Digital
Dilemmas
Hugh McLean-bsme, thb.
What you see is what you get!!
You have no doubt heard that phrase before - like about a million times. There is SLR and TTL - both of which indicate a method by which a more accurate observation and measurement of exposure might be made. However - there are some caveats along the way.
Theoretically, SLR (single lens reflex) is an improvement over the rangefinder or twin lens reflex cameras with WYSIWYG - but sometimes there are other factors involved. Light comes through the lens - hits a mirror and is reflected up against a fresnel focusing screen - then a prism turns the image around so that you see it correctly instead of reversed. The position of the focusing screen ‘simulates’ the position of the film plane or CCD position. I say ‘simulates’ because the actual image by passes the focusing screen during the actual exposure. Ok - big deal! I had a 150 Sonnar lens on my ‘blad’ that was consistently off focus by about 2 inches at the normal head and shoulder portrait range. I would focus on the subject’s eye and the focus would actually be around the area of the ‘ear’ and the eye would be soft. After several tests and much frustration, I discovered that what I saw was not what I got because of the position of the focusing screen that rested on 4 screws that were adjusted up just a tad too high. So here we have an expensive camera coupled to an expensive lens - and it still doesn’t do the job. The point here is that you have to ‘know your equipment’.
I am somewhat disappointed to discover that my new Fuji S2 has a problem with parallax. Parallax probably is not the exact technical term here because parallax normally relates to the rangefinder cameras with a separate viewfinder. I observed the problem with the S2 when I discovered that when an image was exposed in the vertical orientation, there was a significant amount of area that was captured on the CCD that wasn’t visible in the viewfinder. I never noticed this problem with the S1 camera - but then the body is not the same either. This is an important item for me because I crop fairly tight in the viewfinder, and I want the image I see through the eyepiece to be the same as the image that the CCD captures. Such is not the case with the S2. The display on the LCD is clearly not what the CCD captures either. In all fairness though, I haven’t tested any other units to see if the problem is an anomaly with my unit or is a major problem with the S2 in general. I can deal with it, but is a major nuisance that I have to compensate for on nearly every vertical exposure. On most of my other cameras, I would remove the viewing screen and mark with an 00 Rapid-o-Graph filled with mylar ink, on the smooth side of the screen - .8 ratio parallel lines. I like to crop in the viewfinder so that I can print a full frame and not cut off something critical, and the extra guide lines work. I haven’t been brave enough to remove the screen from either of my digital cameras and preform this operation - yet. I will have some kind of mark on the screen to jog my memory that the right hand vertical line will be beyond the viewing screen. I’m not sure how I am going to do that yet - since I am actually capturing what I ‘don’t’ see in the viewfinder.
One of the things I discovered when moving into the digital world, was that there is a fairly extensive equipment learning curve. Quick now - how many adjustments are there on the camera that you currently use - other than f stop and shutter speed - that have an effect on the final image? On the manual cameras - there really are not many. Even the 2000 series blads with the electronic features are relatively un-complicated with adjustable features. I have calculated the number of variables with my digital camera, and it is truly astronomical.
Another problem that I think frequently occurs when changing from manual equipment to ‘digital’ is a tendency to totally trust the camera’s intelligence and let it take control. The new technology in digital equipment is truly remarkable, but it has to be used appropriately to achieve the correct results - and that is not always automatic w/TTL point and shoot. Film gives you a window of error of approximately +2 /-1 stops (with the bias on the plus) and still produce a useable negative. The window of error with digital is considerably smaller at about +/- ½ stop (with the bias on the minus). You have to nail every digital exposure as close as possible - even if it means NOT using it like a ‘point and shoot’ once in a while.
Comments and kvetches to:
misterdigital@comcast.net