use of separate chips, or - whole cards. The fastest ones - do it with plug-in cards, which have their own CPUs - right on the card. Some, even have DUAL processors, on the card. Cameras are now computers. If they are over-taxed - just like you and me - on a really hot day, or outside on a cold day, even - we have problems dealing with the elements. So, a CPU - can also have problems - if it's asked to do too much. AF can fall apart, and focus-tracking - is usually the first to go, but - after that - if TOO MANY focus points are used in a scene - then, this, could, possibly - affect AE, too … just like - if we dress TOO WARM - on a cold day - it could hamper our ability to dig out the driveway, or clear the steps. But, if we dress warm enough to BE warm - but light enough to still maneuver our bodies - then we're agile … see? … But, if we overdo it, our bodies could overheat, impairing our ability to be able to dig out.

Cameras, also - can be overtaxed, by being given too many AF tasks concurrently, resulting in a slowing of CPU functions, and impairing its ability - to resolve and attain accuracy in AE … make sense?

Chris T Loc: from England across the pond to New England

Richard - the one for the 80D was a very long time, ago, now - when it was first released - what's that - 2015, or thereabouts? … Anyway - don't think it's there, anymore. The other ones I've read - like the one for the KP … and another for the X-T3 … are still out there. Not sure if I can find them again. I do tend to bookmark everything - but, that means I now have an OVERTAXED BM System, and some of it has now spread out to other things - like the Reading List. They are both overdone, now, and it'd take me a month of Sundays, to find anything again. I thought you had the EOS 70D, Richard - not the 80D. Anyway - the 70D has DPAF - doesn't it? … So, it's possible YOU could run tests, but, oh - that's only 19 Focal Pts.

I don't think those kinds of numbers cause any confusion. But the 80D with DPAF and 45 Focal Pts. - could have been compromised. If so, then, definitely - designs which have DPAF and a greater count of Focal Points - could run into the same problem - theoretically, anyway ….