1.4 teleconverter with T-mount (astrophotography)

[jmamer]

Hi All,
I'm trying to do some astrophotography with my
D60. I have a 1.25" T-mount and a EOS compatible
coupling ring (and a telescope, of course). Here's
the problem: when I put the T-mount on the camera
it works fine. The D60 can be used in arpeture
priority and focussed manually. When I add the 1.4x
teleconverter (and inexpensive Tamron 1.4x, again compatible with EOS), I get an Error 01 and the camera
will not take the picture.

The 1.4 teleconverter works just fine with the rest of my lenses. The problem seems to be when I attach it to the T-mount.

Any and all suggestions appreciated.

thanks
john

[NKGuy]

What happens if you tape over the contacts on the teleconverter?

[jmamer]

nkguy wrote:
What happens if you tape over the contacts on the teleconverter?


I was going to try this, I wanted to see if anyone
had a non-tape solution, or knew of a brand of
teleconverter that worked, or had another set up
that worked. The D60 is new, and so I'm still
a little obsessive about it. My concern is bits of
sticky tape dropping into the works. If I have to
tape, what's best? Or is there a good reason not to?

j

[Kenmc]

I use my D30 on a Meade SCT all the time. I use it to estimate the air glow before hooking up the film camera. I never had any problems, but I have tried to increase the field by moving it closer to the scope not further. Here is my 2 cents.

First I think the T-ring or the threaded extension tube is shorting out the contacts on the front side of teleconverter. I would put the tape here, not between the camera and the teleconverter.

Next, Why use aperture priority? The scope cannot send back a value for the aperture setting as a lens normally would. I don't know if the camera would be looking for this or not in aperture mode, but this could be where the error is coming from. I always just put the camera in manual mode.

I have not been too happy with the results of astro pictures from the d30. The only things I have found to shoot are constellations and the moon. The moon is aggravating because it does not fit in the frame so I have to paste photos together to make a complete image. It's not that bad doing that with constellations. It’s easier than over laying negatives! On a positive note I have printed some pictures of Orion 16 x 20 that are nice from the D30. I have some of the moon too, but they are average. I have not been happy with any planetary attempts.

Good Luck and I would love to know if you find something that works. For me I am sticking with my Mamiya for Astrophotography.

[jmamer]

Kenmc wrote:
I use my D30 on a Meade SCT all the time. I use it to estimate the air glow before hooking up the film camera. I never had any problems, but I have tried to increase the field by moving it closer to the scope not further. Here is my 2 cents.

First I think the T-ring or the threaded extension tube is shorting out the contacts on the front side of teleconverter. I would put the tape here, not between the camera and the teleconverter.

Next, Why use aperture priority? The scope cannot send back a value for the aperture setting as a lens normally would. I don't know if the camera would be looking for this or not in aperture mode, but this could be where the error is coming from. I always just put the camera in manual mode.

I have not been too happy with the results of astro pictures from the d30. The only things I have found to shoot are constellations and the moon. The moon is aggravating because it does not fit in the frame so I have to paste photos together to make a complete image. It's not that bad doing that with constellations. It’s easier than over laying negatives! On a positive note I have printed some pictures of Orion 16 x 20 that are nice from the D30. I have some of the moon too, but they are average. I have not been happy with any planetary attempts.

Good Luck and I would love to know if you find something that works. For me I am sticking with my Mamiya for Astrophotography.

I thought that too. I got the same error when I tried
to fire the camera with just the 1.4x teleconverter (no T mount). I also tried taping the outside (T mount side) contacts and got the same result. I suspect that the teleconverter is not correctly interpreting open contacts to the camera and the camera thinks it's not communicating correctly with the lense. ....But that's just a guess.

thanks for the info. I agree with your over all assessment. My previous attempts at astrophotography with my G1 yielded pretty mediocre results.

[chris maddock]

Is Err01 the lens communication error?

If so, I suspect that your problem is that the camera knows something has been fitted, but cannot communicate - because the contacts doen't actually go anywhere in your setup.

There is a small lever switch in the lens mount, just above 9 o'clock as you look at the front of the camera, which is tripped by the end of one of the lens mount bars - for want of a better word! If the lens (or whatever you fit) trips that, then the camera wants to communicate but fails because your scope doesn't have any electrical bits in it.

Try (on the T-mount) trimming a bit off the offending part of the bayonet fitting, so that this switch is not activated. You'd probably only need a couple of millimetres removing, so you won't lose structural strength - indeed, I'm sure I've seen T-mounts that were "trimmed" in manufacture.

HTH
Chris

[jmamer]

Hi Chris,


Thank you, that's just what I needed. The t-adapter by
itself misses the lever. The 1.4x teleconverter touches
the lever. The activation setup on the lens side of the teleconverter is where the problem is, I think.

Now if I could just get this dratted evening coastal fog to lift.....

John

chris maddock wrote:
Is Err01 the lens communication error?

If so, I suspect that your problem is that the camera knows something has been fitted, but cannot communicate - because the contacts doen't actually go anywhere in your setup.

There is a small lever switch in the lens mount, just above 9 o'clock as you look at the front of the camera, which is tripped by the end of one of the lens mount bars - for want of a better word! If the lens (or whatever you fit) trips that, then the camera wants to communicate but fails because your scope doesn't have any electrical bits in it.

Try (on the T-mount) trimming a bit off the offending part of the bayonet fitting, so that this switch is not activated. You'd probably only need a couple of millimetres removing, so you won't lose structural strength - indeed, I'm sure I've seen T-mounts that were "trimmed" in manufacture.

HTH
Chris

[PatrikR]

Chris! Right on the Money!

Thanks you saved a ton of gray hairs... I filed of about 2 mm of an old tokina mount and now it works just fine.

Thanks.