Sharpness in landscapes

[StormyOne]

I find some of my landscapes turn out a bit 'woolly' looking and although I can correct much of that in post processing, I'd rather attain that front-to-back sharpness I'm after at the time of shooting. Sometimes I get what I want and sometimes I don't, but it's a bit of a lottery at the moment.

I've read that a smaller aperture will increase depth of field, and the recommendation was f/16 - f/22 for landscapes. This seems too much for my camera (D90) and almost always produces the 'woolly' look I dislike.

Could anybody shed any light on what sort of settings would maximise depth of field with the clarity I'm after? I'm fully aware there isn't a blanket 'rule of thumb' that covers every and any situation, but I think if I had a better understanding of aperture settings where landscape photography is concerned I'd stand a better chance of being able to tweak the camera settings to suit the occasion.

Edit: From what I've been reading I think it's something known as defraction that's causing the problem I'm clumsily attempting to explain.

[kencaleno]

Originally Posted by StormyOne

I find some of my landscapes turn out a bit 'woolly' looking and although I can correct much of that in post processing, I'd rather attain that front-to-back sharpness I'm after at the time of shooting. Sometimes I get what I want and sometimes I don't, but it's a bit of a lottery at the moment.

I've read that a smaller aperture will increase depth of field, and the recommendation was f/16 - f/22 for landscapes. This seems too much for my camera (D90) and almost always produces the 'woolly' look I dislike.

Could anybody shed any light on what sort of settings would maximise depth of field with the clarity I'm after? I'm fully aware there isn't a blanket 'rule of thumb' that covers every and any situation, but I think if I had a better understanding of aperture settings where landscape photography is concerned I'd stand a better chance of being able to tweak the camera settings to suit the occasion.

Edit: From what I've been reading I think it's something known as defraction that's causing the problem I'm clumsily attempting to explain.

Diffraction happens once you go smaller than F11-Diffraction is where light rays enter a small opening(aperture),overcrowding to get through occurs,so rays that don't immediately get through bounce around between lens elements and diaphragm blades,and even ones that do squeeze through interfere with other rays,causing blurring.(Diffraction) Although smaller apertures do give a deeper depth of field,diffractionaffects sharpness-It's a trade-off.

Regards, Ken

[fletch]

If you really care about the science the wikipedia article on difraction is very detailed.

Diffraction - Wikipedia, the free encyclopedia

If your not bothered the best thing you can do is go take some photos. Set up a scene and shoot with various different aperture settings and compare the results.

Just a though, is it definately diffraction? Unless you are printing lagre or pixel peeping the effect is quite slight, especially at f/16. Could it be high ISO or long exposure noise being generate by your camera due to the smaller aperture requiring longer/more sensitive exposures? If you could post a example that would be great.

[StormyOne]

Originally Posted by kencaleno

Diffraction happens once you go smaller than F11-Diffraction is where light rays enter a small opening(aperture),overcrowding to get through occurs,so rays that don't immediately get through bounce around between lens elements and diaphragm blades,and even ones that do squeeze through interfere with other rays,causing blurring.(Diffraction) Although smaller apertures do give a deeper depth of field,diffractionaffects sharpness-It's a trade-off.

Regards, Ken

Thanks, Ken, your explanation makes sense and I now know the term's diffraction and not defraction too! I realise it's a trade-off and I guess what I'm looking for is the optimal settings that give maximum depth of field and minimal blurring caused by diffraction.

My understanding is that sensor size and number of pixels will make a difference, with more pixels and full frame sensors allowing a smaller aperture to be used before the affects of diffraction are obvious.

Originally Posted by fletch

If you really care about the science the wikipedia article on difraction is very detailed.

Diffraction - Wikipedia, the free encyclopedia

If your not bothered the best thing you can do is go take some photos. Set up a scene and shoot with various different aperture settings and compare the results.

Just a though, is it definately diffraction? Unless you are printing lagre or pixel peeping the effect is quite slight, especially at f/16. Could it be high ISO or long exposure noise being generate by your camera due to the smaller aperture requiring longer/more sensitive exposures? If you could post a example that would be great.

I'm not absolutely certain it's diffraction causing the problem, no, but it's definitely not high ISO or long exposure noise. The shots aren't noisy, they just don't have the front to back clarity and sharpness I'd like.

I've already tried what you suggested about varying the settings for the same scene and comparing the results and I think that's partly what's puzzling me. I seem to get better results from larger apertures which contradicts everything I've read about increasing depth of field so I am wondering if there's something else going on.

I've attached an example to this post. This one's taken at f/13 as, unfortunately, I got so miffed with the results from other attempts I deleted them! Hopefully it exemplifies what I'm getting at though as it just doesn't seem very sharp, with very little definition in the textures of the wall, buildings or trees. It's not very well composed and the sky's over-exposed but ignore that, it was only taken for experimentation with settings and except for the conversion from RAW to jpeg there's been no processing.

[Elmo]

You also might want to see where your focus point is. In this case about 1/3 distance into th scene would likely work.

[Aegea]

What lens are you using? Do you see this softness with other lenses?

[StormyOne]

I'm using an 18 - 105mm zoom mostly for landscapes (it's the most suitable of the two I have). I'm fairly new to photography so have yet to build up a collection of lenses.

[Aegea]

If you are not using a tripod, I'm tempted to guess camera shake, because of the small apertures. Maybe try some shots at say f/8 and see what they look like.

[StormyOne]

So, camera shake will be more evident with smaller apertures? I have been shooting hand-held, but I do everything I can to minimise that (lean against something, hold my arms close to my chest etc.) and both lenses I have are equipped with VR (vibration reduction).

I'm not suggesting you're wrong, it might well be that; as I stated I'm not certain what the problem is. I'll certainly take your advice and see what happens at f/8.

I didn't have a tripod, but I bought one yesterday and although it's not an expensive one, it's nice and sturdy with a quick release head included. I'll see if using that makes a difference too.

Thanks very much for your help. I really would like to know what the problem is so I can avoid it, obviously, but don't have the experience to guide me.

[Aegea]

Smaller aperture = slower shutter speed, hence more possibility for camera shake to appear.