Autofocus issues with Nikon D500 & Sigma 500 f4 with 1.4 teleconverter

Hi Hope someone can advise? I am having problems with soft focussing using the above combination. Basically I can only obtain sharp images using AF-S & single-shot focus. With any of the AF-C combinations the images are consistently out-of-focus whereas with the "bare" lens images are sharp. I have tried using the Nikon "Fine-Tuning" system as well as the Sigma Dock but with little success, and I can find no positive advice on how to interface the Nikon "Fine-Tuning" system with the Sigma Dock. Any help and advice would be most welcome. Thanks Geoff D

Hi

Hope someone can advise?

I am having problems with soft focussing using the above combination. Basically I can only obtain sharp images using AF-S & single-shot focus. With any of the AF-C combinations the images are consistently out-of-focus whereas with the "bare" lens images are sharp.

I have tried using the Nikon "Fine-Tuning" system as well as the Sigma Dock but with little success, and I can find no positive advice on how to interface the Nikon "Fine-Tuning" system with the Sigma Dock.

Any help and advice would be most welcome.

Thanks

Geoff D

Sorry - I cannot help much. As far as I know Nikon Fine Tune and the Sigma dock cannot be used in combination with each other. The D500 has adequate speed AF with [b]Nikon f8[/b] lens combinations. The problem might be that the Sigma lens/converter combination is not compatible with some Nikon AF combinations. Does the Sigma website list a possible upgrade for using the Sigma lens combined with the Sigma converter on a Nikon D500? Has anybody else any suggestions?

Sorry - I cannot help much.

As far as I know Nikon Fine Tune and the Sigma dock cannot be used in combination with each other.

The D500 has adequate speed AF with Nikon f8 lens combinations.

The problem might be that the Sigma lens/converter combination is not compatible with some Nikon AF combinations.

Does the Sigma website list a possible upgrade for using the Sigma lens combined with the Sigma converter on a Nikon D500?

Has anybody else any suggestions?

I have a feeling the camera will hunt when asked to focus with small aperture lens/converter combos. Often the notified max aperture can be a little optimistic and adding a converter can push this past the usable light levels needed to focus. Add to this the age of the cameras focus technology you may well be at the edge of your kits ability to perform properly in af-c. As I have a feeling the af-c setting may well require fairly consistent light levels to perform and you may well be pushing it to the edge. Focus sensors seem to change with every new model as it is a major selling point.

I have a feeling the camera will hunt when asked to focus with small aperture lens/converter combos.
Often the notified max aperture can be a little optimistic and adding a converter can push this past the usable light levels needed to focus. Add to this the age of the cameras focus technology you may well be at the edge of your kits ability to perform properly in af-c. As I have a feeling the af-c setting may well require fairly consistent light levels to perform and you may well be pushing it to the edge.
Focus sensors seem to change with every new model as it is a major selling point.

[quote]I have a feeling the camera will hunt when asked to focus with small aperture lens/converter combos. [/quote] I have no particular problems getting my Nikon f8 lens combinations to AF with a Nikon f8 AF body - which is what the D500 is. I agree f8 combination AF is a little slower and needs a little more contrast. The OP reports AF works with "single shot" settings but not AF-C settings - strongly implying the problem seems to be some AF incompatibility between the Sigma lens/converter and the Nikon D500 body.

Quote:I have a feeling the camera will hunt when asked to focus with small aperture lens/converter combos.


I have no particular problems getting my Nikon f8 lens combinations to AF with a Nikon f8 AF body - which is what the D500 is.

I agree f8 combination AF is a little slower and needs a little more contrast.

The OP reports AF works with "single shot" settings but not AF-C settings - strongly implying the problem seems to be some AF incompatibility between the Sigma lens/converter and the Nikon D500 body.

Many thanks for your comments. There are well-known issues with the D500 & Sigma 500 f4 plus converter in burst mode where every other shot is soft. This lens frankly has caused me all sorts of problems and I am now on my second example which has just returned from Japan after a lengthy repair job, so maybe it's just that I dont trust this lens now? The cause I think is focus shift in AF-C mode as the last time I noticed this issue was in good light at f5.6 & f6.3. Regards Geoff D

Many thanks for your comments. There are well-known issues with the D500 & Sigma 500 f4 plus converter in burst mode where every other shot is soft.

This lens frankly has caused me all sorts of problems and I am now on my second example which has just returned from Japan after a lengthy repair job, so maybe it's just that I dont trust this lens now?

The cause I think is focus shift in AF-C mode as the last time I noticed this issue was in good light at f5.6 & f6.3.

Regards

Geoff D

[quote]Many thanks for your comments. There are well-known issues with the D500 & Sigma 500 f4 plus converter in burst mode where every other shot is soft. This lens frankly has caused me all sorts of problems and I am now on my second example which has just returned from Japan after a lengthy repair job, so maybe it's just that I dont trust this lens now? The cause I think is focus shift in AF-C mode as the last time I noticed this issue was in good light at f5.6 & f6.3. [/quote] This is a difficult and unsatisfactory experience. [i]I suggest you quickly thoroughly test the lens/converter to see if they work as a reasonable photographer would expect. [/i] If instead the returned lens and converter has the same issue and they cannot work properly on a D500 despite having a Nikon mount I suggest talking to the retailer and ask them to talk to Sigma. The lens/converter may be "unfit for purpose". If they are "unfit for purpose" you seem to be entitled to a full refund [b]from the retailer[/b] (even though did not make the lens) if less than 6 months old, and a refund less deduction for usage if more than 6 months old. If as you indicate the lens/converter has been out of use for some time going to and from Japan; even if more than 6 months old the usage deduction should leave you with more than second hand value. Good luck!

Quote:Many thanks for your comments. There are well-known issues with the D500 & Sigma 500 f4 plus converter in burst mode where every other shot is soft.

This lens frankly has caused me all sorts of problems and I am now on my second example which has just returned from Japan after a lengthy repair job, so maybe it's just that I dont trust this lens now?

The cause I think is focus shift in AF-C mode as the last time I noticed this issue was in good light at f5.6 & f6.3.



This is a difficult and unsatisfactory experience.

I suggest you quickly thoroughly test the lens/converter to see if they work as a reasonable photographer would expect.

If instead the returned lens and converter has the same issue and they cannot work properly on a D500 despite having a Nikon mount I suggest talking to the retailer and ask them to talk to Sigma.

The lens/converter may be "unfit for purpose".
If they are "unfit for purpose" you seem to be entitled to a full refund from the retailer (even though did not make the lens) if less than 6 months old, and a refund less deduction for usage if more than 6 months old.

If as you indicate the lens/converter has been out of use for some time going to and from Japan; even if more than 6 months old the usage deduction should leave you with more than second hand value.

Good luck!