matija

Hi,

I'm in the process of upgrading my astrophotography setup and considering the Apollo-M MAX camera with the IMX432 sensor for my 2000mm focal length RC telescope.

Currently, I'm using a ZWO 294MC camera and wondering if the Apollo-M MAX would provide a worthwhile improvement.

Primarily, I'm interested in capturing deep space objects. The 12-bit depth and lower resolution of the Apollo-M MAX caught my attention. I'm concerned about how these specifications might negatively impact my images compared to the ZWO 294MC.

If anyone has experience with both cameras or insights into the potential drawbacks of switching to the Apollo-M MAX, I'd greatly appreciate your input. Additionally, any considerations specific to pairing this camera with an RC telescope would be helpful.

https://player-one-astronomy.com/product/apollo-m-max-pro-usb3-0-mono-camera-imx432/

Thank you for your time and expertise!

Matija

@tomato Yeah I'm looking at the mk2 as i'm buying new. The bolt system scares me a lot.

@ollypenrice,

I'm looking at the Mesu200 variant that has three screws in the middle of the angled wedge. No other form of PA. Is it still easy in that case?

Matija

@Elp

Thanks for the reply,

Yeah, I don't mind the wight.

Do you use the 3 screws on the canter of the wedge to PA? And what software do you use?

Thanks!

@licho52Upgrading to CEM120/Mesu200 and and NINA/PHD2

Hello!

I've had an EQ8R for a while now but I want to upgrade as the guiding performance is not good enough for my 2000mm telescope.

A while back I came across mesu200 while browsing some stuff for my other big telescope that uses SiTech, and it got me thinking.

Is the mesu200 easy enough to polar align from scratch every night? I can get within a few arcmin with a laser but then its onto the screws. I've been traveling with the EQ8R for over a year now so I'm used to the weight(I think the mesu is even lighter).

My only real concern is the polar alignment and maybe balance. Can it be done quickly?

Thanks!

Matija

@vlaiv Is there any way to prove that the error is caused by the mount / that its a mechanical problem?

2 hours ago, dan_adi said:

Get a refund and buy a Mesu mount.

@dan_adi Im trying to get one but the seller refuses to accept the mount is faulty. He says its 100% perfect and that the error is coming from outside the mount.

4 minutes ago, vlaiv said:

This is from PHD2 log file that you posted on google drive:

If above is correct and you have 240mm entered as focal length (maybe you used 60mm F/4 guide scope with 240mm prior to switching to OAG and forgot to change focal length?) - then your error is exaggerated by x8 and in reality it is much much less.

Try checking what FL you have entered in ASIAir and correct if needed and then see what sort of guide RMS you get (it will still behave the same - but will probably report much smaller numbers - like 0.5" peaks instead of 4" or whatever the value was).

Ah yes, I forgot. this graph is from when I used a guide scope. 240mm is right

@vlaiv I have a 10" RC at f8 so 2000mm and am ASI485MC with 2.9um pixels that ive set to bin2.

@windjammer My problem is the two up spikes and then a down dip of 2.5" that repeats every 189s or 1 worm rotation.

20 hours ago, vlaiv said:

Skywatcher mounts are hit and miss affair, I'm afraid.

Almost no works very well out of the box for such a demanding application and if you want good performance - you need to do two things:

1. mechanically improve the mount

2. tweak guide settings to best suit your particular mount.

I had to do a lot to my HEQ5 to make it behave in satisfactory way. First order of business is stripping down mount, changing all the bearings for high quality SKF ones and cleaning and re lubing the thing. Next to that, I did belt mod on my mount, changed saddle plate, added Berlebach planet tripod, but you probably don't need to do that as your mount already has belts and decent saddle plate?

Make sure that you also "tune" the mount when assembling it back together. Tune out any backlash / play in gears by adjusting tension where it needs to be adjusted. Maybe lookup EQ8 stripping / tuning videos on youtube. I'm not sure if there are any, but I've seen such tutorials for smaller mounts and they are helpful.

Next is guide settings. I've found that skywatcher mounts need to "accelerate" slowly when doing corrections. They are not very stiff / solid mounts. This means slow correction speed - like x0.25 sidereal. You'll also need to play with aggressiveness settings and other parameters. Min motion parameter (I'm here talking about PHD2 params - not sure how ASIAir handles those things) is also very important - and is often misunderstood one as it is expressed in pixels and not arc seconds. It therefore depends on guide system.

As far as guide exposures are concerned - I'm firm believer in longer guide exposures - but this can be used only if mount is smooth enough, so mechanical tweaking is important.

One thing that you can and should do to tame your periodic error is to do periodic error correction. This will reduce total deviation and will make guide system work less to correct for errors - which is a good thing. Ideally guide system should be minimally employed.

From above guide graphs - I think that you have significant amount of backlash in the mount - and that is something that you need to tune / tighten up while re greasing / changing bearings.

whenever you see pattern like that - it might be sign of backlash issues. In ideal world - one correction is enough to return mount to where it should be. In reality it often takes 2-3 corrections of varying intensity as there is a lot of noise in the data, but as soon as you see that you need a lot of corrections - this means that mount is not responding to correction properly. Either correction is wrong, or mount "responds" to it - without really moving. This is what backlash does. Instead of correction moving the mount it is "spent" clearing the backlash before teeth properly engage again. It can also be sign that there is a lot of lag / flexibility in the setup. To move large mass - you need to accelerate it and it takes time for that to happen. If everything is not rigid and there is flexibility - then this time goes up (think of pulling something with inelastic and elastic rope - with regular rope it will start moving right away as you pull it, but with elastic rope it will take some time for it to start moving).

Hope this helps

@vlaiv

The mount has been tuned and is in the best possible working order.

I tried all possible settings but it still has +-2.5" movements.

A thing I noticed is that it guides ok (+-1") near NCP and very bad everywhere else. Especially the south.

Here is the guide log: https://drive.google.com/file/d/1y-N9JJ4s8g2SWP23eYG_GLFiTeztDZ4A/view?usp=sharing

I cannot do PEC on asiair.

Thanks!

Hello!

For the last few months I've been having a lot of trouble with my EQ8R-Pro. The thing is moving up and down when guiding by 2.5"-3", making it useless for astrophotography. I already sent it back to get repaired but the problem persists. They don't want to refund the money so all I'm left with is to try and find an answer here.

Like I said, the mount guides terribly(I will attach 3 examples). I tried everything from better PA, better balancing, making sure its level, making sure seeing is good, making sure there is no wind, making sure its on solid ground, making sure there is no gable snag and so on but nothing seems to fix the issue. I am using an ASIAIR but the same thing happens on PHD2. I unfortunately do not have guide logs but my PA is 30".

I tried pretty much all settings, guide rates, aggressions and exposure times. Same thing all the time.

I am using a 12.8V battery to power the mount. SW recommends 13.7V but I'm not sure if that's the problem... or can it be?

I'm guiding with an OAG on a 2000mm 10"RC with 5s exposures to prevent seeing effects on guiding.

On a few of the graphs I drew the worm rotation period(189s)

This error repeats every worm cycle.

What else is there to do, check or fix?

I'm lost here. I spent all my savings on this rig that I now cannot use and I feel miserable.

Thank you!

Matija

@Stuart1971how can I tune the RA?

@Stuart1971 My RA axis scrapes a lot and loudly when slewing. Has this anything to do with it?

@Stuart1971 I use asiair and guide with the built-in guide software

Hello!

My eq8r has been guiding rather poorly. The main problem is the huge jumps in the RA axis. I'm on asiair so I don't have PPEC. I'm perfectly balanced and very well polar aligned. I use a 240mm fl guide scope and a 485mc.

Ill attach a few images of my guide graph that displays the issue.

Any help is much appreciated!

Matija

@vlaivThat sounds great. Ill capture data in BIN1 and then perform that after stacking. Now the real question is(sorry if you already answered in more technical terms because I'm a little slow and don't quite get all the details of AP:)), will it fix the effects of bad seeing?

@vlaiv So binning my 294MC (BIN3) won't ruin my colors and data as some said? I find that 1.41"/pix is quite perfect for my usual conditions. So when imaging, I select bin3, and that is it?

Thanks!

Hello!

I have a 10" RC on the way with 2000mm of focal length. I also have an ASI294MC Pro camera. My resolution with this setup is 0.47"/pix which is not good at all for my average seeing. I was debating getting a reducer, but that would ruin my nice FOV, so I decided to ask around about binning on this particular OSC camera.

The MM variant of the 294 has a mode that when binned 1 has some very small pixels and at BIN2 it works normally. The MC variant is not like that. Its working normally at bin1.

I wonder if binning 2 will actually work and let me image the night sky under poor seeing conditions.

Thanks!

Hello.

Recently I've been getting terrible-looking stars despite what looks like perfect collimation. All my stars look elongated. I will post pictures to help answer this question. I use a Cheshire eyepiece. My telescope is a SkyWatcher 250PDS.

Thanks!

Hello!

I'm wondering how I can get PPEC on my asiair plus. My mount likes to have high PE and guiding just isn't enough. I know the synscan app has some option for PEC but nothing can be found in Asiair itself. I connect the mount to the air via an eqmod cable if that's important. Its a skywatcher mount that allows for PPEC.

If you can help me get this working it would be great!

Thanks!

11 minutes ago, Tomatobro said:

is the power in port connected to 12 volts?

@Tomatobro the 12v dc input port on the side of the mount is connected but the one on the bottom back of the mount isn't. My volt meter isn't showing any output on the 3 out ports.

Hello.

My EQ8R Pro doesn't want to power my asiair with its power out ports. Why is that and what can be done? My mount gets 5A trough the power cable.

Any ideas?

14 minutes ago, vlaiv said:

There might be a chance that you have a faulty mirror.

That sort of softness that is visible in the image is indicative of spherical aberration.

Spherical aberration with newtonian can either be due to simple coma corrector used - like 2 element sky watcher x0.95 one, or due to poor parabola on the mirror.

This will only show as softness when viewing at high power - like planetary and lunar views and of course - like stars being little balls in high resolution images.

Alternative to that would be that seeing was really poor on particular night and that created bloated stars.

If you want to check if your scope has spherical aberration (you say you did not use coma corrector) - take out of focus image of bright star - on both side of focus.

Try to defocus it only slightly so that you still get rings visible, and do both sides of focus with roughly equal level of defocus.

Here is guide of what you should be looking at:

When you defocus star pattern slightly and have perfect mirror - you should get first row in above table. Note level of defocus - one that still shows a bit of rings. Your star will have "hole" in the middle when you start defocusing as you have central obstruction.

In any case - perfect parabola will show same pattern regardless if you are in / out of focus.

If you get two different images for same level of defocus - one where edge is fuzzy and center is darker and other where edge is better defined and center is brighter - you have some level of spherical aberration present in the system.

Since you have camera - you can also post images here for analysis.

 

And @vlaiv at 2.9um and a 1/1.2" sensor, do you think, id be possible that a part of the problem is the very inaccurate backfocus? I'm missing 48.5mm of it.