Low light focusing

[Raymondb]

Hi everyone.

Focusing under very dim lighting condition had always been a problem with our digital camera, especially the C-750.

How do you overcome that? Care to share?

Cheers.
Raymond

[C-720]

tripod + adjust the apeture + Shutter?

[Davey]

Some tips off the top of my head.

1. Bring along a small torchlight. (Serious! But torchlight beam has limited range) May be good to find a way to mount it to the camera No kidding, just check out this site: Custom AF Assist Lamp
2. C-750 has a Focus Lock function. Use the torch with function. (i.e. on torch, focus lock, off torch, snap!)
3. External flash with focus assist lamp.
4. Invent an AF focus assist lamp that is small enough to attach to the flash mount and triggered on during focusing (and perhaps still allow the built in flash to pop-up)

Thinking of building something like the one in the link above. Anyone interested?

Cheers,
David

[dbcs]

If you do not have the equipment suggested above with you, try focusing on areas with good contrast or areas such as at the edge of the subject, re-compose and take the shot.

[Raymondb]

Has anyone tried experimenting with the "hyperfocal distance" theory?

If I'm correct, for C-750, when you set the focal length to 6.3mm (widest), F-stop to F8, and manual focus set to 1m: Everything that are within the distance (from the camera) of between 500mm and infinity will be acceptably in-focus. Try it and see if it work.

Cheers.
Raymond

[C-720]

Woh many "high-hand" here! Good to listen and share such valuable info.

[kahheng]

Originally Posted by Raymondb Hi everyone. Focusing under very dim lighting condition had always been a problem with our digital camera, especially the C-750. How do you overcome that? Care to share? Cheers. Raymond

The best way to overcome focusing deficiency in low light is to use Manual Focus (i.e., don't use AF). With your C750, e.g, in the Program mode, just press the menu button and hold down till you see the MF/AF indicator appear on your LCD. Use the L/R arrows to switch between AF/MF and the UP/DOWN arrows to adjust focusing distance.

The point is to guesstimate the distance to your subject and rely on the inherently larger "depth of field" that most consumer digicams have to get your subject sharply focussed.

Works all the time. You just need to try out a few shots and learn to guess the distance. (it's all very retro - your Dad should be able to help you with this)

This is also good for fast snapshot photography at parties to reduce the shutter delay due to AF time.

[Davey]

Recently I got hold of a laser pointer with swappable "filters". Experimented with it for focusing on low/zero contrast objects as well as focusing in the dark. Seems to work pretty well.

Below is a sample photo of a plain white wall in low light, focused with the help of the laser pointer image. For actual photo, need to use focus lock and switch off laser pointer before metering and snapping.



Impt: Do not shine laser image onto anyone's face/eyes!

Cheers,
David

[Raymondb]

Originally Posted by Davey Recently I got hold of a laser pointer with swappable "filters". Experimented with it for focusing on low/zero contrast objects as well as focusing in the dark. Seems to work pretty well. Below is a sample photo of a plain white wall in low light, focused with the help of the laser pointer image. For actual photo, need to use focus lock and switch off laser pointer before metering and snapping. Impt: Do not shine laser image onto anyone's face/eyes! Cheers, David

Ya. I had one also. It worked.
You can just project the laser image to the shirt of the subject and focus on it using auto-focus. The laser image offer a kind of borders that the camera needed for focusing.

Cheers.
Raymond

[Raymondb]

Can look here for more info on hyperfocal distance.

http://dfleming.ameranet.com/hyperfocal.html

Raymond

[sensires]

Originally Posted by Davey Recently I got hold of a laser pointer with swappable "filters". Experimented with it for focusing on low/zero contrast objects as well as focusing in the dark. Seems to work pretty well. Below is a sample photo of a plain white wall in low light, focused with the help of the laser pointer image. For actual photo, need to use focus lock and switch off laser pointer before metering and snapping. .... Impt: Do not shine laser image onto anyone's face/eyes! Cheers, David

Now that's a really useful tip!! ... hehe, imagine a red beam shining from your camera in the dark ... very spy-gadety ... cool!

[Davey]

Originally Posted by sensires Now that's a really useful tip!! ... hehe, imagine a red beam shining from your camera in the dark ... very spy-gadety ... cool!

If only the laser pointer has a filter that just projects lines (vertical lines or grid pattern). Most AF cameras using contrast detection uses detectors that are sensitive to vertical lines.

Cheers,
David