Archived posting to the Leica Users Group, 1998/10/20
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Martin: I knew all of what you had written below and knew I had made a mistake with spot after I had developed the rolls from the first game. I have used spot successfully in the Dragon boat pictures plus an exposure compensation. This produced well exposed slides because it avoided the bright water around the boats. The two top pictures as well as the rest on the football page were done with the full field averaging mode. When shooting with a 400, the white can become a lot of the field of view. The conclusion that I have come to in consultation with Ted is to use full field auto and use an exposure compensation if there are bright jerseys on the field. Regards, Robert At 06:09 PM 10/20/98 +0200, you wrote: >> Now to how I shot it Saturday. I used the spot metering to measure off >> the visiting teams uniforms and the field. I then put it on auto full >> field and compared the reading, they were the same. The sky was cloudy >> and the sun was poking out every now and then. This is why I shot on >> auto rather than manual. When I developed the slides, I noticed that >> any picture with white jerseys in it was underexposed. I had this same >> problem the previous week but though it was because I was using spot >> auto. >> >> I guess my question is, should I shoot on manual, what should I meter >> off? >> > >Any reflective exposure meter (such as those in cameras) is calibrated >for 18% grey. So, to get correct exposure, you need to point it towards >something that reflects roughly 18% of the infalling light. If you meter >off something lighter than an 18% grey card, it will get underexposed. >If you meter off something darker, it will get overexposed. > >A good guideline is grass, which is pretty close to 18%. I frequently >meter off grass and then use that as my exposure, remetering if the >light changes. > >An alternative is to meter off something else, and then adjust with >exposure compensation, the final exposure. So, if you where metering >off the light jerseys, dial in an exposure compensation of +1.5 or >+2 to get them white on film. > >With auto, unlike manual, the camera is going to remeter for each time >you press the shutter release, unless you lock the metering. So it is >not only going to take varying lighting conditions into consideration, >but also if you point the camera at a lighter or darker subject. > >Furthermore, as you probably already know, spotmetering only measures >a very small amount around the centre of the picture. So, whatever >happens to be in the centre (a white jersey, a blue helmet, green grass) >is going to determine the exposure of the entire shot. With a roughly >even mixture of bright white and dark blue jerseys and green grass, >centreweighted metering would probably have saved more shots. Rarely can >you stick a camera on spot metering and auto exposure and just shoot >away. Almost always this will result in incorrectly exposed pictures, >although if you make artsy-farsty B&W prints, you could become famous ;-) > >A combination of the above factors (spot, auto, reflectivity of the >subject, etc) resulted in the white jersey guys being underexposed. > > >Regards, > >M. > >-- >Martin V. Howard, Application Systems Laboratory, | >Dept. of Comp. & Info. Sci., Linkoping University, | Just "DOHH" it! >SE-581 83 Linkoping, Sweden. Tel +46 13 282 421, +----------------+ >Fax +46 13 142 231; marho@ida.liu.se; www.ida.liu.se/~marho > > > >