New Spectroscope.... So far

[theodog (Jeff)]

Thanks Al.
I have finally finished the cover and attached a ST7.
It took 8 frames to cover the sky spect with a refocus for each frame.
Some work needed to re-enforce the structure for mounting on the scope due to its mass.

[Merlin66 (Ken)]

Looks more and more like a spectroscope every day!
What's the final weight, excluding the camera??
The alignment of the slit/ grating/ camera horizontal pixel needs just a little improvement.
What slit width do you think you're using?
The response down in the UV (H&K lines) looks promising!!
Gaffa tape around the joints will help.
Take a few flat images to verify no light leaks and minimum vignetting.
This can be done by setting it up on the scope, cover objective with white T shirt and illuminate with a Quartz Hologen lamp; you'll need one for each setting of the grating.
Looking forward to some good results!
For the record, what do you think it's cost so far?

[theodog (Jeff)]

Originally Posted by Merlin66

What's the final weight, excluding the camera??

Unit without camera's is 3.0kg

Originally Posted by Merlin66

What slit width do you think you're using?

I have no idea. I just close it down and then open it until I get a 0 image. I am experimenting with finding a way by using the image. I need this to complete a scale for the slit adjustment screw.

Originally Posted by Merlin66

For the record, what do you think it's cost so far?

Probably $600. Both lenses could be sourced from e-bay for ~$100 each, slit US$15 surplus shed, Flip mirror $150?, Bintel and 600l/mm grating US$150 Optimetrics, Aluminium and wood from scrap ~$50, Screws and threads ~$20-$30. And plenty of paper, patience to make the bits.
Great project for those inclined 'though.

[Merlin66 (Ken)]

So, for the price of a "Hot Shot" eyepiece and a bit of work, you get a scientific instrument which will give more useful information than 100 astro-photographs!!!!
BTW there's a link in my project article on how to measure the width of the slit using a laser torch.
http://www.iceinspace.com.au/index.p...63,339,0,0,1,0

[theodog (Jeff)]

Oh my apologies, the most important part was the help and support from IIS (in particular Ken & Al) and the Astronomical Spectra Forum.

[sheeny (Al)]

Looks good Jeff!

I'll have to do a project like that myself one day, given the price for buying an SGS or LHires.

Al.