How to verify a new lens

[neuroanatomist]

Agree that more detail is needed in your case. A lens problem must be extraordinarily bad to show as a specific spot on an image. Look through the lens, and if there

[HiFiGuy1]

Also would be worthwhile testing the camera with different lenses to make sure it is not a problem with the camera itself. So far, except for the lens projector, the suggestions have not allowed for a certain elimination of the lens or body as the culprit, even though the ideas have real merit of their own.


If you see the problem with the lens in question, and it goes away using your other lenses, it

[snatesan]

Thanks guys for the advice.


I am going to test the lens as Croubie and neuroanatomist suggested and will let you know.


Meanwhile I uploaded some photos to flickr, please take a look and comment when you get a chance.


www.flickr.com/.../72157627311641695


Thanks!


Satheesh

[Daniel Browning]

From the flickr link:


"100% cropped image of IMG_7541. The area I am concerned is where contrast changes at the bottom of the basket which appears as noise."


I still don

[ham]

I

[freelanceshots]

I don't see any issues right off hand. What camera body are you using?

[Sheiky]

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

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]

[snatesan]

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.

[neuroanatomist]

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).

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).

[HDNitehawk]

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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).

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.