Tamron 150-600 G2

[Dukatum]

Hi all,

Yesterday got a Tamron 150-600 G2 Nikon mount delivered. But immediately I found that when I'm zoomed in at 600mm and the focus is set to 2.2m (7.2ft) which is the lowest (furthest left) on the focus ring, it's incredibly slow to find and lock on focus, sometimes just not even focusing at all. Right now I'm testing this against my garden fence in lots of light (half direct sun, half in shade).

If I put the focus all the way to the right, so infinity, the focus lock is quick. Is that normal? it has really put me off as it's the first thing I experienced as soon as I put the lens on and tried my first shot. Last week I had rented a Sigma 150-600 sport, I didn't notice anything obvious like that, but I also wasn't looking/testing it.

Thanks

[Saorsa]

Does the lens have a range limiter? Using it might help.

What focus point are you using and which camera?

The lens is at f6.3 at 600mm and not all cameras focus well at that aperture.

[Mike Buckley]

when I'm zoomed in at 600mm and the focus is set to 2.2m (7.2ft) which is the lowest (furthest left) on the focus ring, it's incredibly slow to find and lock on focus, sometimes just not even focusing at all.

It could be that you're trying to focus on something that is closer than the minimum focusing distance.

[Manfred M]

Rob - with a super long focal length lens like that one, I suggest that you set your camera to single point focus and use that.

Unfortunately, when shooting long, there are often many things between you and your subject and your camera has trouble determining what to focus on unless you help it along by telling it what you are trying to shoot.

[Dukatum]

Hi, thanks all for replies.

Yes there is a focus limiter, this didn't seem to make any noticeable difference in performance from what I could tell, it limits to 10m-to-infinity, and when focusing from infinity to locked-focus is still quick but from 2.2m focus to lock-focus is 2+ seconds.

I've tried using F/6.3 through to F/11 at 600mm with no difference in performance.

When focusing from minimum focus (2.2 metres) to my garden fence (roughly 20-35 metres depending where I stand in my house) it takes about 2 seconds, from infinity to focus is just a quick snap (feels really nice) well below 1 second to focus.

I've repeated this testing in the last couple of hours, got some blazing midday sun in England right now so lighting conditions are not to bad, I'm focusing on a well textured tree, and garden fence and using single point focus, not on continuous.

I've tried it on both Nikon D7000 and D5100 with the same result. When I try my Tamron 70-200mm it's just snappy to focus all the time.

I'm a bit unsure whether this 150-600 performance is to be expected and I just need to adjust my expectations, or if I've got an issue.

Thanks.

[Manfred M]

Have you checked your camera manual for the specs on the aperture requirements for the autofocus system to work? Some cameras are limited to lenses that are f/5.6 and faster, and the lens you have is f/6.3 at the long end.

[paintingwithlight]

...and when focusing from infinity to locked-focus is still quick but from 2.2m focus to lock-focus is 2+ seconds.

This article: http://www.kenrockwell.com/tamron/150-600mm.htm reports that "...its silent autofocus really does work very well" and "Autofocus is fast and sure." The article date is December 2014 and the author tested the lens on a D810.

Is it possible that a firmware update for your cameras would help?

Best of luck.

-Michael

[DanK]

I don't know anything about the specific performance of that lens, but some of what you are experiencing is to be expected.

You wrote this:

I've tried using F/6.3 through to F/11 at 600mm with no difference in performance.

It shouldn't make any difference. Your camera keeps the aperture wide open--as wide as the lens will go--while focusing and shuts it down while taking the capture.

In general, you can expect a deterioration of focusing performance as focal length increases, and the difference can be quite noticeable. For example, I have tested this with my 5DIII, which as an excellent AF system, and my Canon 100-400 II, which is considered to be exceptionally good in terms of AF for a zoom of its length, and I see a big difference in AF performance between 100 and 400 mm. I think the reason is simply DOF. For example, here are the DOF numbers, shooting a Canon crop sensor camera at f/6.4 and a subject at 5 meters:

FL 150mm: total DOF 0.26 m
FL 600mm: total DOF 0.01 m

As a result, at a longer focal length, the area on which you want to focus--if the camera is focused at a different distance--is much more blurred when the focal length is long. This causes slower AF and sometimes causes the AF to hunt.

That's why short lenses don't have focal-length limiters. The longer the focal length, the more useful it is to have the focusing range limited to avoid hunting.

[Dukatum]

Thanks again all,
Here is an example video to show what I mean. https://1drv.ms/v/s!Asvr7hL0h3rQhpF93d5gNXqsCXPQHw

Dan,
you make some excellent points, and I suspect what you cover in your post is exactly what my experience is, and this is most likely just my unrealistic expectations. There is a Nikon D500 in the cupboard not 2 metres away from me but I'm not allowed to see it until my birthday in 11 days time, the wife is generous and cruel at the same time Maybe this will make a difference compared to my old D7000.


Michael,
the Ken Rockwell link is for the previous edition of the lens. The G2 is meant to be even better performer in all aspects. I believe my D7000 is right up to date on firmware but I will go double check now, thanks.

I might also need to get hold of the Tamron Tap-in device that allows for fine tuning the AF of the lens much like the Sigma dock.

thanks all for your replies and help.

[Saorsa]

Have you checked your camera manual for the specs on the aperture requirements for the autofocus system to work? Some cameras are limited to lenses that are f/5.6 and faster, and the lens you have is f/6.3 at the long end.

I think that is the problem and why I asked which cameras he was using. I think that both of those older Nikon models that are best at 5.6 and wider.

[Dukatum]

I think that is the problem and why I asked which cameras he was using. I think that both of those older Nikon models that are best at 5.6 and wider.

Took me a while as I can not find the info in the manual but I am finding reference that the D7000 should be fine up to f/6.3 (although there is reference to another thread post stating f/5.6 as mentioned in this thread) : , but maybe this is just "too close to the edge" in my case.

I'll keep hold of the lens rather than return it, and see how it performs on the new body when I get my hands on it.

It's been educational, thanks all, I'll get back to appreciating just how difficult shooting BIF is now, got some Red Kites over the house right now going through some ritual.

Thanks all.

[Saorsa]

Took me a while as I can not find the info in the manual but I am finding reference that the D7000 should be fine up to f/6.3 (although there is reference to another thread post stating f/5.6 as mentioned in this thread) : , but maybe this is just "too close to the edge" in my case.

I'll keep hold of the lens rather than return it, and see how it performs on the new body when I get my hands on it.

It's been educational, thanks all, I'll get back to appreciating just how difficult shooting BIF is now, got some Red Kites over the house right now going through some ritual.

Thanks all.

f-stops are a calculation t-stops are reality. At the telephoto end you may be getting the same f value but less transmittance.

You've got 21 elements in 13 groups.

[Shadowman]

Rob,

Is there another object you can use to test focus, I'm sure most manuals list fences as very difficult objects to focus on.

[loosecanon]

As one gets closer it is more difficult for the focus system to identify where correct focus is, so many cameras slow focus mechanisms so as to avoid hunting as the lens goes past correct focus and then has to go back.

Secondly as one gets closer one has to move the focusing elements more, and in a big telephoto these are heavy glass and metal components, so the focus system has to work harder.

The reason why a focus limiter switch is fitted is because going into these closer distances always slows the focus down, so if using the lens at a longer distance the limiter will speed up finding correct focus.

[rpcrowe]

Dan mentioned...

"In general, you can expect a deterioration of focusing performance as focal length increases, and the difference can be quite noticeable. For example, I have tested this with my 5DIII, which as an excellent AF system, and my Canon 100-400 II, which is considered to be exceptionally good in terms of AF for a zoom of its length, and I see a big difference in AF performance between 100 and 400 mm. I think the reason is simply DOF."

I have to experiment with this. I have not noticed a slower focus speed at longer focal lengths. I was shooting the Blue Angels at various focal lengths - 100-400mm and didn't notice any discernible difference in focus speed on my 7D Mark-ii and 100-400mm f/4.5-5.6L IS II lens. This shot was done at 400mm...

Of course, I was shooting fast and furious and could easily have missed the differences in AF speed. The aircraft were going quite fast and were fairly close to my shooting position which was at the end of the runway...
I was using the default focusing with the center cluster of points.

[DanK]

Richard,

See loosecanon's explanation. I am not certain you will see this at distances that great. I did my tests indoors. I haven't measured, but I would guess that the distances were in the range of 4-12 m.

Dan

[William W]

Took me a while as I can not find the info in the manual

You won't. Nikon don't put it there.

Subsequent to my comments on that older thread, I found this reference list for Nikon.

***

. . . I am finding reference that the D7000 should be fine up to f/6.3 (although there is reference to another thread post stating f/5.6 as mentioned in this thread) : , but maybe this is just "too close to the edge" in my case.

Probably more accurate to state the D7000 might be fine up to f/6.3.

Note that the D7000 "should not" AF with any lens that has a Maximum Aperture smaller than F/5.6, but as John mentioned in the thread you referenced, his works OK at an equivalent max. aperture of F/8 - that is when using a Nikon Lens and a Tele-extender.

Brian Grant's comment regarding what lens is being used has significance - less about the F/stop and more about the transmittance - and the mechanics of each individual lens's AF, I would expect: and as already mentioned likely more relevant at close Subject Distance focusing.

WW