'Rule of Thumb' aperture settings?

[g3ck0]

I have a 18-55 IS kit lens from my XSi and was wondering if there are any 'rule of thumb' apertures for different scenarios? Being totally new at this, these are my guesses:

View of the city from a viewing tower - f/11
Urban shots of building architecture - f/8
Close of shots of museum exhibit - f/4
General walking around the city - f/5-6

Are these numbers close?

[rnourse]

As a general rule of thumb I'd say yes... they're close to what I use.

Of course the more you play with your camera the more you'll learn about what to expect so the more you play the better you'll get!

[SOK]

The aperture/subject combinations you've listed certainly might obtain good shots in some situations, but it would be misleading to think of them as a 'rule of thumb'.

A suitable aperture will be dictated by exposure requirements and required depth of field.

Using your museum exhibit example; F4 might be the optimum setting, but it might be too wide to keep the entire subject in focus. Or, it might be too narrow to allow for a proper exposure.

You have to think in terms of balancing the other 2 influences on exposure (shutter speed and ISO), and using the best combination of the 3 to convey the story you're trying to tell.

Additionally, all 3 factors have secondary effects (shutter speed dictates movement; aperture DOF; ISO noise and detail) that need to be considered and managed.

Tripods, lenses with IS, flash and even HDR can broaden the scope of what exposures you can achieve, but you still need to balance the primary and secondary effects of your exposure controls.

So, while it doesn't hurt to think in terms of "I want a smaller aperture for my landscape to maximise my DOF", putting numbers against situations and rote learning them is not advised.

[rral22]

SOK is right. There are no "rules of thumb" that can be memorized to make things work. You need to understand the way aperture controls DOF and make your decisions based on that at the same time as you must balance your choices with the shutter speeds available to you at the aperture you want.

It's a skill, and it is learned by experience, and it is also a personal choice about the photograph you envision at the time. Think of it in that way, rather than some rules to learn, and you will learn to master it more quickly.

[SkipD]

I have a 18-55 IS kit lens from my XSi and was wondering if there are any 'rule of thumb' apertures for different scenarios? Being totally new at this, these are my guesses:

View of the city from a viewing tower - f/11
Urban shots of building architecture - f/8
Close of shots of museum exhibit - f/4
General walking around the city - f/5-6

Are these numbers close?Those numbers mean absolutely nothing by themselves. One needs to consider the available light at the time, ISO value setting, and shutter speed setting in addition to the f-stop numbers used.

If you are merely using the automated Av exposure mode and not really caring about the shutter speed, it's possible that the values listed above may work. However, there a lot of variables to be considered such as required depth of field, necessary shutter speed for the subject motion involved, amount of available light, etc.

In other words, such a simple list has very little value in my opinion.

[breathless]

I agree with previous responses.
There is this (http://www.google.com/#hl=en&q=f8+and+be+there&aq=0s&oq=f%2F8+and+&aqi=g1&=Google+Search&=I%27m+Feeling+Lucky&fp=1mZ_-PL2Zjc) and this, (http://www.google.com/#hl=en&q=sunny+16&aq=f&oq=&aqi=g10&fp=1mZ_-PL2Zjc) however.

EDIT: above Google search terms - "f/8 and be there", "sunny 16"

[g3ck0]

I agree with previous responses.
There is this (http://www.google.com/#hl=en&q=f8+and+be+there&aq=0s&oq=f%2F8+and+&aqi=g1&=Google+Search&=I%27m+Feeling+Lucky&fp=1mZ_-PL2Zjc) and this, (http://www.google.com/#hl=en&q=sunny+16&aq=f&oq=&aqi=g10&fp=1mZ_-PL2Zjc) however.

Thanks, this is exactly the kind of stuff that I was looking for although I totally agree with the advice of the other photographers here saying it's all about balance. I guess it all comes down to experience :)

[birdfromboat]

the only one I really try to remember is the 'sunny f 16' I learned so long ago.

sunny day with brightly lit subject, f16, exposure is 1/the ISO of the film you are using.
ISO 100 with a bride in sunlight, go f16 at 1/100 and bracket cuz there aint no such thing as a perfect rule. And get a digital camera, its a heck of alot easier and looks more professional. Unless its a hasselblad. Why would you ask a question like this if you had a hasselblad?

[g3ck0]

Who mentioned anything about a hasselbad?

Anyway, was is meant by 'bracketing'?

[Mosca]

I've always felt, when in doubt use f/8; it was nice to see that "f/8 and be there" search!

Don't forget about using your stop-down view, to see through the viewfinder what your depth of field will look like, and learn to use the DOF markings on the lenses. Those both have helped me overcome some of my lack of experience.

[birdfromboat]

I said something about a hasselblad.
Bracketing refers to many things, it is the practice of taking shots that are set for a higher exposure and a lighter exposure than what you would use normally. Some cameras will do it automatically, you set them up to bracket, decide how much, then take three successive shots hoping one is a succesful shot.
you can bracket the aperture setting ( one at f5.6, one at f8, one at f4.0 for an extreme example) but that messes with the depth of field so much that the three shots will be very different. better to bracket the shutter speed, (f5.6 at 1/125, one a little faster for a less exposed shot, one a little longer for a more exposed shot for example)

Another rule of thumb I remembered for you- never try to handhold at a focal length more than the shutter speed
a 400 mm lens at 1/400 is touch and go, but at 1/200 you are probably wasting your time. 50mm at 1/125? fire away with confidence in your handheld shooting skills. shooting the moon with a 200mm at 5 seconds- get a tripod.

[g3ck0]

I've always felt, when in doubt use f/8; it was nice to see that "f/8 and be there" search!

Don't forget about using your stop-down view, to see through the viewfinder what your depth of field will look like, and learn to use the DOF markings on the lenses. Those both have helped me overcome some of my lack of experience.

Yea, I never understood the stop-down thing. Stopping down would be taking something like f/5 down to f/4? When I use my DOF button on my XSi, the image does dark, how do I use this to judge DOF?

Also, what is the formula again for shutter speed vs. focal length again for non-blurry handheld photos? I saw something like, from birdfromboat said:

focal length = 1/shutter speed

or something I also saw

focal length = 1/(shutter speed*1.6)

[joe mama]

Yea, I never understood the stop-down thing. Stopping down would be taking something like f/5 down to f/4?


Just the opposite. Think of it like you're going "down" the list of f-ratios. Also of confusion for many is that a smaller aperture means a larger f-ratio and a larger aperture means a smaller f-ratio. This is especially confusing because many take "aperture" to by synonomous with "f-ratio".


When I use my DOF button on my XSi, the image does dark, how do I use this to judge DOF?


You don't. I mean, that is the purpose of the button, but it simply doesn't work well, as you've noticed.


Also, what is the formula again for shutter speed vs. focal length again for non-blurry handheld photos? I saw something like, from birdfromboat said:

focal length = 1/shutter speed

or something I also saw

focal length = 1/(shutter speed*1.6)


Normally, it's expressed thusly:

Shutter Speed = 1 / Focal Length

It's not a "formula" so much as a "guideline" and it applies to static objects as an estimate for the minimum shutter speed required for a sharp picture. The focal length in the formula is in terms of 35mm FF EFL, so for 1.6x cameras, you would multiply that value by 1.6. For example, since a 200mm lens has an EFL of 320mm on 1.6x (200mm x 1.6 = 320mm), you would use 1/320 as a reference shutter speed for a handheld pic of a static object using a 200mm lens on a 1.6x camera.

Aside from the fact that this "general estimate" varies by quite a bit from person to person, when objects are in motion, all this goes out the window. At the longer focal lengths, the minimum safe shutter speed to prevent blurring due to camera shake is already high enough to account for some degree of motion, but not for the shorter focal lengths.

Anyway, the best way to gauge it is through your own personal experience. However, I would offer this word of advice -- a more noisy image without motion blur is pretty much always prefereable to a less noisy image with motion blur (assuming motion blur is not a desired element of the photo). So, go with the higher ISO if needed to keep the shutter speed up, until you have a feel for what shutter speeds work for you in various situations with various focal lengths.

[egordon99]

It's the other way around, stopping down means using a BIGGER f# (smaller aperture), so you stop down from f/5.6 to f/8.

The "formula" is just a rule of thumb, and only deals with camera shake, NOT subject motion. But like you said, it's more or less shutter speed should be 1/focal length*1.6 (for crop bodies)....

So shooting with a 400mm lens, you should try to have at least 1/640s. To be "safe" (and to help with the math), I just double the focal length.

BUT if you have an IS lens, you can easily forget the rule-of-thumb, as long as you keep subject motion in mind. I can get a sharp shot with my 100-400L at 1/200s as long as the subject isn't moving too fast (I've actually gotten sharp handheld 1/60s shots at 400mm!)

Rule-of-thumb for subject motion-As fast a shutter speed as you can :lol:

Yea, I never understood the stop-down thing. Stopping down would be taking something like f/5 down to f/4? When I use my DOF button on my XSi, the image does dark, how do I use this to judge DOF?

Also, what is the formula again for shutter speed vs. focal length again for non-blurry handheld photos? I saw something like, from birdfromboat said:

focal length = 1/shutter speed

or something I also saw

focal length = 1/(shutter speed*1.6)

[Mosca]

Yeah, the DOF preview button. I was referring to stop down metering. It's tough to use in dim light.

I used to ignore all those numbers on the lenses; they didn't mean anything as long as the shot was framed and focused. Now that I'm getting the hang of this stuff, I can use the numbers to approximate the DOF at the different f-stops and focal lengths. Experience will allow a professional to estimate and know this already; the numbers are for those of us who aren't there yet. They will let you know how much of the scene in front of and behind your subject will be in acceptable focus.

[g3ck0]

So not much use for that DOF buttons near the front of the camera?

[SkipD]

So not much use for that DOF buttons near the front of the camera?The button's purpose is simply for previewing depth of field to get an idea if the final image will look the way you want it (relative to things at different distances from the camera being adequately in focus, that is). It works for that, though it is hard to see the results in a low-light situation.

[Mosca]

Big difference in the DOF/stop down metering button on an APS-C and a 35mm film camera. I wish my 40D had that nice, big, bright viewfinder that my 1N does.