Sun 17-Nov-13 04:18 PM | edited Sun 17-Nov-13 04:38 PM by Kropotkin
OK. So I have my new D800. It doesn't feel as good to handle as the D7000 (not by a long way) but the quality of the pictures really does seem close to medium format. Very excited about that.
But I'm quite confused about camera live view. This seems one of those cases where the manual doesn't give much information and there is a lot of confusion amongst users and even writers of books.
Here is an example:
In A mode. F22. (Active D Lighting off). WB auto. ISO 200.
I'm in a room lit only with weak ambient lighting.
The picture in the monitor is very very dark, more or less black. When I take the image the image is reasonably exposed - as I would expect. The camera has just worked out the exposure (1 1/2 seconds) and got a reasonable exposure. So; the monitor image was not giving an exposure preview.
According to the manual (p46) (and it is quite clear) pressing the OK button will give an exposure preview taking account of aperture, shutter speed and ISO. It doesn't. Pressing it makes no difference at all to the image displayed in the monitor. It does put up a level meter which (in A mode) will show any EV I have set. But, again, there is no change to the image in the monitor display.
To complicate matters: with OK off (or on - it makes no difference) if I open up the Aperture the image in the monitor does become brighter. At a wide aperture it starts to look quite like the actual photograph which is captured.
Based on all that it seems that in Aperture mode the following are the case:
1. The image in the monitor is an attempt to show what the exposure will look like. However this is not very reliable. (At least in the conditions I am testing in - very low ambient light resulting in long exposures, longer than a second).
2. The function of the OK button is not as described in the manual. It does not show an exposure preview. It simply pops up a levels meter to show current EV settings.
However, another explanation is possible:
1. What I'm seeing on the monitor is an optical view. This is why it gets brighter when I open up the aperture.
2. The OK button is not working to show an exposure preview - either because of a setting issue or camera fault?
To do a test. It just happens that I'm testing in the evening. I'm trying 'extreme' settings as a way of producing a noticeable effect.
Based on a video I found it seems that B is more likely.
The monitor shows a consistent brightness. When you press the OK button the meter shows up and the monitor should show an exposure preview. It doesn't in my case. (Possibly because of the unusual settings; but then if that is the case it fails).
Sun 17-Nov-13 05:11 PM | edited Sun 17-Nov-13 05:15 PM by Kropotkin
This is an interesting answer. I don't want to get into semantics but you have said "predict a change". You have not claimed that the exposure preview will actually show what the final image will look like.
This is what it seems to do. I am in "non-preview mode". I press the OK button. The image in the monitor does not change. However if I now dial in say -2 EV the image in the monitor changes (becomes less bright). But - this change is applied to what was in the monitor before. The end result is still not an absolute preview of what the final exposure will look like.
(In 'normal conditions' the monitor would show a reasonably bright image which would be close to a normal good exposure).
Justin what's happening is you're exceeding the capabilities of the LiveView system by using an f22 aperture in a dark room. Preview mode is an aid in arriving at the correct exposure by giving you the meter setting on the right of the screen and the histogram. Review the Exposure Preview info on page 46 of your D800 manual.
You will get a greater preview range if you use manual mode and adjust the aperture, shutter speed and ISO so you are close to centering the meter scale and histogram. If you increase or decrease the exposure by + or - 6 EV or so you'll see the effect of exposure changes.
Interesting question. Since I had my d800 close by, I tried your experiment with two different lenses, AF and MF mode "A". On the preview screen with EV bar and histogram displayed, I did not see any effect on the preview screen or histogram when I changed iso or EV. However, when I changed the aperture, I saw the expected effects on both screen brightness and histogram.
Mon 18-Nov-13 11:53 AM | edited Mon 18-Nov-13 11:56 AM by Leonard62
>If the OK button only shows aperture changes how can page 46 >be correct? > >I don't understand. > > If you put the camera in manual mode, the OK button shows changes in aperture, shutter speed and ISO settings.
In the Auto modes like A, S or P you need to vary the exposure compensation using the +/- button to see the effect of a change in exposure. If you just change the aperture, shutter speed or ISO in the auto modes there is no change because the exposure stays correct.
I don't think the section on page 46 is very clear in explaining this. However if you know they mean you change the exposure compensation then it makes sense. They do reference page 130 which is exposure compensation.
I think you are right. The explanation on p46 isn't very clear. It led me to believe that it was doing some sort of complete representation of what the captured image will look like. I don't think it is doing that. It seems to me that it is about (in A mode) showing EV changes in the monitor image. The monitor image is electronically controlled to be bright and stable. Then the OK mode will show an approximation of EV changes to this monitor image.
However I have to specifically say that in A mode when I change the aperture the lightness/darkness of the monitor image changes. This happens whether or not I am in OK mode. However; this only happens in the range of about F11 - F22. (As GiantTristan noted changes to ISO have no effect). I think what is happening here is that above a certain F stop there isn't enough light to illuminate the monitor and it gets darker. But this shouldn't be confused with it trying to show you the effect of EV changes. Once you are into a 'normal' aperture range the image in the monitor stays stable. It isn't effected by aperture changes. These changes at small apertures led me astray and made me think that this was it trying to show you the effects of exposure. It isn't. It just needs a certain amount of light to function normally.
Finally; the question of the Manual mode. You are correct about how in manual mode it does show all changes to aperture and ISO etc. The firmware patch fixes it so you have the option of turning off preview mode in M mode. Before the patch it was always on in M mode.
Anyway. That's all clearer for me. Hopefully others too. Thanks
>However I have to specifically say that in A mode when I >change the aperture the lightness/darkness of the monitor >image changes. This happens whether or not I am in OK mode.
Surely it shouldn't do that.
Thom Hogan's D800 guide is a bit clearer on LV than the Nikon User manual. Page 479 says that in all exposure modes except Manual the camera uses unseen ISO changes to keep the LCD image fully viewable and appearing to be exposed properly. The LV image will look the same in P, A and S modes even if you set exposure compensation. Pressing the OK button in LV brings up the metering bar and tells the camera to emulate exposure.
I'd be grateful if someone could try a test. In low ambient light conditions in A mode. Set ISO 200. F11. Then change the aperture to F22. Mine gets darker.
Assuming this is not a glitch in my particular unit I think it may be like Len suggests above. I'm exceeding the capabilities of the LV system with this test. It assumes that you are using reasonable settings. Ie. Thom Hogan is correct but he could have added a caveat that this only applies within a reasonable range.
>"Surely it shouldn't do that. " > >Well. It is a bit confusing. > >I'd be grateful if someone could try a test. In low ambient >light conditions in A mode. Set ISO 200. F11. Then change the >aperture to F22. Mine gets darker. > >Assuming this is not a glitch in my particular unit I think it >may be like Len suggests above. I'm exceeding the capabilities >of the LV system with this test. It assumes that you are using >reasonable settings. Ie. Thom Hogan is correct but he could >have added a caveat that this only applies within a reasonable >range. > >--Justin
I just tried it (A mode, ISO 200, f/11) and LV gets darker as I change aperture to f/22. So my D800E is behaving the same as yours.
>If you put the camera in manual mode, the OK button shows >changes in aperture, shutter speed and ISO settings. > >In the Auto modes like A, S or P you need to vary the exposure >compensation using the +/- button to see the effect of a >change in exposure. If you just change the aperture, shutter >speed or ISO in the auto modes there is no change because the >exposure stays correct.