[Dimeman]

just read the poll on---- how you focus.
What method gets the shaper images?? Lots of great answers and techniques.


On my old Super Program I could never get perfect sharpness. (even using eyeglasses or the by using the correction diopter lens)

On my ZX30 (auto focus)I just got last week, the 2 -12 exposure test rolls I shot, all had much crisper images than my Super Program (manual focus) .

[icywarm]

My best 'luck' has been with a M series 75-150, I like that the zoom and focus is on one ring, which means I can follow action and get it just right.

[erickallemeyn]

I've never had good luck with manual focus. A split focusing screen does help enormously, but after I've micro corrected my lenses the autofocus on my (digital) is more accurate than I can ever be

[wlachan]

The Super Program on the market are so old many of them might be serviced in the past. One nasty secret with old Pentax manual focus cameras is that they used copper washers sandwiched between the front & rear bodies to alter exact the film plane distance. They came with different thickest but often being mixed up when serviced. Some even are with missing washers afterward and causing the body to focus pass infinity.

[Wheatfield]

With a good and properly calibrated viewfinder and a good split image or microprism screen, manual focus will win every time. Unfortunately, with Pentax DSLRs there is no such thing as a good viewfinder and you need to buy a good screen on the aftermarket and then get the thing calibrated.

[Ron Boggs]

Both auto and manual methods move internal lens elements to achieve focus. Both auto and manual can select the same internal optical set-up and thus the same focal point/same focus. Both auto focus motors and manual fingers can at times be too slow or can "overrun" it and miss focus. Both focusing algorythms and brains can missjudge true focus. Both mechanical viewing or eyeball viewing can be unclear making focusing difficult. I think there are more commonalities than differences.
Personally have always preferred manual focus. Currently shoot manual focus 95% of the time.

[Gillies]

After I switched to digital I've relied on AF with only a few, but important ones being out of focus. It was all my fault, but since my eyesight ain't what it used to be, I only noticed after I downloaded them.
I recently bought a split screen so I can manual focus from now on and so far every shot has been bang on.
As for the rest of the settings, I also use manual mode for 95% of my shots, using only the green button to get me to a starting point. It's what I'm used to and I'm usually never in a rush.

[Dimeman]

Since I just had my Super Program serviced by Eric I will have to run some test rolls to see how it is now. Could be it was off calibration a little.

Thanks for the replies.

[Lowell Goudge]

My feeling is that on average, AF gives closer focus than MF, but when you nail it in MF it is sharper.

Here are some things to consider.

MF accuracy is largely dependant on the focusing collar rotation (throw) from min focus ti infinity.

Except for some wide angle lenses I have, most of my MF lenses are more than 270 degrees. they are very slow to focus but very presise, the exception is my series 1 70-210 which is only 180 degrees, much quicker to focus (good for action) but not as accurate.

in comparison my sigma 70-200F2.8 only has a 90 degree focus throw. It is almost impossible to manually focus accurately, but is dead on in AF mode.


My experience is that most AF lenses are not really designed for MF use, and therefore it is not fair to compare focusing with these lenses in terms of accuracy with true MF lenses.

the exception for me in focusing accuracy is with fast wide angle lenses, the shorter the lens, the lower my shooting percentage. the dof is just too much to get it right, even sith split image.

[Marc Sabatella]

It's simply a matter of your skill with MF (as well as with AF) and luck of the draw. Either is capable of practically perfect results or really bad results.

[philbaum]

I was at the home of a friend of mine, who is a Canon shooter, had a D40 and just purchased a D50. Anyway, his wife was wanting to look through my camera at a still life scene she set up in the kitchen. She couldn't believe how much brighter my Pentax K20 viewfinder was than the Canon. I think part of the reason was i had a fast F50 on, and perhaps another reason was i had a Katzeye "bright finish" focusing screen on and it looked a lot brighter than his D40 for sure.

I'm not sure that this is a question to provide a definitive answer to. Macro people will have one answer, landscape people might have another. UWA lens users might have a different answer compared to telescopic folks. If focusing on wildlife in brushy areas, different answer again compared to clear vision areas, daylight versus night scenes, one needs both methods at times, i'm thinking.