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.
 

37 minutes ago, swsantos said:

I had followed that thread for a while as it was evolving and at some point the one who tried the Blind Spot battery plate posted...

>>>>I'm afraid the Blind Spot battery plate doesn't work well with it: it seems to be current-limited, because when I ask it to slew the scope, it will be fine for a few seconds, and then the motors start making a loud grinding noise, and they're basically twitching in place. I then plugged in my LiFePo battery from Bioenno, and it slews without a problem. I double checked that the belts weren't slipping.

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

4 hours ago, TxOliver said:

While trying to figure out the best wat to power my mount, I came upon this neat cable. Goes from a pd USB C (now found on most usb power packs) to a 5.5 x 2.5 barrel connector. Puts out exactly 12v and should carry up to 3 amps. Very convenient 

DSD TECH MagicConn SH-CP12A USB Type C PD to DC Power Cable-12V https://a.co/d/iGiEQZB

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.

2 hours ago, Alan White said:

Removed the cap head screws so it is flat.
The M10 bolt has had the spacer washer shortened to get a more solid grip and boy is it a solid grip.

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

11 hours ago, Alan White said:

I have to share my Mini Vixen Fest going on.
Two Hal130 tripods, the Porta for my Ha Solar and the 130 riser and my super (Not Vixen) 
Rowan AZ75 mount.
All we need is the GP mount showing its face in a future shot.

Does it show I like Vixen, no of course not, the two 103 scopes are not shown!
Perhaps one day a nice APZ and an equatorial for good measure perhaps....hmm
 

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

On 10/11/2023 at 15:43, Albir phil said:

I suppose it would give you a measurement of sorts, but in the end sky quality is something we have to accept, are you thinking more like build up your own sky quality maps using the exposure meter. I think it would give you a idea on the night which you could then compare with other nights in the same location.,it is something I thought about at one time but never tried it Good luck 🤞👍

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.

52 minutes ago, Stu said:

Agreed! Yes, f7 to f8 4” does seem to be a sweet spot and with fpl-53 they give excellent performance at great prices!

The larger you go, the longer the focal length needs to be to control the CA properly, particularly in a doublet so they do get big, fast! My Vixen Atlux was enough of a beast at 150mm f9 and 20kg, and I know @John has ‘been there’ with his 150 f12 cannon (Istar?? I think that’s right). So equally 130mm seems a good next step up giving a meaningful performance increase in a package that remains manageable. The 125mm f7.8s being a fine example. If I hadn’t found the Tak, I would likely have grabbed on of the SM Carbon Fibre ones from FLO 👍

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.

7 hours ago, DirkSteele said:

I fear for the prospects of the company here as even idiots like me who spend way too much money on scopes won't spend 20k on a 4" scope.

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 😁

2 hours ago, DirkSteele said:

Opposite actually. Only has the 2” Feathertouch on it so the heavy lens pulls it forwards so need the scope far back in the tube rings to balance it. But balance it does when I do that.

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.

14 hours ago, DirkSteele said:

Probably not adding much having read all the replies but I would be big advocate for a 5” scope when you already own a 4”. The increase in light grasp is as much as 70% which is very noticeable on DSOs at the eyepiece and the extra resolution on planets and double stars is also obvious. Given average seeing conditions, 5” will often show all that can be seen on the planets.

It is however, amazing how quickly the scope seems to scale up with that extra 25-30mm of aperture. Even a lighter weight doublet will be that much longer such that moment of inertia becomes a factor meaning a more robust mounting solution is desirable.

The below image exaggerates things a little as the 105/650 has a long sliding draw tube to keep transportation length down but compare it to my 130/1200 (both set to transportation length).

On to the mount. My Tele Optic Ercole is more than up to the task of 2 4” class refactors, both triplets which with finders, diagonals and eyepieces was probably c.16kg.

 

But it started to struggle (above 200x magnification) with my 130/1200 which is around 12kg with the same accessories.

 

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

3 hours ago, fireballxl5 said:

Yes,  thanks for the link though use of PHD2 would seem to rely on using a separate guide scope & camera. 

I was wondering if it was possible to guide the mount with controls from SharpCap's feature tracking function, which would be using measurements of planetary features from the imaging camera. 

Can the mount be guided from an external computer,  such as a PC or ASIair?

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

14 hours ago, fireballxl5 said:

I've been using my AZ100 / OMC300 combo to image Jupiter and although aligned so that Jupiter can be re-centered fairly reliably, the planet does drift out of the camera ROI quickly. I've mainly been addressing this by moving the ROI but wondered if this could be avoided by using the Feature Tracking function in SharpCap.

Has anyone tried the Feature Tracking function to enable a motorised AZ100 automatically track Jupiter?

I'm unable to use my scope currently to try this owing to a hand injury so any info confirming this would be appreciated. 

CS, Andy

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.

On 27/11/2023 at 17:42, jasonbokor said:

Any thoughts on using the Pegasus Astro carbon fiber tripod that comes with the NYX-101, as a light weight tripod for the AZ-100? It's rated at 50kg and has pier extensions to give it a little height. The mount only weighs 2kg plus the plate and extenders.

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?

47 minutes ago, Stu said:

I agree, the AZ75 goes much better on something like a Uni-28 rather than a CF tripod. It’s still a pretty light setup but feels more stable. Not tried a T-Pod but they are more than I want (can!) spend on a tripod currently, given I have a Planet, Uni-28 and the Gitzo which I’m happy with. Would be interesting to see and use one for reference though.

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

53 minutes ago, vlaiv said:

You can't make extended light sources appear brighter even when using optics. We always see equal (or less) surface brightness of objects, no matter how big or fast our telescope is.

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.