10-17mm and extension ring

I have just purchased a Tokina 10-17 and have a SEA&SEA NX compact dome. The question is do i need the SX extension? I have looked through the forum and cannot find if anyone is using the dome without it. I have the 40m but this is too deep.

Thanks

With the NX Compact dome you need the SX 20mm extension ring. No ring with the larger NX Fisheye dome. If you use a 1.4 teleconverter you can use your 40mm extension.

I have just purchased a Tokina 10-17 and have a SEA&SEA NX compact dome. The question is do i need the SX extension? I have looked through the forum and cannot find if anyone is using the dome without it. I have the 40m but this is too deep.

 

Thanks

With the NX Compact dome you need the SX 20mm extension ring. No ring with the larger NX Fisheye dome. If you use a 1.4 teleconverter you can use your 40mm extension.

Sea & Sea zoom chart calls for SX extension with both the Compact dome and the Fisheye dome. I use the extension with my fisheye on the MDX-D300. Haven't tried without it.

Thanks guys - I was aware to the S&S charts but was just wondering if it is possible - it is very difficult to get one at short notice in the UK it seems. I suppose it is all about the nodal or focal point distance from the sensor. Given the cropped sensor it is already at 16mm so add another 1.4 and it seems not worth it to me. back to the drawing board or is the credit card!!

This looks like my only solution - so essentially use the lens as prime at the 10mm end and i suppose add the telecon with the 40 and it gives you the extra 20 but the 1.4 compensates for the nodal point being moved. Not sure if that is a question or a statement of my understanding...

With the NX Compact dome you need the SX 20mm extension ring. No ring with the larger NX Fisheye dome. If you use a 1.4 teleconverter you can use your 40mm extension.

According to my local camera shop i will lose autofocus with the 1.4 TC is this correct?

Not with Kenko, AF works .

According to my local camera shop i will lose autofocus with the 1.4 TC is this correct?

But only at apertures wider than F4?