Help - Exposure problems

[BazEP]

Hi
hoping someone can help me. I am getting to grips with a new Nik D300 body, i've been using a d40 previously. One thing I can't understand is the massive difference in the level of exposure between my jpeg and raw outputs. I try not to do anything at all in camera to the jpegs (I do use Active D-lighting but I thought this was applied to both jpeg and nef format? maybe not) so can't understand the big difference. Example - I took the shot below with no EV bias, AP, matrix metered, auto WB, IS using a 50mm, 1.8d 1/640s @ 2.8 (think the exif should still beintact if you want to have a look at the settings, I may have missed something).

I use UFraw and the gimp for processing and when I opened the image in UFraw and set the exposure bias to 0.0 and it has gone really dark. I reset all the other variables in ufraw to make sure it wasn't the curves or anything else in there making this happen.

Why is there such a massive difference in these pics? I'm stumped.

from raw


from jpeg



ps - first time posting pics on here so hopefully it's worked.

Cheers

 

[RicherSea]

set the exposure bias to 0.0 and it has gone really dark. I reset all the other variables in ufraw to make sure it wasn't the curves or anything else in there making this happen.

That's probably the issue right there. I don't shoot, and have never used, a Nikon, but I certainly know the JPEGs from my Canons do not have anything close to zero setting applied to them, they have a fair bit of positive brightness, contrast and saturation applied.

You are trying to compare something with no processing, and something with probably quite aggressive processing applied, and obviously they aren't going to look the same.

Try changing the settings in UFraw and see if you can make them look the same. That will tell you roughly what the camera is doing to the RAW to get it's own JPEGs. I use Lightroom for RAW processing and there is an option to re-produce Canon's JPEG settings. I don't know if there is a similar option in UFraw.

Hope that helps.

 

[redhed17]

According to Thom Hogan's excellent guide book for the D300, only Nikon NX can read the NEF properly if D-Lighting has been applied. If you are using another RAW converter he says you are going to end up with under exposed images because the camera reduces the highlight and shadow data recorded.

He advises that brightening the NEF which is under exposed because of D-Lighting has been applied will result in noisier images. He says he would rather not use D-Lighting and just ensure that the scene doesn't have channel blowout by setting the exposure correctly. He says wouldn't use D-Lighting anyway, preferring to set the correct exposure.

D-Lighting is designed for difficult high contrast scenes and shouldn't really be left on all the time. BazEP's image doesn't really look like an image which would benefit from D-Lighting and is nothing that couldn't be sorted with correct metering and maybe some Exposure Compensation imho.

 

[BazEP]

According to Thom Hogan's excellent guide book for the D300, only Nikon NX can read the NEF properly if D-Lighting has been applied. If you are using another RAW converter he says you are going to end up with under exposed images because the camera reduces the highlight and shadow data recorded.

He advises that brightening the NEF which is under exposed because of D-Lighting has been applied will result in noisier images. He says he would rather not use D-Lighting and just ensure that the scene doesn't have channel blowout by setting the exposure correctly. He says wouldn't use D-Lighting anyway, preferring to set the correct exposure.

D-Lighting is designed for difficult high contrast scenes and shouldn't really be left on all the time. BazEP's image doesn't really look like an image which would benefit from D-Lighting and is nothing that couldn't be sorted with correct metering and maybe some Exposure Compensation imho.

understood I think - thanks for that. I've only had the cam a short while so still getting to grips with it. I'll have a play and a think on the the Active D-lighting as elsewhere I've seen great results especially in very bright conditions (which that session was, it's just that pic which was in the shade). It can all be sorted from the RAW file anyway but I wanted understand what was really happening.

Need to sort out CaptureNX now...

 

[G2EWS]

Hi BazEp,

I don't think you need to get to technical here. The camera is making the jpeg image what it thinks it should be. The RAW file will contain all of the data so you can manipulate it in PS or adjust your settings before taking the shot.

What bothers me is that the D300 and subsequent Nikon cameras tend to over expose shots and need a bit of negative compensation anyway.

May be tempted to re set the camera and start again if it was me.

Best regards

Chris

 

[redhed17]

I would learn to use the exposure options rather than try to rely D-Lighting to try and save images, as you are losing some of the dynamic range when using. it. It can be as easy as using the Exposure Compensation once you get experience of how the camera measures different scenes. :shrug:

D-Lighting is of most use when shooting Jpeg in high contrast situations (big difference between the brightest and darkest parts of the scene) where little of no post processing is planned.

 

[BazEP]

thanks guys
I nearly always ran with a neg ev on my d40 to be honest. And I always shoot raw (with basic jpeg, in case i wanted to send off snaps to friends and family for eg) and expect some pp. Even if it's just a fiddle with curves and contrast so makes sense to drop the AD. I'll have a play...

thanks for all your help