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Author Topic: Sony F828  (Read 4328 times)

dwdallam

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Sony F828
« Reply #20 on: March 06, 2005, 05:37:16 pm »

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Small-format cameras like the 828 are better at macro stuff than full-frame 35mm DSLRs precisely because achieving a useably wide DOF with a full-frame DSLR like the 1Ds can require stopping down to the smallest aperture of the lens (like f/22 or f/36). I did a personal macro photography project last summer with the 1Ds photographing black widow spiders. Even shooting at f/32, I wasn't able to get a frame-filling shot of the spiders where the entire spider was in focus. . .

Well, that is one area that I guess I can be pleased with for the F828. I do like to do macro stuff also. I find the time and technical nature of it rewarding. So would that spider photograph, even though all of it is not completely in focus, be worthy of display?

When you say f22 and f32, do you mean f2.2 etc?

Thanks for having patience.
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Jonathan Wienke

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« Reply #21 on: March 06, 2005, 06:33:02 pm »

Nope, that's f/32, not f/3.2. And yes I still consider the image to be display-worthy in spite of the fact that the legs aren't 100% in focus. The fur on the fangs is clearly visible and sharply focused, and it definitely has visual impact.

Howard, no I haven't changed my position on depth of field. I purposely didn't go into the whole circle of confusion thing precisely because there is some room for personal taste and print size and viewing distance of the print to alter the preferred circle of confusion value. That negates none of the value or correctness of what I said. As to the reference point for focal distance being the "center of the lens" that's kind of silly. With zoom lenses, (especially push-pull designs) the center of the lens moves significantly as the lens is zoomed, and with many prime lenses (the Canon 50/1.8 comes to mind) the entire optic group moves in and out as the lens is focused. I have never seen a lens with the nodal point/entrance pupil/center of the lens marked on the lens barrel, but even cheapo film cameras like the Canon Rebel TI have a mark on the body indicating the location of the film plane. The "center of the lens" is a moving target for measurement purposes; the film/sensor plane is not.

In practical terms the distinction is irrelevant, as the difference in DOF calculated from the "center of the lens" vs from the film plane is irrelevant in real-world circumstances; much less than the 1/3 stop aperture adjustment increments that most photographers are limited to, whatever CoC value you choose to use. IMO a factor that in the vast majority of shooting conditions is going to have zero effect on selected aperture isn't worth worrying about or nitpicking over.

IMO you're just trying to nitpick everything I say to make me look bad and you look good, and I'd appreciate it if you'd quit. You'd be doing yourself and everyone else here a favor if you did.
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howard smith

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« Reply #22 on: March 07, 2005, 12:07:00 am »

Andy, I have no "spat with JW."  The only problem I have is the misrepresentations made about DoF.  If you think novice photographers find DoF too confusing, you are selling their intelligence short.  I personally don't care what you, JW or anyone else think DoF is or isn't.  I just wish you wouldn't take the position that a "newbie" can't comprehand it.  So carry on.
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dwdallam

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« Reply #23 on: March 07, 2005, 02:58:22 am »

I posted some new pics that are of deep DOF concern here:
http://www.idlethoughtsandchaos.com/photo/
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howard smith

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« Reply #24 on: March 07, 2005, 09:31:36 am »

An important factor in depth of field is the focus distance.  This is usually not a big deal if the distance and/or depth of field is large.  Frequently in closeup work, the depth of field is measured in fractions of an inch, even at the lens' smallest aperture.  In these cases, misfocusing by a fraction of an inch can be a huge error, producing disappointing results.  Where (or on what) the camera is focused can be critical.  In some cases, there may be nothing (or very little) in the image that falls where the focus plane should be to get the desired results.

Unfortunately, the photographer sometimes (frequently?  always?) deligates this vital part to the camera.  The photographer may not know where (on what) the camea is deciding to focus.  There may be nothing in the image for the camera to use to focus on to get the desired depth of field effect.
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dwdallam

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« Reply #25 on: March 07, 2005, 06:21:41 pm »

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An important factor in depth of field is the focus distance.  This is usually not a big deal if the distance and/or depth of field is large.  Frequently in closeup work, the depth of field is measured in fractions of an inch, even at the lens' smallest aperture.  In these cases, misfocusing by a fraction of an inch can be a huge error, producing disappointing results.  Where (or on what) the camera is focused can be critical.  In some cases, there may be nothing (or very little) in the image that falls where the focus plane should be to get the desired results.

Unfortunately, the photographer sometimes (frequently?  always?) deligates this vital part to the camera.  The photographer may not know where (on what) the camea is deciding to focus.  There may be nothing in the image for the camera to use to focus on to get the desired depth of field effect.
Howard, yes I have expereinced that also. Sometimes my old Sony would focus on teh body of an insect, not the head, for example, and then teh whole focus effect is cahnged, like you state. With the new F828, at least it has three difff settings for focus, which will help. But manual should be best. We'll see as I have more time in it.
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