AF points (7/9/45/??) and AF-assist

[peety3]

Disclaimer: I read Canon Rumors a lot. From there, I learn stuff. And I hear rumors.


A recent rumor suggests that Canon can't deviate from the current 1-series "standard" of 45 autofocus points (and therefore the lower series must have a focus point layout that aligns with some of the 1-series 45-point layout) because of the Speedlite AF-assist lamp pattern.


I'm thinking through this, and something doesn't seem right: as far as I know, the AF-assist lamp doesn't zoom. Therefore, the pattern would appear very tightly in the center of the frame with wide-angle lenses, and/or widely outside the frame with super-telephoto lenses. If that's the case, why would the design/layout of the AF-assist lamp matter to the focus point count? There'd be no guarantee that a line or junction would fall beneath any particular focus point now.

[coastalkid88]

Peety3 please do yourself and us as a forum a favor and stop reading that s#*t. Its full of lies, rumors, and wrong information.






They are one of the biggest disgraces to the canon community and canon has repetedly said they assume no affalition with this site there's a reason for it.




Canon rumor is evil
And filling you brain with nonscense rumors




Coastal kid

[coastalkid88]

The reason that they haven't changed the auto focus system is that all of the af points on all of the cameras fit into the grid of the 45 point system. When using the af-assist beam the flash uses that specific af point to calculate the focus distance so yes it depends on which point you select. All of the flashes are only compatable with 45 af points that are available with the cameras and therefore their not going to reinvent their whole system to add extra af points to system that allready works fine




And just WHY does this cr*p matter
Does this even effect any one I mean really.




Who needs more than 45 af points.

[Fred Doane]

And just WHY does this cr*p matter Does this even effect any one I mean really.

Who needs more than 45 af points.

coastalkid88,

We all know your 21 and a professional and have the answer to everything butI don't believe youaddressed the original question/statement. He didn't say anything about 45 points not being enough or needing more. He states...

"and therefore the lower series must have a focus point layout that aligns with some of the 1-series 45-point layout) because of the Speedlite AF-assist lamp pattern"

First of all with the 1Ds Mark III all the focusing points are not selectable. Only 19 of the points are selectable. The remaining points can be set with a custom function to assist theselectable focusing points (when using an aperture of 5.6 or smaller) but can not be selected.

Second I know I for one would like to see the points be spread out a little further to the edges. I don't like needing to focus and recompose with my 85 1.2 at close distances.Doing socan throw what I want out of focus from the slight recomposition with such shallow depth of field of much less then 1 inch.

I see your new to the forum, welcome. It's always great to hear from professionals that do this for a living every day. Share some of your work and let your images do the talking.

Fred~

[Keith B]

Second I know I for one would like to see the points be spread out a little further to the edges. I don't like needing to focus and recompose with my 85 1.2 at close distances.Doing socan throw what I want out of focus from the slight recomposition with such shallow depth of field of much less then 1 inch.


Fred~

Amen brother!

[peety3]

Peety3 please do yourself and us as a forum a favor and stop reading that s#*t. Its full of lies, rumors, and wrong information.

Coastal kid, do us all a favor and tone down your language. Oh, and perhaps read the post. I was discussing a concept, which has nothing to do with rumors. Apparently you didn't get that part of the post.

[Maleko]

Second I know I for one would like to see the points be spread out a little further to the edges. I don't like needing to focus and recompose with my 85 1.2 at close distances.Doing socan throw what I want out of focus from the slight recomposition with such shallow depth of field of much less then 1 inch.


Fred~
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Amen brother!
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Ditto to that! Can be SO frustrustrating at times.

[peety3]

The reason that they haven't changed the auto focus system is that all of the af points on all of the cameras fit into the grid of the 45 point system. When using the af-assist beam the flash uses that specific af point to calculate the focus distance so yes it depends on which point you select. All of the flashes are only compatable with 45 af points that are available with the cameras and therefore their not going to reinvent their whole system to add extra af points to system that allready works fine
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So you've just walked into the trap. The flash AF assist lamp does not zoom. It projects the same pattern (by angle of coverage) no matter what you're shooting. Stick the camera on a tripod 20' away from a wall, aimed at the wall with a flash on top. Stick a wide-angle lens on, half-press the shutter, and the AF assist lamp will only illuminate the very center of the frame. Change the wide-angle for a 600mm, half-press the shutter, and the AF assist lamp will illuminate more than the frame. Therefore, the AF assist grid can't be assumed to align with the AF points except for one or a few key focal lengths. Assuming there are no flaws in my thinking above, why does anyone care about the AF assist lamp when they talk about limits of changing the AF system?

[Joel Bookhammer]

Hey Peety3 you make a very good arguement, I m shooting with a 40D and when I have the 85 1.2 on between 1.2-2.8 Im stuck with haveing the subject perfectly lined up with one of the autofocus sensors. I would like too see more, maybe not more then 45, but I think they should cover the frame more then what they currently do. Sure the 7D has more points, but as far as I know which i may be wrong they dont even cover the same amount of area as my 40D does.


But then again I could be wrong.


Thanks


Joel

[Daniel Browning]

Second I know I for one would like to see the points be spread out a little further to the edges. I don't like needing to focus and recompose with my 85 1.2 at close distances.Doing socan throw what I want out of focus from the slight recomposition with such shallow depth of field of much less then 1 inch.

I would like that too, and they can make some small improvements, but unfortunately it will not be possible to make a big improvement until the optical viewfinder is replaced with an electronic viewfinder, as explained here:


Why are the autofocus sensors clustered around the middle of the frame?