Planning on buying a Skywatcher 150/1200pl explorer, what is the cheapest goto mount that would keep a planet in frame for at least 3 mins.

[JokubasJar]

I intend on using the telescope for visual observing and planetary photography. What cheap computerized mount would keep a planet in frame for a couple of minutes, it doesn't have to be perfect since I would still run it through PIPP. I just don't want the hassle of tracking manually with slow motion controls.

Edited September 14, 2020 by JokubasJar

[Cosmic Geoff]

Any Goto mount should do this. But if budget is a problem, you do not need Goto for this.  An equatorial with RA drive should suffice.

[happy-kat]

How much does your telescope weigh?

[vlaiv]

I already did similar calculation couple days ago in another thread, but for general benefit, I'll do it again here.

You want something like EQ5 mount to hold such scope and you only need RA motor (get stepping motor for this - not simple DC motor). In theory, EQ3 mount could hold this scope as well, but if you want to do visual as well, see if you can get EQ5 class mount - OTA is long and there will be too much shake on EQ3.

In any case, 150mm scope will have optimum sampling rate for planetary imaging of 0.35"/px (or 0.175"/px if using OSC camera). If you use 640x480 ROI on your planetary camera to get best FPS, that equates to 112" in width if X-axis of sensor is aligned with RA.

EQ3/EQ5 class mount will have about 30-40" peak to peak periodic error - planet should be all the time in 112" frame - with any sort of decent tracking it will be on sensor long enough to be recorded (I would say one hour easily).

Btw, very good choice for planetary observing and imaging.

[vlaiv]

3 minutes ago, happy-kat said:

How much does your telescope weigh?

I've seen 6.4kg being quoted but it does come with EQ3-2 mount, like here:

https://www.firstlightoptics.com/reflectors/skywatcher-explorer-150pl-eq3-2.html

I think it is a bit under mounted for planetary visual in this configuration - shake will be too large, but it is viable imaging platform, one just needs to add this:

https://www.firstlightoptics.com/sky-watcher-mount-accessories/single-axis-dc-motor-drive-for-eq3-2.html

in fact, I'm not sure if that one is stepper motor, so probably better upgrade would be this:

https://www.firstlightoptics.com/sky-watcher-mount-accessories/enhanced-dual-axis-dc-motor-drive-for-eq3-2.html

[AstroMuni]

The 1200pl is quite long as well, hence you will need to have a sturdy mount that wont shake too much with the wind.

Edited September 15, 2020 by AstroMuni

[bobro]

Although my CG5 (EQ5) is perhaps a bit light for carrying my 150/1200 PL for DSO imaging purposes (though that's how I use it), it is fairly solid and handles the OTA reasonably well for long exposure DSO imaging and should be fine for visual. Planetary imaging uses short exposures and is less demanding on mounts than DSO imaging.

A suitable tracking (not goto) stepper motor for the EQ5 is: https://www.firstlightoptics.com/sky-watcher-mount-accessories/single-axis-dc-motor-drive-for-eq5.html

 

[JokubasJar]

Could I alternatively get the 150/750 eq3-2 variant and use it with a 2x barlow? It weighs less which would help with mount wobble. Would it produce worse or similar results? I plan on using a ZWO ASI 120MC-S with this rig.

Edited September 14, 2020 by JokubasJar

[JokubasJar]

My apartment is also quite high in the city I live in and I normally bring my telescope out on a balcony, would it help if I would make some sort of wind shield to block the wind from shaking the scope?

 

[happy-kat]

What telescope do you currently use, only it might be more tricky to observe using a reflector on a balcony depending on the size of the balcony because of where the eyepiece is.

Does your balcony see Polaris for setting up an eq mount.

[Cosmic Geoff]

7 hours ago, JokubasJar said:

Could I alternatively get the 150/750 eq3-2 variant and use it with a 2x barlow? It weighs less which would help with mount wobble. Would it produce worse or similar results? I plan on using a ZWO ASI 120MC-S with this rig.

 

7 hours ago, JokubasJar said:

My apartment is also quite high in the city I live in and I normally bring my telescope out on a balcony, would it help if I would make some sort of wind shield to block the wind from shaking the scope?

You mean change the whole outfit?  That opens up a wider set of possibilities (depending on your budget).  The 150/750 would be less of a 'wind sail' as well as being lighter. You would definitely need a barlow lens with it for planetary imaging. And it might require more exotic eyepieces for general observing.  If working in a windy environment you should think of using a heavier mount, e.g. EQ-5.  A wind shield would only be partially effective and could itself be a hazard in the event of really high winds.

[happy-kat]

Might be a 127mm mak on a altaz tracking mount might be a fit for the location and the eyepiece is at the bottom rather then potentially over the edge of the balcony.

[Chris]

8 hours ago, JokubasJar said:

My apartment is also quite high in the city I live in and I normally bring my telescope out on a balcony, would it help if I would make some sort of wind shield to block the wind from shaking the scope?

 

I was going to say get an EQ5 with the motor drive kit, but on a balcony I agree with Happy Kat that you would be better off with a Skymax 127 maksutov or a Celestron 6SE SCT.

[RobertI]

Whatever you go for, if you can stretch to the 2” tripod legs it will add significantly to the stability.