Tamron 150-600, help needed

[Ted Evans]

Has anyone suggested it might be either atmospheric haze or turbulence?

The morning was clear and calm.

 

[Derrel]

I notice the same thing with mine, closer subjects are nice and sharp but at a distance, not so great.

Thom Hogan's review of the 200-400 VR Nikkor also mentions the same thing; he lists the example of say bears and birds; at closer ranges, very sharp, but at longer ranges, the bear fur starts to be blurred, not resolved very well. In the OP's second great blue heron shot, it looks to me like the focus is behind the bird, a little bit. In the first heron shot, YES, the focus point on the eyeballs is NAILED, but it's obvious that the DOF band does not extend even to the bird's wing.

I have noticed a similar thing with the 300/4 AF-S and other lenses too; at longer distances, it's possible to miss the focus on smaller subjects/targets. At 100% you can see a focusing "miss" of even a foot at 70,80,90,100 feet with my 300 or my 400mm lenses, same with the 70-200 or 70-300...at those intermediate ranges of say 60 to 200 feet, the focus squares can "miss" the target a bit, most often back-focusing just a little bit.

I would do a focusing microadjust check on a good, high-contrast target. The issue with something like a GBH...at that range, the head and eye is going to be a VERY small,small target...in fact, it's extremely likely that the AF square in use will actually cover, and in fact overlap the target area, the way an iron rifle sight will cover the entire head--and more!-- of a woodchuck at say 75 yards...your "sight" is in fact, bigger than your target...sometimes you will miss.

 

[JacaRanda]

Has anyone suggested it might be either atmospheric haze or turbulence?

Sort of.

 

[Ted Evans]

Here is the focus point on the second image.

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

 

[wezza13]

I too think exactly the same with my 150-600 on my D600 and D7000.

Up close-ish it's fine, but at a distance it isn't the best.

Then again, I've never tried adjusting the micro-focus as not too sure how to do it properly.

Anyone know a reliable way to do it?

 

[480sparky]

Perhaps it's moisture rising from the water.

 

[JacaRanda]

Perhaps it's moisture rising from the water.

Sounds like he is experiencing the issue on most if not all images shot beyond a certain distance.
With a different camera I have experienced the same thing, but only on occasion. For me, I just chalk it up to user error (I still make lots of them), and having a $1000 super zoom lens.

 

[Derrel]

Here is the focus point on the second image.View attachment 108722

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

In this scenario, it looks almost like the reflection is sharper than the bird is...meaning about 18 inches behind the bird; the focus distance on a reflection is mirror to subject to focal plane...so 10 feet away from a mirror, the focus distance is 20 feet. But to answer the question in this scenario--NO...there is NOTHING that would show missed focus by being sharp, because the target has nothing but AIR behind it, until it gets to the reeds...

Look at your first shot as a guideline: you have the bird's near wing OOF, but the head is sharp...the AF squares in the camera are not exactly in dicative of what the AF sensor actually "sees". Looks to me like the second shot is front-focused by a foot and a half or so....look at the water...the front of the bird's breast is the sharpest spot...there's something white on the water's surface, hard to tell due to compression how far in front that is, but it might be 5 feet or so...the focus looks in FRONT OF the bird to me, and the body is just at the back of the DOF plane.

Shooting over water and air, it's hard to tell focus point except RIGHT AT the water's surface. At 150 feet at 600mm, you have 9'3" total DOF, with 1/8 of the DOF about a foot deep.Depth of Field, Angle and Field of View, and Equivalent Lens Calculator - Points in Focus Photography

If you have 9-point or 11-point or 21 point AF enabled, the system might be factoring in just a tiny bit of the area around the "active" AF point. Again, the AF brackets are NOT the actual, precise, exact physical location the sensors see; in many critical lab test, you'll see that the AF system's sensor actually reads a bit low in the bracket in horizontal mode, and I've also seen them be a bit to the outside edge of the far-side brackets. Not sure what AF mode you're in...9?11?21? Single?

Thom Hogan's sit had an article on this 5,6 years ago, and he used small metal poles in the ground as test targets, about two-inch diameter pipes. A GBH's bill is about 1 and 3/8 inches high; do you think the AF square in the finder can actually lock in on that small a target, reliably, at 150 feet. That is an incredible degree of precision; you would do far better to use 9-point AF and aim for the body. Again, the target is VERY,very small at 150 feet.

If you want to test the focus, you will need a different test platform than open water. There are a number of factors that COULD be at play! The lens might not be well-calibrated to the camera. if this is a consistent issue, it could be in how you are using the camera; for example, SINGLE-point AF on a bird's head at 150 feet is very likely to have bigger error chance than 9- or 11-point, and allowing the camera to sample a bigger physical area, so it can compare data points.

I saw this issue 10 years ago on sports shots with a 300mm lens and low-contrast jerseys; the lens could NOT focus...when ALL the AF points were activated (D1h), the multiple points gave lock-on in 3/4 second, for hundreds of frames per day; with the next camera and 70-200, multi-point group dynamic AF made it possible to focus on almost anything, with almost no effort (D2x). But SINGLE point AF is like a rifle; hit clean, or miss clean. One, single, small data point can miss the target, easily, when the target is far away, and small.

 

[JacaRanda]

Here is the focus point on the second image.View attachment 108722

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

I would think yes. I can't find anything in focus at all.
Do you have the focus limiter set to 15m or full? Could it possibly have been super confused when going from a close distance to the 150' and decided not to do anything?
I mentioned something like that when I first got mine, and Derrel responded with some information regarding many lenses of the type having similar issues.

 

[JacaRanda]

Here is the focus point on the second image.View attachment 108722

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

SINGLE-point AF on a bird's head at 150 feet is very likely to have bigger error chance than 9- or 11-point, and allowing the camera to sample a bigger physical area, so it can compare data points.

^^^Super important. It's often a waste of time and effort to try to find the head with a background full of foliage. At that point it's all about the body.

 

[Braineack]

Yeah when I'm dealing with a tough target, I try to aim for most contrasted spot on same plane. A lot of times the edge of a subject against a clean bg.

using tapatalk.

 

[Ted Evans]

Here is the focus point on the second image.View attachment 108722

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

In this scenario, it looks almost like the reflection is sharper than the bird is...meaning about 18 inches behind the bird; the focus distance on a reflection is mirror to subject to focal plane...so 10 feet away from a mirror, the focus distance is 20 feet. But to answer the question in this scenario--NO...there is NOTHING that would show missed focus by being sharp, because the target has nothing but AIR behind it, until it gets to the reeds...

Look at your first shot as a guideline: you have the bird's near wing OOF, but the head is sharp...the AF squares in the camera are not exactly in dicative of what the AF sensor actually "sees". Looks to me like the second shot is front-focused by a foot and a half or so....look at the water...the front of the bird's breast is the sharpest spot...there's something white on the water's surface, hard to tell due to compression how far in front that is, but it might be 5 feet or so...the focus looks in FRONT OF the bird to me, and the body is just at the back of the DOF plane.

Shooting over water and air, it's hard to tell focus point except RIGHT AT the water's surface. At 150 feet at 600mm, you have 9'3" total DOF, with 1/8 of the DOF about a foot deep.Depth of Field, Angle and Field of View, and Equivalent Lens Calculator - Points in Focus Photography

If you have 9-point or 11-point or 21 point AF enabled, the system might be factoring in just a tiny bit of the area around the "active" AF point. Again, the AF brackets are NOT the actual, precise, exact physical location the sensors see; in many critical lab test, you'll see that the AF system's sensor actually reads a bit low in the bracket in horizontal mode, and I've also seen them be a bit to the outside edge of the far-side brackets. Not sure what AF mode you're in...9?11?21? Single?

Thom Hogan's sit had an article on this 5,6 years ago, and he used small metal poles in the ground as test targets, about two-inch diameter pipes. A GBH's bill is about 1 and 3/8 inches high; do you think the AF square in the finder can actually lock in on that small a target, reliably, at 150 feet. That is an incredible degree of precision; you would do far better to use 9-point AF and aim for the body. Again, the target is VERY,very small at 150 feet.

If you want to test the focus, you will need a different test platform than open water. There are a number of factors that COULD be at play! The lens might not be well-calibrated to the camera. if this is a consistent issue, it could be in how you are using the camera; for example, SINGLE-point AF on a bird's head at 150 feet is very likely to have bigger error chance than 9- or 11-point, and allowing the camera to sample a bigger physical area, so it can compare data points.

I saw this issue 10 years ago on sports shots with a 300mm lens and low-contrast jerseys; the lens could NOT focus...when ALL the AF points were activated (D1h), the multiple points gave lock-on in 3/4 second, for hundreds of frames per day; with the next camera and 70-200, multi-point group dynamic AF made it possible to focus on almost anything, with almost no effort (D2x). But SINGLE point AF is like a rifle; hit clean, or miss clean. One, single, small data point can miss the target, easily, when the target is far away, and small.

Thanks for the suggestions Derrel.

OK, this first image is about 120', 600mm, f11, 1/30, ISO 200, mirror up, remote shutter release and AF.

This appears to be somewhat front focused to me, what say you?

This one is identical except, manual focused in live view expanded.

Focus point at end of red line. Overcast and calm condition.

They still do not seem sharp to me and the definition is not very good.

 

[Ted Evans]

This is a different subject and very poor definition IMO. The first image is about 130', 600mm, f11, 1/30, ISO 200, mirror up, remote shutter release and AF.

This one is the same but with manual focus in live view expanded.

Red line end is focus point.

 

[Ted Evans]

Here is the focus point on the second image.View attachment 108722

When looking at the RAW image at 100%, I see nothing in the frame that is clear. If it was a focus problem, would not something be sharp?

I would think yes. I can't find anything in focus at all.
Do you have the focus limiter set to 15m or full? Could it possibly have been super confused when going from a close distance to the 150' and decided not to do anything?
I mentioned something like that when I first got mine, and Derrel responded with some information regarding many lenses of the type having similar issues.

It was set to 15m and there were a number of images taken in a span of a few minutes at the same distance.

 

[Derrel]

Good focus on the rock! Shows exactly just how very limited the depth of field band truly is! As far as poor definition...yeah...not that great. But in fairness, this lens is KNOWN for its loss of sharpness above 500mm, and also, f/11 is a very small aperture that will show the softening effects of diffraction on a high-MP sensor with those teeny-tiny little pixels. That is simply, too small an aperture opening NOT to cause light squeezing through it to be diffracted. As some reviewers have pointed out, this lens loses quality at the longer end, and it might be an option to shoot at 500mm and crop in later at the computer. STILL--this is a better quality image than many people would be able to get with say a cheap 300mm zom lens and a 2x converter...these images seem pretty free of CA, and the corners are not absolutely God-awful...the image quality looks "okay". even out to the corners, and things are not riddled with horrific green- and purple- fringing. A,lso, 1/30 second with a 600mm lens...man, that is one HECK of test of tripod/head/stability and oscillation resistance....that is a very sketchy speed for a 600mm lens on anything except the absolute BEST legs and the BEST tripod head...and 1/30 second is just about the WORST possible speed you could use...it's too slow AND it's too fast for maximum possible image quality...1/30 means that ANY shutter slap, or ANY mirror vibration, or ANY harmonics in the pod or the body or the lens will be present, probably for the entire length of the exposure...a 1- second exposure might actually be sharper. Seriously. Maybe even 2 seconds! 1/30 is one of the most0-dangerous speeds for sharp images. Nothing will "dampen down" during the exposure...if the van is rocking...don't come a...

The test shots were made under VERY challenging situations and settings, as far as bringing in a killer-sharp shot: zoom lens, at the maximum zoom, at too small an aperture to NOT be impacted by diffraction (every singe frame shot at f/11 will suffer from diffraction), and the 1/30 second speed is going to be VERY demanding of all conditions...not criticizing, just pointing out that this is the lens at its extremes, at a marginal speed, in the real-world. On the plus side, LOW color fringing, and pretty good image quality across the entire frame on a high-MP sensor! THis is four and a half to five stops below the minimum safe speed for a 600mm lens--but then again, it looks like a dull, overcast day, with flat lighting; flat lighting ALSO contributes to lower contrast.

The last image cleans up pretty well with some unsharp masking applied and a micro-tweak of the curves...and it looks to me like the focusing is on-target.