My point is more to do with merchantable quality of goods. If Canon advertises a feature, then that feature should be usable. It is reasonable to expect that AF could be left on, as zooming in and out is normal behaviour whilst filming something. AF cannot be left on during very slow zooms on the long end of the lens, because it produces an unpleasant effect on screen.

It's like advertising a car that has self-leveling suspension, but not mentioning that you can't drive it up hills.

Hear you. But even zooming in the shot is something I only do for dramatic reasons, combining that with AF... I think normal AF is workable if you follow a moving object or pan from figure A to B and need to do refocus. If you use a mattebox, the AF Instant focus version is blocked anyway, so only nomal AF is working. And it works!

I think that Canon was so happy with the 'speedy AF two way instant focus system' that the marketing department only told you the goodies.. But I remember the Panasonic HVX200 without saying what the real CCD resolution was...

Michael: there are many very happy A1 shooters at work on the moment I did not hear anyone complaining like you do. You complain about everything.

We all know that the A1 is a very good camcorder, that goes without saying. I am a (quite) happy A1 user myself. But I don't think it would bring users in this forum any further if we only sing our praises. To know the cams limitations - that's important as well. Because maybe weak points could get fixed in the future.

Therefore my intention is not to complain but to observe and to share. Period. And if there are weak points - I don't want to draw the curtain over them.

Can you try to shake the camera hard (what you did before) while zooming with AF on at the same moment, and describe what is happening? If you can't see it on monitor, try a 42" screen, please report your findings.
What exactly do you want me to find out? Please explain, thank you. (But I don't have a 42'' screen).

Meanwhile I had a phone call with Canon Service in Germany.
The service member promised to watch the demonstration clips (http://www.filefactory.com/f/f5656740836b15ad/) to unterstand the problem. And he promised to call me back as soon as possible.

I will keep you informed ...

Thank you Michael. I look forward to hearing what Canon have to say about this issue.

I just received a phone call (conference call) by a Canon Service team in Germany:

(1) They had watched the two demo clips and they DID notice the focus pulsing problem. They asked me about further technical details (distance to object, f-stop).

(2) Their first guess was that the two clips show EXTREME lighting situations: low contrast boy in front of low contrast tapestry; low lit woman in front of bright background lighting. (I agreed but replied that the problem occurs under NORMAL lighting/contrast situations just the same.)

(3) Their second guess was that the problem might occur in long telephoto focal lengths and/or open iris zoom shots only. (I replied that more or less depth of field sure makes this problem less or more visible, but the pulsing DOES NOT DISAPPEAR in medium focal length and/or medium f-stop zoom shots.)

(4) Their final guess was that this AF pulsing is NOT FIXABLE - not even via firmware update - but probably is related to the design of the AF system. (I put into perspective that there ARE cams on the market that do not show this problem, e.g. the FX1.)

(5) The Service team promised to forward the information to Japan.


Chris, could you please change the title of this thread, since it may mislead fellow users as well as Canon when browsing through this forum. The problem remains NOT SOLVED. Thank you.

I have exactly the same focus problem with my A1 (PAL). There is only one solution: disable AF and use manual focus. I would be also happy if Canon could fix it.

Nevertheless, the camera is really professional...

Thanks Michael for your report. I suspect current owners are not likely to see a fix, so as Gabor says, the only workaround for this "quirk" is to keep AF off.

In almost every other respect this is a great camera.

I just received a phone call (conference call) by a Canon Service team in Germany:

(4) (I put into perspective that there ARE cams on the market that do not show this problem, e.g. the FX1.)



Since I owned the Z1, I've got some perspective on that too. The Z1 could not auto-focus when shooting into the sun or strong backlighting. I think this is a case of selective memory where the grass always seems greener on the other side of the fence.

Shooting low contrast subjects at long focal lengths it seems you lacked proof and were not convincing to the Canon Service team that this is a serious problem.

Nothing is more irritating than when someone with a problem gets replies from others who say "mine doesn't do that!" And while I don't dismiss the seriousness of the problem for you, for me it's not happening at all. So while I have no idea how many cams are affected, I know that not all of them are.

But if I felt as strongly about it as you do, I would return or sell the A1 and go back to the Z1. But no regrets here. The A1 picture quality and control is superior, even given some of the other limitations like the smaller LCD screen or lack of an OIS button. The eyes have it.

Thanks Tom for your input.

Just to be clear, you're saying that your A1 does NOT show any symptoms of focus "pulsing" at long focal lengths in AF mode (in 24F or 30F)?

Makes me feel a little miffed that I've managed to get two units in a row that DO show this problem.

Still like you say, the picture quality is so much better than my FX1, and I leave AF on so infrequently that in lieu of any response from Canon, I'm happy to live with the quirk.

Thanks Tom for your input.

Just to be clear, you're saying that your A1 does NOT show any symptoms of focus "pulsing" at long focal lengths in AF mode (in 24F or 30F)?

I did not try 24F or 30F. No focus pulsing at 60i remotely resembling what you had in your first A1. Also your first clip, the one of the bag on the patio deck was not a long focal length. THAT test I tried to duplicate, i.e. a low contrast object from 8-10 feet and there was no hint of the extreme herky-jerky focus pulsing I saw in your video.

I will try 24F and 30F shortly and report my observation here.

Wait...Alex, tell me how you want me to run the test, so I can best duplicate the conditions.

<snip>
I will try 24F and 30F shortly and report my observation here.

Looking forward to your findings Tom. I've been able create shots that have focus pulsing in 24F but nothing but perfect focus in 60i (haven't tested 30F).

I just shot the 24F. Need a few minutes to capture and play it back.

Indoors on tripod
OIS off
F3.7
1/100th
-3db
Diffuse light from window
10 ft focal distance
zoomed from 30% to 95% at preset zoom speed 4

etc...

Now to review the result, standby...

First observation...Wow...24F is gorgeous! The only other time I tried it was when I posted IMATEST MTF50 resolution results which showed the vertical resolution to have a drop of 10.6%. But I don't know how you can spot it in actual video. Beautiful!

Second Observation: I did (5) zooms from about 30% to 95%. The first zoom I did with the remote control, and it was faster than the zoom (4) setting on the rocker switch for some reason, too fast in fact. On the second and third zooms I used the rocker but realized OIS was on. There was no deleterious effect from OIS being on. Great! Only the 5th zoom was OIS off. Really no difference or harm having it switched on while on the tripod. Where it likely would pose the problem would be when panning. Anyway, I do mostly the run 'n gun shooting so OIS is always on for me.

Third Observation: I'm saying this as honestly as I can, but I think the autofocus while zooming in 24F from what I just saw is awesome. I viewed the playback footage on a 50 inch DLP from 7 ft. I wouldn't fathom returning this cam for such an alledged defect. Does that mean I saw no focus pulsing? No, because actually in about 3 of the zooms I can see some extremely minor pulsing during the zoom. It took 4-5 viewings before I spotted anything at all. In one case, I can see an extremely minor pulsing after the zooming stopped. In other cases after the zooming stops, it looks like a still photograph, perfectly motionless. In all instances, it was pixel peeping carried to the extreme. Does this mean that Alex, Michael and Philip are more sensitive or bothered by it? It's really hard to know because we are not looking at the same cam or the same conditions. I'm trying to rule out things that are already acknowledged to be autofocus exceptions like poor contrast or vertical patterns, so the cam has a fair chance to find its expected focus. The test scene presented no problem for the cam.

Fourth (a speculation): This is the one I can't discount. Alex's first cam. The picture of a black nylon bag laying on a wood deck in flat light, a very featureless scene. The focus was simply jumping up and down like hot oil on a frying pan. I've yet to remotely see anything that duplicates that ugly behavior. Now Alex has a replacement camera, and I thought he acknowledged it was substantially better. But is it a case where you are so traumatized by the recollection that you continue to see it everywhere? The cliche' is, if all you have is a hammer, then everything starts looking like a nail!

Fifth observation: In the test scene next to Santa's right ear, there is a gold ribbon that is 1/4 inch wide. Zoomed in from 10 feet, you can see incredible detail to the weave. I'm going to post a 100% crop of that detail at its sharpest and at its worst to illustrate the focus pulsing delta. It isn't much.

But if I felt as strongly about it as you do, I would return or sell the A1 and go back to the Z1.

No, Tom, you probably got me wrong. From the first moment I watched 25F clips of my new A1 on my computer display, I had no more intention at all ever to go back to the FX1. The overall image quality is so much better.

But I might return my A1 if there is a realistic chance that I get a "non-pulsing" unit in exchange, like Alex tried.

So, thanks for you testing, Tom. Could you upload one of your 24F demo clips?

Being objective means remaining open minded about observations. It's a work in progress to remain unbiased, and the opinion has to be open to change as the data accumulates.

What I said in the previous post is how I feel about it viewing 24F on the 50 inch big screen in motion. Looks great.

But what's become obvious using the NLE to step through the frames is the image is going out of focus about every 3-5 frames during the zoom, exactly as has been noted. It's subtle, but undeniable.

The pulsing stops when the zooming stops.

Yes, sometimes its so subtle that its really not noticeable. As I stated earlier in this thread, I plan to just use manual focus in 24F mode from now on anyway, so its a moot point for me. But if I felt the need to use auto focus in 24F I'd certainly do so; the pulsing I've seen isn't a show stopper and I don't exactly record THAT many zooms anyway :)

As for the overall quality of 24F, yes its amazing. The detail is stunning, the motion is perfect and I have yet to break the codec in 24F mode (I've tried).

So, thanks for you testing, Tom. Could you upload one of your 24F demo clips?

Yes, I have an m2t clip to upload. It's 45mb and I'm on dialup so this could take awhile, be patient it's coming.

Yes, I have an m2t clip to upload. It's 45mb and I'm on dialup so this could take awhile, be patient it's coming.
45 meg on dial-up? You are a brave and patient soul sir.

45 meg on dial-up? You are a brave and patient soul sir.

What? I'm 28% there! Only 2.5 hours to go!
Lol...

Right Click, Save Target As...

http://vsdrives.com/movies/StNick.m2t

Wait...Alex, tell me how you want me to run the test, so I can best duplicate the conditions.

Sorry I didn't reply (I was asleep)! :-)

Thanks very much for running the test Tom. Yes, I agree with you that there is a tiny amount of pulsing in the clip - but it's barely visible... very comperable to the amount of interference I see on my camera.

I really appreciate the fact that people have been working together to discover one of the limitations of this camera. It's only by knowing what you can and can't do that you end up being more assured of coming home with usable footage when you're out in the field.

Personally, what I'm taking from this is that when in frame mode AF definately stays off, and I'll spot focus with the IAF button.

That matches how I work normally anyway, but it's good to know what I can and what I can't rely on.

Even with AF on I agree that the pulsing is probably going to be barely noticable in 99% of situations.

Once again, for me this "quirk" does not devalue the camera. The images are absolutely gorgeous and blow my FX1 out of the water!

Tom, thanks for sharing your clip. After watching it my impression is that "my" pulsing is stronger than yours. Anyway, I will not return my A1 since I don't consider it very likely now that the AF of the exchange unit will work any better. AF during zooms stays off from now on.

I really appreciate the fact that people have been working together to discover one of the limitations of this camera. It's only by knowing what you can and can't do that you end up being more assured of coming home with usable footage when you're out in the field.
Yes, that's how I feel about it, too. I very much appreciate this kind of regardful constructive cooperation - the more when it's about possible malfunctions. (It's very easy - but not very rewarding - to praise benefits together. It's much more delicate when it's about limitations - but it pays off!) Thank you, Tom. Thank you, Alex.

Personally, what I'm taking from this is that when in frame mode AF definately stays off, and I'll spot focus with the IAF button.
I never used the IAF botton before - for me it was either AF or manual focus. But since I will stick with the A1 (and with 25F!), I want to learn to work that way (Manual focus plus IAF botton when changing focus plane). I' d love to sharing experience in working that way.

I totally agree with you both. I'm especially relieved you saw what you needed so as not to needlessly return the cam for service based on opinions alone. The video clip I think really helped there.

If you just have to use IAF on a slow zoom, try changing the AF response speed from the Cam Controls menu. It makes any 'focus pulse' artifact less noticeable. Unfortunately it also retards the IAF push-button when in Manual Focus mode. I kind of like the slow focus mode but would like the IAF button to be fast during over-ride. Only two speeds here, fast or normal (slow...)

Full manual focus/exposure for zooms with any complexity seems to be best.

I just woke up from a strange dream where Microsoft had redesigned the menus on the A1 - it kept popping up confirmation and password screens everytime I changed a parameter. Too scary!

We're sorry, Canon A1 needs to close. Would you like to send a report to Microsoft?

But seriously, the focus speed preset might be an answer for the pulsing. I'm also wondering if servo vibrations while on the tripod have anything to do with it. I can't see any pulsing on handheld with OIS enabled.

... the focus speed preset might be an answer for the pulsing.
Yes, indeed. I never changed the default AF response speed to see if the pulsing might disapperar. But I will test this. Thanks for your proposal, Jay.

I can't see any pulsing on handheld with OIS enabled.
I do, Tom. All my "pulsing" slow zoom shots were handheld with OIM on. But I will test slow zooming with OIM switched off.

I do, Tom. All my "pulsing" slow zoom shots were handheld with OIM on. But I will test slow zooming with OIM switched off.

Okay then. I have to look closer for that.

Meanwhile I have done some slow zooms with AF switched off - no focus pulsing anymore. So far, so good. Then I turned my focus ring and ... nothing happend:

I cannot change my manual focus while zooming!

Please help! I must have overseen something, right?

Meanwhile I have done some slow zooms with AF switched off - no focus pulsing anymore. So far, so good. Then I turned my focus ring and ... nothing happend:

I cannot change my manual focus while zooming!

Please help! I must have overseen something, right?

Nope, you can't focus and zoom at the same time. One motor for both functions I believe, so you can do one or the other.

Nope, you can't focus and zoom at the same time. One motor for both functions I believe, so you can do one or the other.
Darned! That's bad. And the manual does not say anything about this limitation.

I'm not so sure that the explanation of "one motor for both functions" is correct, but the fact remains that you can't zoom and focus at the same time on any DV or HDV camcorder that has an auto servo lens.

... you can't zoom and focus at the same time on any DV or HDV camcorder that has an auto servo lens.
I didn't know that. Thanks, Philip and Chris.

I put my right hand inside the wrist strap to hold the cam, my left hand underneath for support with my thumb on the zoom ring. Then I use my third hand to operate the focus ring. Is this how you are doing it?

At last Tom, you admit to being a mutant. I had my suspicions all along.

My own technique is left hand under the lens, thumb and first finger on either side of the focus ring. Second finger on the right side of the zoom ring, up behind the XLR block. Third finger on the iris ring if needed.

I put my right hand inside the wrist strap to hold the cam, my left hand underneath for support with my thumb on the zoom ring. Then I use my third hand to operate the focus ring. Is this how you are doing it?
Sure, Tom, normally I would have done so ...
No, seriosly: I was zooming with the upper lever (speed 3) and turning the manual focus ring at the same time trying to make a focus "jump".

My own technique is left hand under the lens, thumb and first finger on either side of the focus ring. Second finger on the right side of the zoom ring, up behind the XLR block. Third finger on the iris ring if needed.
Aha! Your hand is attached upside down!

Actually, I'm almost always on a tripod and like my index finger close to the AF button so I do it the other way round.

Just KNEW you wanted and needed that info.

At last Tom, you admit to being a mutant. I had my suspicions all along.

My own technique is left hand under the lens, thumb and first finger on either side of the focus ring. Second finger on the right side of the zoom ring, up behind the XLR block. Third finger on the iris ring if needed.

Lol...

I'm going to try that, but 3 or 4 fingers operating the rings is guitar-like dexterity I don't have, plus you have to get accurate focus feedback from the eye and maintain the framing. Would you really juggle those 3 rings together at once?

Meanwhile I did some tests to check whether AF response speed (low, middle, high) has any influence on the frequency of the focus pulsing:

My first impression is, that it has no influence.

Would you really juggle those 3 rings together at once?

Oh for a double armed tripod, with focus demand under one hand and zoom demand under the other.

Meanwhile I did some tests to check whether AF response speed (low, middle, high) has any influence on the frequency of the focus pulsing:

My first impression is, that it has no influence.

Yes, I agree. I also couldn't see any difference in the pulsing.

Oh damn.. I totally forgot about this point (currently planing to switch from DVX100 to the A1) ... can the A1 be switched to manual zoom somehow? This is a really great feature of the DVX so you can do "real" (manual) crash zooms and stuff... please don't tell me the A1 only has a servo controlled zoom *sigh* :-(

Oh damn.. I totally forgot about this point (currently planing to switch from DVX100 to the A1) ... can the A1 be switched to manual zoom somehow? This is a really great feature of the DVX so you can do "real" (manual) crash zooms and stuff... please don't tell me the A1 only has a servo controlled zoom *sigh* :-(

Sorry dude, I think its all servo. I think that manual zoom on the DVX is really one of those features that seperated it from the pack.

Oh damn.. I totally forgot about this point (currently planing to switch from DVX100 to the A1) ... can the A1 be switched to manual zoom somehow? This is a really great feature of the DVX so you can do "real" (manual) crash zooms and stuff... please don't tell me the A1 only has a servo controlled zoom *sigh* :-(

No crash zooms on the A1, (also not on the Sony's Fx1, Z1, V1, etc.) If that is important for you and you want to make the step from dvx to HD, take a look al the all manual JVC lenses. You lose auto focus, OIS.

No crash zooms on the A1, (also not on the Sony's Fx1, Z1, V1, etc.) If that is important for you and you want to make the step from dvx to HD, take a look al the all manual JVC lenses. You lose auto focus, OIS.

Z1 and FX1 do have crash zoom.

XH cameras have an option called "quick zoom." It's like the Z1 and FX1 feature in that it's as close as you can get to a crash zoom with an auto servo lens.

As chris pointed out the quick zoom feaure is pretty fast, but isn't as responsive and has a slight delay, compared to the realtime on the DVX.

It shouldn't be a dealbreaker for you though, the I use the quick zoom all of the time with good results.

Sorry wrong topic, post deleted...

Z1 and FX1 do have crash zoom.
I cannot verify this anymore since I sold my FX1:
Can you manually zoom AND focus at the same time?

You can (almost) crash zoom on the FX1 or Z1 by flicking the zoom switch to "lever" and then twisting the zoom ring to the other end of the zoom. When you flick the switch back to "ring" the zoom speed is about a second from one end of the lens to the other.

With high speed zoom on the A1 you can get from one end of the lens to the other in about 2 seconds - though it has a longer reach, but by my perception it's not even as "crash-like" as the Z1.

Michael, I've just checked and the Z1 and FX1 can be zoomed AND focused at the same time, both using the zoom ring and focus ring or the zoom lever and focus ring.