# 5D3 + teleconverter + Telescope



## weilin (May 15, 2014)

So I have a telescope which I use a T-Ring to EOS adapter with. Like everyone here who shoots (really) far away things, I like attaching my Canon Teleconverters to it. However, with the 5D3 + Telecoverter + T-Ring adapter, the camera won't take a picture and instead complains not being able to make electrical communication with the (non-existent) EF lens that should be attached to the teleconverter. 

Is there a way to disable that error message? If the body doesn't have any lens/teleconverter attached to it, it takes a photo just fine. However, with just a teleconverter, it doesn't. I've been using tape on the contacts to trick the body to taking photos. I use the teleconverter with my 70-200 as well and I dislike having to constantly put/remove tape on the pins... This process is such a hassle, there's got to be a better way. 

I looked in the manual and nothing jumped out at me screaming this is how you fix it... any thoughts?

Wei


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## wickidwombat (May 16, 2014)

you could add a dandelion AF confirm chip to your t ring then you can program exif into it too and it will all be happy


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## weilin (May 16, 2014)

that might work... I will look into this. Thank you!

Wei


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## wickidwombat (May 16, 2014)

just get the good ones about $25 on ebay not the crappy copies
i have one on my samyang 8mm and it works a treat


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## yorgasor (Jun 4, 2014)

I have the same problem on with my Nikon 300mm + EF adapter + 1.4x Extender. It works fine without the extender, but once I include that, everything goes south. I keep a small strip of black electrical tape on the back of my camera, and whenever I want to use this combo, I pull off the lens and stick the tape on the little pins just inside the camera. 

Works like a charm. But it's annoying if you forget to take it off and your next lens all of a sudden won't auto focus for some reason.


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## weilin (Jul 9, 2014)

I have confirmed that the dandelion autofocus confirmation chip DOES NOT work for this purpose. The body is fooled into thinking it's an EOS lens, but the teleconverter isn't buying it. I suspect it's because the EF conconveter is expecting 3 more pins to provide data that the AF confirmation chip does not have. 

Now I'm back to square one...


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## Lee Jay (Jul 9, 2014)

Tape the contacts. The t ring might be shorting them out.


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## weixing (Jul 9, 2014)

Hi,
Do you have problem if you only use the 5D3 + T-Ring?? 

Although I usually don't use teleconverter (I usually use a barlow), but shouldn't be a problem... I do a test on my 6D + 1.4x Kenko Teleconverter (I don't have Canon Teleconverter) + T-Ring and it work as per normal. I look at all my T-Ring and none of them make contact with the DSLR pins.

 Have a nice day.


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## Lee Jay (Jul 9, 2014)

weixing said:


> Hi,
> Do you have problem if you only use the 5D3 + T-Ring??
> 
> Although I usually don't use teleconverter (I usually use a barlow), but shouldn't be a problem... I do a test on my 6D + 1.4x Kenko Teleconverter (I don't have Canon Teleconverter) + T-Ring and it work as per normal. I look at all my T-Ring and none of them make contact with the DSLR pins.
> ...



Not the DSLR pins, the contacts on the teleconverter. I have the same problem and taping the three TC contacts fixes the problem.


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## weixing (Jul 9, 2014)

Hi,


Lee Jay said:


> weixing said:
> 
> 
> > Hi,
> ...


 My T-Ring never contact with the DSLR pins/contacts or the Teleconverter pins/contacts. May be you use a T-Ring not design for Astro use??

Have a nice day.


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## ysengrain (Jul 9, 2014)

I don't understand what/where is the trouble.
I own a 5D III, a convertr (2x) and I "plug" very often a Samyang 500 mm. 
I use manual settings and everything is OK


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## weixing (Jul 9, 2014)

Hi,
For your reference, I took a photo of my 6D + Teleconverter + T-Ring. Notice that the T-Ring do not contact with the teleconverter pins/contacts. 

Have a nice day.


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## lol (Jul 9, 2014)

A workaround would be to not fully fit the TC until it clicks. e.g. release it slightly and turn it so the contacts aren't lined up with the body any more. Of course, you have to be very careful not to let the body fall off if you do this... I didn't say it was a good workaround!

Alternatively, skip the TC altogether and get a barlow for the scope.


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## wickidwombat (Jul 12, 2014)

weilin said:


> I have confirmed that the dandelion autofocus confirmation chip DOES NOT work for this purpose. The body is fooled into thinking it's an EOS lens, but the teleconverter isn't buying it. I suspect it's because the EF conconveter is expecting 3 more pins to provide data that the AF confirmation chip does not have.
> 
> Now I'm back to square one...



did you get the right chip, the chip i got looks identical to the lens contacts...


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