Raspberry Pi Guiding Newbie

[wimvb]

3 hours ago, pete_81 said:

Any last tips before I pack this one in?

Sorry, no more ideas. If it isn’t stable, don’t waste any more time on it. Life is too short, and clear nights too rare. My solution was to get an ASI120MM-S, and finally an ASI290, which both just work. Your camera may work just fine under Windows, so you can probably sell it on with good conscious.

[pete_81]

30 minutes ago, wimvb said:

Sorry, no more ideas. If it isn’t stable, don’t waste any more time on it. Life is too short, and clear nights too rare. My solution was to get an ASI120MM-S, and finally an ASI290, which both just work. Your camera may work just fine under Windows, so you can probably sell it on with good conscious.

Thanks @wimvb, felt that was probably the issue.
What's the potential advantage of the MM-S over the mini? Both monochrome but £70 more expensive for the 'S' to mini?
Just looked up OAG, and to do anything sensible with the longer scope (1200mm), I'd guess OAG would be the best approach, would that affect decision about which may be better suited?

Thanks again for aid on this

[wimvb]

I'm not entirely sure about the differences between the asi120 cameras, other than size and speed (the 120MM-S is usb3 compatible). If you want to go down the oag route, I 'd say that the asi290 is better. The asi120S has too large a body to comfortably fit on an oag. At least that is what I found with my Newtonian and a filter wheel. The 290 has a larger sensor and is more sensitive then either of the asi120 models. You will find it much easier to get stars in the fov to guide on. Usually I can use multistar guiding with my zwo oag/asi290. Only on a few occasions did Ekos have problems finding multiple guide stars. I have so far never needed to move the scope due to lack of guide stars. With the asi120S, I binned 2x2 to get better guiding. The ASI174 mini has a larger sensor, but I wonder wether the pick up prism of most oag adapters can cover the sensor. If not, then having a large sensor is a waste.

If you invest in an oag, then also get a helical focuser for the guide camera. It will make focusing a lot easier.

https://astronomy-imaging-camera.com/product/zwo-1-25″-helical-focuser

Edited June 21, 2021 by wimvb
Typo 130S to 120MM-S

[TerryMcK]

The ZWO ASI120MM mini is fine for guiding whether on scope or oag.

[SiD the Turtle]

On 17/06/2021 at 10:40, pete_81 said:

 

Any last tips before I pack this one in?

Drop the resolution to 640 x 480? In theory that'd reduce the bandwidth requirements.

[pete_81]

Didn't see the point in owning a camera to have 75% of the resolution ignored.
As update, I had seen the ZWO mini on ENSOptical for significantly under the full cost of a new one so thought I'd give it a go. It's presently connected to the RPi running 16-bit mode in the Guiding section of EKOS (just streaming live feed) and has been for the past 45min without dropping a frame running 2sec exposures (connecting only the camera as I did before brings up some odd report in INDI about telescope aperture/focal length missing - this is timestamped and there is no more than 3 sec between each warning - just used matlab to get the max time between each message) so very pleased. And if things do start going wrong, I know I can just drop the bit-level to 8.

Issue therefore put down to Altair not being user friendly without Windows. Moral of story, get the better gear! It just works! 🤣🤐

[wimvb]

6 minutes ago, pete_81 said:

connecting only the camera as I did before brings up some odd report in INDI about telescope aperture/focal length missing

Indi device drivers depend on each other. Somewhere in the documentation there is mention of needing at least two devices: a camera and a telescope/mount. (Without a telescope, the camera can't know fov or pixel scale.) But either of these can be a simulator device. To test a new camera, you connect it to the computer, and create a profile with its driver plus the telescope simulator. You then configure the telescope simulator to match your real telescope (fl and aperture mainly)

[pete_81]

3 hours ago, wimvb said:

Indi device drivers depend on each other. Somewhere in the documentation there is mention of needing at least two devices: a camera and a telescope/mount. (Without a telescope, the camera can't know fov or pixel scale.) But either of these can be a simulator device. To test a new camera, you connect it to the computer, and create a profile with its driver plus the telescope simulator. You then configure the telescope simulator to match your real telescope (fl and aperture mainly)

Yep, I have working profiles, just to emphasise this was single profile just to check the camera performance... The same test highlighted the Altair camera issue, but the 120mm just continued (>1hr without issue).