Al Hart <[EMAIL PROTECTED]> wrote: >Subject: F5 Exposure Problem/Question [v04.n306/3] >I have a problem with exposure when using the F5. >....<snip>.... >BUT! What about the vaunted F5 metering system? Why did it not "see" >the white birds when comparing the picture to the 30,000 in its >database, >then say to itself "This jerk is trying to shoot a white bird in a >mid-toned setting, so I'll help him out by stopping down a bit?" Sure there is a database of 30,000 picture types in the camera which tend to select an appropriate exposure for your photograph. It sounds like the database found a match in the: "sunlight scene with trees and foliage department" and went ahead and properly exposed for that. Or, it picked out something totally inappropriate from its database and went ahead and used that. The database didn't know the white specks were the important thing; it thought that the big green clumps were the important thing to expose properly for. In the vast majority of cases matrix metering will improve the exposure especially under extreme lighting conditions, but it has no artistic notion of what is "important" in the photograph. There is another thing that is going against you here as well. The transparency films that you are using are capable of rendering about a 6 to 8 f-stop range of light intensity. Anything outside that range is rendered as either maximum density (ie black) or minimum density (ie clear film or white). Lots and lots of scenes fall well outside this range (or, well inside this range). In all probablity the scene you photographed was properly exposed for the the background (maybe 80% of the image area) and everything else that the film "faithfully recorded" fell in the 6 stop capability of the film. The important birds fell out of this range and were simply recorded as white. The trick is to make sure all the important information of the photograph falls within the recording range of the film. >Moose Peterson, when asked the question, verbally shrugged his shoulders >and replied that when HE shoots under identical circumstances, he gets >perfect exposures. I doubt if *everything* was identical. I also doubt that all his exposures are perfect too. >As a result of all this, I'm confused. There are a lot of things going on here and the matrix metering does a good job of simplifying the whole exposure process but if you want *critically accurate* exposures you will have to turn the matrix metering off and turn your brain on. There is a lot that has been written about this and it has its roots in the zone system, sensitometry and you can spend a *lot* of time learning about this. And, it is worthwhile if you want to know really what is going on. For, many people though that is just too much. However, at the risk of over-simplifying, you can do some quick things yourself to get tricky exposures under control. First turn off the matrix metering and switch to averaged or center weighted. Take a reading, and remember that. The meter says that the whole scene will be averaged to an 18% grey density (a darkish grey). Now, decide is that what you want? If the scene is back-lit or is a snowy landscape you will have to compensate for that. Next turn the spot meter on. Take a reading of the brightest and darkest part of the scene that contains detail that you want to retain. How many f-stops difference are there, between the brightest and the darkest, if it is greater than 7 or 8 stops, then the film will not record any detail in those areas that fall outside the range. Again, you need to compensate the exposure such that none of the important details that you want are lost. Also bracketing helps too. It is important to stick to one kind of film as well and to use it a lot. That way you will get to understand both the pallette of the film and how it responds to various situations. Has anyone read any articles on the Art of Metering recently? There was an excellent one called: "How to avoid indecent exposure." written in Camera 35 magazine in the mid-70's. It may be in the archives of your local library. >Why did the F5 not properly compensate for the presence of the white >birds in the metered mid-toned backgrounds? It decided that the small white birds were not important. >What is the benefit of the F5's acclaimed RGB metering, if the user is >left to compensate exposures just as with "any old camera?" It helps in a lot of situations but is no match in accuracy for a photographer who understands how to spot meter and knows how his film responds to light. >I don't know where in the Nikon organization to get an authoritative >reply to the question, and so I'm hoping that this group has some >Nikon experts with an answer. I think that Nikon is in the business of selling equipment and is not going to advise you to turn the matrix metering off and turn your brain on. Very best regards, Robert Hudyma, Semi-Tech Corporation, 2800 14th Avenue, Suite 511, Markham Ontario, Canada L3R 0E4. Fax: (905) 475-3652 Email: [EMAIL PROTECTED] The distinction between past, present and future is only an illusion, even if a stubborn one. - Albert Einstein
