AF speed... a matter of perspective.

Marla2008 said:

So everytime I read about "blazing fast" about m4/3, and can't help cracking up laughing...

Click to expand...

What's gotten me cracking up laughing is you saying m4/3 AF isn't that fast, then posting a couple pictures that could have easily been taken with an even slower focusing camera. Pre-focus for the win!

But seriously, when you say your GX1 isn't fast what lenses are you using with it? I have a 5D that is blazing fast with its one good AF point in the middle, but it is only so with fast focusing lenses. When I put the 85mm f/1.2L on there it's pedestrian, both for target acquisition and tracking. E-P3 + 45mm f/1.8 or 12mm f/2 are what I consider fast, even having extensive experience with DSLRs including pro models like the 1D Mark II. Of course I'd pick the DSLR if I absolutely needed the best AF in all situations since it tracks better and is a bit faster in single AF as well, but the E-P3 plus a fast lens loses little to a DSLR in single AF. "Blazing fast" is of course subjective, but m4/3 isn't nearly as far from that reality as you make it sound.

I took 237 shots of the bird show this day. Maybe 10 were out of focus?









This guy was flying faaaast. It's a falcon afterall!

Kevdog said:

I took 237 shots of the bird show this day. Maybe 10 were out of focus?









This guy was flying faaaast. It's a falcon afterall!

Click to expand...

Hard not to get everything in focus with a 25 mm lens at F6.3

--
http://dslr-video.com/blogmag/

duartix said:

Marla2008 said:

(...) Not so bad it constantly gets in the way and makes you miss many shots, but certainly not fast enough not to screw things up from time to time, if you shoot anything that moves at all. And I'm not talking about tracking but just focus acquisition of a moving target.

Click to expand...

I have to share something from the GH2 + M-Zuiko 45mm F1.8 on the weekend...

Two 6 year olds playing badminton (and they were really bad, so they were mostly running around).

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That sounds like the kind of challenge I'm facing

duartix said:

Tried S-AF, focus tracking, Face Detection, the sh*t. I'd say 50% were OOF. In a desperate move I committed the biggest heresy you can think off... yes, I switched to Touch Shutter! :O
~95% hits.
I will say no more...
--

Click to expand...

Wow, I'll try THAT ! True that tho I really enjoy and use the touchscreen interface along with the hard buttons, that is the ONE feature that was too foreign to me as a photographer to commit trying. I'll certainly give it a go now

Touch shutter and half-shutter release I believe function the same, try half-shutter as well that way you can use the camera at your eye and it is blinding fast.

duartix said:

Marla2008 said:

(...) Not so bad it constantly gets in the way and makes you miss many shots, but certainly not fast enough not to screw things up from time to time, if you shoot anything that moves at all. And I'm not talking about tracking but just focus acquisition of a moving target.

Click to expand...

I have to share something from the GH2 + M-Zuiko 45mm F1.8 on the weekend...

Two 6 year olds playing badminton (and they were really bad, so they were mostly running around).

Tried S-AF, focus tracking, Face Detection, the sh*t. I'd say 50% were OOF. In a desperate move I committed the biggest heresy you can think off... yes, I switched to Touch Shutter! :O
~95% hits.
I will say no more...
--
Duarte Bruno

Click to expand...

zaurus said:

m43 in S-AF with focus confirmation has problems when the subject is moving with a high angular velocity. Also, auto-focus gets often fooled when the background is close and contrasty.

Click to expand...

I kind of feeling like reacting like my kids did when they were teenagers, and I said something that was totally obvious: "No, duh?"

S-AF is intended for static subjects, not moving ones. Even on my Canons, if I'm shooting an approaching object I'll switch to C-AF mode. Even with a DSLR, if you focus on a moving subject in S-AF, it's going to focus on the spot where the subject was , not where the subject is when the shutter fires.

That's why DSLR makers invented C-AF.

The mere fact that you replied despite that you considered your point to be obvious speaks highly of you.

Now let me explain why I think you are not addressing the right issue.

I, along with many others, consider C-AF on m43 to be very unreliable. That is why I do not use it and that is why I assumed C-AF is excluded from the context of the conversation .

However, I still need to find a way to shoot sports with the only system I have now, m43 -- and this is the whole point of this thread. I resorted to using S-AF although I know both its definition and purpose as well as the one of C-AF .

Comparing apples to apples, namely S-AF on m43 to S-AF on a low to mid-range DSLR for moving subjects shows for me the second one is faster and more precise for calibrated lenses.

This contradicts directly your statement that S-AF on m43 is as fast or faster than the one on a high-range DSLR -- you did not specify whether you are talking about still or moving subjects.

If you had in mind still subjects as it seems to be the case, then yes, I don't see a difference between m43 and any DSLR system regarding speed of S-AF.

Bob Meyer said:

zaurus said:

m43 in S-AF with focus confirmation has problems when the subject is moving with a high angular velocity. Also, auto-focus gets often fooled when the background is close and contrasty.

Click to expand...

I kind of feeling like reacting like my kids did when they were teenagers, and I said something that was totally obvious: "No, duh?"

S-AF is intended for static subjects, not moving ones. Even on my Canons, if I'm shooting an approaching object I'll switch to C-AF mode. Even with a DSLR, if you focus on a moving subject in S-AF, it's going to focus on the spot where the subject was , not where the subject is when the shutter fires.

That's why DSLR makers invented C-AF.

Click to expand...

I can confirm I have very similar observations regarding AF behavior of m43.

Ednaz said:

One trick I've used with m4/3 that speeds acquisition is to work both eyes open, something not as necessary with an optical finder.

Click to expand...

It's just this point that I don't understand. Why is using both eyes a trick instead of the normal way in general to take photos? Even if one doesn't use it to speed acquisition, one still needs to watch what is outside the frame for many other purposes (re-framing or watching out approaching the frame or the photographer subjects etc.).

BTW I found it always funny seeing people taking photos through a viewfinder and squinting with one eye -- but maybe there is some value in this which I simply don't understand.

Have you downloaded the 1/25 firmware upgrade for the GX1? It seems to improve AFC performance by both acquiring the subject faster and sailing off into inner space much less quickly.
--
Steve Barnett

Marla2008 said:

Thx a lot for the link, I'm gonna study that in... Detail

Click to expand...

Marla2008 said:

One interesting thing : in C-AF I first thought that I had to keep shutter half-pressed to keep focus locked on my target (the way a DSLR behaves, and what seems pretty intuitive to me). My mistake !

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It looks like that is true according to the GX1 Operating Instructions (Revision VQT3018), Page 33:

“AFC” is an abbreviation of “Auto Focus
Continuous”. In this mode, while the shutter button is
pressed halfway, focusing is constantly performed to
match the movement of the subject. When the
subject is moving, the focusing is performed by
predicting the subject position at the time of
recording. (Movement prediction)

AFC is also mentioned in the section on using the burst shooting modes (which require a fully depressed Shutter Button to sustain), Page 85. When Focus Priority is set to ON:

The burst speed may become slower because the camera is continuously focusing on the subject .

Marla2008 said:

Apparently the way it works is : put your focus point where you want it, half press until box becomes green, then let go of shutter and focus point will (hopefully) follow your target around (except many times it screws up doing so). When you want to take the shot, fully depress shutter (works every other time, or refocuses on something else and screws your shot altogether)...

Click to expand...

That AF Tracking functionality (Page 93) appears to be separate and unrelated to AFC operation.

Marla2008 said:

To top that, the Panasonic manual is next to useless at explaining the different settings in detail. If anybody could advise a blog or book going over the GX-1 in decent depth, I'd live that

Click to expand...

You are not alone in your perceptions. The GH2 Operating Instructions appear to perhaps be somewhat more informative, but require seemingly endless loops of cross-referencing to clarify.

zaurus said:

The mere fact that you replied despite that you considered your point to be obvious speaks highly of you.

Now let me explain why I think you are not addressing the right issue.

I, along with many others, consider C-AF on m43 to be very unreliable. That is why I do not use it and that is why I assumed C-AF is excluded from the context of the conversation .

However, I still need to find a way to shoot sports with the only system I have now, m43 -- and this is the whole point of this thread. I resorted to using S-AF although I know both its definition and purpose as well as the one of C-AF .

Comparing apples to apples, namely S-AF on m43 to S-AF on a low to mid-range DSLR for moving subjects shows for me the second one is faster and more precise for calibrated lenses.

This contradicts directly your statement that S-AF on m43 is as fast or faster than the one on a high-range DSLR -- you did not specify whether you are talking about still or moving subjects.

If you had in mind still subjects as it seems to be the case, then yes, I don't see a difference between m43 and any DSLR system regarding speed of S-AF.

Click to expand...

At last, somebody feels my pain and doesn't make me appear like a complete moron, thx for the support Indeed thanks for clarrifying why I still rely on AF-S for a subject that isn't still, because I don't intend to actually track it but take the shot as soon as focus has locked (AF-C, as Thom Hogan a respected Nikon AF system expert explains it, actually never locks , reason why it keeps on tracking).

So I keep on thinking that for anything else than static stuff in good light, PDAF still has the edge, which doesn't mean CDAF is not perfectly usable.

In all honesty, maybe you guys could think abut the following question, if you had a paid gig or just-one-time shoot to do, would you bring your m4/3 set-up or DSLR ? Me just saying

And that still doesn't change the fact you're using the wrong tool for the job. S-AF on CDAF cameras is simply not designed nor intended nor capable of shooting moving subjects. The fact that you're trying to make it do something it's not supposed to do is your problem, not the camera's problem.

You'll find hammers don't do a very good job with screws or nuts and bolts, either.

zaurus said:

However, I still need to find a way to shoot sports with the only system I have now, m43 -- and this is the whole point of this thread. I resorted to using S-AF although I know both its definition and purpose as well as the one of C-AF .

Comparing apples to apples, namely S-AF on m43 to S-AF on a low to mid-range DSLR for moving subjects shows for me the second one is faster and more precise for calibrated lenses.

Click to expand...

--

Bokeh is the aesthetic quality of the blur in out-of-focus areas of an image, or the way the lens renders out-of-focus points of light. Bokeh is not the same as depth of field (DOF).

Marla2008 said:

At last, somebody feels my pain and doesn't make me appear like a complete moron, thx for the support Indeed thanks for clarrifying why I still rely on AF-S for a subject that isn't still, because I don't intend to actually track it but take the shot as soon as focus has locked (AF-C, as Thom Hogan a respected Nikon AF system expert explains it, actually never locks , reason why it keeps on tracking).

So I keep on thinking that for anything else than static stuff in good light, PDAF still has the edge, which doesn't mean CDAF is not perfectly usable.

In all honesty, maybe you guys could think abut the following question, if you had a paid gig or just-one-time shoot to do, would you bring your m4/3 set-up or DSLR ? Me just saying

Click to expand...

I'll say the same thing I said above. S-AF isn't designed to do what you're trying to use it for. S-AF is designed to find maximum contrast and lock on that spot. If the subject moves after focus lock, yes, you get out of focus pictures. The fact that it doesn't work well shooting moving subjects isn't surprising. I'll disagree on the "in good light" comment, above, too. My GH2, at least, focuses as well in dim light as any of my EOS gear, for static subjects.

What would I take on a one time shoot? It all depends on what I'm shooting. When I took a camera to my niece's wedding reception, it was the EOS. For moving subjects, especially in dim light, it's much better. For my vacation in New Orleans, I took m43, and had no problems with any of the subjects I wanted to shoot. For my son's track meet, I took both. The GH2 did better than I expected, but there's no question the EOS was still better, especially for runners coming straight at me.

But I knew that before I bought my GH2. Every camera embodies compromises, and lack of good focus tracking is one of the compromises of m43. Front and back focus issues, OTOH, are a compromise of many DSLRs, along with issues of size and weight. If you chose an m43 camera to shoot action, you can hardly blame the camera because you chose the wrong tool.

--

Bokeh is the aesthetic quality of the blur in out-of-focus areas of an image, or the way the lens renders out-of-focus points of light. Bokeh is not the same as depth of field (DOF).

Marla2008 said:

Thx a lot for the link, I'm gonna study that in... Detail

One interesting thing : in C-AF I first thought that I had to keep shutter half-pressed to keep focus locked on my target (the way a DSLR behaves, and what seems pretty intuitive to me). My mistake ! Apparently the way it works is : put your focus point where you want it, half press until box becomes green, then let go of shutter and focus point will (hopefully) follow your target around (except many times it screws up doing so). When you want to take the shot, fully depress shutter (works every other time, or refocuses on something else and screws your shot altogether)...

Click to expand...

Marla, continuous tracking AF (this is what you are talking about) doesn't work on CDAF systems.

Period.

Marla2008 said:

To top that, the Panasonic manual is next to useless at explaining the different settings in detail. If anybody could advise a blog or book going over the GX-1 in decent depth, I'd live that

Click to expand...

It wouldn't matter if you could understand it becuase tracking AF on CDAF doesn't work.

If you want tracking CAF, get a dSLR.

TEdolph

Marla2008 said:

In all honesty, maybe you guys could think abut the following question, if you had a paid gig or just-one-time shoot to do, would you bring your m4/3 set-up or DSLR ? Me just saying

Click to expand...

Is that your case? Do you absolutely necessary need to catch the first kiss of a groom and bride in a cramped badly lit church otherwise you don't get paid? Or maybe you need to absolutely necessary catch in precise focus racing car number 26 between many other cars passing by just once on a curvy country road otherwise you get fired? Probably not.

What you probably want is to have a handful of keepers of an informal event with some moderate action. You can achieve this perfectly with m43 using a variety of photography techniques. This is because you are inside the event, you are part of it, hence you can dynamically choose where from, what, and how to shoot.

In the OP case of your husband repetitively tossing your daughter, if you want to "freeze" her use shutter priority at say 1/500, S-AF on him and recompose to where she would be.

Besides using S-AF on relatively slowly moving subjects (as seen from the camera's viewpoint!), here are more techniques for moving subjects under more challenging conditions.

You can pan





Flash selectively, sometimes using 2nd curtain sync (my image, used with permission)





Use different angle and contre jour with deep DOF





It seems you are inclined to treat everything as a portrait. There is always one main thing and it is in focus whereas everything else is de-focused almost to oblivion or plays a very limited subordinate role. That main thing is mostly caught and frozen without implied motion. All this narrows down the variety of experimentation you can do with light and technique.

Try to sometimes use the human (face) in the photo as (one of the) a supporting element.

You don't really need C-AF for what you are doing.
HTH.

You can't compair the EP1 - its the slowest m4/3 focusing camera ever made... (well same as the EP2).

My EP1 focuses (with firmware update) as slow as my old Oly 740uz (the first gen of ultra zoom cameras made, so 2003/4 ish)... go figure? I also prefure the MF zoom image on the 740uz, 50% coverage, centred in the full frame image!...

The EP3 does seem as quick as anyone needs for SAF.

I guess for tracking the best m4/3 are gonna be the OMD and the GH2.... probably in that order...

From the limmited tests I have seen I guess the OMD might well be on par with the poorer PDAF systems out there for CAF... but we will have to see!

Repeatedly being trashed gets a little old after 56 posts, lol...

I get your point, I can't focus for the life of me, or even worse understand what focus mode I should use.

I shall suffer in silence from now on. Unless the (pre-ordered as of today) EM-5 brings a futher improvement to the already brilliant m4/3 AF.

Peace guys

Marla.

P.S. I do have a DSLR, and will use it when needed.

Yes, but it still actually locked focus on the birds while they were flying.

zaurus said:

Marla2008 said:

In all honesty, maybe you guys could think abut the following question, if you had a paid gig or just-one-time shoot to do, would you bring your m4/3 set-up or DSLR ? Me just saying

Click to expand...

Is that your case? Do you absolutely necessary need to catch the first kiss of a groom and bride in a cramped badly lit church otherwise you don't get paid?

Click to expand...

isn't that hard.

[snip]

TEdolph

--

Perfection is achieved, not when you have nothing more to add, but when you have nothing more to take away

The smallest act of kindness is worth more than the greatest intention