BetterPhoto Q&A
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Photography Question 
Gary J. Robinson

Photo Clarity

If you take a digital photo of a still object in decent light (not great) with an ISO of 1600 and the shutter speed is greater than 1/1000 and the photo is not as clear as you would like it can only be because it was not focused correctly?

Along these lines I'm trying to find any type of guide that shows the relationship between shutter speed, aperture, ISO and image clarity assuming correct focus.

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10/12/2008 12:36:40 PM

Gregory LaGrange
BetterPhoto Member Since: 11/11/2003

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10/12/2008 1:01:29 PM

Pete H
BetterPhoto Member Since: 8/9/2005

Your question is faulty as Greg points out.

"Clarity" is a function of many factors that enter a grey area in definition alone.


1)A lousy lens will render a image with poor clarity.

2) High ISO's produce "noise" which is generally NOT associated with clarity.

3) Shutter speed as it relates to clarity is totally dependent on subject motion.

4) Digital sensor design and size dictates clarity.

"Clarity" is subjective, NOT objective unless you take into account ALL the factors that produce a sharp image.

A P&S camera can have great clarity. If you compare the P&S to a 35mm DSLR, the P&S has terrible clarity.

..and so it goes....

all the best,


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10/12/2008 4:54:18 PM

Gary J. Robinson   Thanks Pete for the response. I'm trying to improve my ability to take high quality pictures of birds. Typically they are not sitting still, but when they are I'm often disappointed with the clarity of the photos when I think they should be really sharp. I do have a very good lens and camera so the rest is up to me. I typically have the ISO set high because I'm under the impression that it is better to do this than suffer the effects of lower shutter speeds that will require a higher aperture and increase the chances of getting a little bit movement. Seems light is the key and not something you can control so trying to make sure I have all my other settings as optimized as possible.

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10/12/2008 5:11:16 PM

You confuse focus, a.k.a. sharpness, with light levels/intensity, Gary. Your image won't get any sharper with more light.
Since you shoot birds I bet you use a long lens. And so the lack of sharpness/focus in your images is probably due to simple camera shake. Try using a tripod. This is where the unsexy tripod shines!

Have fun!

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10/12/2008 5:58:58 PM

Gary J. Robinson   My lens actually has an optical stabilizer so I don't get any better pictures with a tripod, but I agree with your point.

More light means a faster shutter so less chance of object movement causing blur.

I have to think there is some expected combination of shutter speed and aperture for which a sitting bird should produce a sharp photo. The more light the faster the shutter and the better the image quality until you reach a point where it just can't get any better.

I'm trying to understand this relationship and the combination of settings between shutter, aperture and possibly ISO

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10/14/2008 3:51:01 AM

Samuel Smith
BetterPhoto Member Since: 1/21/2004
  more crop.

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10/14/2008 7:57:16 PM

"My lens actually has an optical stabilizer so I don't get any better pictures with a tripod"

Actually, Gary, you couldn't be more misguided. Who told you that fairy tale? Sorry to burst your bubble, but image stabilization's efficacy drops off fast with any focal lengths over 150mm. At around 250mm the effect is totally overridden by camera shake. I.o.w.: image stabilization does not work anymore! So if you want to shoot birds USE A TRIPOD! And SEE what the difference is with your own eyes in your own photos. The proof of the pudding is of course in the eating.


Good luck!

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10/15/2008 5:01:12 AM

John G. Clifford Jr
BetterPhoto Member Since: 8/18/2005
  Optical stabilization doesn't give the photographer carte blanche to shoot at low shutter speeds. A tripod (turn OS off) or at least a monopod will give you a lot more keepers due to no motion blur.

Some rules of thumb, for clarity:

Shoot at the lowest ISO that will allow you to use a shutter speed of at least 1/250th of a second, at wide open (aperture)

Sometimes manual focus works better... try it

Using a long lens requires marksman-like habits, such as bracing yourself, squeezing the shutter release slowly as to not jar the camera, and following through by remaining as still as possible until after you hear the shutter/mirror mechanism stop moving

Good luck, and remember if it was easy everyone would be good at it.

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11/21/2008 4:09:09 PM

Bob Cammarata
BetterPhoto Member Since: 7/17/2003
  Camera motion is extremely magnified when telephoto lenses are utilized.
As others have mentioned, I.S. (or O.S.) technology does not replace a tripod or other firm support when shooting long.
A sturdy support system and remotely operating the shutter (hands-free) will optimize sharpness.

It was also mentioned that the lowest ISO the light will allow is your best option.
This is true, as long as the available light is adequate and subject movement is minimal ( a large heron poised ready to strike.)
In this scenario, a lower ISO and shutter can be utilized with great results.
You must be ever-wary of camera-shake though.
The act of pressing the shutter button (...or even the mirror on your DSLR flipping up and back down) can result in a blurry image.

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11/21/2008 5:31:03 PM

And, Gary, use the inverse of your lens' focal length as your minimum shutter speed. So if you use a 300mm lens, set your shutter speed at 1/300th of a second or faster.


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11/21/2008 7:16:58 PM

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