Lens sweet spot

[ozimax]

It seems that each lens has a "sweet spot", which of course may vary. I took some test shots this afternoon as I continue my quest to tame the beast, that being the Canon 70-200 F2.8 IS lens. My rough conclusion is that around F8 seems to be the best aperture setting for sharpness at least, with this lens. Any comments from smart people appreciated!

IS was not used on these but a tripod and self timer were, at 100% crop:

200mm F2.8 1/10 sec

(I had to move the watch for the next two because the sun started coming in my room, mucking up the exposure)

200mm F8 1/4 sec


200mm F13 0.6 sec

[Oz_Beachside]

I hope you accept commetns from non smart people, if not I can delete

If I was testing sharpness of lens, I would want to remove variables that cause soft images, like slow shutter speed. These are extremely slow at 200mm... did you consider this test in daylight brightness, so you could get speed faster than say 1/400th s? You might have camera shake in these tests...

brightness would also help keep iso at a good quality, so noise did not appear as non sharp.

[digitor]

What's causing those diagonal lines you can see on the watch face in the 2.8 shot? If it was jpg artifacts, I would have expected to see them in all the shots. Did you have a filter on the lens?

Cheers

[ozimax]

You might have camera shake in these tests...

They were done on a tripod and with self timer.

[Matt. K]

The sweet-spot of a lens may not be just the area of greatest sharpness...but more the area where sharpness and 'wrap around' come together and give the image a special visual quality that seems to be more akin to black magic. The sweet-spot will be a combination of F-stop AND a focal distance.It's this combination that can be hard to find and so damn rewarding when you find it. I once owned a Nikkor 85mm that sang at F5.6 with focus at about 3 metres. Sadly, not all lenses have this magic sweet spot...but they will have a combination where the lens works best. Finding the sweet spot on a zoom lens is almost an exercise in futility as there are too many variables.
I might cop a little flak here but that is my experiance.

[big pix]

The sweet-spot of a lens may not be just the area of greatest sharpness...but more the area where sharpness and 'wrap around' come together and give the image a special visual quality that seems to be more akin to black magic. The sweet-spot will be a combination of F-stop AND a focal distance.It's this combination that can be hard to find and so damn rewarding when you find it. I once owned a Nikkor 85mm that sang at F5.6 with focus at about 3 metres. Sadly, not all lenses have this magic sweet spot...but they will have a combination where the lens works best. Finding the sweet spot on a zoom lens is almost an exercise in futility as there are too many variables.
I might cop a little flak here but that is my experiance.

yep......agree with that, but some people never find the sweet spot

[ozimax]

Matt, I think you are correct. I was just thinking this morning that the permutations, combinations etc etc of modern camera adjustments make microscopic perfection-attainment impossible. The old story that a spectacular moment frozen in time (albeit shakily) is far better than a perfect pixel peeping picture of a wrist watch or any other inane object than doesn't mean anything to anyone, holds true.

(Does all this make sense? It's getting late)

[ozimax]

I really have no idea where the sweet spot of my current lens is, all I know is that it is a very hard thing to master. When I hit the spot it takes spectacular images, but at this stage it's hit and miss, but I suppose that's what makes photography fun. Sometimes it's hard to get it right, like my piano playing!!!

[big pix]

when I hit the sweet spot, my lens sing.......

[Steffen]

when I hit the sweet spot, my lens sing.......

Note to self: listen more carefully!

Cheers
Steffen.

[gstark]

I really have no idea where the sweet spot of my current lens is, all I know is that it is a very hard thing to master. When I hit the spot it takes spectacular images, but at this stage it's hit and miss, but I suppose that's what makes photography fun. Sometimes it's hard to get it right, like my piano playing!!!

Check the exif of those spectacular shots, and note the settings that were in use. Compare those settings amongst those shots, and you may start to see a pattern emerge.

Then use that as the basis for more tests.

What Matt said is spot on, btw; the sweet spot is a combination of settings, where everything just works. Find it, and exploit it.

[jamesw]

They were done on a tripod

a good, heavy tripod?

[ozimax]

They were done on a tripod

a good, heavy tripod?

No, a good but cheap and light tripod (Manfrotto lightweight something or other...). I suspect you're onto something as this may make a difference - the 30D plus grip plus 70-200 2.8 IS is one heavy load for a lightweight tripod!

[jamesw]

I personally do not have much experience with tripod use, but am about to invest in some support gear, and Thom Hogan et al swear by expensive, heavy, stable tripods.

I suspect many other seasoned landscape photogs on here will do the same.

Thom has a fairly rigorous article on purchasing a tripod on his site.

[MattC]

Agree with what MattK said about lens sweet spots...

Tripods have a sweet spot. Performance vs $$$$ vs portability. While I agree with Thom Hogan on using the biggest and heaviest to advantage, there is a limits to how much people are willing to spend and how much they will carry.

My arsenal: G1548/BH-55, G1325/BH-55 and 055MF3/M20. It is the last that hits the spot.

Cheers