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Old Oct 23, 2009, 5:52 PM   #31
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I keep on hearing the term "recompose" what is this exactley ?
It is not always desirable to have the subject of your photo in the center of the photo. So, the idea is you put the center of the frame over your subject, half-press the shutter button and the camera locks focus, then you move the camera to re-compose the shot (so your subject is no longer in the exact center) and fully depress the shutter button. Because you hold the button halfway the camera does not re-focus as you move the camera.
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Old Oct 23, 2009, 5:57 PM   #32
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Here's an example. The center of this frame is the fence in the background. Using the "center and recompose method" you would place the center of the frame in the viewfinder over one of the two people, half-press the shutter and then recompose the shot so neither person is in the exact center. Then take the shot. For my purposes I simply used a non-center focus point so I didn't have to recompose:
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Old Oct 23, 2009, 6:28 PM   #33
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to be honest that would drive me mad not being able to select my focus point on the fly.

but i guess if i wasn't used to it, i could focus and recomp pretty easily as well.

keep in mind that if you are doing something with very small depth-of-field, doing a focus and recomp could throw your plane of focus off. (usually not a huge problem in practice, but could be in certain situations)
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Old Oct 23, 2009, 7:59 PM   #34
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Quote:
Originally Posted by anthony_b View Post
I keep on hearing the term "recompose" what is this exactley ?
Hi Anthony,

The process has been explained well by John.

The downside of this method is that with very fast (large maximum aperture) lenses, the DOF may be very thin. This even becomes more problematic as you approach the minimum focusing distance of the lens because the DOF gets thinner under such circumstances, at the widest apertures.

Probably the most known article about the downside of this technique is:

http://visual-vacations.com/Photogra...pose_sucks.htm

which explains the phenomenon better than I can.

Please realize that the author is talking about very critical focus issues and very critical image requirements. I won't say that the article's thrust is irrelevant for the average shooter -- it's definitely something that any photographer should keep in mind in certain circumstances, it's just not nearly as critical.

Here's a link to a popular on-line DOF calculator.
http://www.dofmaster.com/dofjs.html

If you plug in the K2000, lens FL to 50, and distance to 5 ft, then use f1.4, f2.8, f4, and f5.6, you'll see that the DOFs respectively are @ 2", 4", 6", and 8".

At f1.4, you could well run into a problem with focus and recompose with an area only 2" deep in focus. The most commonly available lens with these specs is the Pentax FA 50 f1.4 which currently sells for $359.

At f2.8, DOF is @4", which gives you a much more significant margin of error. f2.8 is considered "fast" for a zoom, and you'll most commonly find this FL/aperture in the DA* 16-50 f2.8 and DA* 50-135 f2.8 "pro" zooms. $744 for the 16-50 and $820 for the 50-135

At f4, DOF is @6", and you're not likely to run into any DOF problems. The most common Pentax lens where you'll get this combo is the DA 50-200 "kit" tele zoom. $250, or probably more like $100 when purchased with the body and 18-55 in the two lens kit.

At f5.6, DOF is @8", and focus/recompose really hardly is an issue. The standard "kit" lens, the DA 18-55 is probably the most common lens with this combo. $199, or more like @$50 when purchased in the kit.

As your focusing distance gets farther away, or if you use shorter FLs, the DOF gets deeper, so focus/recompose becomes less relevant.

As you can see, for "consumer grade" lenses (and I'm not trying to be a lens snob) focus and recompose should hardly be considered a problem unless there is an unusually large disparity between the location of the initially focused area and the recomposed center of frame.

Hope I haven't just confused the issue farther. . .

Scott
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Old Oct 23, 2009, 8:07 PM   #35
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to be honest that would drive me mad not being able to select my focus point on the fly.

but i guess if i wasn't used to it, i could focus and recomp pretty easily as well.

keep in mind that if you are doing something with very small depth-of-field, doing a focus and recomp could throw your plane of focus off. (usually not a huge problem in practice, but could be in certain situations)
Hi Hards,

It's important to realize that you can select focus points on the K2000 or K-x, you just have to remember which one you've selected. Even procedurally, it's pretty easy to select points, even if you're doing it separately for each shot. You can program the green button to recenter the focus point, so you have the same starting point for each shot, then select the focus point that you need. Even going from one extreme edge to the other, the maximum number of button pushes is 3 including the recenter with the green button.

Scott

Last edited by snostorm; Oct 23, 2009 at 8:12 PM.
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Old Oct 23, 2009, 10:26 PM   #36
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Originally Posted by snostorm View Post
Hi Hards,

It's important to realize that you can select focus points on the K2000 or K-x, you just have to remember which one you've selected. Even procedurally, it's pretty easy to select points, even if you're doing it separately for each shot. You can program the green button to recenter the focus point, so you have the same starting point for each shot, then select the focus point that you need. Even going from one extreme edge to the other, the maximum number of button pushes is 3 including the recenter with the green button.

Scott
ahhh.. gotchya...

if programmed to always start at the middle, i don't see that being a big issue then.

thanks for clearing that one up.
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Old Oct 24, 2009, 12:33 AM   #37
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fwiw. i was down at the local camera shop playing around with oly e-p1 and noticed they had a new pentax k-x in stock. had a chance to play with it a little bit. very nice camera for the money. had a good feel to it, extremely compact (esp compared to my 50d), but not cheap feeling. had alot of features considering its small price tag.
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Old Oct 24, 2009, 8:58 AM   #38
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Something else to consider. Pentax Cameras use all existing Pentax lenses. Sorry for jumping off the discussion like that but since your on a budget, like I was, I found that to be one of the most exciting things. I found a 28 - 105mm AF Lense at a consignment shop for $17 US. Also found a 28mm F2.8 MF for $17. The 28-105 never leaves my camera. However I did use the kit lense for a long time and I also had the 55-300mm lense and they kept me going for almost 2 years. I gotta tell you I dont see me ever "jumping ship" from Pentax.

Rob
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