Tamron 150-600mm focus issue

This isn't about the focus freeze since I had not one since I disabled VR but about inconsistent focus.

Sometimes for whatever reason it is as if the Tam forgot how to focus and hits it wrong very much. Today I lost too many shots because, when uploading and going through them, I noticed focus was hopeless. Slow shots could have suffered some blur but too many of my 1/1600s had the same issue.

Here's some screen from View with the focus indicator.









I don't know how well it shows in these scaled shots but sharpness isn't anywhere it should be.

This is one of the first shots this morning, after that it only went downhill.

What AF mode were you using?
What was the exif?
Were these handheld/tripod/monopod/beanbag?

It's all handheld exactly the same as I shot yesterday. Yesterday she was at her best and I posted some shots showing. Today I'd say at least 70% of my shots suffered blur at 100%. At about every length I shot them from 1/400-500s to 1/1600s.

It's not a user-error I'm very certain about that.

The only difference between yesterday and today is temperature. Yesterday it was reasonable warm for this period, today it was freezing cold.

If temperature is a factor it might explain why she started out normal and went downhill the longer I was outside.

Can we have a higher quality copy of this one

mikew said:

Can we have a higher quality copy of this one

Click to expand...

You can have a print too but that'll cost you.



I see where the focus is about in this one but I had plenty I couldn't even find something sharp.

This time it is easy for me to understand this is a Tam issue. I shot it all day yesterday, took the card out of the cam, put it back in and shelved it. This morning I took the cam, powered it up and started shooting again. The lens hasn't been removed nor have any settings been changed. Yesterday as perfect as possible, today she shot like a lens from the dollar store.

The sun is out now so I'll shoot again in a bit. I still didn't change anything to the cam nor lens so I'm curious what will happen now.

Here's one to rule out shake. There's plenty of contrast to focus at me thinks.





I took about 40 of these fellows since I rarely get them close. You know how many sharp shots I got?

Yeah, that many.

I almost wish it is a user error since that's easiest to solve.

I'm just back from shooting and quickly ran through the shots and all is well again.



What changed? Nothing I can think of but the temperature outside.

I've found focus points/boxes are not always where we think they are, especially at a long distance. If there's a 50/50 split (sometimes even less) in the box between subject and background it's a crap shot. Also contrast over distance has been an issue for me. These factors combined can easily push keepers well below 50%.

Last winter I had a problem with my D610. The temps were REALLY frigid, and the screen went blank after I had been outside for a while. It must have been the battery because once it warmed up, everything went back to normal. Might not be the Tamron lens itself--maybe the body and lens can't communicate well if the battery is especially cold?

Rick M said:

I've found focus points/boxes are not always where we think they are, especially at a long distance. If there's a 50/50 split (sometimes even less) in the box between subject and background it's a crap shot. Also contrast over distance has been an issue for me. These factors combined can easily push keepers well below 50%.

Click to expand...

It was more like below 25%. It happens indeed that focus points aren't really accurate but when I shoot a dog at that distance and it manages to miss focus completely, I start to wonder. It has been doing that the whole morning and in the afternoon it was as if it never happened. The only good morning shots were those I took right after going out. After those it went downhill that rapidly the last batch barely contained a good shot.

Which makes me wonder what exactly makes her hit that wrong. Either mine has temperature issues or there are specific conditions regarding light or the sun that she can't handle. I can't say I had many problems when buying the lens and it performed great for a while. Then she was shelved for a while because light was too low and when i picked her up again, all those issues started. That's also when the temperatures went down.

hark said:

Last winter I had a problem with my D610. The temps were REALLY frigid, and the screen went blank after I had been outside for a while. It must have been the battery because once it warmed up, everything went back to normal. Might not be the Tamron lens itself--maybe the body and lens can't communicate well if the battery is especially cold?

Click to expand...

I wondered if it could not be the D750 because cold could easily affect it too but I have been shooting other lenses in much colder conditions than today and I never had the issue with any other lens. Admittedly, with a short lens doing landscape, it has to miss focus quite some before I'd notice. But when shooting my 200mm which is a PITA to focus, all is fine. It's only the Tam.

The annoying part is that I can't find any reason that makes much sense. The temperature makes most but it's not as if I'm on the North Pole. If she couldn't handle cold for some mechanical reason, that information would be out there already since there are places much colder where the Tam is shot.

I can understand how the mechanical part of their VR could lock up focus but why focus itself is inconsistent, I simply can't find any good explanation for. And without that, a solution is practically impossible. If I'd know this or that triggers it, I could work around it.

I suspect you have discovered that you need to be warm or maybe in less restrictive clothing in order to handhold the 600mm at slower speeds. And guessing from the EXIF on the one, that the faster shutter shots had a fairly tight DOF.

Eyelight said:

I suspect you have discovered that you need to be warm or maybe in less restrictive clothing in order to handhold the 600mm at slower speeds. And guessing from the EXIF on the one, that the faster shutter shots had a fairly tight DOF.

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I'll try shooting in boxers only tomorrow.

My f/ is about always 6.3 or 7.1 if the light lets me and this afternoon I wore and shot the same as this morning.

This is yesterday; http://nikonites.com/telephoto/24828-post-your-150-600-tamron-shots-46.html#post417239

This morning I could not get a sharp shot on distances I could throw the lens and hit the bird.

What are we talking about temperature wise in numbers? "Cold" varies

Rick M said:

What are we about temperature wise in numbers? "Cold" varies

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The kind of cold you like your beer to be.

It was barely freezing but since the lens is constantly exposed to the wind, she suffers some degrees more minus. But unless she runs on liquids, that should not be a problem. All I know is my problem started when temperatures went lower but light is different during this period which could be a factor too.

Since I disabled VR, it can't be much but light, temperature or wear.

J-see said:

I'll try shooting in boxers only tomorrow.

My f/ is about always 6.3 or 7.1 if the light lets me and this afternoon I wore and shot the same as this morning.

This is yesterday; http://nikonites.com/telephoto/24828-post-your-150-600-tamron-shots-46.html#post417239

This morning I could not get a sharp shot on distances I could throw the lens and hit the bird.

Click to expand...

Main point was our muscles do not perform as well at lower temps.

DOF does not exist at 100%. I think if you look shot by shot, you will see some are shake and some are off focus and some are a combination.

Eyelight said:

Main point was our muscles do not perform as well at lower temps.

DOF does not exist at 100%. I think if you look shot by shot, you will see some are shake and some are off focus and some are a combination.

Click to expand...

I'm not excluding user-error but out of 160+ shots, I didn't have 30/40 sharp shots. That I messed some up is perfectly understandable but that many would actually require effort.

If tomorrow the early conditions are identical, I'll see if the behavior is too.

Which shots were better?

Close or distant subject?

Higher or lower shutter speed?

Background of sky or no sky?

Eyelight said:

Which shots were better?

Close or distant subject?

Higher or lower shutter speed?

Background of sky or no sky?

Click to expand...

The only good shots were the ones taken directly after leaving the house. Of the rest I only used a landscape and a mistscape shot of which I didn't even check the sharpness for the second.

Overall about all settings and scenes suffered; sky, land, tree, short to long end, slow to fast shutter and even single to group focus. So it was consistent in being inconsistent. Some of those shots were "perfect" contrast subjects to focus at and the focus marker showed in about every shot in ViewNX but behind the square, nothing but blur.

Some hours later I go out and do the same and don't have any issue. In an hour or so I'll try again and see if it repeats this behavior. If, I know certain weather or light conditions trigger it.

I had bad series in the past too, not often but it had those days. I know VR does ruin fast shots but this is without VR. It's that I'm paying close attention to its behavior now and that makes me aware something more is going on.

The question is; hardware or nature. I hope it's nature.