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Old Aug 9, 2008, 11:54 PM   #11
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To clarify my question on uv filters. I know it prevents uv glare but I was wandering about other lighting situations like low light shots indoors and outdoors. Sorry!
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Old Aug 10, 2008, 10:31 AM   #12
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You are welcome, you will find this is a great place to learn; I did not know anything about photography when I showed up here just about two years ago. To answer your first question, if the lens has an A setting on the aperture ring then the easiest thing is to use that setting and control aperture on the camera. Nearly all autofocus lenses will either have an A setting or not have an aperture ring at all (which means it is always in A).

As you have noted, there are various viewpoints on UV filters. They are primarily used as "protection" for the front lens optics. Some also maintain that they cut haze, especially at higher elevations. I started out with Tiffen and Hoya UV filters on every lens. I never found them to improve anything and found that sometimes they causes flare issues and detracted. I have since taken them off and I never use them. I do mount the hood if I am walking with the camera or I have the lens cap on.

Tim
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Old Aug 10, 2008, 11:53 AM   #13
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NonEntity1 wrote:
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Dawg,
My understanding may be wrong but I believe if you are using Av mode with an M lens it will only use the widest aperture, it does not matter what value you set the aperture ring to. Now if the lens does not have the mechanical lever to control the aperture (like those really cheap 500mm lenses) Av will work perfectly but not on an M lens with the mechanical lever.

I initially thought the same way you do but someone else on this forum corrected me. I tested it and found that changing the aperture ring in Av mode did not change the exposure, even with the shutter speed staying constant.

Tim
Tim Here are a group of 6 photos taken with a 50mm f/1.7 Pentax lens in AV mode. The first 3 are with me only moving the Aperture ring and the second 3 are with using the green button. EXIF is posted with it. I'll also shoot three with my Vivitar Series one Group 3 all manual lens that I've gutted the pin out of to modify from a Contax Yashica mount to a K-mount. These will be a little later.

The first is f1.7 with out the green button. Shutter speed set by the camera is 1/4000. Sorry about the focus on some of these I rushed them a little.
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Old Aug 10, 2008, 11:58 AM   #14
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This one is at f8 and the shutter speed is 1/180 second. The Shutter speed is slowing down to compensate for less light allowed by the aperture setting. Showing the camera knows where the aperture is or rather knows what the light value is and is compensating without me doing anything to it.
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Old Aug 10, 2008, 12:01 PM   #15
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This one is at f/22 without using the green button. Shutter speed is 1/15 of a second. The camera is still compensating automatically with out my input.
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Old Aug 10, 2008, 12:03 PM   #16
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Thanks again Tim. I don't want to spend extra if I don't have to. I've been playing around with it today and the one thing I've noticed is some lack in clarity, especially with close-up flower shots. I've played around with the focus and still not getting great sharpness. Its not terrible but not giving me the clarity I would like. Sure its a lot to do with the quality of the lens. Heres an example that hasn't been altered from when I took it. It seems like I will have to edit the photo to sharpen. Let me know what you guys think.


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Old Aug 10, 2008, 12:10 PM   #17
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This one is at f/1.7 and I pusshed the green button and the AE-L button. Shutter speed is again at 1/4000 of a second. The same as it was without using the green button. The camera is compensating in the same way as it did without using the button. The lens is comunicating with the camera by means of the aperture pin. No button needed really.
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Old Aug 10, 2008, 12:14 PM   #18
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maverick96 wrote:
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Thanks again Tim. I don't want to spend extra if I don't have to. I've been playing around with it today and the one thing I've noticed is some lack in clarity, especially with close-up flower shots. I've played around with the focus and still not getting great sharpness. Its not terrible but not giving me the clarity I would like. Sure its a lot to do with the quality of the lens. Heres an example that hasn't been altered from when I took it. It seems like I will have to edit the photo to sharpen. Let me know what you guys think.

Not bad. You will find as a lot of the professionals say...Every photo can stand some sharpening. Just don't over do it. A lot of the photos you see and think are so extra sharp have been sharpened some. The post process is really just a continuation of the process.

Dawg

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Old Aug 10, 2008, 12:15 PM   #19
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This one is at f/8 with the green button. shutter speed is at 1/90 second.
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Old Aug 10, 2008, 12:19 PM   #20
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This one is at f/22 with the green button. Shutter speed again is the same as it was when I didn't use the green button.1/15 of a second. Now If I'm using a screw mount manual lens then you need to stop it down as you suggested. The Aperure pin will not mate up to allow the camera and lens to communicate.But with most if not all K-mount manual lens they will work fine in AV mode with out all that button pushing going on.

Dawg

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