Sigma 135mm

[Abitconfused]

This image: f/5.6, 1/640, ISO: 100. Nothing here is sharp and the DOF is deep enough at f/5.6. I couldn't reveal the point of focus because Capture NX-D kept locking up my system.

[Abitconfused]

Not all is ill. f/2.8, 1/160s, ISO: 640. This image is sharp enough for me. I like the bokeh and the limited DOF. The subject of interested is well isolated from foreground and background. The problem I have is inconsistency. Many images are less than this sharp for no reason I can discern.

[NorthernFocus]

heavy sigh You definitely have a compatibility issue with that lens. If I were in your shoes I'd send it back.

[NorthernFocus]

Not all is ill. f/2.8, 1/160s, ISO: 640. This image is sharp enough for me. I like the bokeh and the limited DOF. The subject of interested is well isolated from foreground and background. The problem I have is inconsistency. Many images are less than this sharp for no reason I can discern.

Nice shot by the way.

[Abitconfused]

Ed, if you had provided some examples earlier on you may have saved yourself and the rest a bit of time. Based all the information you've provided it seems appropriate to refer you to the ages old rule that when shooting handheld (with a lens that has no VR) you keep your shutter speed at 1/focal length or faster. IOW on that lens 1/135s or faster. Or use a tripod and a hands-off shutter release.

I disagree, see photo taken at 1/640s. Where are we now?

[NorthernFocus]

I disagree, see photo taken at 1/640s. Where are we now?

See post no.15.

[rpcrowe]

I get so used to Image Stabilization in most of my lenses (and now IBS with the A6500) I sometimes neglect to use a high enough shutter speed when shooting with a non stabilized longer lens.

I have found that lack of image sharpness is often caused by one of three problems: listed in order of probability...

1. Too slow shutter speed, especially with a longer non-stabilized lens. The 1/focal length x crop factor shutter speed recommendation is only that, a recommendation. It all depends on the photographers holding technique, physical condition and environment such as wind, etc... Quite often double that shutter speed may be required to ensure sharp imagery.

2. Focus point on wrong area. This often happens when you allow the camera to choose the focus point and that is also a fairly frequent cause of non-sharp images. BTW: I don;t think that trees or foliage are great subjects for testing focus.sharpness.

3. Finally, there are lenses which do not focus correctly, even expensive lenses such as the 85mm f/1.4 Sigma with its razor thin DOF wide open can have this problem. Occasionally there are lenses which have been damaged in some way. I once purchased a used 17-40mm f/4L lens which was slightly off focus. A trip back to Canon remedied this...

However, IMO, operator error accounts for more soft images than do faulty lenses. But, here are faulty lenses

BTW: Us Canon guys can get the excellent EF 135mm F/2L lens for one thousand buck at B&H...

[george013]

......
BTW: Us Canon guys can get the excellent EF 135mm F/2L lens for one thousand buck at B&H...

Yeah, but then you shoot Canon

My Nikon lenses 28-70 and 80-200 where pro lenses without stabilization. I need much faster shutter speed as that rule of thumbs.

George

[Abitconfused]

I am going to try the tripod in earnest. I may be stuborn but not so hardheaded I cannot admit the error may be mine! Stand by for a definitive tripod test! Thank you my friends!!!

[george013]

And just one focus point, and NO af-c. Mostly af-c doesn't block exposure when not in focus. And try the trick with manual in live view. That effort is cheaper as a paperweight, which ever one.
Good luck.

George

[Stagecoach]

This image shows focus point using 134mm. F/2.8, 1/80, ISO: 100. While this may appear acceptable at first glance, we are talking about a lens reviewers describe as very sharp. This is not very sharp.

Ed,

I'm not sure, or would anyone else be, what you expect 'Sharp' to look like. Viewing this on my screen I would rate it as a 'Sharp' image where the focus plane is.

Is this image produced from the Raw file ?
If so have you applied 'Capture Sharpening' ?
Have you applied 'Output Sharpening' when you downsized it ?

[xpatUSA]

Ed,

I'm not sure, or would anyone else be, what you expect 'Sharp' to look like. Viewing this on my screen I would rate it as a 'Sharp' image where the focus plane is.

Is this image produced from the Raw file ?
If so have you applied 'Capture Sharpening' ?
Have you applied 'Output Sharpening' when you downsized it ?

I found a slant-edge in the image. It shows no signs of over-sharpening. In the absence of the sharpening you mentioned, the edge response is quite good:



The 10-90% of 1.48px would be really good, if it were unprocessed raw (1.26 would be about perfect).

This is worth a read:

http://www.falklumo.com/lumolabs/art...ess/index.html
.

[Abitconfused]

I conducted a test of the 135mm using a heavy-duty Manfrotto tripod and ball head. The D810 camera was set to a 5-second timer. The evidence is obvious. I was quite mistaken. I believed the lens was soft but it was my use of the lens that was improper. Any error is with me and not the lens. I apologize for making so fundamental an error.

Fountain f/1.8, 1/5000s, ISO: 100...


The images are sharp by any standard and the bokeh is pleasing.
Droplets f/2, 1/8000, ISO: 100...


The lens produces exceptional results.
Parking f/11, 1/250s, ISO: 100...

[NorthernFocus]

Glad you sorted that out, Ed. Actually this exercise may have been a blessing in disguise. It's a good example of how important technique can be particularly when shooting telephoto lenses.

I've been through enough similar experiences that now when I have issues with a new bit of gear I tend to come down on the opposite side. I assume it's me until proven otherwise

[george013]

Did you use single focus so you are telling the camera where to focus?
I'm not sure if I understand you well. You where using a 5 sec timer? If I'm correct that means the camera waits for 5 sec, mirror up, exposure, mirror down. Rather use the exposure delay(?). In that case the sequence is mirror up, exposure delay, exposure,mirror down. That delay is max 3sec with the D810 I noticed. A little bit confusing for me, somewhere after the D700 Nikon changed the names.
Have fun.

George

[Abitconfused]

Single focus point using timer on mode dial. That seems adequate for me especially given the mass of the camera, lens, ball head and tripod. Anyway it’s working fine.

[DanK]

Glad it worked out


Sent from my iPhone using Tapatalk

[george013]

Single focus point using timer on mode dial. That seems adequate for me especially given the mass of the camera, lens, ball head and tripod. Anyway it’s working fine.

I do believe it's adequate for you. But what's left is the mirror slam.

George

[Abitconfused]

Classic Newtonian physics. However, given the momentum of the mirror, whatever cushioning Nikon uses, and the enormous mass of the D810 + Sigma 135mm while mounted on a ball head and tripod that could support an elephant (yes I overbuy at times) I suspect the mirror slap effect is negligible.

[Manfred M]

Classic Newtonian physics. However, given the momentum of the mirror, whatever cushioning Nikon uses, and the enormous mass of the D810 + Sigma 135mm while mounted on a ball head and tripod that could support an elephant (yes I overbuy at times) I suspect the mirror slap effect is negligible.

Actually the issue has nothing to do with the size and weight of the tripod and head. Small internal vibrations are set up when the mirror slap occurs and depending on which source you believe, it tends to impact exposures from around 1/100th sec through to around 1/4s. Unless you are pixel peeping and doing a very large image, you might not notice this effect all that much. Longer lenses tend to accentuate this issue.

That being said, when I shoot in this shutter speed range and a tripod, I generally use the mirror lock mode on the D810. That vastly reduces the issue, although end of shutter travel also has a minor impact on vibration as well.