Starflyer

I have a Coronado SolarMax II 60 / BF10, and have imaged on and off with an old USB 2 CCD camera for a few years. I want to make the most of the sun's activity building up and so I'm in the market for a new camera.

What are people using these days, I have my eye on a 174MM, but is this the best solution? Also what tilt adapter are people using, I haven't needed one with the CCD, but with the move to CMOS I guess I'll need one?

I have a fast mini PC with an m2 nvme drive so I should be able to capture at decent speeds.

Cheers,

Ian 

8 hours ago, AstroGS said:

Thanks for your feedback - any chance you are using the mount with Asiair?

 

Afraid not, I value my ability to choose cameras not made by ZWO, and to run software of my choosing. I run a mini PC and power box mounted on top of my OTAs.

There's an iOptron Facebook group that's quite active, you should get some answers there. 

I've owned a number of Skywatcher EQ6 variants over the years, the quality of these was quite varied, the AZEQ6 GT being the best performer.

A few years ago I bought a CEM60 EC and it has performed flawlessly since then, so much so that I now own two of these mounts. People complain about the difficulty in getting the CE mounts balanced, personally I see it as a benefit, an EQ mount can be just as much out of balance but you'll never know it due to the axis resistance.

All mounts can have problems out of the box, I'd guess I see around an equal number of reports of problems between Skywatcher and iOptron mounts.  I'm biased, I regularly get a guiding rms of below 0.4 arcsec at 17KGs / 1200mm focal length with an OAG, but I'd always buy iOptron now.

On 28/03/2023 at 11:34, Coco said:

Ive discovered that 60 minutes cool down isn’t enough, the little fan just doesn’t cool it fast enough, I now use a house fan.

 

I noticed this with my VX10 and then CT10, the fans were sucking air down the tube, I flipped them around so they blow up the tube.  Cool down time is much reduced, it breaks up the static layer of warm air on the surface of the mirror, and it has the added benefit of keeping the secondary pretty dew free.

Thanks for the answers!

I found this excel sheet, it's called 268TradeoffEstimator_b.xls, it shows a lot of stuff that's over my head but looks useful.

I think I'll try Mode 1, gain 0, with 300s subs for L and 420s subs for RGB, does that make sense?  Of course if I see a large amount of blown out stars or galaxy core I'll have a play until I get a better result.

I get a decent FW figure from Mode 1 / gain 0 and a similar DR to Mode 0 / gain 26

Does anything stand out as glaringly wrong with my assumptions?

Cheers, Ian

Good afternoon

I'm after some advice on mode, gain and offset.  I've had my QHY 268M for about a year now and shoot only 10 minute narrowband subs, mode 1, gain 56, offset 30 from my Bortle 6 garden, which works well for me.

I'll shortly be heading off to darker skies (Bortle 2) for a long weekend and want to try and image some galaxies in LRGB.  I've had issues in the past with my Atik 460EX blowing out the cores of galaxies and really want to avoid this as it ruins images.

I'm guessing mode 1 isn't the best choice for LRGB unless I go for very short subs, something I want to try and avoid for processing reasons, unless there's overwhelming reasons why I should stick with it.

I'll be shooting at f/4.8 with my CT10 if that makes a difference.

Cheers, Ian

I think you're over thinking the problem.  You don't need to compensate for the exact amount of backlash, any amount of compensation over is fine, any amount under will show as a dogleg in the first part of the U curve.

If you want to get it close to save a second or two on each focus run then decrease it until you start seeing a dogleg and then add a decent percentage to cover any variation.

Example of backlash, taken from the N.I.N.A page.

On 10/02/2023 at 08:12, newbie alert said:

 

So your arc secs per pixel is the same as your pixel per pixel is it? 🤔

ASI 174MM Mini, OAG at 1200mm fl

9 hours ago, newbie alert said:

I have the same mount, looked astonished on your guiding as mine doesn't guide like that but then I see you're on pixels...which could be absolutely anything 

It's in arc seconds.

Hey Carl, I love my iOptron CEM60 mounts, and I'd say go for a CEM70 but it's over your budget and that's without a tripod, it'd be a mount for life though.  You may get away with a CEM40 or a GEM45 but the Esprit 120 is a big, long, lump and I'd want to find someone to speak to who's successfully using that combo before buying one.

This is 17KGs, I still can't image in wind but when it's calm it performs amazingly.

Cheers, Ian

Thor's Helmet is very low down, you'll have been imaging through a large mass of atmosphere, if you're imaging over any buildings or houses, even in the distance, then this will make the seeing even worse.

Apart from checking settings and running the guiding assistant, try a run at a higher altitude and see what you get.

Disable Norton permanently, it's awful 😐

The calibration works over 25 pixels and afaik that's set and can't be changed.  I aim for about 12 steps, you're getting four or five steps at 1050ms calibration step size, try dropping it to 350ms, that should sort it out.

I've only taken a quick look on my tablet but it looks like you have some pretty bad sensor tilt, this will affect your ability to judge and set your backspacing properly.

If it were me I'd analyse the subs in ASTAP to get a handle on the tilt and find where it's coming from / how to correct it before going on to tweak the spacing.

On 25/01/2023 at 14:37, Stuart1971 said:

Hi,

No there is no movement on anything physical at all, and with other stacks pointing in the same area of sky, the tilt that appears comes from all different angles, it’s not at all consistent, sometimes from the bottom left corner, sometimes all across the top, and also from the left, BUT, the actual images done look any different…so I think it’s an anomaly with CCD inspector somehow, as the figures it churns out are just not right at all, I have some that show 40% curvature and 35% tilt, and yet the images look pretty much the same as above….and those about were all with approx 15-17% curvature, and between 1-9% tilt….really odd….

Have you tried the analysis with ASTAP?  I think it's reached the stage where it's better than CCD Inspector now.

If you're already using NINA then consider getting a mini PC to fix to your scope or mount instead.  You can then easily remote into this from your laptop.

I've rebuilt a few Skywatcher mounts over the years, the most important thing I learnt is that less grease is better than too much.  If you pack the bearings with grease you'll get stiffness and stiction, I thin smear is far better.

I had a night off absolutely dire seeing on Wednesday, I thought the same as you; something must be wrong.  After rebalancing twice and making sure everything was tight I noticed the FWHM was really high, autofocus was really struggling and I packed up, I've never seen it so bad.  I set up last night and everything was back to normal, I know clear skies are in very short supply but don't be too quick to tinker with a working setup.

It's probably not your mount but poor atmospherics, that said, it's best to set up your worm backlash in the average temp you'll use the mount at.  I'd say ~ 10°C for the UK, if you set it up too cold it'll bind in the summer.

Use a proper, separate, USB hub if you can.  The USB hubs built into ZWO cameras are notoriously flaky, it'd be an even more expensive try out if you bought a new camera only to find it hasn't solved your problem.

9 hours ago, nickarp2000 said:

Success

I reseated the dec connectors and updated the firmware on the dec and ra axis.

Everything back to normal.

Thank you for the suggestion, at least it wasnt a complete disaster.

Merry Xmas

Nick

Good to hear you got it sorted Nick, it was probably only the cable, but you need (or it's best) to have matching firmware on the handset, main and motor boards anyway.

1 hour ago, nickarp2000 said:

Brilliant, thank you .

I will swap them over tonight to see if its a cable issue

Thanks for your help

Nick

I didn't even swap the cable, just unplugged and replugged each end a few times.

It's this cable, I had it play up on mine a few months ago, unplug and replug a few times, it fixed mine, no issues since.

Just measured my QHYCFW3, 17.08 to 17.12, hope this helps.

Steppers click when they stall, I doubt any damage has been done to the gears.

On 15/11/2022 at 14:48, Andy56 said:

I'd done a search on the PHD2 Help file for "pulse" but it returned no results so I'm assuming its not referred to as pulse guiding. I've had another look through and found it's referred as "pulseguide" so my original search did not find it.

You need to enable pulse guiding in the EQMOD setup, see the second image in the NINA help page.

Also check the pulse guide rate on the right hand side of the normal EQMOD page, set it to 0.5 - 0.8.

Create a new profile in PHD2 and use the wizard to populate the information, make sure that the guidescope focal length and pixel size are correct.  To get the best calibration I do the following; in PHD2 go to Tools - Drift Align and press slew, once the slew had finished close the Drift Align tool, this has taken you to the best area in the sky to run the calibration, perform your calibration.