Sigma teleconverters.

[Nod]

For once, I'm asking a question rather than offering my opinions/advice!

Can anyone tell me if a Sigma 2x telecon will physically fit on the back of a Nikon 70-300 VR lens? I know the Nikon telecons all have glass elements that physically make contact with the rear element of the Nikon lens. It's just that I would like a little more reach than 300mm. If the low aperture is a problem (not sure it would be on my D700), I'll just use it behing my Sigma 70-200, giving me an extra 100mm over my current long end and keep a wideish max aperture.

 

[Mike.P]

The Sigma teleconverters have a protruding front element so if your lens doesn't have a recessed rear element it will not fit.

If it does then no doubt someone else can tell you if it actually works.

Edit: just look at the rear element on your 70-200mm .. that will probably give you an idea.

 

[PsiFox]

I used a kenko 1.4 TC on a 70-300 VR.

I was always told keep a sigma TC for sigma lenses.

N.B with the kenko one the 70-300 would still AF, or perhaps I just never had it on when it was to dull out.

 

[Nod]

I already have a Kenko 1.5x telecon but IQ is so compromised, I don't use it. I was hoping that the Sigma would be better and would fit the 70-300. I suppose I should follow my own normal advice and take my lens to a shop and try it to see if it physically fits! (And how much IQ is affected.) I'd rather not go down the 70-200 route since it's considerably heavier and bulkier than the 70-300 VR (and it isn't an OS one).

 

[PsiFox]

Is the 1.5 old The 1.4 was fine on it?

 

[Soda Farl]

I already have a Kenko 1.5x telecon but IQ is so compromised, I don't use it. I was hoping that the Sigma would be better and would fit the 70-300. I suppose I should follow my own normal advice and take my lens to a shop and try it to see if it physically fits! (And how much IQ is affected.) I'd rather not go down the 70-200 route since it's considerably heavier and bulkier than the 70-300 VR (and it isn't an OS one).

Only Kenko t.c's can be used with the 70-300vr it is not designed to be used with one.

 

[Nod]

Thanks for all the advice. As I said, probably my best bet to be sure is to take the 70-300 down and try it very carefully on a 2x Sigma telecon. I should probably take the 70-200 down as well and give them both a test to see what sort of IQ I end up with at assorted apertures. It would be nice if the 70-200 was as good with the telecon as it is without one but that's unlikely to be the case, I know! Better go down and rearrange the bag to take both longer lenses down tomorrow!

 

[pete.rush]

This is my understanding of how things work:
Reporting TCs: A TC-compatible lens (e.g. 400/5.6) detects the presence of a TC through the extra contacts and reports the correct f-stop for the combination to the camera.

Non-reporting TCs, or taped TCs, or TCs with non-TC-compatible lenses: The lens does not detect the TC and just reports its own f-stop. AF may still work, because the camera doesn't know about the true f-stop, and tries to AF even if the combination is outside the specs.

Kenko DGX: Unlike the above TCs, the DGX manipulates the communication between the lens and the body so that the f-stop is always reported correctly for the combination, and so that AF is retained even if the combination is above f/5.6. From your and others observations that f/8 is reported but AF still works, my guess is that wide-open f-stop and used f-stop is reported separately and the camera looks at the wide-open f-stop to determine if it should try to AF.

Personally unless you have fantastic light conditions a 2X TC on either of your lenses won't produce great results. Nikon's slightly different to Canon, Canon limit autofocus to f5.6 for all but there 1D series camera's, with Nikon autofocus still works (I've been led to believe) but with both brands it depends on the compatibility of the lens with the TC as only certain lenses work.

TCs are really designed for the faster prime lenses not zooms because the optics can handle the drop off in image quality and hit on the auto focusing, but you can use a zoom and TC but be aware you'll need decent light conditions to get anything worth while image wise

 

[Nod]

AFAIK, the AF on the D700 can handle almost anything, but that's obviously something I'll be wanting to test! With the 70-200 f/2.8, that'll only be reduced to f/5.6 which is faster than my (now sold) 150-500 Sigma was wide open and the body never had any problems AFing with that!

I'll give all options a test and see what results are like - and will compare them to crops of my current line up to see if the purchase would be worthwhile. I think the Sigma 2x is a normal stock item at my favourite shop, so I should be able to have a play, since they know I'll buy it from them rather than use them as a showroom for the interweb!

 

[Soda Farl]

Thanks for all the advice. As I said, probably my best bet to be sure is to take the 70-300 down and try it very carefully on a 2x Sigma telecon. I should probably take the 70-200 down as well and give them both a test to see what sort of IQ I end up with at assorted apertures. It would be nice if the 70-200 was as good with the telecon as it is without one but that's unlikely to be the case, I know! Better go down and rearrange the bag to take both longer lenses down tomorrow!

I have a 1.4 and a 2x Sigma teleconverter they are not compatible with your 70-300. The 1.4 is great on the 70-200 the 2x not so much.

 

[markyboy.1967]

Have a look at a thread I had called " very very impressed". I tried the Sigma 1.4tc on my Nikon 600 AFS

 

[pete.rush]

Have a look at a thread I had called " very very impressed". I tried the Sigma 1.4tc on my Nikon 600 AFS

If you get the right lens, even the 1.4x and 2x TC stacked in the right conditions can get you great results or either of the TCs on there own. (Canon 300mm f2.8 and Canon TCs)

300mm F2.8 (MKI) + 1.4x and 2x TC (MKII) stacked

Canon 300mm f2.8 + 2x TC (MKII)

Of course with everything, you need the right conditions to get the best results.

 

[Nod]

I have a 1.4 and a 2x Sigma teleconverter they are not compatible with your 70-300. The 1.4 is great on the 70-200 the 2x not so much.

Thanks for that, Tommy. The 1.4 behind the 70-200 only gives me a 280mm long end. Maybe marginally faster than the 70-300 but no gain in focal length. With the D700, I can ramp up the ISO a bit to couteract the relative slow speed of the lens and I could crop the 280mm image a little to give the impression of longer length but I hate PP (wasted) time!