T2i - Severe Image Quality Issue

R

rlf1810

Hey guys,

I've been having a heck of a time getting any decent video whatsoever out of my camera. Everything I shoot no matter the ISO or lens used has severe noise/artifacts in most of the frame, notably shadows. I am using a Fotodiox lens adapter with good Pentax lenses, if that has anything to do with it, and using the neutral profile in camera with contrast and sharpness turned down a bit. At first I thought it was my render settings but, alas, that is not the case.

Have any of your experienced this, or any suggestions as to what might be causing it?

Samples:

http://i607.photobucket.com/albums/tt156/rlf1810/12-6-20103-39-19PM.jpg

http://i607.photobucket.com/albums/tt156/rlf1810/12-6-201010-53-27AM.jpg

P.S. This camera is brand new, I've used it for <200 photos or videos.

-Robert
 
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Do the pentax lenses have manual aperture? If you're going through an adapter, the lens loses all connectivity with the camera meaning you lose autofocus, the cameras ability to set the aperture, etc. It won't matter what you set the aperture to on your camera, the blades won't close on the lens.
 
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PaulGriffith said:
Do the pentax lenses have manual aperture? If you're going through an adapter, the lens loses all connectivity with the camera meaning you lose autofocus, the cameras ability to set the aperture, etc. It won't matter what you set the aperture to on your camera, the blades won't close on the lens.
Click to expand...


The lenses have manual aperture adjustment rings.
 
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Ok, got it back from Canon. They claim it was in working order all along.. Of course, when I test it the problem is as obvious as ever. So now what? Is it possible that the SD card has something to do with it? I've been using those cheap Transcend Class 10 cards, and yes, I low-level formatted them. I also tried a class 4 PNY that didn't make any difference.
 
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My experience with auto lenses is that the iris blades require something to hold a pin in place on the mount for them to operate correctly even when using the manual ring on the lens. My experience with this issue is with nikon/ nikkor lenses.
 
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UPDATE: Ok I'm starting to wonder if my monitor really is at fault. I noticed that when the screen is filled with black, it's covered in noise-like spots. The monitor is a ViewSonic VX2250wm set to 1920X1080 resolution. It adjusts sharpness automatically and I can't control it. So as a not-so-scientific test, I played back the same file on my old laptop without an hd monitor and the noise is practically gone. Is this just my eyes playing a trick on me or do I have a legitimate problem here?
 
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Murdock said:
It might look better on our old monitor because it doesn't have the same resolution?? IDK
Click to expand...

This.

The lower resolution monitor is probably tricking you in a similar fashion that a smaller monitor will make you think an image is sharper than it actually is ... well, not technologically similar as the reasons are different, but psychologically similar. On a higher resolution monitor with better contrast and color depth you will be able to perceive the noise in the blacks.

As far as your camera is concerned, I think Knightly is onto something. On my AE1 (FD lenses) there is a physical switch that engages something in the lens. This lets you see the aperture that you've set on the lens.

It's possible that your Pentax glass is acting the same way, although it should be holding open rather than closed if that were the case. At least I think one of my FD mount lenses behaves this way.

The other problem you might be having, although it doesn't look like it is that your adapter may not be able to set the correct FFD for those lenses on your camera. AFAIK APS-C cameras don't have the same sort of flexibility of lens choices that other formats might.

Honestly, it's not going to be possible to find a solution without some disciplined testing. Here's what I suggest:

At a minimum you need at least 1 "kit" lens designed for this camera. Rent one from a local shop if you don't have one. This is in addition to the setup you are using.

Find a scene outdoors in broad daylight, or light one indoors. Take video clips on the "kit" (or any EF-S lens) starting at your lowest ISO move upwards, taking a separate clip for each ISO. I would probably attempt to do this at the open end of the lens, somewhere in the middle of the stop range, and at the minimum aperture (highest fstop). Then repeat this process on your adatper/lens setup. For the test keep frame and shutter rates constant.

Somewhere in there you should have at least 1 "properly" exposed clip on each lens.

I would also repeat this test in stills mode as well. Not stills from video clips, but actual still photographs.
 
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