buzz

I have Tak and WO refractors with QHY cameras. I have ditched OAG's in favour of a separate guidescope and now have space for a rotator. Thread sizes are either 54 or 48. I use Pegasus stuff and wondered what folks thought of their Falcon rotator.... or are there better ones out there? cheers

Aggression is quite different to guide rate. PHD2 does not care about the guide rate - which is the speed at which the mount corrects the tracking. The calibration routine takes it into account automatically. The aggression is the amount. DEC drift is slow and smooth, so kicking it with a high guide rate in alternating directions is not a great plan, regardless of the correction duration. On the Rainbow, I had better DEC RMS error if I turned off the guiding outputs.

That is a good target for this time of year. Out of interest, do you know if you can set independant guide rates for RA and DEC? The Rainbow could only have the same rate on both.... but DEC did not like the fast tracking rate and often its RMS was worse than RA, no matter how delicately I set the aggression.

This is really interesting and thanks for sharing the guide log. Have you checked the tracking error with guider outputs disabled? I had the Rainbow and it was ±25 arc second, which was alright... but it could swing quite quickly at almost 1 arcsec/second, which was hard to keep up with. Knowing the rate of change is often a clue to the best guide algorithm. PPEC was a bit touch and go with the Rainbow.

Is it available yet? Any reviews?

I found my 10 micron's mount clamp was difficult to tighten sufficiently and it also seemed to relax as it got cold. Lovely polished silver knobs but completely useless for gripping tight. When I first started using it I managed to catch a large refractor sliding out. I now always put a safety tether on my scopes - the sort used for stage lighting. It loops round the front of the clamp and through the back of the tube rings, preventing a complete slide out. My Paramounts grip better, but I still do it as an insurance policy.

Hi - the company that normally makes my pier adaptor plates is no longer doing custom work. I need a custom aluminum plate for the top of my TPod. Does anyone have a recommendation for a machine shop that I can use? cheers

Does anyone know of a place I can get 54 and 48-mm male threaded dustcaps? I need them for my cameras.

When I wrote my book The Astrophotography Manual, I wanted to explain how to collimate an RCT. I gave myself a 5 page budget. There are many, many alternative possible ways of collimating and in the end, I tried most of them, if only to discount them. The chapter took 25 pages. Those techniques that rely on anything other than mirrors are flawed - there is no guarantee that mirrors are centered in housings or center spots are centered. In essence, it takes three passes. The first checks the secondary spacing to ensure the focal length is right (big difference to field curvature), second does basic alignment with tools such a centered laser and hall-of mirrors and lastly, using star test to do the last little bit. There are some other variations that work too but you have to distinguish between folks' suggestions, that just get lucky with one technique compared to a robust method that works in all cases. I spoke to the astronomer who wrote a positive review for a US collimating tool. Turns out he only used it to adjust the secondary. Rather misses the point as it is the primary that is the PITA.

I'm leaning towards the GT102. It will accept the same flattener and reducer as my FLT132. Good chance that one of my spare Lakeside focus brackets fill fit too.

Found the review on CN. Very interesting, Esprit gives the Tak a run for its money. Unfortunately its focal length is a bit short for my needs and only 20% longer than my Tak85.

Sam - good points. Maybe it has something to do with the red color (it matches with my MyT). Do you have any links to the Esprit comparisons? I have nothing against SW - their mirrors are often fantastic.

Thanks for the suggestions - the sharpstar quaduplet looks nice but is a bit short and close to my Tak85 native focal length. As already mentioned, I previous had a FLT98 and FLT110 (which I sold to buy the FLT132). I used the Flat 68 from the FLT132 on my FLT98 but I never found a spacing that gave a good outer field, so I only used it with a reducer making it only 500 mm FL. I sold both to buy the Tak85. Nice to hear about the rotolock, has to be better than my original DDG focuser, which wagged around like a puppy tail. Nobody used the StellaMira (or the Orion-badged equivalent)?

I'm looking for a good performance and value 600-something focal length refractor for deep-sky imaging, which is relatively portable. Over the years I have had several WO scopes (FLT98 / FLT110 / Star 71 / ZS 73 ) and still have an FLT132 (feathertouch) and RedCat. I sold the FLT98 to get a Tak85 - but the Tak106 is too close in focal length and more than I want to spend. The FLT132 and Redcat have good optics, most of the others were good to ok optically but their focusers were a mixed bag. I have the new reducer for the FLT132 - but the assembly is a bit of a beast for portable use. Both the GT103 and SM104 have similar specs. I am not familiar with either of their focus mechanics or how they compare optically. I'm wary of fancy glass claims as it does not necessarily make for a better image. I wondered if anyone had insights into these two? Shame I cannot get Mr Reid to contribute!

The major problem lies with how one defines 'beginner'. Some want to do astrophotography with their iPhone. Remarkable as it is and while some will get some images, it is not the right tool for the job. Some starters will want a full explanation of how to use a photo-editing suite like Photoshop. That is a book in itself. The subject depth is an issue with some books that cover a broad church. When you delve, however, there is precious little insight in any of the tricky subjects like guiding, autofocusing and image processing. Publishers restrict page count and it is a tricky decision on what to leave in and what to take out. I'm one of the few authors who includes a bibliography and acknowledges the work of others. In the list above, Charles' stands out.

My book, The Astrophotography Manual, is intentionally not a beginner's book. It is aimed at existing practitioners who want to progress. Astro books go out of date very quickly and some of these are already showing their age. I have just published a new book, aimed at beginners, called "Capturing the Universe" which is bang up to date.

To polar align - it depends on what reticle they are using. If it is a clock face, like the latest EQ ones, you would set a single orientation with 12 - 6 line vertical, center the reticle (once only) with the two adjusters by rotating RA axis and then just read off the setting from any smartphone app.

My ROR came from homeobservatoryuk.com a company in Norfolk, for the price of a reasonable 4-inch refractor. Really nice job and well-built wooden obsy. Fitted with motor and remote control, which I then ASCOMized.

There were several working units at Astrofest last weekend. I was told it was shipping.

It is now a year on from the "November update" on their website, with no sign of saleable units. Anyone got news? I really liked the concept

I think that is about it , the link in the subscription email showed the same- Teleskop Express informed me they would be getting units next month.

Some new news on their website now. Looks like its electrical interface has developed. I'm guessing if you can control a modem or printer via a HTTP webpage, there is no reason why you couldn't do the same with a mount to align it and point it in the right direction. Full robotic control (via ASCOM say) would be the icing on the cake.

Is there any news on availability? The website is unchanged for several months now and it feels like the days of the Sinclair QL

For info - there is a new version of the software on the GoldFocus website. It does not appear to be radically different but I notice it has fixed the ASCOM focus disconnect bug. It also now has an updated instruction supplement that takes you the intricate process of collimating a dual mirror system.