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View Full Version : Graininess and Blurriness



fierceshoes
08-06-2007, 04:31 PM
I keep getting comments that my photos are grainy and blurry even though I use a tripod and remote shutter release. Would this be due to the 18-200 Sony kit lens that I'm using or something else? I've also tried using the auto focus to see if it's "me." Most of the ones that I've gotten the comments on, I've used a macro filter to get really close to the subjects.

Is this question too vague? I know there are probably lots of variables that could be causing these problems but I'd be curious to know if there's any advice someone could give me to try?

Thanks!

Turn
08-06-2007, 05:14 PM
what ISO
what shutterspeed
are you using?

I read some comments a bout the lens that you're using and it seems to be a decent lens.

DonSchap
08-07-2007, 11:08 AM
One thing I will say is that the TAMRON AF18-200mm f/3.5-6.3 XR DiII LD does not respond well when you mess with it's optics. It is cut to an extreme from end to end and that makes for a really tight optical measurement. Definitely less receptive to alteration than other lenses, because there is simply less glass (Di-II) at the camera end than on Di or earlier-type glass.

In fact, if you add a circular-polarizer filter, there is a good chance that you will lose your ability to autofocus at around the 135mm focal length, because your maximum aperture of the glass is now around f/8. That's the limit of most autofocus sensors.

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This lens simply is NOT a simple PRIME and has probably some of the most active elements ever designed into a lens to give you such extreme focal range. When you bend the light with an add-on filter, you change the entire dynamics the lens is using to get the image to the sensor.

Your best bet for macro lensing is to use a Minolta AF 50mm f/1.7 PRIME (fixed focal length) lens or one of the earlier zooms, like the Minolta AF 35-70mm f/4. They are not nearly as complicated and will probably deliver a much sharper looking image overall.

I believe you are just trying to get too much out of the one lens. It wasn't designed for that ... and your images are probably agreeing. :o

Now, macro lensing ... I still feel you probably should use the extension tubes to keep from messing up the optics with some kind of lens.

I can try and demostrate this ... but it will take a little time.

DonSchap
08-07-2007, 06:50 PM
A little while later ...

With the EF 12mm Extension Tube on the TAMRON AF18-200mm f/3.5-6.3 XR Di-II LD Aspherical (IF) lens. I had to use the EOS 20D with this lens, because as hard as it may be to believe, I am not equipped to do it with the SONY. No extension tubes!

Please note: all images were simply reduced in size to fit within the website's image restrictions. Although it might have helped, there has been no enhancement to the image at all.

Anyway ... here is a standard keyboard at 30mm at almost 0 inches. Note the actual texture of the key's surface. Blurry? Hardly!
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This is the same keyboard, at 200mm, at about 6 inches, using the 580EX on the hot shoe with the built-in diffuser and white shield bounce as the light source. It's not all that clear, but it was a handheld shot.
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Now, I'm not sure if you would consider these looking granular or all that blurry. They are what they are. Perhaps better lighting ... it was a quick snap. :o

This is a 25mm Extension Tube with the 18-200 lens at 200mm and about three inches
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You'll notice that the magnification increases with the additional tube length ... and I've noticed the distance between the keyboard and the end of the lens getting closer and closer. So you lose the wider settings altogether. The 30mm focal length is impossible with the 25mm Extension Tube added. You smack right into the keyboard before you ever reach it. I can't be specific about where this transition takes place without further testing, but it seems to offer a decent image, none-the-less.

This is a combination of both extension tubes (12mm + 25mm) stacked together @ 200mm on the lens
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Like I said, it is not as sharp as the 30mm shot ... but graininess and blurry ... I'm not so sure. Even a dynamic lens like the 18-200 has its limitations. There is a definite depth of field issue ... of about 3 millimeters. :eek:

I sincerely hope this advice and demonstration provided some insight into your issue. They don't pay me a lot for this ...

fierceshoes
08-08-2007, 02:41 PM
Awesome info! Thanks for letting me pick your brains.

DonSchap
08-08-2007, 02:53 PM
Well ... what's left of them, anyway :rolleyes: