Was this the correct test?

T

toohuge

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All,

I purchased a lens recently - knowing that full well - that it had some significant chips/scratches to the real element....

The lens appears to work perfectly when out and about and when I first received it, I performed the following test to see if the marks would have an affect on the final image:

Set the camera on a tripod
Set iso to base (in this case 64)
Set lens to infinity focus so nothing is in focus
Photograph a blank piece of white paper
Cycle up through the apertures

I performed this test a few times and couldn't see any degradation to the images. I then took the lens out and shot a few images on the walk to see how it would react and the images are below:

DSC_3705 by Chris Reynolds, on Flickr

DSC_4169 by Chris Reynolds, on Flickr

DSC_3570 by Chris Reynolds, on Flickr

DSC_3675-2 by Chris Reynolds, on Flickr

Is there another test I should be doing or should I have done my test differently?

Thanks
 
Do you think you have a problem?
 
toohuge said:
No ! - im just surprised there is no affect and I’m worried I’ve missed something
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If its a prime it looks OK to me , if its a zoom just to put your mind at rest try the test you have already done at different Focal lengths.
If its a Canon lens ( I don't know anything about Nikon) and its EF on a crop camera you are not using the whole image circle so if the marks are on the outer edge you won't see them anyway.
 
My only thought, as the lens looks like it is performing AOK, is what did the previous owner do to it to have caused "some significant chips/scratches" and are they all physical damage i.e. are you sure that none are fungal growth???
 
troutfisher said:
If its a prime it looks OK to me , if its a zoom just to put your mind at rest try the test you have already done at different Focal lengths.
If its a Canon lens ( I don't know anything about Nikon) and its EF on a crop camera you are not using the whole image circle so if the marks are on the outer edge you won't see them anyway.
Click to expand...
It's a prime lens on Nikon FF - and thanks! I thought I had done the test correctly!
 
LeeRatters said:
If you picked it up for a good price and it works with no issues, enjoy it ;)

Just obviously be aware of the resale value and possible difficulties.
Click to expand...

Thanks @LeeRatters - I usually by things down on the heavily used scale of things as I don't sell much :ROFLMAO: and most of my stuff gets beat up from travel etc. Not too worried about resale as I am hoping I've bought cheap enough that I can sell cheap enough! - That's what I tell my parents at least :p
 
Use it how you would use any lens, if you’d see a problem, there is a,problem, if you don’t, there isn’t
No point trying to find something that would never show in your usual everyday usage.
 
Box Brownie said:
My only thought, as the lens looks like it is performing AOK, is what did the previous owner do to it to have caused "some significant chips/scratches" and are they all physical damage i.e. are you sure that none are fungal growth???
Click to expand...

Yep - the scratches look like small chips / chisel marks!

As the rear element appears to stand proud of the lens opening, I imagine the previous owner put the lens in a bag without the cap on and it's been scraped by either a tripod plate or lens foot - something like that.

It's seen some use, but the focus ring is smooth and it appears to af ok!
 
TCR4x4 said:
Use it how you would use any lens, if you’d see a problem, there is a,problem, if you don’t, there isn’t
No point trying to find something that would never show in your usual everyday usage.
Click to expand...

Thanks @TCR4x4 that's what I intend to do - it's a fast prime so I intend to shoot it wide open / with big apertures anyway!
 
I saw some tests where they stuck bits of paper on a lens to simulate 'damage' it had to be almost postage stamp size to spoil the image.
However it will depend on the lens and probably aperture setting.
 
troutfisher said:
If its a prime it looks OK to me , if its a zoom just to put your mind at rest try the test you have already done at different Focal lengths.
If its a Canon lens ( I don't know anything about Nikon) and its EF on a crop camera you are not using the whole image circle so if the marks are on the outer edge you won't see them anyway.
Click to expand...
Just a factual correction. The outer portion of the image circle is not formed by the outer parts of the lens. All parts of the lens form all parts of the image. Damage to the outer edge of the glass will degrade the entire image - usually by lower contrast and increased flare. In this case, that does not seem significant.
 
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