Nikon Z8 + Sigma 500 f4 - Soft focus (Sharp on D850)

[tigger4t]

I really want to go mirrorless to take advantage of the AF options, pre-shoot, etc. but can't afford to replace my lenses as well. Does anyone have any experience of using a Nikon Z8 + FTZ with Sigma 150-600 C and / or Sigma 500mm f4 lenses please? Sigma say that they are compatible but that's not the same as practical experience of course.

Alos wondering if the Nikon 180-600 is a better lens than the Sigma 150-600 C?

 

[nmerc_photos]

Yes I've used both the Z8/Z9 with Sigma glass. It compares essentially with older F mount Nikon glass in my mind. It's noticeably slower AF, worse IQ, etc. than Z counterparts.

The sigma options are great on a budget, but my goal anytime I suggest that someone buy them is that they look to upgrade to native glass ASAP.

I would definitely suggest the 180-600 over the Sigma 150-600.

 

[tigger4t]

Yes I've used both the Z8/Z9 with Sigma glass. It compares essentially with older F mount Nikon glass in my mind. It's noticeably slower AF, worse IQ, etc. than Z counterparts.

The sigma options are great on a budget, but my goal anytime I suggest that someone buy them is that they look to upgrade to native glass ASAP.

I would definitely suggest the 180-600 over the Sigma 150-600.

Many thanks - the Z 180-600 is appealing but a stretch on the budget unfortunately

 

[Tibor Hrnko]

Sigma 500 F4 Sport + FTZ adapter is a great lens on Nikon Z9. I use it extensively. It works better on Z9 than on D500 IMO.

 

[nmerc_photos]

Many thanks - the Z 180-600 is appealing but a stretch on the budget unfortunately

Understandable. The best camera/lens combo is the one you have on you!

I do not think the difference is -that- much, and know tons of people still in love with their 150-600s. Also - if you never shoot anything "better", you'll never know what you're missing. Which could be a benefit all of its own. I was so happy with my 100-500 long before I ever shot a 600 f4.

 

[Fer.Saravia]

I really want to go mirrorless to take advantage of the AF options, pre-shoot, etc. but can't afford to replace my lenses as well. Does anyone have any experience of using a Nikon Z8 + FTZ with Sigma 150-600 C and / or Sigma 500mm f4 lenses please? Sigma say that they are compatible but that's not the same as practical experience of course.

Alos wondering if the Nikon 180-600 is a better lens than the Sigma 150-600 C?

Hello!
I have Sigma 500mm F4. I used it for a while with D500 and D850. It gave me a lot of work to adjust the focus on D850. But I managed it and loved that combo.
Now I have Z8 with FTZ. And the Sigma is going great!!!! I also have 500mm PF and Z 180-600. But nothing like the Sigma. Whenever I can carry it, it goes with me. Most of the time with the TC 1.4x.
This Sigma is the best lens I have ever owned.
Good luck in what's to come!

 

[MrFotoFool]

Though I have not used the Sigma 150-600 Contemporary, I can virtually guarantee you the Nikon Z 180-600 (which I do use) will be better in terms of sharpness and autofocus. Also with such a large lens it will be nice not to make it even larger with the addition of the FTZ adapter.

 

[tigger4t]

I decided to go for the Z8 and the Z 180-600 and have had fantastic results already from a few trips using that rig.

However, yesterday's outing with the Z8 and Sigma 500mm f4 Sport resulted in ZERO usable shots - every image was soft, not just the BIF but even static test shots of foliage where that lens on my D850 would have been tack sharp. Every image, irrespective of the distance involved is soft.

For example, this uncropped image was taken on a monopod, at 1/400th f5.6, ISO 250, -1EV. Focus was firmly locked onto the dried leaves in the centre of the image but they are extremely soft. I can accept that heat distortion might have affected some of the shots taken over water but the tree below was close and would have been crisp had it been taken on my D850.

I am completely at a loss to explain this - any ideas or should I just get Sigma to recalibrate the lens.

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[tigger4t]

I'm still trying to get to the bottom of this problem and this image seems to suggest the cause to me. The bird was obviously static, shot at 1/400th on a monopod with auto-area AF and the focus point locked firmly on the birds body (not the eye). This image seems to suggest that the lens is front-focussing which I thought was not possible on a mirrorless camera like the Z8 as focussing happens at the sensor. Any ideas or suggestions please?

The same lens on my D850 had an AF Fine Adjustment value of -1 after calibrating with Focal.

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[hef19898]

First, barely see the eye of the bird, and I onow where to look. Black eye in black head, badly lit is disaster for AF, let alone subject detection.

I'd try to shoot something more like a test chart, without subject detection, to find any issues, if any. And take it from there.

Second, Nikon does not guarantee function of third party lenses on the FTZ. So, the above nonewithstanding, compatability issues might cause problems. Again, I'd try it with subjects and conditions better suited for testing, starting with single-point AF without subject detection.

Also, shoot from a tripod, IBIS and VR off, with either a remote release or self-timed shutter. And confirm, as part of those tests, AF accuracy by switching to MF, zooming in and focus peaking before taling the shot. And use AF to focus, switch to MF, take the shot.

 

[tigger4t]

First, barely see the eye of the bird, and I onow where to look. Black eye in black head, badly lit is disaster for AF, let alone subject detection.

I'd try to shoot something more like a test chart, without subject detection, to find any issues, if any. And take it from there.

Second, Nikon does not guarantee function of third party lenses on the FTZ. So, the above nonewithstanding, compatability issues might cause problems. Again, I'd try it with subjects and conditions better suited for testing, starting with single-point AF without subject detection.

Also, shoot from a tripod, IBIS and VR off, with either a remote release or self-timed shutter. And confirm, as part of those tests, AF accuracy by switching to MF, zooming in and focus peaking before taling the shot. And use AF to focus, switch to MF, take the shot.

Many thanks for your feedback - I appreciate that the eye isn't visible but I would have thought that there was enough contrast between the bird and the sky to get accurate focus - is that not the case? The majority of shots taken on my day out were soft focus whether VR was on or off - the worst ones being when I was tracking BIF. It was as if the lens AF couldn't keep up with the Z8.

I shot some test charts over the weekend using the Z8 with Sigma 500mm f4, Z8 with Z 180-600 and D7200 with Sigma 500mm f4 and I can't actually see much difference in sharpness between any of the resulting charts which just confuses me more !

 

[hef19898]

Tue focus plane, from what I can tell in looking at it on my phone, in your last image seems to be on the birds head somewhere at the border between the lit and non-lit portions.

If you had the impression that the lens AF coupdn't keep up with the Z8, it could be compatability issues. One other thing I'd try, as your test chart shots were all fine, would be to try non-subject detection AF modes, single point and such, as small as possible, for panning and BIF.

So far it seems that the Z8 is fine, as is the lens. Even the lens-Z8 combo works on test charts. Which hints at some issues with this combo in certain circumstances, e.g. light, AF mode, VR/IBIS and so on. Difficult to properly test for so, and since I don't own any of the equipment, I have no real world experience. All I said so far comes from general trouble shooting, testing and diagnosing experience and knowledge, so take it eith a grain of salt.

Maybe one other thing to check would be software / firmware issues: Check which FW camera and lens are running and dig if there are compatability issues. Nikon wont help, I guess. But maybe Sigma can.

 

[hef19898]

Well, worst case, that's just how that combination works and behaves, which would mean to either change and adopt the way you use the gear, from settings to technique, or change the lens... Hope not, you seem to like the lens, and I hatebto change lenses I like, even they are broken without beyond any doubt...

 

[tigger4t]

Tue focus plane, from what I can tell in looking at it on my phone, in your last image seems to be on the birds head somewhere at the border between the lit and non-lit portions.

If you had the impression that the lens AF coupdn't keep up with the Z8, it could be compatability issues. One other thing I'd try, as your test chart shots were all fine, would be to try non-subject detection AF modes, single point and such, as small as possible, for panning and BIF.

So far it seems that the Z8 is fine, as is the lens. Even the lens-Z8 combo works on test charts. Which hints at some issues with this combo in certain circumstances, e.g. light, AF mode, VR/IBIS and so on. Difficult to properly test for so, and since I don't own any of the equipment, I have no real world experience. All I said so far comes from general trouble shooting, testing and diagnosing experience and knowledge, so take it eith a grain of salt.

Maybe one other thing to check would be software / firmware issues: Check which FW camera and lens are running and dig if there are compatability issues. Nikon wont help, I guess. But maybe Sigma can.

Thanks - all suggestions are greatly appreciated. have contacted Sigma and they tell me that there are no compatibility issues and in fact other members have said that their Sigma 500s work fine on the Z8 and Z9 but they are open to further discussions and looking at evidence.

On my Mac it looks as if the focus plane is actually on the fence panel in front of the bird rather than on the head though which is why I suspected front focussing. I might try to do some Fine AF Tuning with a test chart and see how that pans out.

 

[Fer.Saravia]

Evidently something seems to be wrong.
I have Z8 and also Sigma 500 F4 and Nikon 180-600 and as I was saying before, whenever I can carry the weight of the 500 and don't need the zoom, I prefer it over the 180-600, always!
I suggest doing more controlled tests and with better light conditions.
I leave some example photos. Z8 + 500 F4 + TC 1.4x

 

[tigger4t]

Evidently something seems to be wrong.
I have Z8 and also Sigma 500 F4 and Nikon 180-600 and as I was saying before, whenever I can carry the weight of the 500 and don't need the zoom, I prefer it over the 180-600, always!
I suggest doing more controlled tests and with better light conditions.
I leave some example photos. Z8 + 500 F4 + TC 1.4x

Thanks - great images

 

[Woodpecker]

I don't own a Sigma 500 f/4 but use another 500 f/4 with FTZ on a Z8, so my statements are what George Clooney would call an educated guess ...

1. I had similar issues with my 500 f/4 when using a TC, although the lens was perfect when used naked. Reason was as an issue with the TC. It had got a hit somehow and the result were soft images due to minimal mechanical distortion in the TC.
2. I had to swap the FTZ once for a similar issue. I needed a second one and the one I bought was faulty.
3. My 500 f/4 lost IQ after some time bing used on the Z8. I gave it to Nikon and they told me that the VR in the lens got out of tolerance. According to one reason could have been that there are differences between what happens when a DSLR (in my case D850 or D4s) gets switched off while the VR on the lens switched on compared to what happens if you do the same on a MILC (in my case a Z8). This has to do with the fact that the Z8 has VR function integrated itself and thus interacts differently with adapted lenses. If I have my 500 f/4 on the camera the function for switching VR via menu is greyed out and the only thing the camera does is showing whether the VR is switched on or off at the lens itself. As I mentioned I don't know the Sigma 500 f/4, but it could be possible that you have a similar problem. At least you should be able to check with your D850. If something like this happened you should experience soft images with the D850 now as well.
4. As I haven't used Sigma lenses for a long, long time I don't know for sure, but I think I remember that Sigma as well as Tamron has something like a USB adapter for their lenses to make adjustments including focussing optimization. Is it possible that you made such adjustments at the lens during the time with the D850 and simply still have them in the lens ? If yes, it is probably worth a try to reset these to default.
   The sample image with the bird might look soft, but there also seems also to be some issue wirth front focus. Looking at the details in the gap of the wooden fence that are sharper, I think that this seems actually quite a bit in front of the bird.
5. Although generally AF fine adjustment is considered as being not necessary on MILC's I don't where the limits are here. If the corrections you had to make on your DSLR were rather big (e.g. somewhere beyond +/-12) It might be necessary to do something on the MILC as well, although it is not common having to do this.

Just some thoughts ....