shutter curiosity

[mishkin madness]

hello,

it has been awhile!
i was just curious of whether or not what i read the other day was accurate. that a camera with a 220 shutter opening, while being able to transfer less light then a 150 opening, may appear as slightly fuzzy. whereas the 150 camera may appear sharper due to the speed of the shutter opening?

if this is true, in what ways? obviously there would have to be more light for the 150, and less for the other. could this give more credence to the use of "restricted" 150 to 180 shutter cameras?

or am i covering a topic that was discussed years ago?.....

[Alex]

I think Cameraguy has in the past mentioned his like for a shorter shutter speed for producing a "sharper" looking image, especially for action sequences.

Other considerations include where on the f-stop range one is when deciding which shutter speed to go with (assuming your camera has the option).

If one is shooting at F.1.6 with a 150 degree shutter, the additional light that would expose the film with a 220 degree shutter will also increase the f-stop to over 2.0, this can be critical for focus on some cameras.

Some also don't like the potential "strobeyness" that can be seen with a shorter shutter time. Others like the "strobeyness" because it can convey a mood. (Saving Private Ryan used even shorter shutter times than 150 degrees, but I don't know what the range actually was.)

I would say that neither shutter works best in all situations, but either can be used, it's just a matter of preference.

[cameraguy]

yes yes, a smaller shutter angle gives a sharper image. Too small and the image will strobe when there is action on the screen. And yes Saving Private Ryan on the beach is a good example of strobing (big time). The angle there must have been like 50 degrees or less. Also just about every music video I see on TV these days has massive doses of strobing during dance stuff.

The softer image that the larger shutter angle cameras give is good if that is look you want. Of course you can solve the problem by using the Canon 814/1014 XL-S which gives both 220 and 150 as options (I think the 814XL Black model does too but no 24fps).

My favorite angle these days is 160-170. Canon, Minolta and Nikon used this range a lot in the 60's to early 70's.

[mishkin madness]

well, now this makes a little more sense to me. as i have a few cameras i use for different things, i thought it was my imagination, as i could have betted some images from one camera were sharper than another.
my sankyo cm400 has a 150 shutter and the images appear crystal, although action can "strobe" the image as it is only 18fps. yet when i use a canon 518sv with i think 180 shutter at 24fps, the image appears a touch out of sharp. as i recently picked up a 814 with a 220 shutter, i have a theory....

with a 150 shutter @18fps leave the fstop as per light reading.

with a 180 shutter @24fps stop it down 1 fstop past light reading.

with a 220 shutter @24fps stop it down 2 fstop past light reading?

would it be correct to say that the longer the opening, the further closed one can put the fstop for sharpest image?

i use predominantly k40, which at fstop 1.2 i have found to get images very well.

curiously awaiting....

[Alex]

Underexposing doesn't make the picture sharper if there is movement in the shot. It does increase the depth of field which can aid in keeping what you want in focus, in focus.

[mishkin madness]

o.k, that makes sense. But for a still shot, medium close up, light reading 5.6, wide angle, with either a 180 or 220 shutter, is there a way to get a crystal image? or would i be better using a 150 shutter for non action shots?

since the last posts i have been trying to think around the issue with perhaps adding lenses, coloured etc, but as i am into k40 at the moment this is no real help.

and going digital does not even enter the ring..

[cameraguy]

Originally posted by mishkin madness:
o.k, that makes sense. But for a still shot, medium close up, light reading 5.6, wide angle, with either a 180 or 220 shutter, is there a way to get a crystal image? or would i be better using a 150 shutter for non action shots?

<font size="2" face="verdana, sans-serif">150, 180 and 220 shutters all would require a different f stop to achieve the same exposure. The shutter angle directly affects the shutter speed. The formula is

(fps X 360) / shutter angle = shutter speed

Shooting 24 fps with a 150 angle give

(24 X 360) / 150 = 57.6

Answer is really 1/57.6 or 1/60th of a second for a nice round answer.

A 220 shutter angle at 24 fps is 1/40, so its easy to see that the 220 angle is longer and requires less light. But being longer also means more blur with motion.