p.1 #1 · 1Ds3 AF: learning to understand how it works
After having shot with three different 1Ds3's the last months, I have come to the conclusion that I need to change my way of looking at how the new mkIII AF works. Especially when it comes to focusing at infinity. Coming from a 5D, that have large autofocus sensors, I basically pointed an AF point over a distant subject, and the subject would be in focus. When I do the same routine with the 1Ds3, it doesn't always mean the target ends up in focus. I think this has something to do with a combination of smaller autofocus sensors and how it reads contrast. If, for some reason, the 1Ds3 AF can't read enough contrast, it still gives an AF confirmation (One SHot), but the shot will suffer from a front focus (mostly) or a backfocus. To illustrate what I am talking about, please take a look at the following presentation.
All shots were done using 1Ds3 + 135L with the center AF point (no PP except for a small resizing). But I get the same results consistently with any of my other lenses.
1) I pointed the center AF sensor in the middle of the chimney. The sensor was a few times smaller than the actual chimney, so the only contrast it could read was from the bricks of the chimney itself. AF gave a confimation, but the shots were all OOF. I have also included some crops of the bottom of the frame. You can easily see that these crops are somewhat sharper than the crops of the area of focus. Also, you can see that by f/4 DOF has become large enough to create the illusion that the chimney is in focus (which it isn't when you compare the shots when they are truly in focus). I don't know where the actual focus is, but it appears to be just outside the frame (bottom). BTW My 5D wouldn't have had any problems nailing this shot while focusing in the middle of the chimney because of its larger AF sensors:
2) I pointed the center AF sensor over the edge of the chimney. It should be obvious that in this case it easily reads the contrast between the edge of the chimney and the sky. All shots were infocus. The bottom of the frame isn't in focus, like it should:
I do get the occasional mis-focus shots also when focusing closer (under infinity). I will have to monitor that closely, but it looks like this mostly happens when the lighting conditions make it difficult for the 1Ds3 AF to get a proper contrast reading and/or when there are many small details surrounding the target and/or when contrast is "muddy". In other words, it seems the 1Ds3 AF needs good light on the subject/object and very clear and "simple" contrast to make a proper reading. Aiming for edges of subjects/objects can be of big help here
p.1 #2 · 1Ds3 AF: learning to understand how it works
Hi Daan, I don't know any autofocus system that I have found 100% reliable at infinity.
I've often blamed the lenses, but I just don't think AF is 'designed' to work at or near the end of the range.
I did some test shots recently on my 450D with several lenses and when focused at infinity (using AF) they all gave slightly different 'infinity' distances (that is a little bit back from infinity).
I ended up using liveview to get a precise result. At nearer distances the lenses all worked fine.
p.1 #4 · 1Ds3 AF: learning to understand how it works
Pixel Perfect wrote:
Does not inspire confidence in Canon's AF at all on these mk III's.
That's exactly my problem. While I'd love to own and use one for its other features, when I tested a Mk III I didn't trust the AF at all. Simply too many OOF shots under conditions where even my old 1D would nail it. What a disappointment given my commitment to Canon glass ...
p.1 #6 · 1Ds3 AF: learning to understand how it works
Guys, the points I am trying to make here are:
1) Since the mkIII's are using a newly designed AF, there is a learning curve involved. It obviously doesn't work the same as the mkII AF or any other previous AF system. So, instead of emphasizing how the new AF differs from the old AF (and how much that sucks), maybe it is time to learn new ways here (or at least be openminded to them)
2) The above results are not unpredictable. Nor did I make this post to prove how unreliable the 1Ds3 AF is. Far from it. In fact, I can repeat the whole shoot while using other lenses under different weather conditions and still and up with excatly the same results. Time and time again. Different than before? Sure. Unpredictable or even unreliable? No!!! I just have to know how to use the 1Ds3 AF properly. This appearantly demands some adaptation from my part. And I am ready to learn
@ Pixel Perfect: the lens was at the infinity marking.
p.1 #7 · 1Ds3 AF: learning to understand how it works
Daan,
I appreciate your thoughts, but when I focus on an eye in studio for beauty/glamour shots - the AF should work. It works on the 5D, the 1DsII, and even the XT for goodness sake. Missing a model standing 12 feet away because there isn't some huge amount of contrast is inexcusable, in my mind.
p.1 #8 · 1Ds3 AF: learning to understand how it works
Numfar wrote:
Daan,
I appreciate your thoughts, but when I focus on an eye in studio for beauty/glamour shots - the AF should work. It works on the 5D, the 1DsII, and even the XT for goodness sake. Missing a model standing 12 feet away because there isn't some huge amount of contrast is inexcusable, in my mind.
Sorry to hear about your problems
However, I am not saying your problems are related to a lack of contrast. There can be a lot of causes for it. It could even be that the f/5.6 DOF is hiding the mis-focus to some extent. It is impossible for me to say something of value about it since I don't know your gear and/or situation.
All I can say is that when it comes to focusing on an eye (even in low light), my 85L II, 135L and 70-200mm f/4 IS are all spot on 90% of the time (2-3 meters shooting distance). In both AI Servo and One Shot, using both the center and outer AF points. My 85L II and 135L did need some MA though.
p.1 #9 · 1Ds3 AF: learning to understand how it works
Using a depth of field calculator, I guessed the chimney was about 20ft away:
@F/2.0 = 0.79 ft
@F/2.8 = 1.1ft
@F/4.0 = 1.57 ft
It is no wonder that the chiney is out of focus for the in focus shots, it is supposed to be, as you mentioned.
Your 135mm my also need some AF adjustment for the 1ds3, mine needed a small amount, and it turned it into a razor sharp lens!
Do you AF expansion enabled? You need to go to AF - C.FnIII and disable AF expansion, this is enabled from from the factory BTW. Once this has been done you will find your AF reliability will increase dramatically.
p.1 #10 · 1Ds3 AF: learning to understand how it works
If the camera can't read enough contrast, I think I prefer it to give no focus confirmation, or a flashing green dot. Or an indication that AF will be less precise.
p.1 #11 · 1Ds3 AF: learning to understand how it works
lexvo wrote:
If the camera can't read enough contrast, I think I prefer it to give no focus confirmation, or a flashing green dot. Or an indication that AF will be less precise.
p.1 #13 · 1Ds3 AF: learning to understand how it works
Thanks for the quick work and analysis, Daan B. I do agree with you for the most part----and in short, this has been my experience with shooting the 1DS Mark III for the past six months in a variety of conditions.
Any focus issues that I've seen have involved "contrast" situations. It is NOT a microadjustment issue with Canon lenses (at least not with mine), but rather the ability of the camera AF system to consistently lock focus where I want it to.
And to be sure, the Canon 5D is simply "easier" to use, and I liken it to a point and shoot for the pro. The 1Ds Mark III is more complex less forgiving camera, and demands that you know it well to consistently produce great images. In studio my Mark III has performed flawlessly. Only on location in difficult light "contrast" situations have I experienced issues. I won't go so far to say that some Mark III camera bodies don't have focus issues, but I will go so far to say that many oof issues can also be attributed to unfamiliarity with the characteristics of the Mark III.
I recently returned from Alaska shooting only with the 1Ds Mark III. The Mark III was subjected to many difficult light situations, particularly while shooting the brown bears in Katmai. It was a learning experience to be sure. I was troubled by "focusing issues" having only about a 50% keeper rate. But in retrospect, considering how and what I was shooting at the time, the in focus rate was probably similar to other cameras I have shot. And now knowing (and learning) subsequently how this camera handles, I am confident that my keeper rate for in-focus shots from the Mark III will climb dramatically. It remains the best DSLR I have used.
It is knowing the characteristics of a particular camera, whether advantageous or a shortcoming, that allows me to react and still produce a great image.
You can see some of my Alaska images, both 5D (2007) and 1Ds Mark III (2008) at www.houseoflandscapes.com
p.1 #14 · 1Ds3 AF: learning to understand how it works
kdphotography wrote:
Thanks for the quick work and analysis, Daan B. I do agree with you for the most part----and in short, this has been my experience with shooting the 1DS Mark III for the past six months in a variety of conditions.
Any focus issues that I've seen have involved "contrast" situations. It is NOT a microadjustment issue with Canon lenses (at least not with mine), but rather the ability of the camera AF system to consistently lock focus where I want it to.
And to be sure, the Canon 5D is simply "easier" to use, and I liken it to a point and shoot for the pro. The 1Ds Mark III is more complex less forgiving camera, and demands that you know it well to consistently produce great images. In studio my Mark III has performed flawlessly. Only on location in difficult light "contrast" situations have I experienced issues. I won't go so far to say that some Mark III camera bodies don't have focus issues, but I will go so far to say that many oof issues can also be attributed to unfamiliarity with the characteristics of the Mark III.
I recently returned from Alaska shooting only with the 1Ds Mark III. The Mark III was subjected to many difficult light situations, particularly while shooting the brown bears in Katmai. It was a learning experience to be sure. I was troubled by "focusing issues" having only about a 50% keeper rate. But in retrospect, considering how and what I was shooting at the time, the in focus rate was probably similar to other cameras I have shot. And now knowing (and learning) subsequently how this camera handles, I am confident that my keeper rate for in-focus shots from the Mark III will climb dramatically. It remains the best DSLR I have used.
It is knowing the characteristics of a particular camera, whether advantageous or a shortcoming, that allows me to react and still produce a great image.
You can see some of my Alaska images, both 5D (2007) and 1Ds Mark III (2008) at www.houseoflandscapes.com
Ken, thanks for confirming my findings. It is good to know you also experience a difference between the 5D and 1Ds3 regarding AF. I agree with you that the 1Ds3 is a though beast to tame (my own words). But IMO it is worth the effort, because the files are so nice
Instead of bashing the mkIII AF, maybe it is time to accept its strong and weak points and learn how to deal with them. At least, this was the intention of my post. I am glad you feel the same way
p.1 #16 · 1Ds3 AF: learning to understand how it works
Daan B wrote:
Ken, thanks for confirming my findings. It is good to know you also experience a difference between the 5D and 1Ds3 regarding AF. I agree with you that the 1Ds3 is a though beast to tame (my own words). But IMO it is worth the effort, because the files are so nice
Instead of bashing the mkIII AF, maybe it is time to accept its strong and weak points and learn how to deal with them. At least, this was the intention of my post. I am glad you feel the same way
BTW Those bear images are wonderful!
At what point have Canon ever indicated that the AF of the mk III was so vastly different that you would need a entirely new way of mastering it? And if true why have they not been bending over backward to get this message across and help users master these cameras. It's in their interest to ensure happy customers and avoid negative feedback.
Sounds more like you've been dumped in it and left to waste months using trial and error to find workarounds for it's foibles. And many very experienced users don't seem to have found that winning combination yet.
p.1 #17 · 1Ds3 AF: learning to understand how it works
I am absolutely and continually ASTONISHED at the level of dismissive attitudes I see from photographers regarding this absolutely UNACCEPTABLE performance in a top-level camera.
Some seem to think "top-tier" means you should be some sort of bizarra AF expert before you should expect it to work. The OPPOSITE should be true.
I've used numerous 1 Series cameras, and NEVER has AF been a CHORE.
NEVER has AF been difficult.
NEVER...until I bought the 1D3.
It is SCREWED UP, people!!
-And no amount of excuses...explanations...and outright blindness will change this fact!
You guys just AMAZE ME!!!!!
Sheesh.
"AF is always difficult at infinity" What the HECK??
What planet are you from!??
That has NEVER been a problem unless pointing at a detail-free blue sky!
What the heck is happening to photog mentality these days that so many will come up with these absolutely stunning and ridiculous excuses for a $4500 MESS??
I've had it!!
(can you tell?)
M
dhphoto wrote:
Hi Daan, I don't know any autofocus system that I have found 100% reliable at infinity.
I've often blamed the lenses, but I just don't think AF is 'designed' to work at or near the end of the range.
I did some test shots recently on my 450D with several lenses and when focused at infinity (using AF) they all gave slightly different 'infinity' distances (that is a little bit back from infinity).
I ended up using liveview to get a precise result. At nearer distances the lenses all worked fine.
p.1 #18 · 1Ds3 AF: learning to understand how it works
Pixel Perfect wrote:
At what point have Canon ever indicated that the AF of the mk III was so vastly different that you would need a entirely new way of mastering it? And if true why have they not been bending over backward to get this message across and help users master these cameras. It's in their interest to ensure happy customers and avoid negative feedback.
Sounds more like you've been dumped in it and left to waste months using trial and error to find workarounds for it's foibles. And many very experienced users don't seem to have found that winning combination yet.
Whayne,
I agree with you that Canon should have gotten some kind of general message (not only CPS) across on how the use the mkIII AF, especially since it is a newly designed system. I also am kind of shocked to learn that QC basically sucks after having owned two 1Ds3 "duds".
However, I don't share your sentiment entirely. You seem awfully frustrated about the mkIII AF for someone who doesn't even own any of the cams. For my body of work (people photography) the 1Ds3 hasn't let me down at all. Meaning, shooting people in either controlled lighting or natural lighting at an average distance of 1-5 meters. Like any (new) tool it has it weaknesses and strengths. You are asking me to keep on whining about the weaknesses. What good that will do? I'd rather focus on its strong points and learn how to deal with its weak(er) points. Which should be no problem because they seem consistent
I was hoping by posting this thread I could contribute to a more constructive approach on dealing with the mkIII AF. Too bad you seem to be offended by that...
p.1 #19 · 1Ds3 AF: learning to understand how it works
Markuson wrote:
I am absolutely and continually ASTONISHED at the level of dismissive attitudes I see from photographers regarding this absolutely UNACCEPTABLE performance in a top-level camera.
Some seem to think "top-tier" means you should be some sort of bizarra AF expert before you should expect it to work. The OPPOSITE should be true.
I've used numerous 1 Series cameras, and NEVER has AF been a CHORE.
NEVER has AF been difficult.
NEVER...until I bought the 1D3.
It is SCREWED UP, people!!
-And no amount of excuses...explanations...and outright blindness will change this fact!
You guys just AMAZE ME!!!!!
Sheesh.
"AF is always difficult at infinity" What the HECK??
What planet are you from!??
That has NEVER been a problem unless pointing at a detail-free blue sky!
What the heck is happening to photog mentality these days that so many will come up with these absolutely stunning and ridiculous excuses for a $4500 MESS??
I come from an era when, believe it or not, we had to do our own focusing. We even sometimes had to find our own exposure.
I know that these systems can fail and I'm a a pro and I can't afford out of focus pictures on a job.
Bothers you, fine. Doesn't bother me in the slightest, because I know how to use my gear without having my hand held.
No AF on any camera is 100% perfect all the time, the Canon system is generally very good, but it can fail in certain circumstances and at or near infifnity is one of them if the AF doesn't have anything contrasty to work from.
p.1 #20 · 1Ds3 AF: learning to understand how it works
Daan I'm annoyed because I wanted to update my 1D II the day the 1D III shipped but I always hold off on new releases. I'm glad I did and I have every right to be annoyed when I'm thinking of slapping down that sort of money. My 1D II is now 4 yo and I would like to update it and IMO their is still no suitable replacement.
I'd love to know why an engineer thought giving an AF confirmation for an OOF shot was a good idea. Is that in the manual. Apart from this quirk, nothing you said is new. In the chimney example I'd never place the AF point over the centre of the dark brickwork, always on the edge and would not trust the beep if placed elsewhere.
Daan as long as your happy with your camera that's all that matters.
