Shot A, Shot B

wev

Senior Member
Contributor
Better light today and more time. Using the second body like yesterday, I saw the issue a number of time. Here are some examples, chosen because they were all at full burst speed, so taken within a single second. As before, nothing done but a crop and compression for size.

TestA.jpg


TestB.jpg


TestC.jpg
 
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thequeenscheese

Senior Member
I know nothing of this or how it really works, but could there be residual image on the sensor still at high speed shooting?, similar to a plasma tv leaves a ghost when u turn it off ( just an example obv there 2 different things ? how quickly can the sensor/s clear themselves? does this even matter?

maybe it's worth contacting the lens manufacturer and nikon to see what there take on it is?
 

Bob Blaylock

Senior Member
Better light today and more time. Using the second body like yesterday, I saw the issue a number of time. Here are some examples, chosen because they were all at full burst speed, so taken within a single second. As before, nothing done but a crop and compression for size.

It's not as easy to tell, as there is much less recognizable background in these shots than in your earlier shots, but on careful examination, it still appears to be the case, again, that the background is more blurred in the lighter shots than in the darker shots in the same set. This was with the same lens on a different body, right?

So the issue appear to be with the lens. Probably a sticky aperture. Have you tried my other suggestion, with the lens off of the camera, working the aperture linkage by hand and watching how the aperture responds?
 

wev

Senior Member
Contributor
So the issue appear to be with the lens. Probably a sticky aperture. Have you tried my other suggestion, with the lens off of the camera, working the aperture linkage by hand and watching how the aperture responds?

I just did. It is odd. When I initially look through, the aperture is fully open. If I slowly move the lever up, it stays open. If I move it quickly, it snaps down to a tiny opening. If I continue to flick it quickly, it snaps open then immediately back to tiny. If I go slowly, or even moderately, it opens wide and stays wide.
 

Bob Blaylock

Senior Member
I just did. It is odd. When I initially look through, the aperture is fully open. If I slowly move the lever up, it stays open. If I move it quickly, it snaps down to a tiny opening. If I continue to flick it quickly, it snaps open then immediately back to tiny. If I go slowly, or even moderately, it opens wide and stays wide.

Looks like we've found your problem, then. The aperture should respond smoothly and consistently to the position of that linkage, regardless of the speed at which you move it. Some times, it's staying open when it should close down.

I just now downloaded one of your pictures, and examined the EXIF data to see how the lens is identified. It appears to identify as a G-type lens, which means no aperture ring, right? The sole control of the aperture should be via that linkage.

If it's not mounted on a camera, and nothing is touching that linage, then it should be spring-loaded so that the linkage moves downward, and the aperture closes to its smallest setting. If the aperture was wide open when you first looked at the lens, with it not mounted on the camera, and nothing pushing that linkage upward, then that's not right. The aperture should only open up when that linkage is pushed upward, and should immediately close back down when the linkage is released.

I see, also, that at 600mm, the maximum aperture is ƒ/6.3. That's only a stop up from the ƒ/9 that it's supposed to be at in your pictures; which seems consistent with the variance that we're seeing. The EXIF data don't seem to indicate what the minimum aperture is. I'd be curious to see this same issue manifested in pictures that were supposed to be at the minimum aperture.


In any event, it's obvious, now, what the problem is. Your aperture is sticky. You might be able to loosen it by repeatedly working that linkage manually, but you'll probably need to have the lens taken apart, and the aperture mechanisms cleaned and lubricated by someone who has the proper skills, equipment, and materials to do so. I'm just barely on the edge of thinking that might I dare attempt such a thing on my primitive non-AI lenses from the 1960s and 1970s. I understand these more modern lenses to be a whole other order of complexity, rather far beyond what any amateur ought to think of attempting.
 

wev

Senior Member
Contributor
Looks like we've found your problem, then. The aperture should respond smoothly and consistently to the position of that linkage, regardless of the speed at which you move it. Some times, it's staying open when it should close down.

I just now downloaded one of your pictures, and examined the EXIF data to see how the lens is identified. It appears to identify as a G-type lens, which means no aperture ring, right? The sole control of the aperture should be via that linkage.

If it's not mounted on a camera, and nothing is touching that linage, then it should be spring-loaded so that the linkage moves downward, and the aperture closes to its smallest setting. If the aperture was wide open when you first looked at the lens, with it not mounted on the camera, and nothing pushing that linkage upward, then that's not right. The aperture should only open up when that linkage is pushed upward, and should immediately close back down when the linkage is released.

I see, also, that at 600mm, the maximum aperture is ƒ/6.3. That's only a stop up from the ƒ/9 that it's supposed to be at in your pictures; which seems consistent with the variance that we're seeing. The EXIF data don't seem to indicate what the minimum aperture is. I'd be curious to see this same issue manifested in pictures that were supposed to be at the minimum aperture.


In any event, it's obvious, now, what the problem is. Your aperture is sticky. You might be able to loosen it by repeatedly working that linkage manually, but you'll probably need to have the lens taken apart, and the aperture mechanisms cleaned and lubricated by someone who has the proper skills, equipment, and materials to do so. I'm just barely on the edge of thinking that might I dare attempt such a thing on my primitive non-AI lenses from the 1960s and 1970s. I understand these more modern lenses to be a whole other order of complexity, rather far beyond what any amateur ought to think of attempting.

Yes, no aperture ring.
The lever is down when the lens in unmounted and the aperture fully open
If I move it up at anything short of a rapid flick, it stays as it is, fully open
If I flick it, it shuts to a pin hole, which, as I then slowly push the lever up, opens until it is full.
Once fully open, it remains that way
It is never fully closed

The lens, my Tam 150-600, will be going back on Monday morning and I will start crying into my beer soon afterwards.

Thanks for all your imput
 

mikew_RIP

Senior Member
Yes, no aperture ring.
The lever is down when the lens in unmounted and the aperture fully open
If I move it up at anything short of a rapid flick, it stays as it is, fully open
If I flick it, it shuts to a pin hole, which, as I then slowly push the lever up, opens until it is full.
Once fully open, it remains that way
It is never fully closed

The lens, my Tam 150-600, will be going back on Monday morning and I will start crying into my beer soon afterwards.

Thanks for all your imput

Sorry to hear that but remember it does have a limited life,you may have worn it out :D thankfully its a great warranty with it,hope its a quick turn round.
 

wev

Senior Member
Contributor
Had a nice chat with Tamron Service this morning after my walk. They acknowledged that the issue is with the aperture mechanism and will repair/replace the lens as needs be. They will also be checking the soft focus, focus freeze, and some visible dust under the front glass.

I am just back from FedEx and feeling withdrawals already.

Maybe a beer will help. . .
 
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