Lens Reviews Question

T

taxboy

Suspended / Banned
Messages
1,985
Edit My Images
Yes
I'm thinking about upgrading one of my lenses and have started my internet research. In most of the reviews there will be a comment such as x is sharp in the centre but the corners are soft. This will usually be accompanied with a crop from an image in support of this.

I have a probably stupid question. How far into an image is this going to be noticeable before sharp meets blurry, and, at what size print is this likely to be noticeable.

Presumably there is no standard for a corner so any tips on interpreting a review would be much appreciated.
 
I think much will depend on the intended use for the lens. A typical landscape will have corner to corner detail that oftens benefits from good resolution across the frame. Meanwhile a portrait lens will often be used for shots where the corners are normally outside the region that is in sharp focus and soft corners aren't a big issue.....they can even enhance a shot (albeit unwittingly)

Back to your question about the boundary of sharp and blurry.......it will vary from lens to lens (and sensor size) with the gradient and absolute limits being undefined.

Bob
 
The other thing to note is that if you have a 'crop' body camera and use a FF lens, the 'soft' corners may well be outside the crop area of your sensor!
 
Too good answers there, so I'll just add...

Generally, the more you pay the better the lens in terms of corner softness, but wide open all lenses will be softer at the edges just more noticeably on cheaper lenses, the more you stop down the less obvious the difference becomes but they are still softer at the edges even at f8; it just rarely matters by then

The wider the range of the lens the softer it is likely to be, so a cheap 50mm lens at f4 is still likely to be sharper than an expensive 24-120mm wide open at f4

The best answer really is just to work out exactly what you want the lens to be able to do, and once you've figured out what that is just buy the most expensive you can afford that fits the bill

If your budget means you can only just buy the cheapest zoom in the range you want you might be better off buying a fixed focal length and either walking forwards/backwards a bit or cropping!

Dave
 
Just to add to the above.

All things are relative.

Frankly the 'softness in the corners' of a fantastic lens is barely worth this threads existence, whereas the edges of a cheap kit zoom wide open might make it unsuitable for your intended use.
 
Thanks for that. You've more or less confirmed that I'm over thinking things and getting drawn into the Internet trap of pixel peeping just because it's possible to do so
 
You must log in or register to reply here.
Back
Top