baptiste_autin

Thank you all for your answers.

I made some new tests, avoiding white colors this time, and the pictures are still underexposed (as the histograms show it).

The only thing that comforts me is that I get the same result using the builtin flash of the D80 (my only point of comparison up to now), which probably means that my Yongnuo is not faulty (furthermore, it works well in M mode, and, in i-TTL mode, the flash output changes if the scene changes, so it is not stuck at a minimum value either).

So, well, I think I'll keep my Yongnuo... Maybe I'll even get another one, a 560 for example, to add more light, if needed.

And it's true I'm not using a very luminous lens (an AF-S Nikkor 18-70mm f/3.5-4.5G), so I guess I can't expect to get the same result as with a, say, 50mm f/1.8, for example)

Yet I would be curious to see how an SB-900 would perform in the same conditions, in terms of metering, as well as in terms of global power.

Thanks for your answer!

My pictures were taken with the "matrix" metering mode. I just gave a try with the two other modes (central, spot) but unfortunately the results are not significantly different.

I will make more pictures including more colors, like you said, and I will report here the results, even if I don't quite understand what you mean by "average grey". When I look at the histogram of the first picture (the one with no compensation), 95% of the pixels are concentrated in the first half of values (the lowest), so I think it should be pretty easy for the camera to guess that the picture is underexposed...

Underexposure and flash Yongnuo 568EX

I just received a Yongnuo 568EX for my Nikon D80, and I did a couple of tests.

Unfortunately, all my pictures in "i-TTL" are underexposed, by about 1 or 2EV. So I have to compensate every time I use iTTL.

The manual mode seems to work normally (even though I'm slightly disappointed by the power of the flash).

And now I am seeing on the forums that others have faced the same problem.

So, my question: has anyone NOT encountered the problem using Nikon+568EX ? (with Canon it seems there's a workaround)

Has anyone more information (official, or not) about this issue? Does anybody know if *ALL* 568EX work like this?

I hesitate to send my flash back.

This is my first cobra flash, and I lack experience as well as points of comparision.

This is a picture I made at night with the 568EX (FC+0) and the D80 (M, ISO 320, 18mm, 1/160, f/3.5) in I-TTL :

http://baptisteautin.com/files/DSC_5478-yn-0.jpg

The same with the builtin flash of the D-80 :

http://www.baptisteautin.com/files/DSC_5475-builtin-0.jpg

With the 568EX (FC+1) :

http://www.baptisteautin.com/files/DSC_5480-yn-1.jpg

Thanks for your help.

<p>In Photoshop, I pushed the levels to +2.50 on two versions of the same NEF: one imported with ACR 3.7 ("image settings", without correction), and one imported with NX plugin (without correction). The shadows in the ACR version appear more noisy and posterized than in the NX version.</p>

<p>See by yourself:<br/>

<a href="http://abcedaire.free.fr/DSC_0004_ACR.jpg">http://abcedaire.free.fr/DSC_0004_ACR.jpg</a><br/>

<a href="http://abcedaire.free.fr/DSC_0004_NX.jpg">http://abcedaire.free.fr/DSC_0004_NX.jpg</a>

</p>

<p>Maybe the difference lies in the colour space, since I noticed that the amount of noise depends on the colour space selected when you import in ACR (I think NX files are tagged with a peculiar "Nikon sRGB 4.0.0.3001"). In particular, ACR introduces some unpleasant bluish nuance on my sweater, whereas NX gives a more accurate grey tone.<br/>

Or maybe there is some special noise treatment that NX does over the shadowy parts, to preserve them a little.<br/>

Or maybe ACR is just sucking somewhere.<br/>

I don't know.</p>

<p>You may say that's not a problem: if I want to correct exposure, I can just do it during the import, so I can recover the shadows. Sure. But that experience is not a good sign anyway: you need to have the best quality possible if you intend to make some treatments in PS.</p>

<p>One thing is sure: I'll switch to ACR only the day when ACR gives me EXACTLY the same file as NX.</p>