Excellent images, love the granulation.

Nice proms indeed Pedro!

Nice set there Pedro!

For me the Baader Tri-band SCT offers great value for money and in a range of sizes to suit local seeing.

http://astrograph.net/epages/www_astrog ... Telescopes

Hiya folks, Looking to get the SPOD back up and running. Would be using the excellent images that are posted here on this forum. I'm also looking to be able to use an animation as SPOD image too. I'm interested in any suggestions / ideas / comments etc that people have. Where possible will take ever...

That's excellent Dave!

Lovely shots Brian! Autumn has well and truly arrived for me, and work is sooo busy i've not had no sun for several weeks. This weekend is looking grotty weatherwise too.

Very good!

Good proms Raf! I always struggle imaging them too!

Enjoy Colorado!

I already changed the original cardboard spacers of my 150mm with thicker ones made from an aluminum foil but I didn't make any check of the resulting correction in calcium light compared to the original configuration. Mark, do you remember which thickness have you used ? I used foil that is used f...

You can pop the achromat lens out if its cell and increase the air space gap with cardboard strips to Decrease blue astigmatism , A bit of trial and error plus tedious guesswork involved but it works. Use a cheap scope! I did this with my Meade AR5 and improved perfomance in CaK, it's far from perf...

General rule is with achromats longitudinal aberrations are worse that latitudinal aberrations, and with apochromats latitudinal aberrations are worse than longitudinal aberrations. There will be some exceptions to the rule, the 115/7 being one and the TOA ortho apochromats for example. I found this...

I would hazard a guess that the 115mm/f7 triplet is a reasonable performer in CaK (or Ha or Na) based on this spherochromatism chart 115trip2.jpg http://shop.tecnosky.it/Articolo.asp?SessionID=7AF5C7A2-19D6-47EB-B6CA-6FBFF6001C93&GetInfo=TS115&AddScore=TS115&Score=1 The curve is about as close to th...

christian viladrich wrote: ↑

Tue Sep 18, 2018 7:49 pm

The only drawback of the TOA 150 is its the price and ... its aperture. I wish I have a TOA 200 ;-)

Thanks Bart, I thought that might be the case.

Brilliant!

Well said Apollo.

That was my thought too Pedro, I quite fancy the idea of something for quick grab and go full disks that I can just carry the scope and mount out in one go (in between the clouds!) - be interesting how you get on Pedro. You don't have clouds where you are very often so give it a try covering the sen...

Interesting comparison Raf. I did something similar several years ago with CaK. I get some reasonable images with my ED80 at higher magnifications I find, once I'm upto about f15-f25. Frederics website has some great measurements of spherochromatism https://airylab.com/astronomy-test-reports/ Regard...

Looking good Franco! Another cloudy weekend for me.

I want to try a few ideas with my skybender, these recent threads have been giving me some ideas

I wonder if it will stop tracking when the sun goes behind a cloud?

Good results!

I think I will be buying one very soon too.