White Background

[peterindb]

I've been trying to get a clean white background on my pix, using the Zack Arias Blog advice. I believe I got a decent result this time...

Two speedlites on the background, and a clean tile board on the floor.

C&C welcome....My daughter is posing in what I believe is the fifth position in ballet.

[speedneeder]

The background looks very white to me I like it.
I also like the shadow on the floor in front of the subject.

[rpcrowe]

Nice!

[Geoff F]

Is that colour fringing that I am seeing particularly on her arms and legs?

That is a common problem with mixed lighting sources particularly when light is coming from behind. But I will leave this to the real experts who are more familiar with this type of shot.

[John C]

I think I see it too, especially when I hit the 'expand' button. Its should be fixable in processing. I like the expression, pose, white background and shadow.

[Photon Hacker]

Is that colour fringing that I am seeing particularly on her arms and legs?

That is a common problem with mixed lighting sources particularly when light is coming from behind. But I will leave this to the real experts who are more familiar with this type of shot.

As far as I know color fringing is due to chromatic aberration in the lens.

[Dave Humphries]

As far as I know color fringing is due to chromatic aberration in the lens.

Most is, but I don't think that's the whole story here.

This isn't the classic manifestation of CA.

I think the background is too blown and has bled around the subject edges and the sharpening may have introduced further effects.

It's a good start Peter, but it can probably be improved upon. I say that as an observer, not a doer though
(meaning it's better than my first attempt would be)

[Colin Southern]

I've been trying to get a clean white background on my pix, using the Zack Arias Blog advice. I believe I got a decent result this time...

Two speedlites on the background, and a clean tile board on the floor.

Just don't over-power the background, as it results in loss of hair fine detail as you can see around the yound lady's hair. Normally just go 1/3 to 2/3 above a normal exposure for the background -- not 2 stops as some people suggest (no need to nuke it half off the planet as it's a highlight anyway).

[peterindb]

Thanks, everyone,

I'm almost tempted to get a light meter at this stage.

Maybe I'll experiment with different lens and speedlight power next...It's not work if you're having fun, right?

[Photon Hacker]

Thanks, everyone,It's not work if you're having fun, right?

Haha. Hackers (Like computer programmers who enjoy it) would disagree.

Will the light meter be actually useful?.

[peterindb]

Interesting discussion. I don't claim to have a sure answer.

Here's a magnified section of my photo showing the fringe effect...





Here's a picture I got from looking up "chromatic aberration" from Google images...




Finally, an example from a subject with fringing from an overexposed white background (credit to zackarias.com)...




Whatever that is, I can make it go away by desaturating the purples and magentas in lightroom.

[Colin Southern]

Haha. Hackers (Like computer programmers who enjoy it) would disagree.

Will the light meter be actually useful?.

Light meters in the studio are ESSENTIAL, unless you want to waste a LOT of time getting lighting ratios correct. Case in point - had a big shoot last weekend - I setup the lighting while the MUA was working on the model - setup backfround lights first (white seamless) @ F11 + 0.6 stop - setup key @ F11 - setup fill @ F11 (was using light table, so not the usual fill @ approx -1.5 stop) - setup hair light at F11 + 2 stops.

Took an overall reading (the light is cumulative) - took a test shot (dropped hair light down by 1 stop) and "Job Done". Trying to do that without a lightmeter would be nigh on impossible.

[Dave Humphries]

Interesting discussion. I don't claim to have a sure answer.

Here's a picture I got from looking up "chromatic aberration" from Google images...

Hi Peter,

I did the search you did and unfortunately that is right in the top row of results
However, I feel it's a bad example of the most commonly observed artefact, which is lateral CA.

Much further down is this example;

(image source credit)

Have a look at the tutorial on Using Lens Corrections here at CiC. Scrol down to section 3, which covers CA very well.

So yes, the problem could be axial CA and blooming, Sean's tutorial suggests things to try to reduce these (in addition to not having the background too over exposed).

Hope that helps,

[peterindb]

Thanks Dave!

Good luck on your project 52.

Peter