With my cameral securely mounted to a tripod, I plan to photograph a certain forest path which my wife and walk nearly every evening. The plan is to shoot this path from one vantage point during each the four seasons, then mount four exposures under one piece of glass. The vantage point is important. There is a subject of interest approx. 12 feet in front of the camera and then the path recedes about 150 yds into the distance. Composition dictates the lense will be 50'cron. My questions is what F stop will give the most acceptable focus. I've read that 5.6 to 8 is the 'sweet spot' but then stopping down to 11/16 will give sharper depth of field. I certainly will experiment but was wondering if anyone had an opinion. As always, thank you.

-- Jim Ford (anniejim@dellnet.com), November 25, 2000

Answers

Jim:

The 50 f2.0 does loose a tad of sharpness at f16 compared to f5.6 or f8, but that may not be as important as the extra depth of field you'll get depending on what you are after. Take several shots at different apertures and also maybe focus bracket. You should be able to get everything in focus from 12 feet to infinity without much trouble.

-- Andrew Schank (aschank@flash.net), November 25, 2000.

The markings on my Summicron 50mm lens indicate that f/11 will cover from 12 feet to infinity. Is this lens similar to the "50'cron" you mention? Depth-of-field tables probably give more exact numbers. I would be disappointed with any Leica lens if I had to worry whether it would give a good enough inmage at f/11 or f/16 as compared with f/5.6 or f/8. Thaat is to say, why lay out the money for Leica gear if this is going to be a serious consideration with it?

-- Keith Nichols (knichols@iopener.net), November 25, 2000.

I have read that some landscape photographers, when using hyperfocal settings, under estimate the marking's ability to render the maximum amount of sharpness. Since in real life, focus is actually on a plane... and the degree of "unsharpness" is dependant on magnification and the f-stop. The degree of "acceptable" softness is what the depth of field settings indicate. if very critical sharpness is required, many photographers use the depth of field markings for one f-stop less than what is actually set for the exposure. If the exposure is using f11, then set the infinity mark to the f8 DOF marking.

Each composition has a portion that HAS to be sharp and parts that can go slightly soft without effecting the overall pictorial effect. If you must choose, I'd put the focus on the foreground object at the expense of infinity sharpness. foliage will blend together in the background, but a larger foreground object would jump off of the print if it is soft. I often bracket my DOF, just like some folks bracket exposure... then I pick the one that works best.

Since you are going to work on this for a year, it would be worth a roll of test film now to establish your process. Write down all of the parameters for the test... distance, f-stop, framing, etc... and upon reviewing the test shot, pick the ones that work for you. When it is time for the real ones... just set everything the same, and there you go.

-- Al Smith (smith58@msn.com), November 25, 2000.

Jim, I'm with Keith. I checked my 50 Summicron and found with the lens focused to 10 meters, at f/8 everything from 5 yards to infinity will be in acceptably sharp focus. Fire away!

Regards,

-- Bob Fleischman (RFXMAIL@juno.com), November 25, 2000.