Night photography and aperture setting - conflicting info?

On many tutorials online people suggest using the widest aperture on their lens. Although I completely understand why we would want to set it at this it doesn't make sense since I'm limiting my depth of field (and for a landscape I would expect to have to set it to the largest aperture value (ie. f22 or something equivalent to have everything in focus).

So question is, do I set it to the smallest f stop (ie. 2.8, 1.8, etc) or the largest (ie. 18, 22, etc)?

I also assume I would only use the upper and/or lower ends of f stops - why/when would I use the f stops in between (5.6,11, 15, etc)

Generally, you would want to shoot at around f/11 to f/13 for landscapes...but that's just in general. All the settings are useful. It depends on your subject and how you want the photo to turn out.

Look at a depth of field table. Factor in your camera to subject distance and focal length.

Britt340 wrote: Look at a depth of field table. Factor in your camera to subject distance and focal length.

Plus the focal length of your lens is a factor too.

Using a 12 mm lens, on a crop sensor camera, at f/2.8, with a focal point 200 feet from the camera, the near limit of the DOF is 8.42 feet in front of the camera, and the far limit is at infinity. Online Depth of Field Calculator

For comparison, if you are using a 18-55 mm kit lens at 18 mm, and wide open at f/3.5, with that same 200 foot focal point distance the near limit of the DOF is then 14.6 feet in front of the camera, and the far limit is still at infinity.

Britt340 wrote: Look at a depth of field table. Factor in your camera to subject distance and focal length.

thanks for the tip, but unfortunately I'm not very good at guesstimating the distances of building/landscapes - which is why i just play is safe and set to f22 and focus on infinity. Hopefully over time I can better hone this skill and determine my distances better.

Martini wrote:

Britt340 wrote: Look at a depth of field table. Factor in your camera to subject distance and focal length.

Plus the focal length of your lens is a factor too.

Using a 12 mm lens, on a crop sensor camera, at f/2.8, with a focal point 200 feet from the camera, the near limit of the DOF is 8.42 feet in front of the camera, and the far limit is at infinity. Online Depth of Field Calculator

For comparison, if you are using a 18-55 mm kit lens at 18 mm, and wide open at f/3.5, with that same 200 foot focal point distance the near limit of the DOF is then 14.6 feet in front of the camera, and the far limit is still at infinity.

Thanks for the DOF calculator. Too bad I can't use this out in the field when I am shooting.

Is the subject in the tutorial the sky or mostly far from the camera? Even f/1 can be focused to include infinity within the DOF. Depending on the gear "infinity" can be pretty close for some cameras. For instance using 18mm @ f/2.8 on an APS-C format DSLR the hyperfocal distance is less than 20', and with focus set there DOF extends from 10' to infinity. That would be fine for a lot of landscape photography. If the goal is to get as much stars in the sky that look sharp (rather than star trails) they would want to use a fast shutter speed.

Besides aperture DOF is effected by focal length and focusing distance. You can have shallow DOF with f/22 and deep DOF with f/2.8.

Wi1tt13 wrote: Thanks for the DOF calculator. Too bad I can't use this out in the field when I am shooting.

There are apps for phones. Also this DIY paper model lightingmods.blogspot.com/2008/05/diy-de...ield-calculator.html

I've used the online calculators to make some notes on common settings I would use.

Digital DOF scales as a feature for our cameras is long over due.

Henry Peach wrote: Is the subject in the tutorial the sky or mostly far from the camera? Even f/1 can be focused to include infinity within the DOF. Depending on the gear "infinity" can be pretty close for some cameras. For instance using 18mm @ f/2.8 on an APS-C format DSLR the hyperfocal distance is less than 20', and with focus set there DOF extends from 10' to infinity. That would be fine for a lot of landscape photography. If the goal is to get as much stars in the sky that look sharp (rather than star trails) they would want to use a fast shutter speed.

Besides aperture DOF is effected by focal length and focusing distance. You can have shallow DOF with f/22 and deep DOF with f/2.8.

The subject in one of the tutorials was the sky, but I'm not trying to shoot the sky for night photography. I am more trying to shoot buildings or anything that is lite up at night (of course sky is included, but not the subject.

Henry Peach wrote:

Wi1tt13 wrote: Thanks for the DOF calculator. Too bad I can't use this out in the field when I am shooting.

There are apps for phones. Also this DIY paper model lightingmods.blogspot.com/2008/05/diy-de...ield-calculator.html

I've used the online calculators to make some notes on common settings I would use.

Digital DOF scales as a feature for our cameras is long over due.

Wow, thank you. I didn't think about searching for an app.

Wi1tt13 wrote: The subject in one of the tutorials was the sky, but I'm not trying to shoot the sky for night photography. I am more trying to shoot buildings or anything that is lite up at night (of course sky is included, but not the subject.

If you are shooting large things (buildings, bridges...), and including most of the thing in the composition, whatever focal length lens you choose, the field of view is going to force you to be far enough away that large apertures will give you plenty of DOF.

Reasons to keep the exposure short as possible would be to take less time, conserve power, keep the sensor from heating up (noise), and to freeze movement. With film there is also the issue of reciprocity failure. If you don't have any of those concerns, or have reasons to want a long shutter speed then go for it.

Henry Peach wrote:
Besides aperture DOF is effected by focal length and focusing distance. You can have shallow DOF with f/22 and deep DOF with f/2.8.

I didn't know that. I love learning new things everyday. This forum is great. Thanks Henry.

www.freedigitalphotographytutorials.com/...hotography-settings/

Wi1tt13 wrote:

Britt340 wrote: Look at a depth of field table. Factor in your camera to subject distance and focal length.

thanks for the tip, but unfortunately I'm not very good at guesstimating the distances of building/landscapes - which is why i just play is safe and set to f22 and focus on infinity. Hopefully over time I can better hone this skill and determine my distances better.

BTW, f/3.5 is commonly called the "bigger" aperture, not f/22. As the actual iris opening is physically larger at f/3.5. Our happy f/-stop scale is a ratio that stands this on its head.

My main interest is landscape, and I rarely shoot smaller than f/14. Very small apertures like f/22 typically soften the image slightly. When I do use f/22 it's usually for close subjects, not landscapes.

Kelly Cook

I was thinking along the same lines as Kelly, might help you to learn more about how aperture works. Since the aperture is a fraction, for example f2 means the lens is open 1/2 the focal length (for a 50mm lens that would be 25mm). At f16 the aperture is 1/16 of 50mm (you do the math, I can't figure it in my head quick!).

For situations with lower light you'd need more light coming into the camera, so you need to have the lens more open or use a higher ISO or a slower shutter speed to get enough light (although with too slow a shutter speed you'd be more likely to get blur from shutter movement).

If you're getting conflicting info. maybe look at the source of information; anybody can do a blog/website and there's a lot of info. online that isn't necessarily accurate. You might try photography organizations, or photography magazines for articles and links to reliable resources.