Focusing in the dark - when autofocus takes too long...

dugrant153 · 11-11-2007, 09:28 PM

Hey folks,

I was shooting at an event and was having problems focusing on in the dark with my PEntax K100D. I was shooting with a Pentax DA 40mm Limited combined with the AF540FGZ flash. To my understanding, the flash should shoot a beam and help autofocusing in the dark... but it only turned on once during all of my shots...?

I've been thinking about trying to manual focus, but I find that autofocus is way more accurate. So... here are my questions:

1) Is there any way for me to somehow improve my manual focusing technique when autofocus fails?

2) How can I improve the autofocus so it doesn't hunt in the dark for 2+ seconds (or even fail to focus)?

The situation is a dimly light dinner room.

Thanks!

little laker · 11-11-2007, 10:36 PM

dugrant,

I'll share a little secret with you, but don't tell anyone.

Turn your camera on and press menu.
press the right arrow twice bringing you top setup.
press the down arrow twice to BEEP.
check that box.

It'll beep when you have it in focus.
Although it won't help you when your in a noisy situation it'll help you learn to focus

With a concert theres a good chance that you'll be far enough away from the stage to just stick your lens to infinity and leave it there.
Infinity is what looks like a sideways 8 on your lens. I don't know about the 40mm, but anything beyond 8' on the kit lens would be in focus if you had the lens on this mark.

If you happen to be close enough to require focusing you've got incredible seats and should just sit back and enjoy the show

dugrant153 · 11-13-2007, 01:30 AM

thanks for the reply. However, I know how to use the autofocus function

My problem is that the autofocus sometimes focuses wrong. It will sometimes confirm focus and beep when the picture is clearly not as focused as it should be (yes, it is in AF mode). I then find that I have to release and press the shutter again in order to get it to focus ... (or it will just hunt for a while)... and then I'll switch to manual focus, but by then I'll miss the shot.

Seems like manual focusing is the only answer? From the shots I do, the distance and object are constantly changing, so leaving focus in infinity wouldn't work?

blende8 · 11-13-2007, 02:26 AM

For manual focus there is only one answer:
Practice, practice, practice ...
Become familiar with your lens, know the focus ring by heart ...

If this is really your business, you should think of investing into a split image screen, which helps a lot for manual focussing.

code4code5 · 11-13-2007, 12:29 PM

Originally posted by dugrant153

thanks for the reply. However, I know how to use the autofocus function

If you rotate the focus ring slowly once you get close to your target focus, using the "beep" method that was earlier described, the camera will confirm the focus with the focus point indicator superimposed in the viewfinder and the large green octagon illuminated in the viewfinder.

You can also set the camera to not release the shutter unless the target is in focus, thereby using a "trap" method. As soon as your target is in focus, the shutter will release. I often use this when photographing my three year old with my manual lenses.

I captured this using trap focus as she was running up to me.

Gaelen · 11-13-2007, 01:58 PM

Where is the setting for that? It gave me an interesting idea for an event I'm shooting in a few weeks

little laker · 11-13-2007, 09:07 PM

Just stick your camera on auto focus with a manual lens on and you can shoot using the focus trap method.

This of course won't work with a auto focus lens.
However I've recently read that you can somehow slide a piece of paper between the lens and body to utilize this method.

**NaClH2O** · 11-14-2007, 07:26 PM

Originally posted by dugrant153

Hey folks,

I was shooting at an event and was having problems focusing on in the dark with my PEntax K100D. I was shooting with a Pentax DA 40mm Limited combined with the AF540FGZ flash. To my understanding, the flash should shoot a beam and help autofocusing in the dark... but it only turned on once during all of my shots...?

I've been thinking about trying to manual focus, but I find that autofocus is way more accurate. So... here are my questions:

1) Is there any way for me to somehow improve my manual focusing technique when autofocus fails?

2) How can I improve the autofocus so it doesn't hunt in the dark for 2+ seconds (or even fail to focus)?

The situation is a dimly light dinner room.

Thanks!

dugrant

manual focusing isn't hard. Honestly! At 58 my eyes ain't what they used to be and I despaired of ever being able to manually focus with any degree of accuracy. I then saw a post by Godfrey (a regular over at DP review) who posted this wonderful set of exercises that help you learn to manual focus. They work! here is the link.
Re: Is a KatzEye required for those using manual focus?: Pentax SLR Talk Forum: Digital Photography Review

NaCl(like any other craft it takes practice)H2O

dugrant153 · 11-18-2007, 05:20 PM

thanks for all the replies. I recently purchased a Pentax SMC-M 28mm F2.8 lens and had to manual focus the whole weekend. Wow, after some practice it's becoming pretty normal to me now. And I hunt less than my autofocus in dark light :P haha

little laker, your technique does work for objects far away. When I took landscape shots, I just set the focus to infinity and left it there. But when I wanted to focus on items closer up, I had to reset the focus as infinity usually focused the background only.

not sure I can go back to autofocus now :P

11-11-2007, 09:28 PM	#1
dugrant153 Veteran Member Join Date: Oct 2007 Location: Vancouver, BC Photos: Gallery Posts: 1,059	Focusing in the dark - when autofocus takes too long... Hey folks, I was shooting at an event and was having problems focusing on in the dark with my PEntax K100D. I was shooting with a Pentax DA 40mm Limited combined with the AF540FGZ flash. To my understanding, the flash should shoot a beam and help autofocusing in the dark... but it only turned on once during all of my shots...? I've been thinking about trying to manual focus, but I find that autofocus is way more accurate. So... here are my questions: 1) Is there any way for me to somehow improve my manual focusing technique when autofocus fails? 2) How can I improve the autofocus so it doesn't hunt in the dark for 2+ seconds (or even fail to focus)? The situation is a dimly light dinner room. Thanks!

11-13-2007, 01:30 AM	#3
dugrant153 Veteran Member Join Date: Oct 2007 Location: Vancouver, BC Photos: Gallery Posts: 1,059 Original Poster	thanks for the reply. However, I know how to use the autofocus function My problem is that the autofocus sometimes focuses wrong. It will sometimes confirm focus and beep when the picture is clearly not as focused as it should be (yes, it is in AF mode). I then find that I have to release and press the shutter again in order to get it to focus ... (or it will just hunt for a while)... and then I'll switch to manual focus, but by then I'll miss the shot. Seems like manual focusing is the only answer? From the shots I do, the distance and object are constantly changing, so leaving focus in infinity wouldn't work? Last edited by dugrant153; 11-13-2007 at 01:40 AM.

11-13-2007, 12:29 PM	#5
code4code5 Veteran Member Join Date: Oct 2007 Location: Denver, CO Photos: Gallery Posts: 438	Originally posted by dugrant153 thanks for the reply. However, I know how to use the autofocus function If you rotate the focus ring slowly once you get close to your target focus, using the "beep" method that was earlier described, the camera will confirm the focus with the focus point indicator superimposed in the viewfinder and the large green octagon illuminated in the viewfinder. You can also set the camera to not release the shutter unless the target is in focus, thereby using a "trap" method. As soon as your target is in focus, the shutter will release. I often use this when photographing my three year old with my manual lenses. I captured this using trap focus as she was running up to me. Last edited by code4code5; 11-13-2007 at 12:34 PM.

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11-11-2007, 10:36 PM	#2
little laker Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 5,697	dugrant, I'll share a little secret with you, but don't tell anyone. Turn your camera on and press menu. press the right arrow twice bringing you top setup. press the down arrow twice to BEEP. check that box. It'll beep when you have it in focus. Although it won't help you when your in a noisy situation it'll help you learn to focus With a concert theres a good chance that you'll be far enough away from the stage to just stick your lens to infinity and leave it there. Infinity is what looks like a sideways 8 on your lens. I don't know about the 40mm, but anything beyond 8' on the kit lens would be in focus if you had the lens on this mark. If you happen to be close enough to require focusing you've got incredible seats and should just sit back and enjoy the show

11-13-2007, 02:26 AM	#4
blende8 Veteran Member Join Date: Feb 2007 Location: Bremen, Germany Photos: Albums Posts: 1,521	For manual focus there is only one answer: Practice, practice, practice ... Become familiar with your lens, know the focus ring by heart ... If this is really your business, you should think of investing into a split image screen, which helps a lot for manual focussing.

11-13-2007, 01:58 PM	#6
Gaelen Veteran Member Join Date: Jul 2007 Location: Coquitlam, BC, Canada Photos: Gallery Posts: 749	Where is the setting for that? It gave me an interesting idea for an event I'm shooting in a few weeks

11-13-2007, 09:07 PM	#7
little laker Veteran Member Join Date: Sep 2006 Photos: Gallery Posts: 5,697	Just stick your camera on auto focus with a manual lens on and you can shoot using the focus trap method. This of course won't work with a auto focus lens. However I've recently read that you can somehow slide a piece of paper between the lens and body to utilize this method.

11-14-2007, 07:26 PM	#8
NaClH2O Site Supporter Join Date: Sep 2006 Location: Bronx NY Photos: Gallery \| Albums Posts: 5,631	Originally posted by dugrant153 Hey folks, I was shooting at an event and was having problems focusing on in the dark with my PEntax K100D. I was shooting with a Pentax DA 40mm Limited combined with the AF540FGZ flash. To my understanding, the flash should shoot a beam and help autofocusing in the dark... but it only turned on once during all of my shots...? I've been thinking about trying to manual focus, but I find that autofocus is way more accurate. So... here are my questions: 1) Is there any way for me to somehow improve my manual focusing technique when autofocus fails? 2) How can I improve the autofocus so it doesn't hunt in the dark for 2+ seconds (or even fail to focus)? The situation is a dimly light dinner room. Thanks! dugrant manual focusing isn't hard. Honestly! At 58 my eyes ain't what they used to be and I despaired of ever being able to manually focus with any degree of accuracy. I then saw a post by Godfrey (a regular over at DP review) who posted this wonderful set of exercises that help you learn to manual focus. They work! here is the link. Re: Is a KatzEye required for those using manual focus?: Pentax SLR Talk Forum: Digital Photography Review NaCl(like any other craft it takes practice)H2O

11-18-2007, 05:20 PM	#9
dugrant153 Veteran Member Join Date: Oct 2007 Location: Vancouver, BC Photos: Gallery Posts: 1,059 Original Poster	thanks for all the replies. I recently purchased a Pentax SMC-M 28mm F2.8 lens and had to manual focus the whole weekend. Wow, after some practice it's becoming pretty normal to me now. And I hunt less than my autofocus in dark light :P haha little laker, your technique does work for objects far away. When I took landscape shots, I just set the focus to infinity and left it there. But when I wanted to focus on items closer up, I had to reset the focus as infinity usually focused the background only. not sure I can go back to autofocus now :P