Easiest / Best way of lens testing

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Looking to tap into the collective wisdom of the best way to test a lens - ideally for an upcoming purchase but thought I'd give my existing lenses a try out as well.

Ideally would prefer techniques that can be applied indoors and I'm not looking to take it to an arguable scientific experiment level. I've Googled initially and I've seen articles that say print a lens chart, others say don't use a printed lens chart etc

All advice appreciated
 
I test using a cereal box in good light to get low ISO and fast shutter speed always wide open, if ifs sharp with good colour then that's fine to me.

Rob.
 
Take photos with it that you would usually take.
Pointless photographing walls and charts and boxes.
 
Those old broadsheets (newspapers) spread out flat on a wall. It helps give an idea of sharpness, decentring. Things like CA and low contrast can be corrected in post and flare can be controlled to some extent with a lens hood so I don’t worry excessively about them.
 
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Test it by going out and taking real photographs - and see if you like the results. No lab coat required :D
 
There are test reports that are far better than anything that you can do your self.
They will tell you everything that you need to know about the technical aspects of a lens.
There are also many tests done showing images taken with about every lens, and done by web sites blogs and by magazines.
Some even report on the Pixi Dust quality of a lens.
I have been buying and using lenses for some 75 years, only once have I been totally disappointed with the performance of a lens.
It was a real shocker, the fact that it was on a Rolleiflex made it even worse.

Not tests that you do for self test your technique. Not the quality of a lens.

If after a year or so, you are still picking up a particular lens. It is probably a good one.
But more importantly it suits the way you work, and the work you do.
 
I have been buying and using lenses for some 75 years, only once have I been totally disappointed with the performance of a lens.
It was a real shocker, the fact that it was on a Rolleiflex made it even worse.

I have far less experience than you, but I've had 2 used lenses through TP that have been terrible. The first, I didn't really know what I was doing, and by the time I'd realised how badly decentred it was (after 2 weeks - enough time to finish the honeymoon) the seller wasn't taking it back. The other I had on evaluation, and it went back painlessly.

To me, it's worth doing the decentring test because *sometimes* you need a lens to be sharp from corner to corner, even though for 70% of shots one or more soft edges isn't noticeable. That way you can feel confident with your kit to just go out & shoot, rather than worrying about bringing the dog with you.
 
There are test reports that are far better than anything that you can do your self.
They will tell you everything that you need to know about the technical aspects of a lens.
There are also many tests done showing images taken with about every lens, and done by web sites blogs and by magazines.
Some even report on the Pixi Dust quality of a lens.
I have been buying and using lenses for some 75 years, only once have I been totally disappointed with the performance of a lens.
It was a real shocker, the fact that it was on a Rolleiflex made it even worse.

Not tests that you do for self test your technique. Not the quality of a lens.

If after a year or so, you are still picking up a particular lens. It is probably a good one.
But more importantly it suits the way you work, and the work you do.


This will only tell you about the actual lens that the reviewer was given/loaned (or even bought), not every copy. As Toni has pointed out, specific copies may well be shockers.
 
I have far less experience than you, but I've had 2 used lenses through TP that have been terrible. The first, I didn't really know what I was doing, and by the time I'd realised how badly decentred it was (after 2 weeks - enough time to finish the honeymoon) the seller wasn't taking it back. The other I had on evaluation, and it went back painlessly.

To me, it's worth doing the decentring test because *sometimes* you need a lens to be sharp from corner to corner, even though for 70% of shots one or more soft edges isn't noticeable. That way you can feel confident with your kit to just go out & shoot, rather than worrying about bringing the dog with you.

I bought a Samyang 7.5 recently that was so decentred it was obvious at first shot. I returned it at once and got my money back, the next example I bought was perfect. This is a risk you take with buying second hand goods. but it does not take an elaborate test to find these things out. a simple shot of a wall will show decentring very clearly.

You will find that the slight differenced between samples of a lens, are usually well within specification, and if you return them under guarantee it is likely nothing can or will be done, apart from them checking the focus position, but even that is not critical on a mirrorless camera as they use the actual focus point directly on the sensor. nearly all mirrorless lenses focus well past infinity and it is not a fault.

An interesting point about the Samyang 7.5mm fish eye, is that though it is exclusively a 4/3rds lens it can have the mount and lens hood replaced with ones made by Nodal Ninja, to fit a Fuji or Canon APS mirrorless, for use as a four around 360x180 lens. and is probably the best of its kind for this purpose.
 
I bought a Samyang 7.5 recently that was so decentred it was obvious at first shot. I returned it at once and got my money back, the next example I bought was perfect. This is a risk you take with buying second hand goods. but it does not take an elaborate test to find these things out. a simple shot of a wall will show decentring very clearly.

You will find that the slight differenced between samples of a lens, are usually well within specification, and if you return them under guarantee it is likely nothing can or will be done, apart from them checking the focus position, but even that is not critical on a mirrorless camera as they use the actual focus point directly on the sensor. nearly all mirrorless lenses focus well past infinity and it is not a fault.

An interesting point about the Samyang 7.5mm fish eye, is that though it is exclusively a 4/3rds lens it can have the mount and lens hood replaced with ones made by Nodal Ninja, to fit a Fuji or Canon APS mirrorless, for use as a four around 360x180 lens. and is probably the best of its kind for this purpose.

I like the Fred Miranda link, not just because he explains the test clearly, but also that he points out many otherwise perfectly good lenses - zooms get a specific mention - may *appear* flawed because they were never designed to be that even. Both the lenses I had were bad enough to spot immediately if you were looking and took pictures that could reveal the fault, though presumably not as bad as your Samyang.

FWIW I have an Optek 6.5mm fisheye that's designed for APS-C/M43, but also works as a full frame unit on my Sony A7. Image quality isn't stunning, but for that type of image it's acceptable: I don't expect the same kind of resolution or edge to edge sharpness that I get from my Sony/Zeiss 55 or even my Sigma 12-24, but it's *good enough* and that's the key thing. The Sammy 7.5 does have a good reputation, and I wouldn't mind trying one sometime.
 
I like the Fred Miranda link, not just because he explains the test clearly, but also that he points out many otherwise perfectly good lenses - zooms get a specific mention - may *appear* flawed because they were never designed to be that even. Both the lenses I had were bad enough to spot immediately if you were looking and took pictures that could reveal the fault, though presumably not as bad as your Samyang.

FWIW I have an Optek 6.5mm fisheye that's designed for APS-C/M43, but also works as a full frame unit on my Sony A7. Image quality isn't stunning, but for that type of image it's acceptable: I don't expect the same kind of resolution or edge to edge sharpness that I get from my Sony/Zeiss 55 or even my Sigma 12-24, but it's *good enough* and that's the key thing. The Sammy 7.5 does have a good reputation, and I wouldn't mind trying one sometime.


Not that many people go to the trouble and expense of getting a canon or Fuji mount to replace the 4/3 one unless they are into taking 360x180 VR pans. so you may never see one for sale. The coverage is sharp to the sudden fall off rim close to the edge.
This was taken on my Fuji XE2 on a Nodal Ninja R20 head fixed directly to the new lens mount. Samyang was closed one stop.

This is it reduced in size for the web . it make an excellent 360x180.

_TXE5387-copy.jpg
 
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