August 22, 2014, 02:37:21 PM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - Sycotek

Pages: 1 2 [3] 4 5 ... 8
31
Last night I finally got a chance to test the AF in low light.  I shot a little tennis action with very poor flood lights.  70-200mm 1/1000s, F2.8, ISO12800.  IMO this is pretty poor lighting and the AF was incredible.  I did not notice any difference when using 12FPS or < 10FPS (I also tried the zone AF, which I never trusted much on the 7D, and it was amazing how the points danced around the players torsos - I was grinning ear to ear).  So in a nut shell, I'm very stoked with the AF performance.

I then decided to try and reproduce the H speed AI AF issue, and sure as nuts, in lower lighting situations the 12FPS AI AF just racked the lens back and forth.  Switch to 10FPS and locks first time.  I got home and tried the 5D II and it also locks first time.  This was by no means an extensive test and I did not try and find that exact lighting point where the 12FPS falls apart, but as a reference 70-200, F2.8, 1/80, ISO25800.

So thats +1 with a low light AF gremlin :(  (not that I'll ever shoot in these conditions in AI AF, but still . . .  .)

Any thoughts about the metering being 0-20ev and the af being -2ev-20ev ? I can' recall where I read the dx constantly meters the scene in servo which could be a reason?

32
I wondered about that, and if disabling iTR (which depends on the metering sensor) would help?  But I'm not sure how the change with frame rate would play into that hypothesis...

On my day 3 tested I did turn off iTr to see if it played into but seemed to do very little in terms of helping the situation - may rerun a few test at L 3fps and itr on/off in that basic 60w room setup rather then original -1 to 0 ev lowlight

33
Hi Guys:

I did notice something the other day - hopefully someone with more experience can tell me if this may possibly be why we have the issue

Metering Range EV 0 - EV 20 (at 73°F/23°C with 50mm f/1.4 lens, ISO 100)
The Canon 1Dx offers a 61-point autofocus system, with autofocus sensitivity from EV -2 to 20 at ISO 100 with an f/1.4 lens.

I'm on the working assumption that the meter tries to see the object prior to af acquisition - but if the meter is 2EV above the AF - it's not going to see what the AF can see?

Or am I way off the mark?

34
Exactly what Sycotek is saying.  I wouldn't normally have too much problem with this failing of the 1Dx in low light/contrast AI-SERVO tracking except for the 3 reasons below.

1.  In the same poor light/contrast situation my older 5D2, 5D Classic and 7D with center point all track in AI-SERVO just perfectly fine (in fact they seem to be as good in AI-SERVO as they are in ONE-SHOT under these conditions).  Whereas the 1Dx in the same exact condition totally craps out.  This seems pretty unacceptable given that it's AF is pretty amazing in every other way.

2.  The fact that when I change the Frames Per Second rate on the 1Dx from 12 to 10 or under, AI-SERVO definitely improves (even though it still totally blows compared to the older 5D2, 5D Classic and 7D).  This causes me to wonder why and if something strange is going on that perhaps Canon can address.  It can't hurt finding things like this out so that people much brighter than me at Canon might make our cameras better and better with firmware updates or whatever they need to to get the job done.

3.  Third, if this was in situations that were so inhumainly dark that nobody should ever even attempt to take a photo then I could just move on and just say that nothing is perfect.  However, where the 1Dx AI-SERVO fails is in moderately dark and low contrast situations.  In my line of work I have need of tracking subjects in a single lamp lighting situation and as it stands the 1Dx camera in AI-SERVO mode cannot be trusted for that.  Like Synotek I just need to know where the baseline is.  However, if that baseline totally sucks compared to Canon's other older cameras I think this is something that should be addressed.

4.  Lastly, in my experience this does not seem to be highly isolated.  My 7 friends and I (all with 1Dx and all received at different times, from different places and from different countries) have all confirmed this exact behavior on all our 1Dx cameras.  I would like to think it was isolated, but at least for us its 100% 7 for 7.

I'm on assignment now and can only respond sporadically, but I thank everyone for all the great interactions on this and all working together to try and solve this problem.  I trust that Canon folks are really smart and will figure something out soon.  Otherwise, this camera is totally amazing and the best I have ever used---even with this issue.


My way of thinking is i need to know where my gear is going to fail before it fails and costs me $$$.

I trust my 7D as for 2 years and 100K+ clicks still going strong - I know what conditions that body will fail me and I know how to get around it.

That's what I am trying to do with the 1DX is find a baseline where the gear gives out. The problem is the baseline is not that good if the 7D kicks the snot out of it for tracking in low light.

As it is I wouldn't trust the 1DX Ai Servo for a bridal waltz at this point - id get hire out a 1ds3 or 1d4 as i know they work perfectly fine in those conditions.

Edit: Case 1 to answer your question - default with first point focus lock priority (otherwise it will fire regardless of focus)

Agreed - even with the issues - you couldn't pay me to give it back - the shop did ask if i wanted them to hold on to it... I immediately yelled something that made me realise i had become a little too attached to my 1DX so much so it reminded me of golem from lor.

For everything that is wrong with it - there are situations i have been able to shoot in that i once could only dream - i hope canon fixes this issue as it is really a remarkable tool.




35
Is this using single point/expansion/zone AF?

Any AF mode

36
My way of thinking is i need to know where my gear is going to fail before it fails and costs me $$$.

I trust my 7D as for 2 years and 100K+ clicks still going strong - I know what conditions that body will fail me and I know how to get around it.

That's what I am trying to do with the 1DX is find a baseline where the gear gives out. The problem is the baseline is not that good if the 7D kicks the snot out of it for tracking in low light.

As it is I wouldn't trust the 1DX Ai Servo for a bridal waltz at this point - id get hire out a 1ds3 or 1d4 as i know they work perfectly fine in those conditions.

Edit: Case 1 to answer your question - default with first point focus lock priority (otherwise it will fire regardless of focus)


37
Thanks to all that have attempted to re-create this:

It's a given that the unit will not focus on -2ev low light via Ai-servo, that's only where the investigation started, if anythig the servo has issues around 1ev.

The real issue initial target lock (first frame) failing under low light - low light as in a normal light in a normal room trying to lock on a face.

7D has Ai-focus which I never use - I was comparing Ai-servo against the 1dx Ai servo. With that said the 7D af points are 4 times as large so target acquisition should be faster by default in low light.

I digress: try working in a normal room with an over head light and try locking on a persons face at 3fps and at 12fps with all points on and first point priority and attempt to lock on the targets face (say 180-200mm from 2m away). Now try an notice just how much faster 3fps is in terms of the af points "dancing" on the targets face.

At 12 fps majority of the time it drives my lens and locks up - if I rack the lens to 0 and attempt to focus the lens won't even rack... At 3-10fps the lens racks (actually tries to focus and gets a lock)

Standard 60w light in a 4x4 room isn't exactly low light ESP considering my gf is white skinned with dark hair and eyes.

The 7D regardless of frame rate gives me the initial lock immediately under the same conditions.

I here what you are saying but my 1DX doesn't have problems locking on target at -1ev like yours while in Ai Servo.  It only has issues at extremely low light coupled with low contrast with a static object.  12FPS works just fine for me in Ai Servo as I cannot reproduce your specific issue.  This leads me to believe there is something else going on here.  Perhaps a bad batch from Canon, but I cannot say.  All I know is what I have posted above.

Thank You! this is the first hint that it may be isolated!

38
I digress: try working in a normal room with an over head light and try locking on a persons face at 3fps and at 12fps with all points on and first point priority and attempt to lock on the targets face (say 180-200mm from 2m away). Now try an notice just how much faster 3fps is in terms of the af points "dancing" on the targets face.

At 12 fps majority of the time it drives my lens and locks up - if I rack the lens to 0 and attempt to focus the lens won't even rack... At 3-10fps the lens racks (actually tries to focus and gets a lock)

Standard 60w light in a 4x4 room isn't exactly low light ESP considering my gf is white skinned with dark hair and eyes.

The 7D regardless of frame rate gives me the initial lock immediately under the same conditions.

I'm not following what you are trying to point out or test?
Are you talking about AI Servo?  I guess that you mean AI Servo, since the AF points don't dance around in One Shot.
 
AI Servo requires the subject to change distance?

On my test if I understand you correctly, both frame rates at high speed and low speed seem to dance around similarly and if I had to pick one, I would say that the 12fps actually dances around more, but I'm not sure what you're trying to convey?

My camera had no problem focusing in AI Servo with a small light on.

The focusing limitations previously were related to low contrast in AI Servo with a subject that is not changing distance, and not necessarily a low light issue, although that doesn't help the situation.

Hi Richard, Thanks for replying :)

The original issue was the Ai Servo and contrast in low light - correct, there is a definite discrepancy between ai-servo and one shot ability to focus on objects in low light - but the reason for it being an major issue (to me anyway) is you can't track what you can't lock onto initially: if the lens doesn't rack or the lens racks to infinity and stops when trying lock onto an object - stationary or otherwise - then you can't track that object to start with. Example - this initial became apparent when trying to track my cousin moving around the house, with a fair amount of house lights on.

My camera exhibits this issue in lighting conditions that it should have no issue in (the 7D for example locks regardless) - same as justaphotographer and the in-store demo unit. However that inability to lock onto the target isn't noticed when enabling 10 fps or lower, there is no issue with re-racking the lens and the af points move over the object at a noticeably higher rate then at 12 fps.

I do apologise for the confusion - I hope this is a little clearer.

39
Thanks to all that have attempted to re-create this:

It's a given that the unit will not focus on -2ev low light via Ai-servo, that's only where the investigation started, if anythig the servo has issues around 1ev.

The real issue initial target lock (first frame) failing under low light - low light as in a normal light in a normal room trying to lock on a face.

7D has Ai-focus which I never use - I was comparing Ai-servo against the 1dx Ai servo. With that said the 7D af points are 4 times as large so target acquisition should be faster by default in low light.

I digress: try working in a normal room with an over head light and try locking on a persons face at 3fps and at 12fps with all points on and first point priority and attempt to lock on the targets face (say 180-200mm from 2m away). Now try an notice just how much faster 3fps is in terms of the af points "dancing" on the targets face.

At 12 fps majority of the time it drives my lens and locks up - if I rack the lens to 0 and attempt to focus the lens won't even rack... At 3-10fps the lens racks (actually tries to focus and gets a lock)

Standard 60w light in a 4x4 room isn't exactly low light ESP considering my gf is white skinned with dark hair and eyes.

The 7D regardless of frame rate gives me the initial lock immediately under the same conditions.

40
@Sycotek and other affected users:  Question on settings - how are the AI Servo 1st and 2nd Image Priority set?  Obviously, with Release priority and Shooting speed priority, OOF shots could be taken.  The manual indicates with Equal priority for the 2nd image, shooting may slow down.  Have you tried setting it to Focus priority for 1st and 2nd?  If it's set to the default (equal priority), I wonder if the camera is inappropriately weighting the shutter release over focus?

The stock 1DX was used as straight out of box (we were watching the flickering green light to signify no focus lock)
My 1DX is set to 1st frame af priority (will not release without af lock)

Watch the green light flicker - easy to see that its out of focus that way. We got the store unit to even halt the lens as it does on mine.

I am in contact with Canon Australia's National Account Manager - and one of the heads of CPS Australia (so I have come to realise)

Since isolating the issue I haven't heard back other then I was jumping the gun a little. I have sent further proof (stock unit repeated issue) and no response as yet - but they do take a few days to get back to Me. Hopefully tomorrow - Although seeing as we tried to warn them prior to the oly games they may wait till its over before bringing it to light.




41
Do you have problem trying to select the AF point with the multi-controller? It's not responsive with my 1Dx. Let me know if you have the same problem. I'm wondering if it's just my 1Dx or it's the same with all 1Dx

thanks

I can't say I have that issue - however You need to enable it - if you haven't then turn the unit on - hit [Q], custom config, select multicontroller (bottom right) and set it to af selector.

42
I would just like to thank all the members that have contributed to this thread.  I'm sure, like me, there are many 1D X owners and soon to be owners following your updates with interest.
I speak for all of us when I say that we appreciate the time you take to post your findings.
Thank you
Peter

:) Hopefully it's isolated and clearly it wont affect everyone as we all shoot in different conditions.

But for those that it does effect - if they could just make note and say if they noticed the issue then we can estimate how wide spread the problem is.

I would love it if its only a handful of bodies - less issues for canon.

In all honesty I was hoping the new shop unit would not show the issue so I could just swap them over and get on with my job.


43
Replicated issue with a brand new 1DX at the store I bought mine from. It's not isolated as I had hoped - staff can't believe it either.

Waiting on Canon now

44
Fashion, and landscapes basically with the 5D3

When i took them back to the store they could visibly see the banding on the back lcd screen it was that bad. So they refunded them without question.

Some people believe i got bad copies - but I'm not game to buy a 3rd.

Metering is very very accurate on the 1DX - i believed it was 0.5 under each shot but if you look at the target points RBG values its protecting the target from blowing a channel - its rather interesting how they did it. It's not right to my eye but its correct via histo.

The 5D3 is basically identical to the 7D (which to my eye always looked good).

I've owned both so was just giving a little input to someone looking at moving up the series. It may not fall inline with everyones experiences but they are mine :)

I agree, if your 5D3's are gone and you have a 1DX, no need at all to have a 5D3 if you don't currently have one.  Here's what I'm going to do.  For football and track, which are outdoors, I'll shoot with the 1DX and 1D4.  For indoor sports, I'll use 1DX and 5D3.  No flash allowed anywhere in indoor sports, especially college.  And for night football games or night sports outside, I'll probably shoot with the 1DX/5D3 combo again.  Also, I can use the 1DX/5D3 combo for weddings.  My 1Ds3 is great for ISO 50-400 shots outside, and fantastic for landscapes, but that stuff doesn't make me any money.  I'd like to take on senior pictures, which in that case I could use the 1Ds3/5D3 combo.  However, I'm not narrow minded enough to believe that the 1DX's 18mp wouldn't be enough vs. the 5D3's 22.  Time will only tell and it could very well end up I sell some cameras and get another 1DX or even a newer camera that comes out.  I am impressed so far though, with the 5D3's and 1Ds3's color.  I did print a few mini-posters and those 21 and 22 mp's came in handy.  Sports though, who knows, I could end up having to shoot in jpeg.  Canon made too many good cameras :)

I love the new jpeg engine - shockingly i shoot a fair amount of work in jpeg now more so where there is good light...

esp when im sending images off at 10MP - shoot and upload no real need for processing as the body does a great job.

45
Fashion, and landscapes basically with the 5D3

When i took them back to the store they could visibly see the banding on the back lcd screen it was that bad. So they refunded them without question.

Some people believe i got bad copies - but I'm not game to buy a 3rd.

Metering is very very accurate on the 1DX - i believed it was 0.5 under each shot but if you look at the target points RBG values its protecting the target from blowing a channel - its rather interesting how they did it. It's not right to my eye but its correct via histo.

The 5D3 is basically identical to the 7D (which to my eye always looked good).

I've owned both so was just giving a little input to someone looking at moving up the series. It may not fall inline with everyones experiences but they are mine :)

Pages: 1 2 [3] 4 5 ... 8