APO triplet with FPL53, DeepSky 80/480

Posted: Sep 25th, 2019

Technical Info

Sarov, Russia

3078

My new acquisition: an APO triplet with FPL53.
Soon it will take its place on the main setup and will capture color with the QHY8L camera.

Resolution: 1800x1200 px

Scale: 1065 KB

Smirnov Andrey

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Comments

Pavel Zhukov

Andrey, what back focus distance do you use with the TSred279 and this triplet?

10 May, 2021 Reply

Smirnov Andrey Replied to Pavel Zhukov

I'm not sure at the moment—the focal point has changed. I put an afocal corrector with a color camera there, and the 0.79x corrector moved to the LZOS 130/6 telescope with a monochrome camera. Otherwise, I took the spacing value from the website, did several test runs, and based on the results, added a 0.7 mm ring to the nominal spacing.

10 May, 2021 Reply

Pavel Zhukov Replied to Smirnov Andrey

Understood, thank you. I had an 80/480 triplet for a while. I found a spacer for it with a Canon 64 mm, but the sensor was offset. I modified it myself, tightening the screws all the way. So it sits closer to the bayonet, but by how much exactly, I don't know. That's why I asked if I can trust the information on the TS website. It says 61 mm there. I also planned to add a 0.7 mm ring because of the filter in the optical path, but now it seems I might need even more.

10 May, 2021 Reply

Pavel Zhukov

P.S. Also, could you tell me the length of the telescope's dovetail bar?

10 May, 2021 Reply

Smirnov Andrey Replied to Pavel Zhukov

Pavel, good day. The length of the swallowtail is 137 mm.

10 May, 2021 Reply

Pavel Zhukov Replied to Smirnov Andrey

Thank you!

10 May, 2021 Reply

Smirnov Andrey Replied to Pavel Zhukov

By the way, I really liked the design of the harness there, and I replicated it in good-quality PETG plastic using a 3D printer. Here are some examples:
https://astronomy.ru/forum/index.php/topic,166015.msg4915732.html#msg4915732
https://astronomy.ru/forum/index.php/topic,166015.msg4843142.html#msg4843142
There are other implementations as well.

10 May, 2021 Reply

Pavel Zhukov Replied to Smirnov Andrey

Interesting, I'll take a look.

11 May, 2021 Reply

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