Deadlake

The issue with the SCT is it needs a night of good seeing to use and also needs to acclimate to be usable. In the end I run out of time to use the C11, I just go for the APO as it's ready to use in thirty minutes. The SCT has more image scale, however it's never as sharp or has the contrast of my APO. The MTF of the APO I have just pulls away when looking at planets compared with the SCT. Why do I have the C11, it's great on DSO, it just goes so deep on the stars I can see. My back yard is SQM 21.

Apparently works very well, the supplied saddle’s knob is badly thought out but can be replaced or a new saddle ordered from ADM. About to take the plunge.

I'd also look at the HAZ31, it's a similar price to the AZ mount pro but weighs just 3.1 kg. A lot of AZ owners are moving off from the AZ pro to the HAZ31 for this reason and from the people I know who have one rate it quite highly.

That's a shame as smaller LiFePo batteries that attach to the mount are not very available this side of the pond..

Blindspot make a battery that fits well, see: https://www.cloudynights.com/topic/708353-rowan-astronomy-az100-arrived/page-27#entry12941485

As you have said not many clear nights, the ES127 is a scope you can take out and it will acclimate very quickly, allowing you to take advantage of available clear nights or periods of good seeing. I have a C11 and it takes a while to be acclimated, apart from NV usage it gets little use on planets as the view is not as sharp as an APO. However where the C11 wins is the depth it can go, just so many more stars that are visible. The C9.25 is actual the best visual SCT in the line up due to the smaller corrector plate resulting in the highest contrast. I would take the advice above and not buy anything until I found out how visual astronomy worked for me. If that was a route I wanted to go down, I'd probable get a mount that would allow faster setup then the EQ5 or EQ6 mounts. A C9.25 would be a great companion to the ES127.

Vixen ASG CB90 would work with this as well, good to know thanks!

Does the base of the AZ75 fit inside the base of the half pier or have you made the base of the AZ75 flat for it to fit flush? thanks

We do however it can vary over the night. maybe there is a better time for doing observations. The phone app is not as good as dedicated unit.

I'm surprised the MTF of a scope and it's effect on looking at extending objects has not been brought up, aka why can you see the Cassini division with a 3" scope where the diffraction limit would require an 8 or 9" scope. However that might be the subject of another thread, back to this thread. Since the above is a little light on numbers here is the effect of aperture and scope type with a change in SQM (Blue rows). I did this to get an estimate of what more I could observe by limiting magnitude when travelling to dark sites and it's a little old as I've moved house since. It's a little darker at SQM 21, and yes I notice the difference. The physical scopes I own on the below chart are LZOS 130mm/F6 and C11. Yes the C11 is full of stars, the extra stars seen is really deep compared to the 130 mm however the lack of sharpness compared with an APO is very noticeable and even if the C11 had many hours to acclimate it's not going to get anywhere close. Also compare the scopes at different sites, in purple. A gain of half a magnitude just by being at a relatively dark polluted site to a dark site is quite large. Site Wimbledon Home Iping Common (45 mins) Garth ( 5 hours) Aperture (mm) Focal Ratio Weight (kg) Focal Length (mm) Eye Piece (mm) Magnification 26 mm Telescope\SQM 18.43 20.67 21.2 21.78 FSQ-85 10.6 12.1 12.3 12.7 85 5.3 5 450 20 17.30769231 TS CF-APO 90 mm 10.9 12.2 12.4 12.8 90 6 4 540 20 20.76923077 SharpStar 94EDPH 10.9 12.3 12.6 12.9 94 5.5 4.2 517 20 19.88461538 SharpStar 100QII 11.1 12.5 12.7 13.1 100 5.8 5.2 580 20 22.30769231 Askar FRA600 11.2 12.6 12.8 13.2 108 5.6 6.5 600 20 23.07692308 SharpStar 121DQ 11.5 12.8 13 13.4 121 5.5 8.92 678 20 26.07692308 LZOS 130/780 (F6) 11.8 13.1 13.3 13.7 130 6 12 780 20 30 LZOS 130/780 (4.5) 11.8 13.1 13.3 13.7 130 4.5 12 585 20 15 FSQ-130 11.5 12.9 13.2 13.5 130 5 13.7 650 20 25 Mewlon 210 13.6 14.5 14.7 15 210 11.5 10 2415 20 92.88461538 GSO 10” RC 13.5 14.7 14.8 15.2 250 8 15 2000 20 76.92307692 BS 10” F2.8 13.5 14.7 14.8 15.2 250 2 12 718 20 27.61538462 BS 10” F4 13.5 14.7 14.8 15.2 250 4 12 1000 20 38.46153846 Mewlon 250 13.7 14.7 14.8 15.3 250 10 16 2500 20 96.15384615 Mewlon 250 Reduced 13.7 14.7 14.8 15.3 250 7 16 1750 20 67.30769231 C11 EdgeHD 14.1 15.1 15.2 15.5 280 10 12.7 2800 20 107.6923077 C11 EdgeHD Reduced 14.1 15.1 15.2 15.5 280 7 12.7 1960 20 75.38461538 12" F4 Dobson 13.2 14.7 15 15.3 300 4 32 1200 20 60 GSO 12” RC 13.9 15 15.1 15.5 304 8 24 2432 20 93.53846154 GSO 14” RC 14.1 15.1 15.2 15.6 355 8 30 2854 20 109.7692308 C14 EdgeHD 14.7 15.7 15.9 16.2 355 11 21 3910 20 150.3846154 GSO 16” RC 14.5 15.6 15.8 16.1 406 8 36 3250 20 125 16” Dob 14.7 15.8 15.9 16.3 406 4 40 1600 20 61.53846154 20” Dob 14.9 16.1 16.3 16.7 500 3.3 65 1650 20 63.46153846 24” Dob 15.2 16.4 16.2 17 4 1700 65.38461538 Key SQM

SM125 or TSA120? I'm not convinced that a doublet will cool down that much quicker then a doublet of similar size and the TSA120 is similar to a 4" scope in handling.

This is exactly the expression from the AP owners when they saw the price list. At the moment the only think that could make me spend that sort of money is a weather machine to control the clouds. I suspect the amount of traffic on Astro sites is down due to the weather…

If you didn’t go for the 5” you could go for one of these 😁

Going with a lighter focuser will just move the balance point and not necessary to make the scope balanced. Harmonic mounts here I come...

Astrograph have a similar 125 mm, slightly heavier however it has a minimum Strehl on the green line of 0.95. https://astrograph.net/epages/www_astrograph_net.sf/en_GB/?ObjectPath=/Shops/www_astrograph_net/Products/AGTEC125F78 I suspect to beat this it is TSA 120 etc territory... However for most nights would you tell the difference between a 0.95 or 0.98 Strehl scope, Thomas Black stated no.

Do you find the 105 /f6.25 a little tail heavy, I was thinking of swapping the FT3545 for the 2.5" flavour but the price....

Going back to 4 vs 5 " the mount is the main factor. I suspect if the mount was the same weight for both the 4 and 5" then the 5" would get most use if the cool down time is similar. I actually find my 5" LZOS perfectly balanced (the extra 1.4 kg of the FT3545 focuser versus the APM stock focuser) and the 4" has poor balance, the FT3545 tips it over and the only way of mounting is using the Y-axis adapter or a Harmonic mount. Has anyone used the AZ75 with the Y-axis adapter?

I’ve not taken mine apart but interesting to see what is inside. For your local meet what mount did you use, the 105 F6.25 is quite heavy when outfitted with a FT 3545, mines 8 kg. Too heavy for the ScopeTech I have and a little over mounted on the AZ100. Thanks

The AZ100 supports the Meade LX200 protocol if that helps. I can control it from my laptop by selecting the LX200 protocol.

This may be a good starting point, https://www.cloudynights.com/topic/697479-guiding-alt-az-mounts-with-phd2/ Also the latest beta build from Rowan seems to track planets better then before, mine kept Jupiter centred for 30 minutes before the seeing made it no point staying out.

Seems a good idea for lighter loads. How light the load needs to be is another question. The spigot size on the Pegasus M12 adapter need to accommodate the AZ100 as well. Pegasus looks like they have just the model, PEG-ADAPT101-AVX that has a spigot for the AZ100 to drop into. Rowan also sells a pier adapter and a half pier with a flat base that also fits the need for a flat base to match the Pegasus tripod mount top. Maybe someone on CN has tried this?

As with all items Avalon TPods have gone up over the last two years considerable since I bought mine.

Could you explain this, gain on a tube is the number of photons multiplied. This is controlled (via gain control) to keep the background noise under control. if you didn't have photon multiplication then not possible to use with H-Alpha filters to see Nebula??? Apart from an eyes adjustment for brightness not sure of relationship you claim for an integration time of 30 seconds, NVD is real time as you an see from the videos which are close to looking thru the NV eye piece.

Here are some local videos enjoy, from @Gavstar

I don’t really see the need to stack with NV, you can make videos of Nebulae as well. Here are some NV pictures taken with a native F2 newt’ish scope. http://www.loptics.com/articles/nightvision/nightvision2.html To be able to fabricate your own custom scope. Also using a supergain tube, which has double the gain as a L3 tube. The SNR is around the same in both cases of the supergain and L3 technology. Note this scope has a Novell corrector to flatten the image, no Parracor works below F2.8.