Urgent help for sony A-100

[johndefreitas]

This may make someone laugh, but I am new to the world of DSLR. I just bought a new Sony A100, got the 75-300mm from Tamron and a UV filter. I know that the filter must be used in sunny days to protect the lens, but I just took soccer pictures in a game starting at 7:00pm with stadium lights, and thought that the towering lights might also damage the lens if not using the UV filter. I took all the pictures (55) in auto and handheld. The end result was a disaster. Dark, bluish, blurry and out of focus. I think that I did a terrible mistake by using the UV filter. I hope that this is the problem. The next fear I have is the Tamron 75-300mm lens I bought from Amazon, and the box smelled old, even though it was sold as new. If not, than my biggest fear is that I might have gotten a lemon. Why do I think this way? Because I took 45 pictures in the same location, with a Sony A100, from a friend, prior to purchasing mine, with a 70-300mm from Sony, without a filter, handheld, and the pictures came out great. Right now I am a man in fear and in need of HELP, hoping that the pig mistake was the filter, but what about the blurry and out of focus? Does the use of the filter cause that as well? What happened to the steady shot? I took the previous 45 shots hanheld. What did I do wrong? If you have a Sony A100, tell me how do you exactly take fine soccer pictures, and with what equipment. Many thanks.
John

[Sintares]

Umm, well the Sony digital forum may be a better place to ask but..

A uv filter is used to reduce the haze caused by uv light, but it also is used simply to protect a lens from scratches and some people put it on permanently.

Some people question the wisdom of putting a $20 piece of glass in front of a $1000 lens, especially when modern lens don't scratch easily and all glass put in front of a lens has the potential to add problems such as lens flare or even to add color casts , especially if the filter is cheap and not multicoated.

So many do not use them at all unless high in the mountains where uv may actually cause a problem, or in a situation such as a beech where flying sand and water may hit the lens and they want to be able to quickly wipe the filter down.

Things to consider.

Did you set the white balance when under the stadium lights ( or correct it later if shooting raw )

Did you set a high enough ISO or a wide enough aperture to ensure you had a fast enough shutter speed to avoid hand shake, as a 300mm lens + the crop factor of the A100 takes you to 450mm, so at full telephoto if you are forced down to slow shutter speeds the IS cannot work a miracle.

What make is the filter ? Is it a good make, with multicoating or a cheap ebay/ camera shop bargin bin filter?

[DonSchap]

I experienced some definite issues with focusing using a low cost UV-filter on my new EF 70-200mm f/2.8L IS USM lens.

Without the filter, the focus was top drawer, when I placed the UV-filter on the lens, it caused enough distortion in the autofocusing elements of that very-pricey piece-of-glass that my focus was a full five inches off at ten feet. I quickly hunted down a HOYA UV-filter and was pleasently rewarded with sharp, accurate focusing once again.

So, to answer your issue... a quick way to determine this is: fire up your camera and take several shots at 300mm and at least 5 feet away from your subject. Do it with the filter OFF and then the same shot with it ON. Get out your freebie "Photoshop Elements" program, run your images side by side, and inspect for results. If necessary, do it outdoors, during the day. I suspect, that indoors, a flash might show the same result

You should know, right away, whether or not you have an issue with the filter.

Good luck! :)

[johndefreitas]

First off, many thanks for your input/help. Stopped today by a photo shop, and the fellow behind the counter, is sure that the Tamron is an old one and not optimized for the current DSLR cameras. He also told me to use the Program vs. Action mode, manually choose AF/C, ISO 800, AWB, and Color/Dec to leave on Night. He suggested getting either the Sony lens 75-300mm or Sigma APO 70-300mm. He says that the UV-Filter has nothing to do with the problem. I will try the next game, but first I have to return this Tamron 70-300mm. He tells me that using the Fast Action mode will automatically give me ISO 1600, thus providing blurry pictures. What do you guys think of this suggestion? He seemed to know his job. Please comment. Thanks for your help.

John