Focus Poll

[480sparky43 43]

Well, I can't really do a forum poll, but I'm asking for your input. I'm trying to get some unbiased opinions in comparing the camera's AF to my new KatzEye focus screen.

Which of the images in the following pairs appears sharper than the other?



Pair A:

1:

2:

Pair B: (I focused on the 'stick' on the right)

1:

2:

Pair C:

1:

2:

Pair D:

1:

2:

These are straight crops from unedited frames. Taken with the camera tripod mounted, with wired release, using a 70-300 Nikkor. All were taken at f/5.6 to prevent as much DOF as possible.

 

[HughGuessWho101 16]

A - 1
B - 1
C - 2 (maybe)
D- 1 (Barely)

Thats my take

 

[nmoody]

A: It looks like you focus in different places. The concrete in the first and the wood in the second.
B: Same
C: 2
D: 1

 

[480sparky43 43]

I let the camera AF for one of the shots, and a manual focus for the other. But I mixed 'em up before posting.

 

[Derrel]

Sparky...saw your post, would love to contribute an answer, but must run...have a paint-drying competition to judge downtown at 5:00...Be back around 10 pm. Hasta!

 

[480sparky43 43]

Sparky...saw your post, would love to contribute an answer, but must run...have a paint-drying competition to judge downtown at 5:00...Be back around 10 pm. Hasta!

That's OK.... I have to go judge a corn-growing contest tonight.

 

[Markw]

I think 1 is sharper on all accounts besides Pair C.

Mark

 

[fjrabon]

straight 1s

 

[amolitor]

There is no substantive differences between the two in any of the cases. The first pair looks different, but the light has changed which gives the appearance of differing sharpness here and there.

In the first set, the focus in #1 is, I think, further back. The metal edge on the right is slightly sharper, whereas in #2 the wood on the left appears slightly sharper. In pair B the focus appears to be further back in #2, or at any rate the green leafy thing is closer to the plane of focus. In C and D there's nothing to be observed.

You are, I assume, trying to test focus accuracy? I'm not sure how this business is helping that.. Are you clipping out the area you focused on, from a larger frame?

 

[sm4him]

This is one of those times when I am reminded how very serious my vision problems are. This is just like those little "tests" they give at the opthamologist before they tell you that you need 3-inch thick lenses and correction for severe astigmatism.

Seriously, I am legally blind without my glasses (which is a misnomer, I realize, as "legally blind" is technically 20/200 WITH corrective vision. With my glasses, I'm about 20/75...but then there's ALL those floaters, lol)--focus is quite the challenge and figuring out which of these is sharper would be like figuring out one of your uber macros. I'd just have to take a complete guess and then rely on hints to finally get it.

I was just sure that #2 in the first pair was sharper, but that doesn't seem to be the prevailing opinion. On the others, I cannot even begin to discern any difference in them.

 

[480sparky43 43]

............You are, I assume, trying to test focus accuracy? I'm not sure how this business is helping that.. Are you clipping out the area you focused on, from a larger frame?

I'm trying to compare the camera AF to my manual focus with a third-party focus screen. These are all 800x530-pixel crops from the original images, no reduction was made to post them, and no editing was done to any of them.

 

[mjhoward]

With any of them being THAT close, go for whichever is the fastest method... AF

 

[480sparky43 43]

With any of them being THAT close, go for whichever is the fastest method... AF

AF doesn't always function.

 

[bratkinson]

1-1-2-1. Although on #3, it's very close.

 

[amolitor]

Still not following entirely what the plan is. Are these crops from where the point of focus should be? There seems to be some depth involved, so the issue of "where is the plane of focus" seems to be arising (although that might be an optical illusion). To be sure, I assume you have a plan here and that the feedback we're giving is useful and so on. I am just curious about what the plan is.

Focus is always SOMEWHERE, right?

As a suggestion for another test, you could place a test object centered in the frame, next to a ruler that extends away from the camera (parallel to the lens barrel). The you could pull your best focus on the test object, and then see on the ruler where the plane of focus actually fell.