Autofocus and flash in low light

Digital_Clarity

Digital_Clarity

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Dave
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I've spent the last year playing with a 400D and mid-range zoom, some of it in bars/clubs and low light environments. The most frustrating thing has been the poor autofocus, and having to use the pop up flash that strobes to allow the lens to focus. Not only does this take a good few seconds of time to acheive, but also completely stuns (and temporarily blinds!) anyone who is having their picture taken.
I have noticed those with superior cameras and flashguns do not have this problem, and do not seem to require any strobing. Is the ability to focus in dark environments acheived by the higher grade camera/lens or by the flashgun?

Also I've also just bought a 500D with Canon 17-55m f2.8 and am also looking for a smallish discreet, and ideally cheap, flash unit it too; any suggestions?

Thanks for your time!
DC
 
Whilst the better bodies do have better AF systems which can focus in lower light conditions, the Canon flashguns also have an AF assist light which projects a set of red lines on the subject which give the camera enough contrast to focus with without pulsing the flash like they do with the built-in unit.
 
I see! Thanks for your reply. So if I were to buy a flashgun with this feature, what would I be looking for in the specs?
Any suggestions?
 
It's usually called an AF assist light/lamp. Most (if not all) of the Canon Speedlites have it, including the 220,430,550 & 580
 
Or, if you are shooting people or in small predictable groups, it should be quite easy to get f/8 or f/11. This gives you enough depth of field to cover the subject easily so you don't actually have to focus each shot at all. Just pre-focus on roughly the right distance, lock it in manual focus, and shoot.

The AF assist lights are quite bright themselves in low light.
 
That's an interesting idea Hoppy, although I suspect it comes with a great deal of risk; I know the frustration of finding [useless] slightly out of focus pictures upon getting home.

Suppose I just need to go out and try it without a flashgun and see how it fairs then think about perhaps forking out!
 
Well, it works from a focusing point of view if you're a bit stuck, but the main reason I would still get a decent flash is because the light will be better, even if you just use it on-camera - no red-eye, better shadows.

And then if you use a diffuser of some sort, Stofen or Lumiquest maybe, or just with the built-in bounce card/high-light panel jobbie, you will get really nice light.
 
I'm really tempted. I probably need to have a play with one to understand the benefits and how much better it makes the shots look.

The main problem of course is that as soon as I take a camera with a flashgun into a bar/club etc I will draw the attention of pretty ladies who want their pictu... wait, SOLD!
 
You could always try...

3389122366_8d7eae77dc_o.jpg


3385807536_f2907ecfa1.jpg
 
As much as I am impressed by the ridiculously out-of-my-league kit, I don't think it would go down well trying to get that past the bouncers.
Is that a torch on the top??
 
Flash In The Pan said:
Yes :nuts:

Works a treat and doesn't have an effect on the final exposure :thumbs:
Click to expand...

Apart from casting a huge sausage shaped shadow from the flash right across the subject's face, no effect at all ;)
 
HoppyUK said:
Apart from casting a huge sausage shaped shadow from the flash right across the subject's face, no effect at all ;)
Click to expand...

Can't it just be mounted underneath - then you'll only get the hood shadow - no sausage, just a doughnut:lol:
 
Rockshifter said:
Can't it just be mounted underneath - then you'll only get the hood shadow - no sausage, just a doughnut:lol:
Click to expand...

You mean like a regular torch with an rubber band? Seen that done, and quite discreet. I have a tiny LED torch on my key ring which would probably be sufficient at close range.

The focus assist light from a flash gun projects a pattern so that it can even focus on a plain wall. Not sure that makes any difference with a normal subject such as a face though.
 
HoppyUK said:
Apart from casting a huge sausage shaped shadow from the flash right across the subject's face, no effect at all ;)
Click to expand...


ummm....no, why would it do that? All it is is a low-powered light to assist focus. It's not a flash, Hoppy ;)

Oh, wait...I see...you think I'd put a flashgun on the hotshoe and then mount a torch in front of it? :cuckoo::lol:

To use it with a hotshoe mounted flash all you'd do is move it round to the side or underneath the lens hood. ;)
 
Probably easier to just strap the "miner's lamp" to your head :D
 
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