How to verify a new lens

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Originally Posted by Daniel Browning

If noise is the issue it could be related to the fact that noise is more noticable in areas that lack detail (such as defocused spots).

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I think this is the issue, at least with the basket shot. The area at the bottom of the basket is outside of the depth of field, so there is no sharp detail to distract you from seeing the noise (but it's there, even ISO 100 has some noise, especially on an APS-C camera like the T1i you're using).

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Originally Posted by neuroanatomist

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Quote:

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Originally Posted by Daniel Browning

If noise is the issue it could be related to the fact that noise is more noticable in areas that lack detail (such as defocused spots).

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I think this is the issue, at least with the basket shot. The area at the bottom of the basket is outside of the depth of field, so there is no sharp detail to distract you from seeing the noise (but it's there, even ISO 100 has some noise, especially on an APS-C camera like the T1i you're using).
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I agree with Daniel's assessment of the basket. So far good advice has been provided.


It seems to me though that we have only been presented random samples with different defects shown on each. If it were truly a bad copy of the lens, wouldn't the so called noise or other problems replicate themselves in the same locations in other pictures. Maybe not as noticeable for whatever reason, but still you should see it more than one pic.


As mentioned by others I think testing with controlled lighting with the targets mentioned before and shot off a tripod would give a better test.


Here is one other thought, I do not know if this was a replacement lens. If itis a replacement for one you still own, I think I would set up tests to compare the two different copies. The real test for me would be to prove that I have indeed made an upgrade.


Maybe this is a good suggestion: Buy five copies of the same lens. Test all five against each other, keep the best one and send the other four back. Then you know you have a good copy.

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Originally Posted by ham

I'm no expert, but that shot of the basket just looks like the sensor struggling for detail.

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I cannot see a direct problem either.


I do have some questions:


1 - I see you shot both in Raw and JPEg, which one did you upload?


2 - Did you apply any edits or changes before you uploaded.


3 - Are you sure you have Auto Lighting Optimizer(which could cause the noise in dark areas), ISO Noise Reduction and other such functions turned off?


Other than that, the pictures look pretty good to me. If it's not a fault in the lens, enjoy it as much as you can [Y]

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Originally Posted by neuroanatomist

Quote:

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Originally Posted by Daniel Browning

If noise is the issue it could be related to the fact that noise is more noticable in areas that lack detail (such as defocused spots).

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I think this is the issue, at least with the basket shot. The area at the bottom of the basket is outside of the depth of field, so there is no sharp detail to distract you from seeing the noise (but it's there, even ISO 100 has some noise, especially on an APS-C camera like the T1i you're using).
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So did you mean this kind of noise is common with T1i for outside depth of field area?

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Originally Posted by Jan Paalman

I do have some questions:


1 - I see you shot both in Raw and JPEg, which one did you upload?


2 - Did you apply any edits or changes before you uploaded.


3 - Are you sure you have Auto Lighting Optimizer(which could cause the noise in dark areas), ISO Noise Reduction and other such functions turned off?


Other than that, the pictures look pretty good to me. If it's not a fault in the lens, enjoy it as much as you can [img]/emoticons/emotion-21.gif[/img]
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I uploaded the JPEG version, nothing is being edited.


I am not sure whether I have Auto Lighting Optimizer and ISO Noise Reduction turned off. I don't know how to change those settings in T1i.





Thanks guys for the advice. I am going to do the lens testing as you guys suggested and will try to take more photos next weekend.

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Originally Posted by snatesan

So did you mean this kind of noise is common with T1i for outside depth of field area?

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I'm still not 100% clear on what you are seeing, but I can say that the T1i does not have any special or unusal noise issues compared to other Canon DSLRs. All types of noise are more easily visible in smooth, undetailed areas (for all types of images -- even computer-generated ones that don't involve a camera at all). There are many causes for lack of detail (such as motion blur, defocus blur due to depth of field, etc.).


If this is the first time you've ever bought an f/2.8 lens, you may not be used to seeing large parts of the image out of focus (and therefore with more noise), so that could be a related factor.

Noise is present in every digital image. The amount varies, and the impact varies. In dark areas, it