Best Test For Lenses

WelshNoob

WelshNoob

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A friend of mine is on holiday and may return with a 10-18mm lens for me. I already have 2 lenses that start at 18mm and I want to see how they'd compare. What easy real world test would you suggest to test the image quality of all three lenses side by side as it were?
 
put the camera on a tripod and don't change camera settings just swap each lens in turn. Use remote shutter release as well, as each lens has 18mm that is what your lenses should be set at. Easy then to compare the difference on a computer. If you have a Spyderlenscal use that as a target
 
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you will only use 18mm when you can't change the lens tbh, including lazyness...
 
Don't be surprised if the 18mm image on the 10-18 is not as good as 18mm on the kit 18-55 also you may find the focal point has moved so you may need to adjust for this.
 
Barso said:
Don't be surprised if the 18mm image on the 10-18 is not as good as 18mm on the kit 18-55 also you may find the focal point has moved so you may need to adjust for this.
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Are you talking about micro fine adjustment? I've got a 60d so this won't be possible.
 
WelshNoob said:
Are you talking about micro fine adjustment? I've got a 60d so this won't be possible.
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No not micro adjusts. What I found out while comparing the 2 lenses was that when I had the 10-18 aimed at a certain point at 18mm, a black cross on a sheet of A4 15ft away the centre focus dot was bang in the middle, but when I changed to the 18-55 at 18 mm the centre focus dot had moved up by about an inch and a half. The camera and tripod were not moved, just a lens swap, this is what I meant by you may need to adjust (should have said focal point). I've googled an answer for this but found nothing yet just 1 person asking the same.
 
At the risk of sounding pedantic; the best test depends what you're testing for.
Distortion, colour, focus accuracy, focus speed, exposure accuracy, focus breathing, etc. Etc.

When you work out what's important to you, you can test for it.
 
Phil V said:
At the risk of sounding pedantic; the best test depends what you're testing for.
Distortion, colour, focus accuracy, focus speed, exposure accuracy, focus breathing, etc. Etc.

When you work out what's important to you, you can test for it.
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Sharpness Phil? Is that possible?
 
WelshNoob said:
Sharpness Phil? Is that possible?
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It's quite easy really, you go out and take a load of shots with both lenses and then compare them.

Yes you can download test charts etc but that won't necessarily correlate to how useful the lens is in the field.
 
I might just add that I wasn't testing for anything specific, I just set out to gain a better picture of what the range and distances looked like through the camera lenses. I used the 10-18 then 18-55 and finally 55-250 so I covered 10 -250 in total on a crop sensor (600D)
 
personally I think there are multiple options here, as Phil says.
for example I bought a 17-40 f/4 over a f/2.8 because I thought that the focusing speed would be better (from reviews)

for landscapes, which might be your thing....get to park, test them against each other on a tripod, and you will need to refocus as someone mentioned.
At the centre and edges make sure you have something detailed to pixel peep at.
Also test them at varying apertures. however, if you're shooting landscapes, you might only be interested in f/16 and above.
Before you can design specifications of a test, you need to know what your requirements are.
for some people perhaps weight and weather sealing are the most important factors for landscape photography!
 
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WelshNoob said:
Sharpness Phil? Is that possible?
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First the question you asked: of course, set up an approximation of something you like to shoot, shoot it the way you like to and compare the results back home on the computer.

To be more scientific, you could use a tripod and mirror lock up etc. But if that's not normally how you work it might be a waste of time.

Now the answer you didn't want:

They'll all be sharp at f8, so if you shoot landscapes on a tripod, they'll do. If you want to know how they 'perform' though, that's a different question. I like lenses that can lock focus in the pitch dark, and that are 'sharp enough' wide open. Of course 'sharp enough' is relative, I shoot people, and most people don't have perfect skin like models, so I spend as much time taking sharpness out of pictures as I do putting it in.

And I'll leave you with 'wow that's sharp' is a crushing blow when I show someone one of my pictures. I'm hoping I'll blow them over with an emotional response to the subject.
 
I see your point phil and whoever sees my pictures never comment on the sharpness per se, it's just something I look for. My other half loves any 'good' pictures of our children even though I can see the focus may be off, or the distracting background etc, she just doesn't see those things.

On a side note, and I wanted to share but didn't want to start a new thread. I was at Chester zoo the other day taking some pictures of the elephant. Lady next to me saw me setting up my shot and said to her other half "you really should have bought the iPad, you'd have got some fantastic photos", did chuckle a little.
 
You can't put sharpness into a shot that just doesn't have it though
 
There are many aspects of lenses but I'd be considering bokeh character and flare resistance as important.
 
Without getting bamboozled by the technical aspects, surely the best way to comparativley test a lens is to just take a load of photos with all the lenses and see if you like what comes out? It's all pretty subjective anyway!!
 
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