Focusing

[wizical]

I have taken a lot of pictures, but I am struggling with some parts of the picture being fuzzy. When I take a picture, The bottom and top of the pen are blurry, but the rest of the pen is fine. Has anyone experienced this type of problem before? If anyone has a solution would be greatly appreciated.

Thanks

 

[Rifleman1776]

It is called depth of field. In plain talk it refers to how near and far away objects, or parts of objects, will be in focus. In some cases that can be many feet. In others only a tiny fraction of an inch. Assuming you are using a non-professional digi cam, your experience is probably the result of holding the camera close to the object (pen) being photographed. The closer you are the less depth of field. Simply laying a pen down and shooting straight on will eliminate the concern for depth of field. But, getting clever and shooting at an angle with the pen in a holder means you are trying to get 4" or more in focus at the same time. Probably not possible with a simple camera. IMHO, we see here, and other forums, folks wanting to get artsy with their pen photos when it isn't necessary. (hold the barbs guys, I know I've been guilty of doing that too) What we want to see is the pen, not your cleverness with a camera. A simple, clear record shot is all that is needed here or in your advertising brochure or web site.

 

[wizical]

thanks,

the camera I use is a pentax K10D with a macro lense, How do I change the depth of field on that?

 

[Daniel]

the easy answer, move your camera farther from the pen.
the long answer
you change the depth of field by changing the apature or f stop. those are the numbers few people understand in there view finder or on the lens of there camera. it will read something like 2.6 a larger number gives you a longer depth of field. for each number you go up in f stop you need to go one step slower in shutter speed and visa versa to keep correct exposure.

 

[gerryr]

Can you provide more specifics about the lens? If it's lens that has a macro feature, that's different from a dedicated macro lens and the things you need to do to increase DOF will be different. But, quickly, having the pen parallel to the sensor plane will solve a lot, if not all problems.

 

[wizical]

It is a dedicated 50mm Macro Lens, it is really great, i have been playing with f-stop too, i know how that works, just finding the right setup is tricky too. thanks for all the help

 

[gketell]

Start at f8 and see how that does. Work you way up to higher numbers f16, f22, etc until you find the lowest f-stop that makes your pen positioning look good.

GK

 

[toolcrazy]

I generally use F16, then adjust the shutter speed according to how much light I have. Doing this you will need a tripod. Also, use the 2 second mirror up shutter timer so you don't jiggle the camera when you push the shutter release. You have a nice camera, I have the K100D and I am very happy with it.

 

[gerryr]

Just don't try to photograph the pen along it's axis, keep it parallel to the plane of the sensor and your DOF problem will be solved.

 

[Rifleman1776]

Originally posted by wizical
<br />thanks,

the camera I use is a pentax K10D with a macro lense, How do I change the depth of field on that?

I haven't read the other replies so this may repeat some advice. So! You do have a good pro quality camera! OK, to add to what I said, among the several things that affect depth of field, the most controllable is aperture setting. The smaller, the more depth of field. Of course, when you gain something, you lose something. In this case the 'something' is light. That must be compensated for with more light. e.g. usually a longer exposure time. Be sure to use a tripod and cable release or self-timer to avoid shake. I would think a camera/lens of that quality would have a depth of field preview. Meaning you can stop down the aperture before taking the picture an see exactly what you have regarding the depth of field.