Hi..

I recently took a group photo of 8 people standing about 10 feet away from me in a lowly lit room.

In order to get the exposure, I used the summicron at F2 and 1/25 secs handheld.

The picture came back sharp and nicely lit. But the problem is, some of the people's faces are not as sharp as the one I focussed on(the central person).

My question is, should I use aperture F4? The exposure would be under I supposed. How do I correct the limited depth of field problem in this case without using flash and loosing light?

I hope u know what i mean...THANKS!.

-- Travis Koh (polar@cyberdude.com), January 04, 2002

Answers

Travis, I guess that you should have used faster film (or push the film you used), unless using flash is acceptable. You could have used 1/15 shutter speed and f2.8; depending upon your ability to hold it steady. You need to understand the trade-offs involved with exposure, decide in advance what is of primary importance to achieve your photographic objective, and then take the appropriate action necessary.

-- David (pagedt@chartertn.net), January 04, 2002.

Travis, in my opinion anything less than 1/50th with a 50mm lens should be on a tripod for good sharpness. To do this, you would need a faster film. You didn't indicate what film you used, but the films available these days are really great. There's an old rule regarding shutter speed: Use the reciprocal of the lens focal length, i.e. 90mm=1/100; 50mm=1/50th etc. I hope this helps you to get the performance your Leica lenses can deliver.

-- George L. Doolittle (geodoolitt@aol.com), January 04, 2002.

There's an old rule regarding shutter speed: Use the reciprocal of the lens focal length, i.e. 90mm=1/100; 50mm=1/50th etc

But since this an RF sans flapping mirror, one might be able to handhold at least one stop slower, no?

-- Tse-Sung (tsesung@yahoo.com), January 04, 2002.

Depth of field is a fact of photography. Use Faster film or a tripod (even a small table tripod)and slower speed/smaller f stop and make sure the subjects are still. Sometimes I thing we Leica M users are allergic to tripods!

If I'm very careful, I sometimes can get acceptably sharp hand held mages with my M3 at even 1/8 second, but I can't count on every one being good, and they don't turn out as well as those taken at low speeds on a tripod..

-- Andrew Schank (aschank@flash.net), January 04, 2002.

Travis helps me make a point many Leica afficionados find unpopular, which is that fast lenses, even with wonderful sharpness and contrast wide open, are severely limited in utility because of shallow DOF, and this is particularly troublesome with the M series because it takes a huge amount of experience to accurately visualize the DOF of each lens at wider apertures especially in the close range, where the DOF scales on the lenses are practically useless.

-- Jay (infinitydt@aol.com), January 04, 2002.

Couldn't resist posting a recent image with my 50 summicron, taken at f2 or 2.8, approx. 1/15...

-- Peter B. Goldstein (peter.goldstein@us.cgeyc.com), January 04, 2002.

Peter- If this shot was under fluorescent light, it looks like it has been corrected with FLD filter, or some other way. Was this on color neg film?

-- Frank Horn (owlhoot45@hotmail.com), January 04, 2002.

Something I've noticed with many lenses in low light (wide apertures) shooting faces at a distance, where skin becomes the major subject manner instead of eyelashes and the like that we usually use as indicators of sharpness, is that another issue raises its head. I suspect this is some sort of chromatic abberation, and while a lot of the subject matter will be sharp, often faces (mostly red and yellow, no blue and green) seem to be in a bit of a fog. Could that be part of the problem?

-- Michael Darnton (mdarnton@hotmail.com), January 04, 2002.

Frank, that picture was taken using Kodak 200 gold print film using a UV(O) filter. Is there a filter you would have recommended for the lighting conditions?

Peter

-- Peter B. Goldstein (peter.goldstein@us.cgeyc.com), January 04, 2002.

Peter- Not really. It looks quite good as it is. That is why I thought you must have used something like the FLD. I don't see the tell-tale greenishness. Perhaps if you had used a daylight slide film, things might have been different. I have had good luck with Kodak Golds under fluorescent, sans any kind of filter. What it might be, is an experienced person doing the printing, and adjusting the color mix.

-- Frank Horn (owlhoot45@hotmail.com), January 04, 2002.

-- Dexter Legaspi (dalegaspi@hotmail.com), January 04, 2002.

There are (at least) two possible reasons for this, both of which can be addressed by using a smaller aperture.

1. If all the people were in a straight line, the ones at the edges will be farther from the lens than the ones in the center. For them all to be 10 feet from the lens they would need to stand in an arc with a constant 10-foot radius from the lens. A smaller aperture and more depth of field will cover this difference.

2. The 50 'cron, like most fast lenses, has a substantial drop-off in MTF as you move away from the center of the frame at f/2. (See Photodo.com for MTF chart of Summicron at f/2). The 'cron is roughly 1/ 2 as sharp at the edges of a horizontal frame as it is at the center.

Edge sharpness also improves with stopping down - by f/8 the 'crons sharpness is pretty even all the way across the chart.

-- Andy Piper (apidens@denver.infi.net), January 05, 2002.

George, I used kodak tcn 400.

well i guess to solve my earlier problem, I would need to stop down aperture to f4 and shhot at 1/8 using a tripod.

but I think to keep the group of people still at 1/8 sec would be a problem.

Pushing the film to 800 could also solve the problem but sigh....I guess I have to accept the limitation in some situation at f2.

-- Travis koh (polar@cyberdude.com), January 05, 2002.

"I suspect this is some sort of chromatic abberation, and while a lot of the subject matter will be sharp, often faces (mostly red and yellow, no blue and green) seem to be in a bit of a fog. Could that be part of the problem?"

Michael, that's an interesting comment - can you post something that illustrates it?

-- rob (rob@robertappleby.com), January 05, 2002.

Travis

The only solution is to use faster film, or try a smaller aperture and see. Or act like a professional, bring your tripod and bore everyone as you take 36 shots at differing apertures. This is a typical photo "problem". My feeling is that you should not be surprised if it does produce a result that disappoints. Not everything is possible! Personally, I think I would have tried to get say four "head and shoulders" people in an arc 5 feet away and in focus and then had the other four "looming" in the background clearly out of focus, but hopefully still recognisable. Then it might have looked intentional and "artistic". There are other possibilities based on this kind of approach.

-- Robin Smith (smith_robin@hotmail.com), January 07, 2002.