Are Your Lenses Obsolete if You Buy A High Megapixel Camera?

[Don Haines]

We have to get over the "out resolve" lens argument, it is specious.

System resolution can be broadly shorthanded down to this equation, it isn't perfect because it doesn't account for atmospheric issues and other factors, so the numbers will never be as good as even this simplified form.

tsr = 1/sqrt((1/lsr) ² + (1/ssr) ² )

Where tsr is total spatial resolution, lsr is lens spatial resolution, and ssr is sensor spatial resolution.

If, for example, we have a sensor that can resolve 100 lppmm, and a lens that can resolve 100 lppmm we get this

1/sqrt((1/100) ² + (1/100) ² ) = tsr of 71 lppmm

Leave the same lens on, good or bad, and double the sensor resolution to 200 lppmm

1/sqrt((1/100) ² + (1/200) ² ) = tsr of 89 lppmm


You will notice that the system resolution, even in this simplified form, can never resolve 100% of the lowest performing portion of that system, so if a 24MP sensor is returning 80% of the potential of a lens then a 50MP sensor might return 90%, how useful that is in real life is a moot point, but it does illustrate that even the most modest lens will show increased resolution when put in front of a higher resolving sensor.

The weakest link in the system is what truly limits the photograph.... usually it is not the sensor nor the lens, but the loose nut behind the viewfinder.....

 

[privatebydesign]

Re: The rising tide floats all boats

...I try and remember that a really sharp rubbish photo is still a rubbish photo...

^^ This.

100% agree, and the corollary of that is that there are an awful lot of very good photos out there that are not 'really sharp'. Anybody that has been to a Steve McCurry print exhibition will understand that..........

 

[bwud]

Re: The rising tide floats all boats

...I try and remember that a really sharp rubbish photo is still a rubbish photo...

^^ This.

100% agree, and the corollary of that is that there are an awful lot of very good photos out there that are not 'really sharp'. Anybody that has been to a Steve McCurry print exhibition will understand that..........

I saw his exhibition in old town Prague a couple weeks back. It made me want to throw all my gear away.

I know a lot of people disparage the work because much of it is staged and posed, but why should I care? It's beautiful.

 

[privatebydesign]

Re: The rising tide floats all boats

...I try and remember that a really sharp rubbish photo is still a rubbish photo...

^^ This.

100% agree, and the corollary of that is that there are an awful lot of very good photos out there that are not 'really sharp'. Anybody that has been to a Steve McCurry print exhibition will understand that..........

I saw his exhibition in old town Prague a couple weeks back. It made me want to throw all my gear away.

I know a lot of people disparage the work because much of it is staged and posed, but why should I care? It's beautiful.

I have seen a couple of his traveling print exhibitions and love them, I have all of his books too. Nobody could ever accuse him of taking sharpness seriously! But his eye for colour and composition is exquisite, I prefer his earlier work and having been to many of the places he has shot I know there is no need to stage much, if any, of that earlier body of work.