Sweet spot for lens
- Thread starter bikeit
- Start date
Fred Kingston_RIP
Senior Member
Best at f=18mm & f/3.5 w/D7000... The aperture changes with different cameras.. There's a review and scoring on DXOmark.com
Rare is a lens that's best wide-open. Typically, it's stopped down 2-3 stops from maximum.
Fred Kingston_RIP
Senior Member
I didn't create the data, I only cut&pasted it... it does show a different F-stop for the different cameras they tested with that lens
BackdoorArts
Senior Member
I believe less in sweet spots than I do in soft spots.
I don't give much credence to DxO Mark in terms of their rating system, but I believe in the data as it's better as showing potential weakness than it is at predicting brilliance. In other words, a 30 rating on a lens doesn't mean it's that much better than a lens rated 22, it just means that under the right conditions one lens will perform distinctly better than another - we just don't know precisely when that will be, so we hedge our bets, not knowing if that is 1% of the time or 100% of the time (and we can't).
My point is that if you look at the data behind DxO's ratings, you'll see areas of red, yellow and green in their various measurement graphs. In my experience, most photographers will not be able to see a difference in lenses firing in the green range in most conditions, and some will not see a difference in the transitions to yellow (and others not until it's pointed out). Every lens will eventually reveal a spot where you notice a degradation in some aspect of the image - color, sharpness, contrast, etc. That's a soft spot, and you need to know them - and most of all you need to know how to use them!! Soft spots can be looked at as "must avoid" areas because of how you use the lens (I have them on my Sigma 150-500mm). But when a lens goes soft it can often be used to your advantage, particularly with portraiture.
What I'm saying is, don't get hung up on knowing what someone else says about a lens - if it's in your bag then shoot with it, all of it, and figure out where it best serves you.
I don't give much credence to DxO Mark in terms of their rating system, but I believe in the data as it's better as showing potential weakness than it is at predicting brilliance. In other words, a 30 rating on a lens doesn't mean it's that much better than a lens rated 22, it just means that under the right conditions one lens will perform distinctly better than another - we just don't know precisely when that will be, so we hedge our bets, not knowing if that is 1% of the time or 100% of the time (and we can't).
My point is that if you look at the data behind DxO's ratings, you'll see areas of red, yellow and green in their various measurement graphs. In my experience, most photographers will not be able to see a difference in lenses firing in the green range in most conditions, and some will not see a difference in the transitions to yellow (and others not until it's pointed out). Every lens will eventually reveal a spot where you notice a degradation in some aspect of the image - color, sharpness, contrast, etc. That's a soft spot, and you need to know them - and most of all you need to know how to use them!! Soft spots can be looked at as "must avoid" areas because of how you use the lens (I have them on my Sigma 150-500mm). But when a lens goes soft it can often be used to your advantage, particularly with portraiture.
What I'm saying is, don't get hung up on knowing what someone else says about a lens - if it's in your bag then shoot with it, all of it, and figure out where it best serves you.