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Home: Video University Forums: Digital Photography for Videographers:
auto-focus in the dark

AbracadabraTV
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Jun 3, 2007, 5:10 PM

Post #1 of 17 (940 views)
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auto-focus in the dark	Can't Post

I am finally trying to solve an auto-focus in the dark problem I'm having with Canon lenses, a 24-70 2.8L and a 70-200 2.8 IS. The receptions we shoot at are nearly pitch black...mostly out-doors or dimley lighted tents.
Our lenses won't lock focus because it's so dark. It's also too dark to manual focus because you can't see what you're focusing on through the view finder. I've seen one photog use a dimable Frezzi with belt pack battery...but that's bad enough when I'm shooting video! Is anyone using an on-camera led light or small self powered light for modeling in addition to their flash? Why are receptions these days only bright enough for bats?
Thanks, Craig

Brackish
Veteran

Jun 4, 2007, 1:52 AM

Post #2 of 17 (926 views)
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Re: [AbracadabraTV] auto-focus in the dark [In reply to]	Can't Post

Hi, Craig.

Doesn't your flash have AF (i.e. auto focus) assist?
I heard that you can use AF assist to focus on
a white wall in the dark at 30 feet!

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

RustyB
Veteran

Jun 4, 2007, 2:08 AM

Post #3 of 17 (924 views)
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Re: [AbracadabraTV] auto-focus in the dark [In reply to]	Can't Post

That's what you need videographers with "terrible" big lights for....to illuminate your subject so your focus will lock! Tongue

I shot one of the worst lit reception EVER tonight, and the photog (with Canon cams), was thanking me for my light. Laugh

But yeah, like Brack says, are you using a Canon flash with the "predator" lights? My Olympus flash works with my Olympus DSLR, and will focus in pitch black, which I guess would be a "must have" for wedding receptions. Lately the only flash I use is a Sunpak 383, so my SLR won't autofocus easily in the dark...if at all.

Seems like using some fast glass would help a lot as well? I have a 50mm f2 coming Tuesday, which I'm hoping will improve the autofocus.

I worked with one photog who used a MASSIVE modelling light ATTACHED to her medium format camera to focus. It was BRIGHT!!! She was one of the most annoying photogs I'd ever worked with...I thought the groom was going to curse her out during the cake cutting. Laugh

Ironically, that was 2.5 years ago, and the bride from that wedding was the assistant coordinator at tonight's wedding!! Wierd!!

Good luck!

the People's Video Collective blog
wedding video and the means of production

Brackish
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Jun 4, 2007, 2:17 AM

Post #4 of 17 (919 views)
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Re: [RustyB] auto-focus in the dark [In reply to]	Can't Post

In Reply To

But yeah, like Brack says, are you using a Canon flash with the "predator" lights?

You know that troublesome photog (discussed in the Members Only forum) who was complaining about a video light messing with his "focusing device" at the reception? I'm guessing the photog was referring to these predator AF assist lights on the flash.

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

RustyB
Veteran

Jun 4, 2007, 2:47 AM

Post #5 of 17 (916 views)
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Re: [Brackish] auto-focus in the dark [In reply to]	Can't Post

In Reply To

But yeah, like Brack says, are you using a Canon flash with the "predator" lights?

You know that troublesome photog (discussed in the Members Only forum) who was complaining about a video light messing with his "focusing device" at the reception?....

Yeah, he's kind of an asshole. Laugh

That must be what he was talking about, however. Those LED's (I think it was something the DJ was using) must trick the predator lights. Next time the DJ will have to rub his booth down with mud, so the predator lights won't see him. Laugh

the People's Video Collective blog
wedding video and the means of production

(This post was edited by RustyB on Jun 4, 2007, 2:48 AM)

Postal Boy
Veteran

Jun 4, 2007, 11:45 AM

Post #6 of 17 (906 views)
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Re: [RustyB] auto-focus in the dark [In reply to]	Can't Post

Strange...I would think that the videographer's lights would eliminate the need for the focus lights...they are only needed when the camera doesn't have enough light to auto-focus...

-Postal

RustyB
Veteran

Jun 4, 2007, 11:57 AM

Post #7 of 17 (900 views)
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Re: [Postal Boy] auto-focus in the dark [In reply to]	Can't Post

In Reply To

Strange...I would think that the videographer's lights would eliminate the need for the focus lights...they are only needed when the camera doesn't have enough light to auto-focus...

-Postal

True dat! I guess those predator lights only come on as needed, now that I think about it. For example, my last three weddings have been Asian weddings of some sort or another, where they walk around table to table greeting guests, which I always shoot from a distance with no light. Last night was DARK, so I was having a tough time focusing...shooting almost all of the reception candid stuff with the shutter at a blurry 1/15th...this made the photog's predator lights blazing red. Laugh

Hey, but at least she could auto focus....I wish my video camera had them!

the People's Video Collective blog
wedding video and the means of production

Brackish
Veteran

Jun 4, 2007, 2:36 PM

Post #8 of 17 (894 views)
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Re: [Postal Boy] auto-focus in the dark [In reply to]	Can't Post

In Reply To

Strange...I would think that the videographer's lights would eliminate the need for the focus lights...they are only needed when the camera doesn't have enough light to auto-focus.

I have personally found this to be true - that the videog light helps the still auto focus.

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Brackish
Veteran

Jun 4, 2007, 2:57 PM

Post #9 of 17 (892 views)
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Re: [AbracadabraTV] auto-focus in the dark [In reply to]	Can't Post

Do you have the "emits" flash AF assist beam turned ON in the custom menu?
Some cams give the options "emits" and "does not emit".

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Brackish
Veteran

Jun 4, 2007, 3:37 PM

Post #10 of 17 (887 views)
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Re: [Postal Boy] auto-focus in the dark [In reply to]	Can't Post

In Reply To

...they are only needed when the camera doesn't have enough light to auto-focus...

I'm thinking/hoping that the AF assist will help in good light, too - but where
the object being focused on is low contrast, such as a solid color.

Anyone know if AF assist beams help in good lighting?

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

AbracadabraTV
User

Jun 4, 2007, 4:21 PM

Post #11 of 17 (886 views)
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Re: [Brackish] auto-focus in the dark [In reply to]	Can't Post

Yes, the AF is on the flash...it's a 580EX...we have 3 on 3 Canons. Lenses are Canon 24-70L 2.8, Canon 70-200 2.8 IS, Canon 10-22. Here's the deal...I'm talking about so dark that I know that someone is standing 20 feet away, because I can see their sillo against the sky, but I can't make out their face. That's how dark these venues are. I see that some photogs are using modeling lights...so I guess I'm going to have to become one of them...The question is which light to get....I thought I'd left those Frezzi back with the video cams...
Tnx, Craig

Brackish
Veteran

Jun 4, 2007, 4:43 PM

Post #12 of 17 (882 views)
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Re: [AbracadabraTV] auto-focus in the dark [In reply to]	Can't Post

In Reply To

The question is which light to get....I thought I'd left those Frezzi back with the video cams...

Sony 10/20 using the 10W? Sony 10/20 on 20W with the Lumequest diffuser?

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Jeko
Enthusiast

Jun 5, 2007, 6:34 PM

Post #13 of 17 (861 views)
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Re: [AbracadabraTV] auto-focus in the dark [In reply to]	Can't Post

Craig,

Although the lens has some influence, focus locking in dim light is much more a function of the base than the lens. The "AF-assist Beam" is Custom Function #5 on the 20/30D and 5D. It simply emmits a red pattern that allows the camera to get a focus lock readily on each of these models.

Try it and I think you will find that it helps.

Jeko

Sony VX2100's, iRivers, M-audio 24/96, Canon 5Ds/20Ds (and too much glass), Vegas6, PhotoShop CS3, Lightroom, etc.

AbracadabraTV
User

Jun 5, 2007, 7:56 PM

Post #14 of 17 (857 views)
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Re: [Jeko] auto-focus in the dark [In reply to]	Can't Post

Thanks Jeko...It does help...I have it turned on on our 3 20d's set at "#2 does emit". Problem is, it's really. really dark! I have no idea why these venues cheap out on the ambient lighting. Outdoors it's tiki torches only...indoors, it's white twinkle lights inside tuille butterfy net mesh around the pillars. Pretty, but you in both cases, you can't even make out people's faces. I've done a test and I need a small incandescent modeling light. I've located one at BH, a friend uses it plus it's rechargable....but they rip you off on extra batteries...almost as much as the lamp.
http://www.bhphotovideo.com/...adylite_15_Watt.html
It works great...I'll just need to buy a few and drag them out after dark. Just another thing to lug around...wasn't this the deal with video? LOL!
Thanks again...I'll let you know how long they last and how well they work.
Best, Craig

Brackish
Veteran

Jun 5, 2007, 8:57 PM

Post #15 of 17 (853 views)
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Re: [Jeko] auto-focus in the dark [In reply to]	Can't Post

In Reply To

It simply emmits a red pattern

Hi, Jeko.

Is this red pattern pretty visible to the eye? What I'm wondering
is ... can the guests see it on the bride's dress, for example?
If so, would you need to turn it off during the ceremony so
it is not seen by the guests?

Also, does it always emit if you have it set to "on" in the menu?
Or does it just come on in low light?

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."

Jeko
Enthusiast

Jun 5, 2007, 9:05 PM

Post #16 of 17 (849 views)
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Re: [Brackish] auto-focus in the dark [In reply to]	Can't Post

It is a visible red grid pattern, but has a limit (guesstimate 40 feet) for its visibility.

It only emits when needed.

Jeko

Sony VX2100's, iRivers, M-audio 24/96, Canon 5Ds/20Ds (and too much glass), Vegas6, PhotoShop CS3, Lightroom, etc.

Brackish
Veteran

Jun 5, 2007, 9:20 PM

Post #17 of 17 (846 views)
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Re: [Jeko] auto-focus in the dark [In reply to]	Can't Post

In Reply To

It only emits when needed.

I wonder how it knows "when needed"? Low ambient light levels?
It can sense the lens hunting?

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"We'll always show up at the wedding with a gift bag for the bride. Inside we have these incredible fuzzy slippers in the teal of our branding."