Someone on dpreview suggested that Canon cameras use a separate processor and not the DIGIC for AF. I asked for clarification, but he did not respond.
9pt AF vs more AF pts
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Someone on dpreview suggested that Canon cameras use a separate processor and not the DIGIC for AF. I asked for clarification, but he did not respond.
increased number of AF points would certainly help if you're shooting high action sports photography. They help to keep focus in check as the subject moves through all 9 AF points.
I do believe they use separate processors too, considering the DIGIC processor is said to be a "imaging" processor, which means it's dedicated to processing the raw data from the sensor into your RAW files, or even compressing them to various JPG sizes and quality rates, and adding NR etc.
51 is good for sports IMHO. but in all other cases, 9 point is enough. and i'd dare say it can often be better, if u allow the camera to select the AF point.
if u manual select, then not much diff. 9 points faster to select. but d300 (n probably d3) allow user to choose 11 point AF instead, for manual selection. they realised not everyone will want to struggle with scrolling thru the 51 pt system :bsmilie:
btw, when u refer to "51 pt", u refer to nikon d3, d300, d700 right? cos i'm not sure if canon has a model with that many af points. if not, sorry for butting into a canon discussion ;p
btw, i used to have only 3 pt AF, and my film camera seems to only have centre AF :angel:
Yeah, that makes even more sense when considering that, for example 1D2N has 45 AF point, but uses same DIGIC processor as 20D.
yup. the digic processors are used for the imaging process. the af process is handled by another processor and in the 1 series, dual of those processors.
from the info on the 1D Mk3.
"Focusing Computation
As with the EOS-1D Mark II N, two separate CPU processors are used, one for AF processing
(including lens driving) and one for the camera. To attain 10 fps with AI Servo AF, the AF
CPU and camera CPU are both the latest microcomputers (AF CPU: 48 MHz, 32-bit RISC;
Camera CPU: 40 MHz, 32-bit RISC). The computing speed is 3 times faster than the
1D Mark II N's CPUs."
The 1D series also allows you to select 11-pt AF.
Using 11-point AF, I am able to get spot metering at selected AF point, rather than just at the center, with the additional option to select peripheral AF points, selected through a C.Fn.
Personally I can't see any diff in that, not that you're wrong of course. Slight focus change when using 85mm with a slight 5-10degree tilt, but not on my 50 1.8.. But that's besides the point anyway. Focus will be off, noticeable or not. That's where having many AF points around the corners might come in handy.
man, this is the funniest bit... 1d mk iii focus problems becos the chips are too powerful.... :bsmilie:
that being said, i still prefer the feel of the 9-ring (or was it 11?) focus switching on my 1D. still a blast to be able to take tons of photos for a travel trip, each file at 4mb or so in RAW.... and don't die just by buying a SERVER FARM to store all my touristy photos!
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it all depends on the kind of subjects you're shooting i guess.
imho, If you're shooting still stuff 1 af-point is good enuff
(of course, if you can toggle the AF-point easily without entering the menu, it makes things easier)
But if you're shooting ridiculously fast stuff (cars...air displays..etc) where you need the camera to motion track the subject across the viewfinder, then the more AF-points the merrier
imho, If you're shooting still stuff 1 af-point is good enuff
(of course, if you can toggle the AF-point easily without entering the menu, it makes things easier)
But if you're shooting ridiculously fast stuff (cars...air displays..etc) where you need the camera to motion track the subject across the viewfinder, then the more AF-points the merrier
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I just had a "DOH!" moment =|
I realised that when I started out using my 400D, it was auto-9pt focus and not center point AF. I'd also shift it to the other af points..
and now I realised that for some odd reason, a lot of my portrait photos back then have the rules of thirds put in place because I'd select the upper right AF point and shoot.
And now my shots are so much more centered.
Argh.
I realised that when I started out using my 400D, it was auto-9pt focus and not center point AF. I'd also shift it to the other af points..
and now I realised that for some odd reason, a lot of my portrait photos back then have the rules of thirds put in place because I'd select the upper right AF point and shoot.
And now my shots are so much more centered.
Argh.
can i say something about the 1Ds II/III's 45-point AF?
I can't live without it, because I frequently shoot alot of wide angle MOVING shots. I hate how the focus plane shifts everytime i recompose when shooting very wide on my 30D/10-22. With the 1D...I don't need to worry so much about that happening really. Up until a few weeks ago, I would've laughed at anything that had more than 9-AF points, but now...I can't imagine what might happen if I didn't have the convenience they bring....lol
I can't live without it, because I frequently shoot alot of wide angle MOVING shots. I hate how the focus plane shifts everytime i recompose when shooting very wide on my 30D/10-22. With the 1D...I don't need to worry so much about that happening really. Up until a few weeks ago, I would've laughed at anything that had more than 9-AF points, but now...I can't imagine what might happen if I didn't have the convenience they bring....lol
Interestingly, it's mostly canon users with no experience of other systems talking about what they need.
Haha..
From sensor cleaner, to live view, to video mode....
as long as it's something that other brands have, canon doesn't, they don't need it.
That is, until canon introduces the same features in their camera and suddenly the feature is desirable, and a must have.
For some people who shoot by and swear by F4 lenses, I can see that recomposition isn't an issue for them. Perhaps if they ever get to shoot with brighter/better lenses they will understand.
Haha..
From sensor cleaner, to live view, to video mode....
as long as it's something that other brands have, canon doesn't, they don't need it.
That is, until canon introduces the same features in their camera and suddenly the feature is desirable, and a must have.
For some people who shoot by and swear by F4 lenses, I can see that recomposition isn't an issue for them. Perhaps if they ever get to shoot with brighter/better lenses they will understand.
"needs vs wants"
you may not need a f2.8 lens if all you shoot are landscapes
and not everyone can afford to have a 24-70/70-200 f2.8 combination for events... i certainly can't.
edit: i'm not saying that F4 lenses are all that you need. i'm saying that F4 lenses are all that I need. i don't make money from my shots.
you may not need a f2.8 lens if all you shoot are landscapes
and not everyone can afford to have a 24-70/70-200 f2.8 combination for events... i certainly can't.
edit: i'm not saying that F4 lenses are all that you need. i'm saying that F4 lenses are all that I need. i don't make money from my shots.
For my personal usage style, 9 AF point got no different from 100 AF points...
The only concern of mine is how accurate it focus. I need the accuracy because I have slim DoF lenses like 85L.
I believe lots of AF points do not help most pictures taking... Be it for potrait, group pictures, landscape (prefer manual focus) etc...
The only concern of mine is how accurate it focus. I need the accuracy because I have slim DoF lenses like 85L.
I believe lots of AF points do not help most pictures taking... Be it for potrait, group pictures, landscape (prefer manual focus) etc...
Well said.. I remember sometime back when the first Liveview came up and almost everyone said we dont need it. then came the sensor cleaning and it was the same. a lot of ppl said that they dont even need anything more than 12MP on the camera.
I am sure if Canon puts a 45pt AF in the lower series like 50D or next versions of 5Ds, everybody is gonna like it.
I used a 1V before and am currently using Nikon D3 and I really find these systems very useful. I am sure that I cannot do without them. Note the use of "I"
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