Also chasing Tack Sharp

[Jon Gilchrist]

This is similar to another thread about sharpness, but what I'm looking for is a lens that is sharp wide open. I have the 50/1.4 and 50/1.8 Mk1 and while they sharpen up nicely at about f4 or 5.6, they leave much to be desired wide open.

Here's what I'm looking for:

Wide aperture (prefer 1.4, but 1.8 would work. Maybe f2.)
Sharp wide open.
Approximately normal length. Something from about 30mm-85mm, 30 would be better than 85.
Autofocus (so Zeiss and Samyang are out)

Any suggestions? I'm seriously considering the Sigma 35/1.4, but I'm seeing conflicting reports of exactly how much better it is than others, and how it compares to other focal lengths. Can I get sharper with a different length?

I currently shoot on a crop body, but may move to FF on one body. I do not need weather sealing. IS would be nice, but not essential. Sharpness is more important than price, but price will be a factor.

 

[Mt Spokane Photography]

Virtually all lenses improve their apparent sharpness when stopped down at least one stop. Most peak at f/4 or f/5.6.

Photozone has some nice curves showing sharpness for various lenses on either ff or aps-c plotted by aperture.

Sharpness is only part of the formula, you need other factors to be right as well, and some things cause a image to appear sharper than it is.

For sharpness wide open, you don't have to look further than the 40mm f/2.8

Sigma 35mm 1.4 on a Nikon D3 (forget the numbers, just look at the shape of the curve)

The Canon 35mm L on a 5D MK II

 

[pierceography]

If you want sharp wide open, you can't go wrong with the 85mm f/1.2L II. You obviously pay to play with the 85, but mine is incredibly sharp even at 1.2... Significantly more so than any Canon 50mm.

The 135mm f/2L is also incredibly sharp open as well... More so than the 85, and the pictures that come out of that lens are something else.

I hear good things about the Sigma 35mm f/1.4. I hope to get one soon myself.

 

[Pi]

The Sigma 35 would be the sharpest wide open fast prime but ... you have your priorities wrong, IMHO.

You excluded 100mm+ but still, I want to mention the 135L. At f/2, it is fantastic.

 

[wickidwombat]

sigma 35 f1.4 and the canon 135 f2L are super sharp wide open
the sigma 85 f1.4 is also very very sharp at f2 its good at 1.4 but not as sharp as the canon 85L is wide open

 

[Jon Gilchrist]

I excluded 100+mm because my current go-to lenses for sharpness are in the 50-55mm range and there have been many times when I can't back up to properly frame my image, but very few times when I needed to get closer. I might be able to sacrifice a tiny bit more range for sharpness, but nothing more than 85mm. As I said before, 35 would work better than 85. As for my priorities, they are my own and well thought out. That they are different does not mean they are incorrect.

I read lots of good things about the 135/2 and the 100 macros, but they're too long to be practical for me. I used the 85/1.2 for a couple days once and was underwhelmed by both the focus speed and ca when wide open.

 

[Mt Spokane Photography]

I used the 85/1.2 for a couple days once and was underwhelmed by both the focus speed and ca when wide open.

CA's with the 85mm L are extremely low, focus is slower though. It will be hard to beat the 85L for CA's. 0.14 pixel at f/1.2! If that's too much for you, you are going to look far and long.

 

[Pi]

I excluded 100+mm because my current go-to lenses for sharpness are in the 50-55mm range and there have been many times when I can't back up to properly frame my image, but very few times when I needed to get closer. I might be able to sacrifice a tiny bit more range for sharpness, but nothing more than 85mm. As I said before, 35 would work better than 85. As for my priorities, they are my own and well thought out. That they are different does not mean they are incorrect.

I read lots of good things about the 135/2 and the 100 macros, but they're too long to be practical for me. I used the 85/1.2 for a couple days once and was underwhelmed by both the focus speed and ca when wide open.

Get FF. This will solve many of your problems. Your lenses will magically become sharper.

 

[Loswr]

I used the 85/1.2 for a couple days once and was underwhelmed by both the focus speed and ca when wide open.

CA's with the 85mm L are extremely low, focus is slower though. It will be hard to beat the 85L for CA's. 0.14 pixel at f/1.2! If that's too much for you, you are going to look far and long.

Yeah, but that's lateral CA. Longitudnal CA is a different matter. Lots of magenta and green there.

Here's a test from a while back, focusing successively on each battery in the first composite, crops of the chrome ball in the second composite. You can see LoCA showing up green in OOF specular highlights behind the focal plane, and magenta in front of the focal plane. Stopping down reduces the LoCA. Watch out for those chrome bumpers and water reflections, people.

 

[Mt Spokane Photography]

Yeah, but that's lateral CA. Longitudnal CA is a different matter. Lots of magenta and green there.

Here's a test from a while back, focusing successively on each battery in the first composite, crops of the chrome ball in the second composite. You can see LoCA showing up green in OOF specular highlights behind the focal plane, and magenta in front of the focal plane. Stopping down reduces the LoCA. Watch out for those chrome bumpers and water reflections, people.

Oops, You would have to point out my error.