2 replies to this topic

[CLJLF]

I have a P8079HP, and in addition of using lenses for wide field, I also wish to use it for more magnified observation. I've seen prime/afocal terms running around, and am I correct that prime doesn't has the eyepiece on the scope and the objective lens in front of the tube, and the telescope directly projecting an image onto the photocathode?

 

I have looked into afocal setups since people say that it is better, but i don't think that I will manage to create a stable stack (With the P8079HP being 18cm long and quite heavy and all). I can do 3D printing so I can custom print adapters for prime that fits into the eyepiece slot in telescopes. 

 

The P8079HP is an inverted image tube, would running such a setup create an inverted image?

 

I am also part of a local astronomy society so I hope to be able to use their telescopes (Which are all reflectors, I would get my own but fast refractors are very expensive). Would there be problems in focusing the image if I configure a prime setup with a dobsonian? Thank you!

Edited by CLJLF, 06 November 2024 - 06:26 PM.

[Lambda]

Hi!

I have a P8079HP, and in addition of using lenses for wide field, I also wish to use it for more magnified observation. I've seen prime/afocal terms running around, and am I correct that prime doesn't has the eyepiece on the scope and the objective lens in front of the tube, and the telescope directly projecting an image onto the photocathode?

 

 

Yes, you're right.

 

 

 

The P8079HP is an inverted image tube, would running such a setup create an inverted image?

 

 

If your upstream optical system (whatever the formula would be) gives an inverted image projected on the photocathode of your P8079HP, the final image obtained on its screen will be rectified / not inverted.

 

P8079HP being an heavy and bulky beast, indeed, for your other questions, it would be really up to you and the mechanical stress applied to the eyepiece holder of the scope you would use. Balance, inertia center, torque... All of this parameters will have to be taken into account in your final design, but at the end, nothing impossible!

 

Good luck.

Lambda

Edited by Lambda, 08 November 2024 - 04:01 AM.

[bobhen]

Prime mode works well on budget "refractors"

 

Get one of the 102mm F5 or 120mm F5 or the 150mm F5 achromats and add a GSO 2" focuser and Prime mode will work without the long optical stack of afocal mode. 

 

Below is my 102mm F5 achromatic refractor with the image intensifier in the diagonal in Prime mode.

 

Bob

 

 

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