geogphotos

F22 - what is the point?

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With digital cameras what is the point of F22.

 

Isn't it always better to change shutter speed and/or ISO speed? 

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Good question. Don't know the answer because I've never used f/22.

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Posted (edited)
14 minutes ago, John Mitchell said:

Good question. Don't know the answer because I've never used f/22.

 

So why is it on the camera?

 

I'm asking because I've ended up with some by mistake - nothing is really sharp, some just about okay when cropped to smallest file size allowed, some useless.

 

Does F22 have any use?

Edited by geogphotos

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Well I would say 22 if for max DoF on a wide, but I am more of a F8 and be there....

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F22 is not critically sharp, but I have used it occasionally.

For expanded depth of field take one shot with subject in focus at a sharp F11, and a second identical shot at F22. Do not change focus or camera position between shots.

Align and combine the two shots in Photoshop.

Now you have only one shot with an expanded depth of field. The F11 subject in the one shot is critically sharp. The F22 surround of the subject in the one shot is sharper than at F11, but is not quite critically sharp. However the surround may be a just right sharpness for that particular image.

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Posted (edited)
13 minutes ago, Bill Brooks said:

F22 is not critically sharp, but I have used it occasionally.

For expanded depth of field take one shot with subject in focus at a sharp F11, and a second identical shot at F22. Do not change focus or camera position between shots.

Align and combine the two shots in Photoshop.

Now you have only one shot with an expanded depth of field. The F11 subject in the one shot is critically sharp. The F22 surround of the subject in the one shot is sharper than at F11, but is not quite critically sharp. However the surround may be a just right sharpness for that particular image.

 

Couldn't you do the same by using the same F11 and different focus points/focal lengths then merging if you want the whole image sharp? 

 

Edited by geogphotos

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Posted (edited)
11 hours ago, Chuck Nacke said:

Well I would say 22 if for max DoF on a wide, but I am more of a F8 and be there....

 

Admittedly I am taking about a Canon 24-105 zoom not a specialist lens. 

Edited by geogphotos

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19 minutes ago, geogphotos said:

 

Couldn't you do the same by using the same F11 and different focus points/focal lengths then merging if you want the whole image sharp? 

 

 

Yes you could, to get absolutely everything critically sharp front to back.

However sometimes you want the subject to be critically sharp with the surround only almost sharp.

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Posted (edited)
10 hours ago, Bill Brooks said:

 

Yes you could, to get absolutely everything critically sharp front to back.

However sometimes you want the subject to be critically sharp with the surround only almost sharp.

 

Can't you just do that with a narrow depth of field?

 

EDIT) Okay me being slow, thanks for the suggestion.

Edited by geogphotos

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1 hour ago, geogphotos said:

 

So why is it on the camera?

 

I'm asking because I've ended up with some by mistake - nothing is really sharp, some just about okay when cropped to smallest file size allowed, some useless.

 

Does F22 have any use?

 

Well, it is a nice round number.

 

I suppose f/22 does allow for very long shutter speeds when wanted (if you don't mind diffraction).

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Posted (edited)

handy way to check how clean your sensor is. Everything shows up.

Edited by John Rodgers
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Posted (edited)

I've been using f:22 recently. 

Needed a max depth of field to capture trees in bloom in the foreground (very close) and the village behind them, handheld (no way to set a tripod there).

Very windy afternoon, the storm was coming, no chance to get 2 identical frames and stack them in post…

My only chance to get the image I wanted was f:22.

I have been surprised by the results, quite good actually.

The Tamron 24-70 f:2.8 still does a very decent job stopped down that much.

I think it really depends on the lens.

Edited by Olivier Parent

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Posted (edited)
11 hours ago, Bill Brooks said:

F22 is not critically sharp, but I have used it occasionally.

For expanded depth of field take one shot with subject in focus at a sharp F11, and a second identical shot at F22. Do not change focus or camera position between shots.

Align and combine the two shots in Photoshop.

Now you have only one shot with an expanded depth of field. The F11 subject in the one shot is critically sharp. The F22 surround of the subject in the one shot is sharper than at F11, but is not quite critically sharp. However the surround may be a just right sharpness for that particular image.

 

Thanks for that idea. I've often focus stacked several exposures taken at F11 with different focal points, but this sounds a useful (and easier) alternative which may give a better blend of sharpness.

 

Mark

Edited by M.Chapman

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43 minutes ago, M.Chapman said:

 

Thanks for that idea. I've often focus stacked several exposures taken with different focal points, but this sounds a useful (and easier) alternative which may give a better blend of sharpness.

 

Mark

 

Yes that's true it is a good idea - I was too dismissive. 

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Posted (edited)

Usually not smaller than f11. Some years ago when started using the Canon 24-105 and 5D (Now II) - I think I got sharper images with f11 - and not the risk of refraction.

 

Wasn't the small apertures better to use in the film days?

Edited by Niels Quist

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2 hours ago, John Rodgers said:

handy way to check how clean your sensor is. Everything shows up.

 

My method too...

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f/22 require quality lenses, and many zoom's aren't sharp enough. In macro-photography you can often go down to f/36 to get more in focus in cost of softness.

 

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I've never been past f16 on a full frame sensor or f11 on the APS-C size.

 

Allan

 

 

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A quick test on a kit short zoom: as geog says, no difference till f22, but that's on an unsharpened RAW. I don't think there would be any QC problems down to f32.

I went to 16, probably for the first time deliberately, for pix of the tables at the street party on Saturday. No problems there. I may do it more often.

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After shooting film for twenty years, most often at f/22, this was the most difficult part of going digital for me. Sensor dust and diffraction were something that forced me to change. Lens design is a big factor. The old tessar (4 element) formula got sharper as it was stopped down, and was used for many macro and copy lenses. Modern zooms seem to vary from lens to lens, but I'm now using f/8-11 often, switching to a 50mm macro when I need more depth of field. 

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The only realistic use I can think of to use F22 is to try and achieve a long shutter speed in some light conditions. Normally of course, you would use a filter but if you didn't have a filter at hand, I guess you could achieve 2 or 3 seconds exposure if the light was right.

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4 hours ago, spacecadet said:

A quick test on a kit short zoom: as geog says, no difference till f22, but that's on an unsharpened RAW. I don't think there would be any QC problems down to f32.

I went to 16, probably for the first time deliberately, for pix of the tables at the street party on Saturday. No problems there. I may do it more often.

 

That's interesting . My micro 4/3 lenses start softening due to diffraction from about f11 onwards, and the lens test charts I've seen also seem to show the same. I tend to find a sweet spot at around f8. What format lens are you using?

 

Mark

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Posted (edited)
7 minutes ago, M.Chapman said:

 

That's interesting . My micro 4/3 lenses start softening due to diffraction from about f11 onwards, and the lens test charts I've seen also seem to show the same. I tend to find a sweet spot at around f8. What format lens are you using?

 

Mark

APS-C. Sony 18-55.

Only tested at 55 though, sweet spot at 11. I'll try wider.

Edited by spacecadet

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6 minutes ago, spacecadet said:

APS-C. Sony 18-55.

Only tested at 55 though, sweet spot at 11. I'll try wider.

 

How are you checking sharpness?

 

Mark

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