Clarkey

11 hours ago, johninderby said:

Not an unknown problem. But a solution..

I assume this is just got the RC version but should not effect the CC's due to the higher F ratio.

I must admit that I have not seen any evidence of this problem with my RC8.

5 hours ago, AbsolutelyN said:

Perhaps get some M42 extension tubes and switch 21mm for 20mm? I can then possibly tweak with 0.3mm / 0.5mm spacers. 

That would be my thought. The 55mm spacing should not be taken as gospel - there is always some deviation. I have a collection of small spacers that get regular outings!

23 hours ago, herne said:

You can use Canon and Nikon DSLRs.  But for dedicated astro cameras you have to use ZWO products.

I'm pretty sure this is correct as DSLRs are not in direct competition with ZWO.

If a laptop is not a preferred option, there are quite a few of us using the Mele Quieter 2 mini PC. Fanless, small and cheap but will run astro control software with ease.

I think it will depend on the coupler. The Sesto senso ones are slightly flexible in the direction of the drive but there is virtually no rotational flexibility. I have certainly not had repeatability issues with this and the Baader Steeltrack.

I guess the advantage is that if the alignment is not perfect it will not put excessive load on the focuser or motor.

Edit. Beaten to it...

I am obviously far too casual about this. I leave my stuff in the garden and go to bed. I have rain alarms but nothing else. Admittedly my garden is not easy to access and cannot be seen from the road, but maybe I should be more careful.

I used to have a PIR in the garage which alarmed in the bedroom. However, it kept going off for no reason so I gave up on the idea.

3 minutes ago, pipnina said:

Which CC worked for you in the end, and what focuser did you use to replace the default one?

I ended up using the SW Aplanatic but it does stick out. I used a parfocal ring to hold it in the right place. With the Baader ST focuser it did not give any tilt issues. However, putting the ST on a 6" scope was a bit of a challenge.

13 hours ago, ollypenrice said:

In my (amateur) understanding the incident photons energize the atoms they strike and these atoms then emit a photon of equivalent energy. Is it accurate to consider this 'the same photon,' whatever that might mean...?  Weird stuff. 😁

Olly

From my rather rusty quantum theory, it must be the same photon for two reasons:

Firstly got the atom to emit energy it needs electrons to move from one specific energy state to another and will only emit certain wavelengths. Given this is not the case, it cannot be happening. (Hence the ability to look at emission spectra).

Secondly, if the photon was to be absorbed and re-emitted it would be in a random direction.

As for the reflection mechanism itself...🤔

Going back to the OP, I only have experience of the F4 TS scopes. In the case of my 6" version I had to replace the focuser, flock the tube and buy a new CC to get reasonable results. Also, I had horrendous reflections that were impossible to filter out. I  going to try it with a OSC camera later to see if this helps.

Unfortunately AP is a frustrating hobby with all its quirks. I have missed countless imaging sessions due to something not working. As stated above, gradually get rid of the problem kit and work methodically. When you get that one excellent result the pain goes away. (Well, mostly). I wish you luck.

I am on my phone so I can't open the raw file. The results with the Aplanatic are good so at least the stars are sorted. I've used a parfocal ring to hold it out slightly. It is now on a Baader Steeltrack so no sagging. I might try the MPCC with the Canon later this year.

Interesting that you found the Baader CC to be ok with the f4 scope. I have one and used it with my TS 6" f4 and could not get good stars even with a smaller sensor than APS-C. I ended up getting the Aplanatic CC and a new focuser. Ended up being and expensive scope!

I also got very bad reflections from my filters so it is "on the shelf" for now. I'll give it a go when I get my OSC camera.

What if both instances of Nina have the same time setting for refocus? If they are started simultaneously they should refocus at the same time. The only possible issue is the amount of time each scope takes to focus. However if you are using synchronized dithering then you should only loose on sub.

As I said, I'm still to sort this issue come the return of astro darkness.

From what I remember the advanced sequencer does not allow for synchronized dithering. There are some other options. One would be to continue guiding during auto focus which I assume would allow the slave to continue data collection. Another option would be to refocus both rigs at a set time.

I have only just started with a dual rig and so far have paused the sequence for focussing so I am still to figure this out myself.

I used a piece of plywood to make a base for my scope. This was bolted into the bottom of the dovetail and kept the scope flat in the boot. This was put on an old duvet for padding. No good if you have a long way to walk but good for car transport.

8 hours ago, AstroMuni said:

But hey make the most of what I have is my policy, until I upgrade.

There was a 130 PDS on AB&S which might be worth a punt.

And you can carry disco balls!!! What more can you ask for🤣🤣

Golf is expensive and even more frustrating and pointless than AP.🤣 

What's wrong with a 120m mini? I use them and they are fine for guiding - and cheap. They are a smallish sensor so the usb 2 is not really an issue.

13 hours ago, Pitch Black Skies said:

2 × 30205M Timken Roller Bearing

6 × 6006-2RS C3 FAG Deep Groove Ball Bearing 30×55×13

4 × 689 2RS Ceramic Hybrid Ball Bearing 9×17×5

I think this is exactly the same as I have used. I'll find out in September if it has improved the mount.

With regards to the question above, I would say the the worm carriers certainly seem to be the main issue. I replaced all the bearings because I had already brought them. However the larger bearings felt absolutely fine and will have less impact on guiding unless excessively worn. I think the most important issue is getting the end float right. Even with the rather poor bearing I removed, the performance was not that bad - but that was because I had over tightened the end float. If you get this spot on (along with the worm carrier) it should give good results. I have now made a tool to adjust this so it is a simple job to set up.

2 hours ago, StevieDvd said:

Personally I would update the focuser for a rack & pinion first

I am also an advocate of the Baader Steeltrack even though it is not a R&P focuser. I have camera and filter wheel hanging off mine but it does not slip. R&P is certainly a good choice but can still have backlash. The ST's do not suffer from this.

Looks much better. Looking at the DEC adjustments it does seem to be under-reacting to the drift (having to make multiple adjustments). Might be worth increasing the aggression or the guide rate.

I think my guiding on the HEQ5 was in the region of 0.7" RMS so this looks similar.👍

Given PHD will guide with an OAG at 2500mm or more with banana shaped stars, I think the ED80 will be a doddle!!

I don't think you can 'over-guide'. However, I don't think you would notice much difference guiding with the ED80 over the ST80 in the final images. I use an ST80 to guide my RC8 at 1600mm FL with a 120 mini so widefield it would be more than capable.

Definitely bigger scope and mount. Pawermates or barlows will just l mean imaging above F10 which is really no good for deep sky. I think 400mm is a pretty good FL for an awful lot of stuff and the next step is looking towards galaxy imaging. Maybe and HEQ5 and RC6 with reducer?

8 hours ago, newbie alert said:

Brain fart

Been there regularly.🤣

Not sure if you can get a direct 12v, but you can get a USB supply which you can always use with an adaptor. Plenty on-line.

I'll add another Hickson 68. Tricky to process because someone decided to put a really bright star in the middle of the group😁.

Imaged on the 23rd and 25th March using an RC8 @ F8 and ASI 1600MM pro in LRGB. In total about 7hrs luminance and an 2 hours each of RGB.

Hickson_68 ST2 AP2.tiff