AZ-GTiX astrophotography payload?

[GTom]

Have seen AZ-GTi's and SA GTi's used with 130pds Newtonians for astrophotography, I was wondering how does the AZ-GTiX compare to those two?

[TiffsAndAstro]

2 hours ago, GTom said:

Have seen AZ-GTi's and SA GTi's used with 130pds Newtonians for astrophotography, I was wondering how does the AZ-GTiX compare to those two?

• Weight (including tube-rings and mounting dovetail) approx 4 kg

4kg is a lot less than i was expecting. the sa gti official payload is 5kg, but the conventional wisdom is to use half that value.

this could be quite cool, but i'd be concerned about the guiding performance before i did it. don't mind someone else trying it out first though to see

i've read these sorts of newtonians can need quite a bit of mods to make them more suitable for imaging though.

 

[Elp]

Azgtix is 6kg when using one scope. It kind of looks similar to my azgti, and I'd never even contemplate putting the 130pds onto it when I had it, not even for visual.

If you want reliable deep sky images, sub after sub, you need to overmount your setup usually. The exception is I've used my azgti at 6.5kg payload with a small refractor (note knowingly I'm likely wearing it out), it works, but usually after dithering the next one or two subs will be bad, any breeze also bad. Over the course of a night/multiple nights you don't want to loose so much data.

[TiffsAndAstro]

17 minutes ago, Elp said:

Azgtix is 6kg when using one scope. It kind of looks similar to my azgti, and I'd never even contemplate putting the 130pds onto it when I had it, not even for visual.

If you want reliable deep sky images, sub after sub, you need to overmount your setup usually. The exception is I've used my azgti at 6.5kg payload with a small refractor (note knowingly I'm likely wearing it out), it works, but usually after dithering the next one or two subs will be bad, any breeze also bad. Over the course of a night/multiple nights you don't want to loose so much data.

its a weird coincidence that my guiding seems to have improved about 25% ish since i've added more weight and counter weights.

do mounts 'wear in' with use over time (and possibly wear out?) 

Edited June 15 by TiffsAndAstro

[Elp]

Balancing will make a lot of difference. Weighing down the tripod may also help stability and dampening. Not sure about added payload. Maybe the mechanics wear in but they're not moving fast enough for it to be an issue so not so sure about this, they may wear out eventually but it'll likely take a very long time, the electronics may give up sooner than the mechanics. People do regrease and replace the standard grease to get better performance.

[Adam J]

9 hours ago, TiffsAndAstro said:

• Weight (including tube-rings and mounting dovetail) approx 4 kg

4kg is a lot less than i was expecting. the sa gti official payload is 5kg, but the conventional wisdom is to use half that value.

this could be quite cool, but i'd be concerned about the guiding performance before i did it. don't mind someone else trying it out first though to see

i've read these sorts of newtonians can need quite a bit of mods to make them more suitable for imaging though.

 

Conventional wisdom is wrong i have been getting <1 arcsecond rms with the SAGTI and a 5kg payload. 

Adam

[TiffsAndAstro]

14 hours ago, Adam J said:

Conventional wisdom is wrong i have been getting <1 arcsecond rms with the SAGTI and a 5kg payload. 

Adam

that's really encouraging. any chance you could share any phd2 settings you've customised? im getting 0.6, 0.8 for a while but it generally moves to around 1.2 to 1.4 which is fine....but if there's some obvious tweaks i can try for a quick win it would be great

i did get these settings from earlier in the thread and ill look to see if they're different to what im currently using. if so ill try them out.

 

Edited Sunday at 13:50 by TiffsAndAstro

[GTom]

13 hours ago, Adam J said:

Conventional wisdom is wrong i have been getting <1 arcsecond rms with the SAGTI and a 5kg payload. 

Adam

Exacty, not the first account where I hear that these little mounts can carry far more than expected by traditionalists🤔😎

[Adam J]

5 hours ago, GTom said:

Exacty, not the first account where I hear that these little mounts can carry far more than expected by traditionalists🤔😎

Kinda, its also worth noting that i needed to adjust both RA and DEC to remove backlash before i was able to get that result. So it is not out of the box performance, although I have not modified it in any way beyond tweaking meshing of gears. 

 

Adam

[TiffsAndAstro]

16 minutes ago, Adam J said:

Kinda, its also worth noting that i needed to adjust both RA and DEC to remove backlash before i was able to get that result. So it is not out of the box performance, although I have not modified it in any way beyond tweaking meshing of gears. 

 

Adam

My Ra and Dec both seem physically backlash free, but a while back using guiding assistant it came up with some scary looking number. So I decided to ignore that, balance better and do a couple of nudges north after slewing just before starting calibration. Also slightly better guidescope focus.

Hopefully I still have some headroom to improve before trying to physically mesh gears more, if they do need it. If I can get below 1" I'll be happy.

Edited Sunday at 18:04 by TiffsAndAstro