Blur at F-40..........
May 21, 2012 00:53:55 #
Lucian
Loc: From Wales, living in Ohio
Archy wrote:
"At high f-stops, there is a phenomenon called circles of confusion.
Here's an explanation:
http://www.luminous-landscape.com/essays/bokeh.shtml "
_____________________
I've always know the cicles of confusion to be something pertaining to longer lenses but with low f-stops, NOT high f-stops as is being discussed here. Since high f-stops generally have everything in focus in all the planes.
Are you sure you understand this term correctly?
"At high f-stops, there is a phenomenon called circles of confusion.
Here's an explanation:
http://www.luminous-landscape.com/essays/bokeh.shtml "
_____________________
I've always know the cicles of confusion to be something pertaining to longer lenses but with low f-stops, NOT high f-stops as is being discussed here. Since high f-stops generally have everything in focus in all the planes.
Are you sure you understand this term correctly?
May 21, 2012 04:08:34 #
Hi Archy,
Right, let's foret about the fact that the picture "appears" to be out of focus..........here's the thing, it isn't....it is pin sharp!
The problem is caused by diffraction. Diffraction is different in different lens' but there is a common element and that is small apertures. The smaller the aperture the greater the diffraction and hence, the subsequent loss of image "shapness".
If you back off the aperture to just under f22,(use 16), don't change anything else you'll see exactly what I mean.
Most people will stop a camera right down to maximise DoF but not realising what the trade off is.
Let me know how you get on Archy.
Take care,
PJ
Right, let's foret about the fact that the picture "appears" to be out of focus..........here's the thing, it isn't....it is pin sharp!
The problem is caused by diffraction. Diffraction is different in different lens' but there is a common element and that is small apertures. The smaller the aperture the greater the diffraction and hence, the subsequent loss of image "shapness".
If you back off the aperture to just under f22,(use 16), don't change anything else you'll see exactly what I mean.
Most people will stop a camera right down to maximise DoF but not realising what the trade off is.
Let me know how you get on Archy.
Take care,
PJ
May 21, 2012 06:40:01 #
Hi Archy,
Right, let's forget about the fact that the picture "appears" to be out of focus..........here's the thing, it isn't....it is pin sharp!
The problem is caused by diffraction. Diffraction is different in different lens' but there is a common element and that is small apertures. The smaller the aperture the greater the diffraction and hence, the subsequent loss of image "shapness".
If you back off the aperture to just under f22,(use 16), don't change anything else you'll see exactly what I mean.
Most people will stop a camera right down to maximise DoF but not realising what the trade off is.
Let me know how you get on Archy.
Take care,
PJ
Right, let's forget about the fact that the picture "appears" to be out of focus..........here's the thing, it isn't....it is pin sharp!
The problem is caused by diffraction. Diffraction is different in different lens' but there is a common element and that is small apertures. The smaller the aperture the greater the diffraction and hence, the subsequent loss of image "shapness".
If you back off the aperture to just under f22,(use 16), don't change anything else you'll see exactly what I mean.
Most people will stop a camera right down to maximise DoF but not realising what the trade off is.
Let me know how you get on Archy.
Take care,
PJ
Archy wrote:
Taken at F-40...SS-1/8...ISO-400...focal length 180 on AV setting using a tripod
can anyone tell me what is causing the blur
.
May 21, 2012 11:23:28 #
GoofyNewfie wrote:
quote=Indi br Why not try manual, and a lower f-... (show quote)
Everyone calling shallow depth of field "bokeh" is one of my pet pieves. Along with people who use words like "pet pieves."
I've even seen the term misused in photography magazines, so who knows, maybe the term is evolving and we aren't. Either way, I applaud you for mentioning it.
May 22, 2012 01:20:50 #
bkyser wrote:
Everyone calling shallow depth of field "bokeh" is one of my pet pieves. Along with people who use words like "pet pieves."
I've even seen the term misused in photography magazines, so who knows, maybe the term is evolving and we aren't. Either way, I applaud you for mentioning it.
Everyone calling shallow depth of field "bokeh" is one of my pet pieves. Along with people who use words like "pet pieves."
I've even seen the term misused in photography magazines, so who knows, maybe the term is evolving and we aren't. Either way, I applaud you for mentioning it.
There are so many posts on this website that have incorrect or misleading information. Just trying to do my part to correct the misinformed. Seems like some posters here concern themselves with relatively trivial matters, Bokeh being one of them. (unless you have a really bad lens) Some people here are now afraid to stop the lens down because of diffraction. So how are you going to get the depth of field needed to get that shot? Focus stacking?
What you need to concern yourself with is compostion, lighting, posing, the effects of exposure ...and I would add concept. Captain C said something the other day that I loved: "measure it with a micrometer, mark it with a crayon, cut it with an axe"
May 22, 2012 09:51:16 #
Diffraction is the main problem with f40 no matter how good you focus, It is impossible to get a clear shot with that fstop.For good depth of field you should never go higher than an f22 becuse the trade off for depth of field isn't worth the loss of sharpness. Most lenses start this process at f/11 and some lenses are more noticeable than others But all lenses suffer this. Just like when you squint your eyes you can se a little better but squint them too much and you have a harder time seeing.
May 22, 2012 10:36:23 #
I am PJ wrote:
Hi Archy, br Right, let's foret about the fact tha... (show quote)
Thank you...........
May 22, 2012 10:37:13 #
GoofyNewfie wrote:
quote=bkyser br br Everyone calling shallow dep... (show quote)
Thank you...........
May 22, 2012 10:39:00 #
djmarti wrote:
Diffraction is the main problem with f40 no matter... (show quote)
Thank you...f-22 it is...no lower.....
May 24, 2012 14:26:36 #
You say everything looked good at f32. There is a phenomenon known as diffraction caused by the diaphragm leaves at very small apertures. This may be your problem.
len
len
May 24, 2012 17:59:05 #
ljmeis76 wrote:
You say everything looked good at f32. There is a phenomenon known as diffraction caused by the diaphragm leaves at very small apertures. This may be your problem.
len
len
Thank you...........
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