Problem or not?

[RVT1K]

Over the winter I found and bought a Tamron 300mm f/2.8 SP AF LD that came with a Tamron 300FNs 2x SP AF tele-converter.

Both work really well with one minor exception and I can't find any information on this to determine if it is a real problem or if this is just the way it will be.

The issue is that while my camera (D4) will recognize the 300mm by itself, when I install the tele-converter, the camera still reports 300mm, f/2.8 instead of 600mm f/5.6.

A minor issue, I know. But I'm curious to find out if this indicates a real problem or not.

Thanks.

 

[Jeff15]

No problem, that's the way it is.....

 

[Derrel]

Agreed -/-without the CPU in the lens or in the converter it does not know what the focal length is. If you wish to use it with a converter add another non-CPU lens number. For example let's say lens number three is the 300 alone and Number four could be the 300+ the converter or 600 F5.6.

You currently do not really have a problem.

 

[RVT1K]

I did make a non-CPU lens entry, 600mm f/5.6. Now I need to remember to select it....

I thought it was odd that the camera does recognize and correctly report the lens alone, it will show 300mm and whatever the f-stop is set to. But with the tele-converter installed it will still show 300mm and what the f-stop would be without the tele-converter. Kind of like the tele-converter is "transparent" and the camera still sees only the lens.

The only "problem" currently is I can't remember if a shot was taken at closer at 300mm or at 600mm.

Thanks for the input.

 

[dxqcanada]

Yes, many old teleconverters are transparent (camera didn't need to know in the old days) ... some (more modern ones) are made with an IC to "add on" it's adjustment to the info the camera reads ... though some of these IC's may not be compatible with modern cameras.

 

[Derrel]

Agreed without the CPU in the lens or in the converter it does not know what the focal length is. If you wish to use it with a converter add another non-CPU lens number. For example let's say lens number three is the 300 alone and Number four could be the 300+ the converter or 600 F5.6.

You currently do not really have a problem.