Question regarding the Sigma and Tamron 100-400mm lenses on the D850 and D500

snerkler

New member
HI,

Firstly I'll apologise for the long winded post. I am interested in buying the Tamron or Sigma 100-400mm as a lighter alternative to my Tamron 150-600mm on my D850, however I'm trying to find out if all of the AF points work all of the time on the D850 (or D500). The reason that I ask is that my Tamron 150-600mm VC doesn't play nice with the D850 and D500 in that beyond around 520mm only these focus points work, ie those for a lens with the equivalent of f4 with a 1.7TC (so I guess f6.9 ish)

Screen Shot 2018-05-25 at 19.14.11.jpg


Now my assumption is that it's due to the Tamron being an f6.3 lens at the long end. However, there are two confusing things. Firstly the Tamron stops down to f6.3 long before 520mm so if it was truly aperture limited then you'd expect the limited AF points from that time, and secondly the Tamron worked fine on my D750 at all focal lengths. I did briefly have the D500 and this exhibited the same problem as the D850 so I'm assuming the issue lies with the new 153 point AF system and maybe the AF sensors aren't as sensitive, or light is restricted more? Obviously while the lens stops down to f6.3 at around 450mm (IIRC) as the lens continues to 'zoom out' there will be a little more light loss, and I guess at around 520mm this is enough loss for the 153 point system to revert to the restricted AF points. I did ask around and apparently the Sigma 150-600mm also has the same issue with the D500 and D850.

As the 100-400mm lenses are also f6.3 I am wondering if they will exhibit a similar issue, ie at 400mm on the restricted AF points will work on the D850 (and D500). Does anyone have either of these lenses and used them on the D850 (or D500) and can confirm whether all AF points work all of the time please?

Cheers, Toby
 

Bikerbrent

Senior Member
I suspect that Nikon may have purposely designed these new cameras to have some issues with 3rd party lenses (wouldn't be the first time). I would suggest you contact Sigma and Tamron directly and ask if they are aware of these issues and if they have a software fix available or in the works.
 

mikew_RIP

Senior Member
Sorry cant confirm as i dont have it now but i used to just use it all points for small birds against a clear sky and thought it worked Sigma100-400 D500

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mikew_RIP

Senior Member
Another example of why i never questioned it, i know its not what you want but you may be able to add this to other info and get the answer.

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snerkler

New member
I suspect that Nikon may have purposely designed these new cameras to have some issues with 3rd party lenses (wouldn't be the first time). I would suggest you contact Sigma and Tamron directly and ask if they are aware of these issues and if they have a software fix available or in the works.
I've already contacted Tamron and their response didn't fill me with the greatest of confidence. They referred me to page 95 of the D850 manual saying that only limited AF points are available with f4 lenses and beyond. If you've seen the manual you will see that that's only some very specific F4 lenses, and for Tamron to think that the D850 (or any modern camera's) AF points only work with f4 lenses and wider worries me a little bit TBH.
Sorry cant confirm as i dont have it now but i used to just use it all points for small birds against a clear sky and thought it worked Sigma100-400 D500

Full image

View attachment 287697

Another example of why i never questioned it, i know its not what you want but you may be able to add this to other info and get the answer.

View attachment 287700

View attachment 287699
That's great, thanks for that I appreciate it. What AF mode did you use, single point, group, dynamic etc? I don't suppose I could trouble you further please? Do you use Lightroom and if so have the AF point plugin that shows you what AF points were used and able to post a screen shot of those please? Sorry to be a nuisance.
 

mikew_RIP

Senior Member
I've already contacted Tamron and their response didn't fill me with the greatest of confidence. They referred me to page 95 of the D850 manual saying that only limited AF points are available with f4 lenses and beyond. If you've seen the manual you will see that that's only some very specific F4 lenses, and for Tamron to think that the D850 (or any modern camera's) AF points only work with f4 lenses and wider worries me a little bit TBH.



That's great, thanks for that I appreciate it. What AF mode did you use, single point, group, dynamic etc? I don't suppose I could trouble you further please? Do you use Lightroom and if so have the AF point plugin that shows you what AF points were used and able to post a screen shot of those please? Sorry to be a nuisance.

A sign of age i cant remember how or what i did apart from activate as many points as i could, sorry again i cant help with the focus point selection, i will put a call out for this guy he may know, he is pretty good on these things
@BackdoorHippie
 

snerkler

New member
A sign of age i cant remember how or what i did apart from activate as many points as i could, sorry again i cant help with the focus point selection, i will put a call out for this guy he may know, he is pretty good on these things
No worries, thanks for your help I appreciate it.
 

BackdoorArts

Senior Member
A sign of age i cant remember how or what i did apart from activate as many points as i could, sorry again i cant help with the focus point selection, i will put a call out for this guy he may know, he is pretty good on these things
@BackdoorHippie

Not exactly sure what I'm being called on to answer here, but I know nothing about the D850 and the limiting focus points on certain lenses seems ridiculous, particularly on f4 lenses (unless they're talking about with a 2X TC where you're dealing with an effective f8 which may only focus in the center).

As for mode and focus points, for birds in flight on m D500 I use AF-C with d153 more times than not since it fills the entire frame left to right.
 

mikew_RIP

Senior Member
Not exactly sure what I'm being called on to answer here, but I know nothing about the D850 and the limiting focus points on certain lenses seems ridiculous, particularly on f4 lenses (unless they're talking about with a 2X TC where you're dealing with an effective f8 which may only focus in the center).

As for mode and focus points, for birds in flight on m D500 I use AF-C with d153 more times than not since it fills the entire frame left to right.

I think that may answer his question regards the D500
 

snerkler

New member
Not exactly sure what I'm being called on to answer here, but I know nothing about the D850 and the limiting focus points on certain lenses seems ridiculous, particularly on f4 lenses (unless they're talking about with a 2X TC where you're dealing with an effective f8 which may only focus in the center).

As for mode and focus points, for birds in flight on m D500 I use AF-C with d153 more times than not since it fills the entire frame left to right.
Thanks for the reply. I think you may have misunderstood about the D850, it does not limit f4 lenses that was Tamron's somewhat baffling response to me. The D850 shares the same AF system as the D500 and AF points only start to limit at f4 with 1.7xTC (which is effectively around f6.9) in which 'only' 37 AF points are available/active. At f8 (f4 with 2xTC) you 'only' get 15 AF points available/active.

The Tamron 150-600mm is f6.3 at the long end which may explain why at longer focal lengths you are limited to 45 AF points on the D850 and D500 I've owned, and the purpose of the thread was to find out whether the Tamron/Sigma 100-400mm (which are also f6.3) also exhibit the same behaviour at the longer focal lengths. The strange thing is I previously had the D750 and according to the manual the AF points start to limit at the same apertures as the D850 and D500 (ie f4 with 1.7xTC) yet with the Tamron 150-600mm all AF points work all of the time.

It would appear the 150-600mm lenses only exhibit this behaviour with the new 153 point Nikon AF system hence why the question was raised whether it was a firmware issue and whether Tamron had released an update, but unfortunately this is when I lost a bit of faith in Tamron when they replied to me that the D850 points were limited at f4.
 

Woodyg3

Senior Member
Contributor
Sorry I can''t help. I have never had any issues with my Tammy 150-600 G1 or 100-400. Both use all 153 focus points on the D500 throughout the full focal length range. This has been the case even in pretty dark situations.
 

snerkler

New member
Sorry I can''t help. I have never had any issues with my Tammy 150-600 G1 or 100-400. Both use all 153 focus points on the D500 throughout the full focal length range. This has been the case even in pretty dark situations.

That’s interesting, maybe it’s my lens then. What focus mode do you use? I use AF-C with single point and if I’m at 520mm+ and select any focus point outside the 37 I posted such as an extreme corner it refuses to focus. That has been the same on one D500 and two D850’s :-/ I spoke to several other people at the time I had my D500 and they said they had the same issue with the Sigma 150-600mm on the D500 too. You can physically select the outer AF points but they just refuse to focus.

I think I’m just going to have to buy the 100-400mm and hope for the best. Unfortunately I’m not blessed with camera shops near me to be able to go and try stuff out, and the only one anywhere close ish to me hasn’t hit the Tamron 100-400mm or has an ETA when they will.
 
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snerkler

New member
I've just 'spoken' to a gent on Flickr who has the Tamron 100-400mm and he's advised me that if you use single point AF then the outer points don't work past 320mm which suggests the 100-400mm suffers the same fate as the 150-600mm which is disappointing. It would appear that Nikon have strictly limited the new AF system to f5.6 and won't let the f6.3 lenses work. Whether this is deliberate so that you buy Nikon lenses, or a limitation of the wider AF spread I don't know.
 

hark

Administrator
Staff member
Super Mod
Contributor
I've just 'spoken' to a gent on Flickr who has the Tamron 100-400mm and he's advised me that if you use single point AF then the outer points don't work past 320mm which suggests the 100-400mm suffers the same fate as the 150-600mm which is disappointing. It would appear that Nikon have strictly limited the new AF system to f5.6 and won't let the f6.3 lenses work. Whether this is deliberate so that you buy Nikon lenses, or a limitation of the wider AF spread I don't know.

I haven't played around too much with the different types of points, but isn't there a way to choose whether to use all the points or a select lower number? :confused: Would that have anything to do with the limitations?
 

snerkler

New member
I haven't played around too much with the different types of points, but isn't there a way to choose whether to use all the points or a select lower number? :confused: Would that have anything to do with the limitations?
Thanks for the reply. No, single point itself will not cause limitations. Obviously with single point you can move the AF selector to any one of the selectable AF points. If you select say the top left corner point and it doesn’t work (like in the scenario I posted) then that AF point won’t work/be selected in other focus modes. For example whilst you might be able to select d153 it won’t use all the 153 points.
 

hark

Administrator
Staff member
Super Mod
Contributor
Thanks for the reply. No, single point itself will not cause limitations. Obviously with single point you can move the AF selector to any one of the selectable AF points. If you select say the top left corner point and it doesn’t work (like in the scenario I posted) then that AF point won’t work/be selected in other focus modes. For example whilst you might be able to select d153 it won’t use all the 153 points.

I'm sorry but I don't think I explained my question well enough. I know single point by itself doesn't have limitations. Is there a setting where you get to choose how many points you want to use? Isn't there something about using all of the points that are available or choosing to use a smaller group of points? :confused: Does anyone know?
 

snerkler

New member
I'm sorry but I don't think I explained my question well enough. I know single point by itself doesn't have limitations. Is there a setting where you get to choose how many points you want to use? Isn't there something about using all of the points that are available or choosing to use a smaller group of points? :confused: Does anyone know?
Ahh sorry, I see what you mean now. Whilst there are 153 AF points you can actually only select 55 (marked by squares), the others lie between these points (marked by dots) and are used by the tracking AF modes (dynamic, 3D etc).

As you rightly say though whilst the user can only select one of 55 points you can restrict this further and just have 15 points available for selection. I always have the max number of AF points available, ie 55 selectable points.
 

hark

Administrator
Staff member
Super Mod
Contributor
Ahh sorry, I see what you mean now. Whilst there are 153 AF points you can actually only select 55 (marked by squares), the others lie between these points (marked by dots) and are used by the tracking AF modes (dynamic, 3D etc).

As you rightly say though whilst the user can only select one of 55 points you can restrict this further and just have 15 points available for selection. I always have the max number of AF points available, ie 55 selectable points.

That must be what I'm thinking of. What I don't understand is why Woody, who has used the Tamron mounted on a D500, hasn't experienced the problem. It does seem like a setting somewhere. Anyway...good luck. I hope you find a lens that will meet your expectations! ;)
 
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