I thought the 70D AF System handled fluorescent better.....not....

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Maybe is not the spectrum of the light but the quantity - too low light for fast focusing and tracking . Neither the 40D nor 70D are known to focus fast or very accurate in low light compared with 6D for example. Both 40D and 70D autofocus sensitivity goes down to -0,5EV which is not quite impressive. In good light the tracking of 70D is very good as we know, but in low light could be different. I have both cameras, but I didn't tested and compared the focus in difficult light conditions, but you gave me an idea...

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

That is to be expected. The flicker with fluorescent lighting is what causes the problem. And the faster the AF system on the camera is, the worse the problem becomes. That is because it is more likely to try and focus during one of the down cycles of the flicker. Slower AF can often ride across the flicker better.

Dale Buhanan said:

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

That is to be expected. The flicker with fluorescent lighting is what causes the problem. And the faster the AF system on the camera is, the worse the problem becomes. That is because it is more likely to try and focus during one of the down cycles of the flicker. Slower AF can often ride across the flicker better.

--
kind regards
Dale
Moderator Canon Powershot and 7D/XXD forums

Click to expand...

Makes sense Dale. I figured it was the quality of the lighting that was impacting it.

What makes me believe this is the 40D does better and since it does have a slower AF System it fits your theory. Not a perfect theory but it fits. The other part is all the 70D frames varied in exposure and color temp. Much worse than the 40D's images under the same conditions.

The ones where the WB was more accurate focused better. I checked some exif data and the 40D shots I had luck with were at 1/250th to 1/320th. Again, not all keepers but a good rate. Last night on the 70D I pushed the shutter speed higher to over 1/500 as the kids are getting bigger, faster and I wanted to exploit the fact that with the 70D higher ISO's aren't an issue. There appears to be a direct correlation with the flicker rate of these bulbs and shutter speed. Especially since the WB was so darn weird. Some images were 1/2 and 1/2 colors temps as if when the curtain was closing the light was changing mid-shot. Even if they were in focus, the WB adjustments would have been murder.

I went out and tested my 24-70L this morning on a target on my garage door in decently lit morning light but no direct sun and it was spot on across the range even with AIServo engaged. Thus I'm less concerned about the lens now. If need be, I'll send it to Canon with the camera for evaluation, etc.

Next time I'm going to use my 580ex to help out.

--
"If you're not having fun at whatever it is you're doing, you're doing it wrong"

Been doing some searching on the impact of fluorescent lighting on AF Systems but if anyone has any good links to read up on, I'd appreciate it. I'm sure I'm not the first to encounter this.

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

What focus mode?

What AF point selection mode?

What lens were you using?

Looking at your gear list I don't see any lens that I would pick. The 24-70 f/2.8L maybe, but, f/2.8 is a stretch for an APS-C camera indoors. The 50mm f/1.8 no way, its slow old focus motor is not suited to action photography. The 35mm f/2 too wide angle for sports in my opinion. Tamron 70-200 f/2.8 again f/2.8 is a stretch for APS-C indoors, I know Tamron's USD drive motor is supposed to be better, but, my experience with older Tamrons in the past is that their focus was awful in low light. The 100-400 L I wouldn't try indoors even on my 6D.

Before I purchased my 6D I used the EF 85mm f/1.8 exclusively for indoors sports. Having the 6D opened me up to using my Sigma 70-200 f/2.8.

pdqgp said:

Been doing some searching on the impact of fluorescent lighting on AF Systems but if anyone has any good links to read up on, I'd appreciate it. I'm sure I'm not the first to encounter this.

Click to expand...

I've never experience focus issues because of florescent lights. Metering, white balance and noise issues most definitely.

TTMartin said:

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

What focus mode?

Click to expand...

Single point. Tried groupings, but it would tend to focus on extended hands / arms vs faces.

TTMartin said:

What AF point selection mode?

Click to expand...

Center, but the 70D, they all work great.

TTMartin said:

What lens were you using?

Click to expand...

see below

TTMartin said:

Looking at your gear list I don't see any lens that I would pick. The 24-70 f/2.8L maybe, but, f/2.8 is a stretch for an APS-C camera indoors.

Click to expand...

The 24-70L works great inside. We have big rooms in our house, etc., but also the Karate Studio is big too. It's a bright lens and focuses fast as well.

TTMartin said:

The 50mm f/1.8 no way, its slow old focus motor is not suited to action photography. The 35mm f/2 too wide angle for sports in my opinion.

Click to expand...

I don't use either for anything moving.

TTMartin said:

Tamron 70-200 f/2.8 again f/2.8 is a stretch for APS-C indoors, I know Tamron's USD drive motor is supposed to be better, but, my experience with older Tamrons in the past is that their focus was awful in low light. The 100-400 L I wouldn't try indoors even on my 6D.

Click to expand...

The new Tamron is every bit as fast as my old Canon 70-200. Excellent lens overall. Turned VC off as it doesn't have a panning mode and movements are erratic anyway. It's good for indoors at Karate as it allows for full body shots isolating my kids and at 200mm I can zoom in on their torso. Sadly, both were experiencing the same issues, thus I know it's the body. Especially since the Tamron is a tack-sharp lens on my 70D elsewhere.

TTMartin said:

Before I purchased my 6D I used the EF 85mm f/1.8 exclusively for indoors sports. Having the 6D opened me up to using my Sigma 70-200 f/2.8.

Click to expand...

--
"If you're not having fun at whatever it is you're doing, you're doing it wrong"

pdqgp said:

TTMartin said:

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

What focus mode?

Click to expand...

Click to expand...

I just want to confirm you were using AIServo.

And what shutter speed and ISO setting were you using?

pdqgp said:

Single point. Tried groupings, but it would tend to focus on extended hands / arms vs faces.

pdqgp said:

What AF point selection mode?

Click to expand...

Center, but the 70D, they all work great.

pdqgp said:

What lens were you using?

Click to expand...

see below

pdqgp said:

Looking at your gear list I don't see any lens that I would pick. The 24-70 f/2.8L maybe, but, f/2.8 is a stretch for an APS-C camera indoors.

Click to expand...

The 24-70L works great inside. We have big rooms in our house, etc., but also the Karate Studio is big too. It's a bright lens and focuses fast as well.

pdqgp said:

The 50mm f/1.8 no way, its slow old focus motor is not suited to action photography. The 35mm f/2 too wide angle for sports in my opinion.

Click to expand...

I don't use either for anything moving.

pdqgp said:

Tamron 70-200 f/2.8 again f/2.8 is a stretch for APS-C indoors, I know Tamron's USD drive motor is supposed to be better, but, my experience with older Tamrons in the past is that their focus was awful in low light. The 100-400 L I wouldn't try indoors even on my 6D.

Click to expand...

The new Tamron is every bit as fast as my old Canon 70-200. Excellent lens overall. Turned VC off as it doesn't have a panning mode and movements are erratic anyway. It's good for indoors at Karate as it allows for full body shots isolating my kids and at 200mm I can zoom in on their torso. Sadly, both were experiencing the same issues, thus I know it's the body. Especially since the Tamron is a tack-sharp lens on my 70D elsewhere.

pdqgp said:

Before I purchased my 6D I used the EF 85mm f/1.8 exclusively for indoors sports. Having the 6D opened me up to using my Sigma 70-200 f/2.8.

Click to expand...

--
"If you're not having fun at whatever it is you're doing, you're doing it wrong"

Click to expand...

TTMartin said:

pdqgp said:

TTMartin said:

pdqgp said:

So I went and shot my kids at Karate. Lighting is horrible. The ceiling is lined with old bare bulb fluorescent tubes that consistently return ugly tones, yellow, blue, white, pink hues all over as the lights flicker and impact even full speed shooting.

My 40D struggled but did lead me to get a number of really good shots. I took the 70D tonight and to utter disappointment, I just deleted every damn image as the focus was so poor.

I thought the newer AF Systems handled fluorescent lights better?

Thoughts?

Click to expand...

What focus mode?

Click to expand...

Click to expand...

I just want to confirm you were using AIServo.

Click to expand...

Yes. However, on single point works very well when shooting their "forms" which end with a strong pause in all movement.

TTMartin said:

And what shutter speed and ISO setting were you using?

Click to expand...

On the 70D auto ISO and last night perhaps too high of a speed of 1/500+ On my 40D I shot slower speeds. Explained earlier in my posts here.

pdqgp said:

TTMartin said:

What focus mode?

I just want to confirm you were using AIServo.

Click to expand...

Yes. However, on single point works very well when shooting their "forms" which end with a strong pause in all movement.

Click to expand...

You should be using AIServo for everything.

Keep in mind the focus system needs adequate contrast to focus. If your focus point is on their white gi the camera may not have sufficient contrast to focus.

My suggestion would be to put your active focus point on their head. This is best accomplished by using the upper focus point.

The camera remembers the focus point based on the orientation, so when you turn the camera between portrait and landscape orientation, the focus point is change automatically to the then upper focus point, after you set it there one time after turning the camera.

If you still have issues, you can micro focus adjust your lens. But, I'm guessing it was trying to focus on the relatively low contrast gi.

pdqgp said:

pdqgp said:

And what shutter speed and ISO setting were you using?

Click to expand...

On the 70D auto ISO and last night perhaps too high of a speed of 1/500+ On my 40D I shot slower speeds. Explained earlier in my posts here.

Click to expand...

edit: 1/500 is not too fast, it is on the low end for action photography. Also, make sure your auto ISO maximum is set no lower than ISO 6400.

If you haven't watched these videos, or even if you have, but, its been a few years, then watching all three videos will be time well spent.

A Look at The Canon Autofocus System

TTMartin said:

pdqgp said:

TTMartin said:

What focus mode?

I just want to confirm you were using AIServo.

Click to expand...

Yes. However, on single point works very well when shooting their "forms" which end with a strong pause in all movement.

Click to expand...

You should be using AIServo for everything.

Click to expand...

I would rephrase that and say everything that's known to have movement. In the case of their forms, they usually pause at specific points of movement and I would then see great results with single point. Servo could work, but works best if combined with rapid firing as if servo doesn't see the movement it's anticipating, as noted in the videos, it will freak out.

TTMartin said:

Keep in mind the focus system needs adequate contrast to focus. If your focus point is on their white gi the camera may not have sufficient contrast to focus.

Click to expand...

No, there dobok's are easy to focus on with plenty of contrast.

TTMartin said:

My suggestion would be to put your active focus point on their head. This is best accomplished by using the upper focus point.

Click to expand...

I try. Sometimes it's difficult with groups of people crossing in front of them. Gotta work with what you have access to.

TTMartin said:

The camera remembers the focus point based on the orientation, so when you turn the camera between portrait and landscape orientation, the focus point is change automatically to the then upper focus point, after you set it there one time after turning the camera.

Click to expand...

Yep. Love that feature.

TTMartin said:

If you still have issues, you can micro focus adjust your lens. But, I'm guessing it was trying to focus on the relatively low contrast gi.

Click to expand...

The biggest problem I think is the flicker. No doubt the lighting is confusing the system. Otherwise the 70D has been awesome. I'll keep practicing with perhaps some other settings.

TTMartin said:

TTMartin said:

TTMartin said:

And what shutter speed and ISO setting were you using?

Click to expand...

On the 70D auto ISO and last night perhaps too high of a speed of 1/500+ On my 40D I shot slower speeds. Explained earlier in my posts here.

Click to expand...

edit: 1/500 is not too fast, it is on the low end for action photography. Also, make sure your auto ISO maximum is set no lower than ISO 6400.

Click to expand...

I agree that 1/500th is too fast for the movement, but rather I meant it was causing more grief when combined with the lighting flicker. Lower speed shutters seemed to work better. At least with the 40D system. ISO Wise, I always leave it open to hit 12,800. 70D noise is no where near a concern for me.

Thanks for the continued feedback.

pdqgp said:

TTMartin said:

pdqgp said:

TTMartin said:

What focus mode?

I just want to confirm you were using AIServo.

Click to expand...

Yes. However, on single point works very well when shooting their "forms" which end with a strong pause in all movement.

Click to expand...

You should be using AIServo for everything.

Click to expand...

I would rephrase that and say everything that's known to have movement. In the case of their forms, they usually pause at specific points of movement and I would then see great results with single point. Servo could work, but works best if combined with rapid firing as if servo doesn't see the movement it's anticipating, as noted in the videos, it will freak out.

pdqgp said:

Keep in mind the focus system needs adequate contrast to focus. If your focus point is on their white gi the camera may not have sufficient contrast to focus.

Click to expand...

No, there dobok's are easy to focus on with plenty of contrast.

Click to expand...

If they are all white or all black that is probably not true. The camera might not be picking up on what you perceive as adequate contrast with your eyes.

pdqgp said:

pdqgp said:

My suggestion would be to put your active focus point on their head. This is best accomplished by using the upper focus point.

Click to expand...

I try. Sometimes it's difficult with groups of people crossing in front of them. Gotta work with what you have access to.

Click to expand...

You can make adjustments to how quickly the AF system responds or not to people walking through. If they walk through regularly that could contribute to your issue.

I have the AF ON button on the back of my camera reprogrammed to AF OFF, so if I see someone is going to be walking through, I can press it temporarily till they pass to keep the focus from jumping to them.

pdqgp said:

pdqgp said:

The camera remembers the focus point based on the orientation, so when you turn the camera between portrait and landscape orientation, the focus point is change automatically to the then upper focus point, after you set it there one time after turning the camera.

Click to expand...

Yep. Love that feature.

pdqgp said:

If you still have issues, you can micro focus adjust your lens. But, I'm guessing it was trying to focus on the relatively low contrast gi.

Click to expand...

The biggest problem I think is the flicker. No doubt the lighting is confusing the system. Otherwise the 70D has been awesome. I'll keep practicing with perhaps some other settings.

pdqgp said:

pdqgp said:

pdqgp said:

And what shutter speed and ISO setting were you using?

Click to expand...

On the 70D auto ISO and last night perhaps too high of a speed of 1/500+ On my 40D I shot slower speeds. Explained earlier in my posts here.

Click to expand...

edit: 1/500 is not too fast, it is on the low end for action photography. Also, make sure your auto ISO maximum is set no lower than ISO 6400.

Click to expand...

I agree that 1/500th is too fast for the movement, but rather I meant it was causing more grief when combined with the lighting flicker. Lower speed shutters seemed to work better. At least with the 40D system. ISO Wise, I always leave it open to hit 12,800. 70D noise is no where near a concern for me.

Click to expand...

The shutter speed shouldn't impact AF, but, the frame rate might. You could try using low speed continuous drive mode and see if that improves the AF.

pdqgp said:

Thanks for the continued feedback.

Click to expand...

pdqgp said:

pdqgp said:

You should be using AIServo for everything.

Click to expand...

Servo could work, but works best if combined with rapid firing as if servo doesn't see the movement it's anticipating, as noted in the videos, it will freak out.

Click to expand...

Hmm, I use AI Servo 100% of the time combined with back button focus for everything (hundreds of thousands of photos taken) and I've never experienced anything like you describe here (freaking out). In fact it is the method I recommend most. Give it a whirl, you'll never go back.

R2

pdqgp said:

Servo could work, but works best if combined with rapid firing as if servo doesn't see the movement it's anticipating, as noted in the videos, it will freak out.

Click to expand...

It's a shame he included that myth in what is in every other way excellent information. Busted! Digital Photography Myths (look for Don't Use AI Servo) tells you how to find out the truth for yourself.

I see the same issue (and opened a thread some time ago) with my 7D . 70D uses the same AF hardware as 7D , although it should use a newer soft for AF calculations .

Let me tell you what I've learned : you need a separated MA for fluorescent light . You need to keep it in mind . I learned that AF calculation (in good lighting conditions ) is 1/50th sec. which in certain moment can match the flickering of fluorescent light and leads AF error . If you compensate this by MA taken under fluorescent light , the amount of your "keepers" will be much higher .

I did it myself (the specific fluorescent light MA adjustment) and it sure (and consistently) works for my 7D and 40mm 2.8 .

PS. Strangely , 550D which followed the 7D has (according to net and my limited experience ) this offset already build-in on software level .

pdqgp said:

pdqgp wrote:
On the 70D auto ISO and last night perhaps too high of a speed of 1/500+

Click to expand...

And there we have the culprit. You are only getting part of the cycle phase of the light in your photo - and that makes a lot of difference, not just to the focusing system but also to the focal plane of the final photo - as even with highly corrected lenses there is a little difference between focal planes. The focusing system of the 70D runs at 30Hz and gets one full lighting cycle to gauge focus position...

Karl Gnter Wnsch said:

Karl Gnter Wnsch said:

pdqgp wrote:
On the 70D auto ISO and last night perhaps too high of a speed of 1/500+

Click to expand...

And there we have the culprit.

Click to expand...

What, auto ISO or the 1/500th? What do you recommend be set where?

Karl Gnter Wnsch said:

You are only getting part of the cycle phase of the light in your photo - and that makes a lot of difference, not just to the focusing system but also to the focal plane of the final photo - as even with highly corrected lenses there is a little difference between focal planes. The focusing system of the 70D runs at 30Hz and gets one full lighting cycle to gauge focus position...

Click to expand...

pdqgp said:

Karl Gnter Wnsch said:

pdqgp said:

pdqgp wrote:
On the 70D auto ISO and last night perhaps too high of a speed of 1/500+

Click to expand...

And there we have the culprit.

Click to expand...

What, auto ISO or the 1/500th? What do you recommend be set where?

pdqgp said:

You are only getting part of the cycle phase of the light in your photo - and that makes a lot of difference, not just to the focusing system but also to the focal plane of the final photo - as even with highly corrected lenses there is a little difference between focal planes. The focusing system of the 70D runs at 30Hz and gets one full lighting cycle to gauge focus position...

Click to expand...

Click to expand...

As mentioned in the videos, it is good when using AIServo, to start the focus system a second before you start to shoot to give it time to acquire and start tracking before taking the photo.