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Author Topic: Concert haze causing out of focus pictures  (Read 3148 times)

jeff92k7

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Concert haze causing out of focus pictures
« on: March 04, 2013, 05:53:46 PM »
Another thread got me thinking about something and I thought I'd ask here to see if anyone else has experienced it.  I was at a concert a few weeks ago and took quite a few pictures.  This particular concert was running a lot of haze.  I noticed afterwards that many of my pictures were ever so slightly out of focus (front focused).  Does typical concert haze throw off autofocus?

Most of my pictures weren't too bad.  It is really only noticeable when pixel-peeping, but a few pictures I took from the back of the room were off by about 40 feet.  The total room length was probably about 200-250 ft, and shooting from the back, the camera would have to focus through the haze filled room to the stage at front.

Is this a common occurrence in haze-filled rooms, or do I need to take a closer look at the lens that I had the biggest issue with?
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Concert haze causing out of focus pictures
« on: March 04, 2013, 05:53:46 PM »

jeff92k7

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Re: Concert haze causing out of focus pictures
« Reply #1 on: March 06, 2013, 10:05:08 AM »
So I guess that since no one has replied to this that I'm the only one to ever experience this issue?
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sandymandy

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Re: Concert haze causing out of focus pictures
« Reply #2 on: March 06, 2013, 10:35:50 AM »
i sometimes got this problem when i use off-center focus points :/

cayenne

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Re: Concert haze causing out of focus pictures
« Reply #3 on: March 06, 2013, 11:00:20 AM »
So I guess that since no one has replied to this that I'm the only one to ever experience this issue?

Well, back "in the day"....I experienced a LOT of haze at the show, and it was a bit hard to focus on most anything terribly well, but didn't seem to matter much at the time.<P>
:)<P>
LOL...I used to take lots of pics back in HS and College at parties (thank God before the internet and FB and the like, I made sure to secure all the negatives back then)...and I noticed that many of the pics got blurred and fuzzy as the night progressed.

I then would just tell everyone, NO...it was my problem taking the pics, it just REALLY looked that way at that particular time of the night at that party.

 ::)

cayenne

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Re: Concert haze causing out of focus pictures
« Reply #4 on: March 06, 2013, 11:13:23 AM »
Statuary Notice:
Do not take this response at face value.

So I guess that since no one has replied to this that I'm the only one to ever experience this issue?

Well, back "in the day"....I experienced a LOT of haze at the show, and it was a bit hard to focus on most anything terribly well
The reason is Pot.

Quote
LOL...I used to take lots of pics back in HS and College at parties (thank God before the internet and FB and the like, I made sure to secure all the negatives back then)...and I noticed that many of the pics got blurred and fuzzy as the night progressed.
Pot again...

Quote
I then would just tell everyone, NO...it was my problem taking the pics, it just REALLY looked that way at that particular time of the night at that party.

 ::)

cayenne
There you go - Pot again...

;)

cayenne

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Re: Concert haze causing out of focus pictures
« Reply #5 on: March 06, 2013, 12:15:57 PM »
Statuary Notice:
Do not take this response at face value.

So I guess that since no one has replied to this that I'm the only one to ever experience this issue?

Well, back "in the day"....I experienced a LOT of haze at the show, and it was a bit hard to focus on most anything terribly well
The reason is Pot.

Quote
LOL...I used to take lots of pics back in HS and College at parties (thank God before the internet and FB and the like, I made sure to secure all the negatives back then)...and I noticed that many of the pics got blurred and fuzzy as the night progressed.
Pot again...

Quote
I then would just tell everyone, NO...it was my problem taking the pics, it just REALLY looked that way at that particular time of the night at that party.

 ::)

cayenne
There you go - Pot again...

;)

Hmm....you're not familiar with some of the slightly more legal possible reasons? Beer? Cocktails? Ball Ping hammer to the forehead?

 8)

Chris Burch

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Re: Concert haze causing out of focus pictures
« Reply #6 on: March 06, 2013, 12:50:17 PM »
I would expect it to be hard to tell the focus precision on a shot from 250ft away through haze.  The haze itself may be lowering the contrast and definition to make it look like it was out of focus even if the focus was spot-on.  I just shot over 4K images of stage performances and a lot of them had excessive amounts of haze (very annoying).  I never felt the focus was off in any of them, but for the most part hated the hazy photos.  The trick is to get your subjects in front of the haze -- then you get crisp shots with the potential for lots of ambient background texture and light.

What auto-focus settings are you using?  I've been shooting with single-point expanded, mostly on one shot.
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Re: Concert haze causing out of focus pictures
« Reply #6 on: March 06, 2013, 12:50:17 PM »

Dantana

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Re: Concert haze causing out of focus pictures
« Reply #7 on: March 06, 2013, 01:44:32 PM »
Maybe this is a stupid question, but at 250', shouldn't you be at infinity with most lenses?
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sandymandy

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Re: Concert haze causing out of focus pictures
« Reply #8 on: March 06, 2013, 02:32:52 PM »
cant the haze somewhat be filtered out? i mean if BW film u use a yellow filter to fight haze. shouldnt there something possible to do digitally aswell? color channels n stuff

jeff92k7

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Re: Concert haze causing out of focus pictures
« Reply #9 on: March 06, 2013, 02:57:15 PM »
What auto-focus settings are you using?  I've been shooting with single-point expanded, mostly on one shot.

I use AI Servo with Back button control and center focus point only for the shots in question. (T2i) (Press and release focus button and it works the same as one-shot - for anyone unfamiliar with back button focus modes.)

You are correct that the haze does make all the images a little soft and reduces contrast, but in the pictures from the back, it is very obvious, even without pixel peeping, that the focus is way off.  The audio mix position (about 1/3 back into the room is sharper than anything on the stage, and from the audience silhouettes, it appears that the focal plane was about one row in front of the mix position.  These were some of the very few pictures I took with my 50 1.8.  I have never taken pictures at that distance with that lens before, but thought I would try it since it framed the stage well and gave a good indication of the crowd size, as well as providing a fairly shallow depth of field that would have looked great had the focus actually been on the stage.
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Vivid Color

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Re: Concert haze causing out of focus pictures
« Reply #10 on: March 06, 2013, 03:52:01 PM »
Maybe this is a stupid question, but at 250', shouldn't you be at infinity with most lenses?

That's what I was also thinking. Why not just use manual focus?

bonedaddy.p7

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Re: Concert haze causing out of focus pictures
« Reply #11 on: March 06, 2013, 04:20:45 PM »
What auto-focus settings are you using?  I've been shooting with single-point expanded, mostly on one shot.

I use AI Servo with Back button control and center focus point only for the shots in question. (T2i) (Press and release focus button and it works the same as one-shot - for anyone unfamiliar with back button focus modes.)

You are correct that the haze does make all the images a little soft and reduces contrast, but in the pictures from the back, it is very obvious, even without pixel peeping, that the focus is way off.  The audio mix position (about 1/3 back into the room is sharper than anything on the stage, and from the audience silhouettes, it appears that the focal plane was about one row in front of the mix position.  These were some of the very few pictures I took with my 50 1.8.  I have never taken pictures at that distance with that lens before, but thought I would try it since it framed the stage well and gave a good indication of the crowd size, as well as providing a fairly shallow depth of field that would have looked great had the focus actually been on the stage.

"mix position" is called Front of house, or FOH. The "Haze" you are referring to is from a fogger, this isn't just water mist though, it's a chemical mix that is slightly opaque to create that "beam" effect with the lights, so it's not as simple as filtering because the fog itself is not transparent. Filters can help, but there's only so far you'll get before the filter cuts the light enough to cause problems. Basically think of it as heavy cigarette smoke. Note that if you put your hand in front of the nozzle of a fogger when it's spraying, your hand will feel quite strange and tingly due to the chemicals, and the stuff I'm used to smells much like a damp wool coat too.

I ran sound and lights at underground events for around a decade and after everything got up and running I'd run around with my cameras to practice. I quickly gave up on auto focus because all the auto focus shots simply never managed to pick the right subject due to the fog. I ended up preferring my AE-1 Program over the Rebel II because of this, and digital was still pretty junky at the time (this was pre-5Dmk1 days). I can't vouch for modern AF since I don't have anything capable of getting focus at events, but this might explain what you're running into.
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jeff92k7

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Re: Concert haze causing out of focus pictures
« Reply #12 on: March 06, 2013, 04:26:03 PM »
Why not just use manual focus?

That's always an option, but my post is less an issue of manual vs auto focus as it is an issue of whether haze (or other particles in the air like smoke, fog, etc) will throw off auto focus.  Besides, have you ever tried to manual focus with the 50 1.8?  The focus ring is impossibly small and not very smooth.
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Re: Concert haze causing out of focus pictures
« Reply #12 on: March 06, 2013, 04:26:03 PM »

Dantana

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Re: Concert haze causing out of focus pictures
« Reply #13 on: March 06, 2013, 04:42:49 PM »
Why not just use manual focus?

That's always an option, but my post is less an issue of manual vs auto focus as it is an issue of whether haze (or other particles in the air like smoke, fog, etc) will throw off auto focus.  Besides, have you ever tried to manual focus with the 50 1.8?  The focus ring is impossibly small and not very smooth.

Sure, but you're 250' away from the stage, something is making the AF focus closer than that (the fog, the crowd, the guy at the board). It seems like manually focusing at infinity would be the way to go, set it and forget it, unless you are also getting shots around the scene at different depths. Then I totally understand not wanting to manually focus in the dark with the tiny ring on the 50 1.8.

If nothing else was in the region of your AF points, I think you've kind of answered your own question, that the environmentals used at the concert are messing with the AF.
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jeff92k7

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Re: Concert haze causing out of focus pictures
« Reply #14 on: March 06, 2013, 04:53:18 PM »
"mix position" is called Front of house, or FOH. The "Haze" you are referring to is from a fogger, this isn't just water mist though, it's a chemical mix that is slightly opaque to create that "beam" effect with the lights, so it's not as simple as filtering because the fog itself is not transparent.

Yeah, I've been an audio engineer for over 20 years.  I've mixed FOH and monitors regularly since I was a teenager.  I also have quite a few years experience in event production and currently serve at my church as the Technical Director overseeing a team who handle all aspects of technical production.   I only recently (last year) got interested in photography.  I used "Mix position" as a generic term since I doubt as many photographers would understand the FOH acronym.

This "haze" was actually haze.   Fog uses a different chemical solution and is a much heavier, short term effect.  Haze (oil based solution) is a different chemical mix that is designed to last a lot longer and "hang" in the air to help produce those lighting beam effects that everyone likes to do now.  I don't want to bore anyone with the technical details though.

I don't even know how many concerts and events I've photographed in the past year, but this was actually the first where haze was being used (and quite heavily).  I'm a newbie photographer, and as such, have never run into this issue before, so I surmised that the haze may have caused the focus issues and thought I'd ask the professionals here before I write it off to cheap equipment.

I suppose it is a little reassuring that you have experienced similar issues.  At least that points to the haze/smoke/fog as being at least partly responsible.
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Re: Concert haze causing out of focus pictures
« Reply #14 on: March 06, 2013, 04:53:18 PM »