shooting modes.

[dxrocnxj]

so i forget what thread it was but everyone was telling what mode they shoot in. now when i have my flash on my camera ive been shooting in auto mostly until i get the right idea and get through the manual sometime soon. :rolleyes:

anyway, when my flash is not mounted, i find myself shooting in shutter priority where i noticed most people either shoot in aperture priority and manual and rarely touch the shutter priority. i just dont understand how manual works just yet.

thought about purchasing "understanding exposure"
its apparently talk of the town in the photo forum.;)

so maybe throw your two sense in, cause you know i love learning. :cool:

[Jason25]

I shoot in A almost exclusively. The only time I don't is when I want to control a different aspect of the exposure, so I shoot in M. Come to think of it, I've never even set my camera to P or S.

[Rooz]

depends on what your shooting. if you are shooting moving objects where you have to maintain a faster shutter speed then shoot in S. most guys who shoot action only use S or M.

i don;t shoot any action photos at all basically which is why i use A and i use M for flash or scenes with difficult lighting.

the main reason people shoot in A is to control the depth of field which can often have the most dramatic impact to the way a photo turns out. ie: you don;t really want to be shooting f11 for a portrait. so you dial in say f4 to try and isolate your subject from the background. etc. the reverse for a landscape, no pointing using f4, so you dial in say f13+ to get most/ all of your frame in focus.

understanding exposure is a great book.

[crum]

newbie question, large aperture isolates subject and limits depth of field, does the dop vary with focal length/shutter?

reducing aperture increase dop, is there a reason not to dial down further than f13 for landscape?

[erichlund]

P - What you set the camera on when you're going to hand it to someone you trust not to run away, but who doesn't really know how to operate your camera. It's snapshot mode. (Note: Until you learn to use the other modes, this could be you. I know, I've been there.)

A - Aperture priority. You set the aperture and the camera sets the shutter speed based on two things, the meter and the exposure compensation you set when you evaluate the light. For many more advanced photographers, this is the most used mode.

S - Shutter priority - You set the shutter speed and the camera sets the aperture based on two things, ... (same as above). This is the most used mode for much of action photography.

M - You set the shutter or aperture as needed for the shot, then adjust the other value based on your reading of the meter and adjustments you make for your reading of the lighting conditions. Some people are purists and use this exclusively. Many use this for flash photography, because they can better control the exposure. Many use this when the lighting is difficult, and they just don't trust the camera to get it right.

You use aperture when you are trying to control the depth of field. Wide apertures (low f numbers) give shallow depth of field and isolate the subject against a blurred background. Small apertures increase depth of field, making more stuff appear in focus. It's possible, with wide angle lenses, to have the appearance of focus from some relatively short distance out to infinity. This is typically used for landscape photography. However, it should be realized that there is only one true plane of focus. The rest just appears in focus because it is not significantly blurred.

You use shutter speed to control subject motion. Often, you want no subject motion, so you need a shutter speed that will be fast enough to stop motion. Action photographers need very high shutter speeds to achieve this. However, you can, for creative reasons, want to show motion. This is often done with waterfalls, where the water just appears as a white blur because a slow shutter speed was used. It gives a sense of motion to the water which makes the waterfall appear more natural in the photo.

[tcadwall]

Crum...

Yes there is a very real reason not to select an f-number higher than f13 or so.... Here is a loose (not very technical description) - Due to the way the light is diffracted as it passes through the smaller opening (higher f-stop = smaller opening), the diffraction begins to affect the resolution capabilities of the sensor(because of the physical properties of the sensor design), and you will be losing resolution due to diffraction. So even though you will theoretically be increasing the depth of field, the actual IQ of the image starts to degrade.

[erichlund]

Actually, I think that's the best (non-technical) description I've seen. It says everything you need to know without goobering it up with a bunch of jargony mumbo jumbo.

The one thing I'd add is that the diffraction limit changes with each increase in megapixels, and not in a good way. Where the diffraction limit on the D70 (so also D40, D40) was about F16, the limit on the D200 (and D80, D40x) and other 10mp cameras is more like F13 or so. I don't know what the actual numbers are, but the physics says that the D300 will be even lower.

This is one reason why the FX format will benefit landscape photographers. If I understand correctly, the full frame sensor has higher diffraction limits than the APS-C sensor. This is purely due to the physics.

It should be noted, however, that just because you have reached the diffraction limit does not mean you cannot use higher values. You just have to understand you are trading image quality for depth of field. Nor is it binary. The image quality doesn't suddenly suck just because you went to f13.1. It degrades as depth of field increases. Even at f22, image quality may very well meet your needs if you really want the depth of field.

[Rooz]

does the dof vary with focal length/shutter?


focal length, yes. shutter speed, no.

[crum]

thx for the answer guys.

how does diffraction exhibit itself as aperture is stopped down?

[Rooz]

basically you lose sharpness and the image becomes softer to look thu alot of the focal plane. different lens' have different tolerances so the f stop will be different for each lens, although anything from f18+ i suppose is going to degrade significantly. i rarely shoot at anything over f13 so i don;t really know 100%.

http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm

[tcadwall]

LOL Rooz, I was about to post that same link since I found it so helpful myself a while back (had it as a favorite).

Problem with that site is that most people don't care to know ALL those details. Since I always want to know 'why', and when I know 'why', I don't forget 'what', I found that page very helpful.

For anyone that doesn't want to get that technical, just scroll down in the article to where you see the pic of the sweater. When you hover over the different f-stop numbers you will see the effect of the smaller apertures. Just remember that the example is from a 20D, and therefore won't be as bad for say a D70s, but for a sensor the same size as the D70s but more pixels... say the D40x it may be more obvious - but then again, there is more that goes into it than pixel concentration alone.

So.... back to the basics... at some point (normally between f8 and f13) diffraction starts to be noticeable. It *can* be sacrificed for DOF, and images *can* be sharpened to fix some of it.... But it is a concept that is good to know so that you aren't going to ridiculous apertures like f/32 because you want the best resolution... since that is NOT what you will get you will get a blurred but deep DOF...