Is there any reason why the following would happen?:
I have D90 set for 0.7 exposure compensation, flash set to 0.0 exposure compensation. The LCD review on camera reflects this. When I look at this same info in View NX (and CNX2), the camera ec reads -0.7 as does flash ec.
I only noticed this by accident. After I have deleted photos from SD card, I have lost the true exposure compensation settings.
There are two places you can adjust the flash compensation - one is the flash setting near the hotshow on the camera and the other is on the flash unit itself. The two adjustments are additive. In addition, you have the Exposure Compensation adjustment for the camera. I'm not sure from your description exactly how you set the camera, but this might help diagnose the issue.
There are reasons why you would use all of these adjustments. I normally use Exposure Comp for the overall image, the flash unit compensation for the strength of the flash relative to the image, and the hotshoe flash compensation when I am going beyond the adjustment in my flash unit.
For example, I might want a neutral exposure of a portrait with a darker background. I would use Exposure Comp at -2.0 to darken the overall image, then use flash compensation at +2.0 to neutralize the exposure on my subject - the light on the subject offsets the exposure comp with extra light from the flash. This works really well for portraits.
Mon 14-May-12 09:33 AM | edited Mon 14-May-12 09:35 AM by cliddell
That's very observant of you! I have just been looking at a couple of flash pics I have and I think I have an idea of why it's done like that...
Assume EC and FEC settings are at 0. When a picture is taken the i-TTL "correctly" exposes the scene.
Now if the camera is set to a certain EC the i-TTL system will take into account that EC setting and slightly over (or under) expose the picture. So that you know that it has done this the figure that it has over (or under) exposed by is there for you to see.
Of course, if the EC is a plus amount and the FEC is a minus amount then it should show the difference amount at the flash settings although I have not tested this out.
All the above is just my "take" on this and would be interested on others comments.
Regards, Clive Liddell Pietermaritzburg South Africa
I would not use iTTL BL - use iTTL FP. FP balances the light for the focal plane rather than the entire scene. BL places emphasis on the background - and you get some unpredictable results. I'm pretty sure the background is your problem.
Using Rear Synch will maintain the exposure based on the ambient light - and that is what you want. Keep in mind that you still can adjust for lighting on your subject. Matrix metering is fine.
However, at this stage I only have the on board flash. My understanding is that when I am in matrix metering mode, the D90 automatically chooses TTL-BL. I have to change to spot metering to get TTL. I don't know much about TTL-FP- something else to read up on.
The positive out of this discussion is that I am learning a lot about lighting and flash (mostly reading and rereading Russ McDonald's CLS blogs. When I have the money, I'll be prepared for using my SBx00 flash(es).
This ended up being less about ViewNX and more about flash but thanks for the input.