Help with Camera Settings for Beam Shots

jeff51 · 2019-10-07T20:20:41.000Z

When trying to take beam shots, I have trouble capturing an image that reflects what I see with my eyes.
I have been capturing in RAW and farting around with color temps in post. I use Darktable for post.

What settings (in camera or in post) are you using to get something that makes for a good beam shot?
If you are doing stuff in post, are you using a base curve correction?
If so is it a line, or a curve that the software matches to your camera sensor?

Frequently the more I mess with an image the worse it ends up looking.
Seems like if I get something that looks good for one light - A light with a different emitter doesn’t look right.

Thanks for the help.
All the Best,
Jeff

Pavlo · 2019-10-07T20:36:41.000Z

Hi Jeff,

I don’t have the answer for you, as I have taken very few beamshots myself, but I can share 1 thing.
Since the eyes can rapidly adjust to see the faint and brightest parts of the beam, we will perceive the beamshot and simultaneously expose both spot and spill of a flashlight.

Since the camera can only take a photo at a fixed exposure, it will be nearly impossible to expose the spill without overexposing the spot, or vice versa, expose the beam and severely underexpose the spill.

I think the only way around it is to take 2 bracketed exposures, and fuse them together. And in this case, there is room for bias and human error, but likely the best way to do it.

If you use take only 1 photo, best to expose for the brightest part of the beam and ensure there is very little clipping, and you can then bring up the shadows for the spill.

jeff51 · 2019-10-07T20:48:31.000Z

Hi Pavlo,
I never thought of stacking exposures. That’s something to experiment with.
I’m not sure my software will do that. I’m a nube when it comes to playing around in editing software.
Sure would be nice to get in a single exposure though.
My biggest problem seems to be matching colors.
Thanks, All the Best,
Jeff

Pavlo · 2019-10-07T21:29:28.000Z

Hi Jeff,

What editing software do you use?
If you use a gray card, or a white piece of paper in the photo, you can then adjust your white balance in post processing with perfect colour temperature and tint corrected for the light source. Eyes are very good a adjusting to different light sources. For example, tungsten lighting is very green, but when exposed to that light long enough, we render everything as neutral.
If you use lightroom, you can easily use the trick above to adjust to perfect white balance and that should fix all the colours in your photo.

Lexel · 2019-10-07T21:58:52.000Z

camera setting

- WB set to manual usually 5000K

Manual aperture, ISO and exposure time → no bad overexposure, can recover dark areas from raw later with same settings on all shots

of course having additional +/-2 exposure shots rendering a HDR picture helps, but the program should be consistent not messing up a comparison between lights

jeff51 · 2019-10-07T22:00:11.000Z

Pavlo:

Hi Jeff,
What editing software do you use?…

Hi Pavlo,
I use Darktable an open source package for editing.

darktable

darktable is an open source photography workflow application and raw developer

All the Best,
Jeff

jeff51 · 2019-10-07T22:12:14.000Z

Lexel:

camera setting

- WB set to manual usually 5000K

Manual aperture, ISO and exposure time …

Hi Lexel,
I’ve been letting the camera pick the color temp for the exposure and then setting the color temp in raw to something that looks right.
Usually something in the 5K to 5.5K range.
I keep the exposure dark enough so I don’t clip the whites.

Does changing the temp in capture effect the output temp if it’s changed in raw?
Thanks for the help,
All the Best,
Jeff

Lightbringer · 2019-10-07T22:24:24.000Z

Pffft. I’ve had side-by-side comparisons of 5700K and 2700K, which look as different as night and day to me in person, but on the camera, no matter what exposure, they look just a shade or two off.

I’ve all but given up taking beamshots, as they always come out lousy.

Lightbringer · 2019-10-07T22:26:35.000Z

jeff51:

I keep the exposure dark enough so I don’t clip the whites.

I made sure of that, too, that nothing is ever whiter-than-white. Even histograms show as much.

jeff51 · 2019-10-07T22:34:52.000Z

Lightbringer:

jeff51:

I keep the exposure dark enough so I don’t clip the whites.

I made sure of that, too, that nothing is ever whiter-than-white. Even histograms show as much.

Lightbringer,
I hear you!
All the Best,
Jeff

Rdubya18 · 2019-10-08T10:39:09.000Z

Thanks for posting this jeff51 . I have been wondering this also as I wanted to post some beam shots , but they are just awful . I thought it was my lack of knowledge / equipment . I can see from this post , it is also quite tricky to accomplish an accurate picture.

Unheard · 2019-10-08T11:31:50.000Z

jeff51:

Does changing the temp in capture effect the output temp if it’s changed in raw?

It shouldn’t, but why not taking shots for testing it?

Best regards,

Thomas