Trouble focussing at fairly dark wedding reception

ajax_andy

ajax_andy

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I know it's quite a common thing for the AF to struggle to find focus in fairly dark conditions, but I had some serious issues today and need some advice!

I shoot with a Canon 7D and Tamron 17-50mm zoom. 2 weekends ago I shot a friends evening reception in quite a dark room with no issues at all... Yet tonight at a wedding I had major problems without it being any darker at all?!

It's not the usual hunting for focus issue, the camera / lens just wasnt even trying to hunt at all. I was pressing the shutter but nothing at all happened about 60 % of the time.

Is this a common issue, and if so why did it only happen now despite having been fine in equally if not darker rooms?!
 
You didnt knock the switch on the lens from auto to manual by accident did you?

Apologies if a silly question, but ive done it myself before :thinking: :lol:
 
snoop69 said:
You didnt knock the switch on the lens from auto to manual by accident did you?

Apologies if a silly question, but ive done it myself before :thinking: :lol:
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Haha no but don't worry I wondered myself at 1st but checked many times and it wasn't that.

Plus I think it'd just fire and be out of focus if I'd done that, but in this case it would have depress but not do anything after that, just nothing at all, not even fully depress and fire or hunt for focus
 
It may be different on your camera but my 5D2 has an option that enables or disables "hunt when AF impossible". Sometimes the lens can't lock from where it is but when it hunts it can lock on. Maybe it's that setting?
 
Don't know about canon but with nikon flashes you can switch on the af light just to help focusing without activating the flash itself. Maybe that's an alternative route to explore.
 
The same can be done with Canon. Believe it's called flash firing enable/disable
 
If you need more help you'll need to give detailed information on the settings, equipment used etc. Without that it's guess work

Also, one shot focus or ai focus or servo?
 
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wealthysoup said:
If you need more help you'll need to give detailed information on the settings, equipment used etc. Without that it's guess work

Also, one shot focus or ai focus or servo?
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Hi... ok no probs:

Canon 7D
Tamron 17:50mm zoom
One Shot Focus
Nissin di866 mark ii
Camera set to manual
ISO 1600
Aperture f/4, then tried at f/2.8
Shutter 100
Autofocus set on lens

Tried zooming in, zooming out, changed flash batteries (in case focus assist was too weak due to batteries running out), moved around the room, got in close, moved further away etc.

Is that the right kind of info? If not just let me know what else and I'll do my best to supply it :)
 
What distance were you from the subject? Also were you using the flash or just the af assist beam? The only other thing I can think off (apart from the things below) is that you might have a custom function set wrong, ill check mine this evening and post here so you can check (pm me if I haven't done it by 7 or 8 as I might forget).

If you put the lens cap on now and try to focus will the af assist beam light up? (it should)

Also, I'm not sure but I assume your Flash only supports centre point focus? If you go somewhere dark with your camera set to centre point only will it manage to focus?
 
wealthysoup said:
What distance were you from the subject? Also were you using the flash or just the af assist beam? The only other thing I can think off (apart from the things below) is that you might have a custom function set wrong, ill check mine this evening and post here so you can check (pm me if I haven't done it by 7 or 8 as I might forget).

If you put the lens cap on now and try to focus will the af assist beam light up? (it should)

Also, I'm not sure but I assume your Flash only supports centre point focus? If you go somewhere dark with your camera set to centre point only will it manage to focus?
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I varied the distance from right up close and personal to quite far back and everything in between, but still got the same issues.

I was using flash the whole time.

I'll try the lens cap trick and see if it does light up, thanks for that tip :)

No my flash supportss all point focussing so it shouldn't matter which focus point was selected as far as i'm aware.

Thanks for your help with this :)
 
Forgive me if I'm 'teaching Granny to suck eggs' but if it makes no attempt to focus then it does sound like the 'Lens drive when autofocus is impossible' setting is disabled in the custom functions menu, if it is then CFIII/4 will be set to 1.
If it is, change it to 0 which will make the lens continually try to AF.
Just out of interest, does it achieve AF if you approximately focus manually first?
 
Use centre-point AF with focus-recompose technique. Pick a contrasty target - anything with a bit of light/dark* and pin the AF point on the transition. Works well in really very low light that way.

*Edit: collars, cuffs, buttons, eyes, whatever - just make sure the AF target is the same distance as the main subject.
 
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Hoppy, he shouldn't need to use focus and recompose with the assist beam firing since it will allow focus on pretty much anything (although high contrast will be much faster).

Edit: although since the af assist beam doesn't seem to be terribly reliable its actually a very good piece of advice in case the op is stuck in an awkward situation
 
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wealthysoup said:
Hoppy, he shouldn't need to use focus and recompose with the assist beam firing since it will allow focus on pretty much anything (although high contrast will be much faster).

Edit: although since the af assist beam doesn't seem to be terribly reliable its actually a very good piece of advice in case the op is stuck in an awkward situation
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OP is using AF assist beam isn't he? It usually works well, but only adds light where there is none, not contrast. AF can work in very low light, but some subject contrast is essential.
 
ajax_andy said:
I know it's quite a common thing for the AF to struggle to find focus in fairly dark conditions, but I had some serious issues today and need some advice!

I shoot with a Canon 7D and Tamron 17-50mm zoom. 2 weekends ago I shot a friends evening reception in quite a dark room with no issues at all... Yet tonight at a wedding I had major problems without it being any darker at all?!

It's not the usual hunting for focus issue, the camera / lens just wasnt even trying to hunt at all. I was pressing the shutter but nothing at all happened about 60 % of the time.

Is this a common issue, and if so why did it only happen now despite having been fine in equally if not darker rooms?!
Click to expand...

Hi

2 Things no one has mentioned as far as i can see.

Is the button battery old if so try changing it

Are the lens contacts clean

Never owned your flash but the 7D with a 430EX with pre flash assist enabled worked in near dark for me.

Good luck

Allan
 
I believe the Nissin only emits a red light for af assist, whereas Canon flashguns emit a pattern, effectively creating a contrast point to lock on.

I'm concerned because I fancy a new pair of Nissins for the price of one canon.
 
Phil, that would explain the difference between my viewpoint and hoppys then (I know Canon and sigma increase contrast with the assist beam) but am not sure about other canons (Hoppy if you don't believe me and have a Canon flash then focus on a black t shirt in a dark room)

Op, on the subject of cleaning lens contacts, people usually suggest using the red pencil rubbers for that (not sure why specifically), while your at it I would suggest doing the same with your hot shoe and flash contacts
 
wealthysoup said:
Phil, that would explain the difference between my viewpoint and hoppys then (I know Canon and sigma increase contrast with the assist beam) but am not sure about other canons (Hoppy if you don't believe me and have a Canon flash then focus on a black t shirt in a dark room)

Op, on the subject of cleaning lens contacts, people usually suggest using the red pencil rubbers for that (not sure why specifically), while your at it I would suggest doing the same with your hot shoe and flash contacts
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Ryan, you're quite right, and as Phil ponted out most flash guns project a patterned AF assist beam.

And yes they generally work pretty well, but the point is that the OP apparently has the AF assist beam working and is still having problems - so use centre-point focus-recompose technique and give it a contrasty target.
 
Hi

Just had a further thought, do you use your hot shoe for other things maybe a mic for video. I ask because sometimes on the 7D if you have a tight fitting item the shoe pushes down wrong often the easy way to tell is will the pop up flash pop if required. If the contact is pushed down a little the flash does not contact correctly. I know this because i had a Rode mic when i used it the pop up used to stick and the 430EX would not work correctly.

There are a fair few threads on the net about this issue not sure if its all the Canon pop ups but mine sure had an issue.

Would still check the buton battery though can fix a host of weird things and very cheap to try.

I guess we all are assuming the flash was in the hot shoe not on a cord or flash trigger?

Allan
 
Wozzaaah said:
Forgive me if I'm 'teaching Granny to suck eggs' but if it makes no attempt to focus then it does sound like the 'Lens drive when autofocus is impossible' setting is disabled in the custom functions menu, if it is then CFIII/4 will be set to 1.
If it is, change it to 0 which will make the lens continually try to AF.
Just out of interest, does it achieve AF if you approximately focus manually first?
Click to expand...

Haha that's ok I don't mind going through every option tbh to pinpoint the issue.

I checked the custom function but it was set to 0 unfortunately so doesn't look like that's the issue :(

No after the manual focus too sadly... still just nothing at all happened
 
HoppyUK said:
Ryan, you're quite right, and as Phil ponted out most flash guns project a patterned AF assist beam.

And yes they generally work pretty well, but the point is that the OP apparently has the AF assist beam working and is still having problems - so use centre-point focus-recompose technique and give it a contrasty target.
Click to expand...

Surely if that was all that was wrong it would have been hunting for focus rather than just jamming and doing nothing at all? or am I wrong on that? :shrug:
 
border_all said:
Hi

Just had a further thought, do you use your hot shoe for other things maybe a mic for video. I ask because sometimes on the 7D if you have a tight fitting item the shoe pushes down wrong often the easy way to tell is will the pop up flash pop if required. If the contact is pushed down a little the flash does not contact correctly. I know this because i had a Rode mic when i used it the pop up used to stick and the 430EX would not work correctly.

There are a fair few threads on the net about this issue not sure if its all the Canon pop ups but mine sure had an issue.

Would still check the buton battery though can fix a host of weird things and very cheap to try.

I guess we all are assuming the flash was in the hot shoe not on a cord or flash trigger?

Allan
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Yeah mounted on camera the whole time :)
 
Sounds like it's working fine now whatever the problem was. Would be worthwhile double checking in a darkened room tonight though. (and yes I did forget to post my settings last night, oops)
 
wealthysoup said:
Sounds like it's working fine now whatever the problem was. Would be worthwhile double checking in a darkened room tonight though. (and yes I did forget to post my settings last night, oops)
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Haha that's ok someone else posted one that might have been an issue but sadly it wasn't that.

Yeah seems fine now, I'll run some tests before it's next outing in 10 days time... maybe it was just one of those odd gremlins that happens from time to time but then sorts itself out :shrug:
 
Now that I think about it actually. How good is the connection with your hot shoe? On an old camera of mine the flash sometimes moved very slightly in portrait mode which caused something strange to happen (think it was ettl not working but might also cause your focus problems). It didn't happen often but did happen every few hundred photos
 
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