"Sweet Spot" for lens...

[chainsawal]

I have been shooting as a hobbyist for a few years... slowly collecting good glass along the way. I currently shoot with a D800 (also have a D7000 and D80) and I have all Nikon lens (24-70 f/2.8, 70-200 f/2.8, 50mm f/1.8, new 80-400mm f/4.5 to 5.6, etc) and one Sigma 15mm f/2.8 fisheye.

Obviously when buying "fast" glass... the appeal it how I can now shoot in low light... better bokeh on portraits, etc...

But I also see many people talking about how you need to take that new expensive f/2.8 and "step down" 2-3 steps to get the best tack sharp focus.

Is there some resource out there shows for each lens what the f-stop range that gives the best "tack sharp" focus?

Can someone explain the rationale behind this is it is true?

Shooting inside with strobes or off-camera flash is easy, but I shoot a lot of sports outside where that lowest f/stop matters... and depending on lighting conditions things aren't always sharp.

I was always under the impression you bought fast glass for the ability to use that wide open aperture...

Please advise...

Chainsawal

 

[fyn]

Personally, I think it's silly to think that you shouldn't use a lens wide-open when the need arises because it's not working "at its sharpest."

You can look your lens up on DxOMark and look through the measurements to find where the lens performs its best if that really bothers you.

 

[chainsawal]

Personally, I think it's silly to think that you shouldn't use a lens wide-open when the need arises because it's not working "at its sharpest."

You can look your lens up on DxOMark and look through the measurements to find where the lens performs its best if that really bothers you.

Thanks for the reply...

To your point, I have been using my lens wide open... but keep seeing these post about that not being the sweet spot and felt like a Noob that was missing out on something!

 

[fyn]

To your point, I have been using my lens wide open... but keep seeing these post about that not being the sweet spot and felt like a Noob that was missing out on something!

This is something I would worry about for studio and portrait photography, not sports. It's probably more important that you get the shot, and not worry about whether your image is going to be the sharpest thing you've ever seen.

 

[imagemaker46]

If I need to shoot wide open I do. If I can get away with shooting at 5.6-6.3 I will. It all depends on the light, really good light, makes even average glass look good.

 

[dxqcanada]

dpreview or photozone are two good sites for that info

example: Nikkor AF-S 24-70mm f/2.8G ED - Review / Test Report - Analysis

 

[chainsawal]

dpreview or photozone are two good sites for that info

example: Nikkor AF-S 24-70mm f/2.8G ED - Review / Test Report - Analysis

Thanks.. very interesting information. Didn't know this existed!

 

[imagemaker46]

To your point, I have been using my lens wide open... but keep seeing these post about that not being the sweet spot and felt like a Noob that was missing out on something!

This is something I would worry about for studio and portrait photography, not sports. It's probably more important that you get the shot, and not worry about whether your image is going to be the sharpest thing you've ever seen.

If it's not sharp, it's a simple delete, if you miss the focus on an image you have failed on a basic requirement.

 

[fyn]

If it's not sharp, it's a simple delete, if you miss the focus on an image you have failed on a basic requirement.

It sounds to me like he doesn't have a problem with missing focus or not getting sharp results. More that he thinks he might get slightly sharper results by going to a different aperture, which is true. My point is that his lenses will produce usable sharp images even at their widest apertures.

 

[ph0enix]

FWIW, it's "stopping" down the lens, not "stepping" down:
Stopping down - Wikipedia, the free encyclopedia

 

[kundalini]

Is there some resource out there shows for each lens what the f-stop range that gives the best "tack sharp" focus?

I like the reviews at photozone.de

Just because you have an f/2.8 or faster lens, doesn't mean you should. There are other adjustments you can make if you want tack sharp images.

 

[480sparky]

.......

Is there some resource out there shows for each lens what the f-stop range that gives the best "tack sharp" focus?

........

If there is, I would ignore it anyway. I bench-test every lens I buy so I know exactly where the sweet spots are on MY lenses.

 

[oldhippy]

.......

Is there some resource out there shows for each lens what the f-stop range that gives the best "tack sharp" focus?

........

If there is, I would ignore it anyway. I bench-test every lens I buy so I know exactly where the sweet spots are on MY lenses.

What is your bench-test method. wanting to test my primes before upcoming photo shoot.

 

[480sparky]

What is your bench-test method. wanting to test my primes before upcoming photo shoot.

Nothing very scientific. Set the camera up on a sturdy tripod, and take some photos in my back yard.

I take a series of shots at each aperture setting, then pixel peep the results at 100% to determine the sharpness of both the center in corners of the lens at all the apertures.

If its a zoom lens, I repeat the procedure for every focal length: marked on the barrel.

Net result: I know what aperture(s) is/are the best, which are acceptable, which should be avoided, and which to never use.

 

[chainsawal]

FWIW, it's "stopping" down the lens, not "stepping" down:
Stopping down - Wikipedia, the free encyclopedia

Sorry... I know it is stop.. not sure why I typed that... thinking one thing and typing another.