saac

So just to follow up on my previous and at the risk of hijacking Rob's thread, sorry Rob! Anyway I think I've managed to get a better collimation on my RASA 8 . It's not the quickest of exercises but  I think I'm happy with it now; the weird star artefacts are gone and the auto focuser got a tighter focus and much quicker than before (produced a nice v curve).  So this is a trial image (180 x 60 s) and I left the UV cut filter in together with the RASA's optical window.  There does seem to be mixed reports out there as to what to do . Celestron recommend removing the optical window when using a filter while Starizona suggest leaving it in to achieve the necessary back focus when using their filter draw.  I didn't really pay any attention to framing the image, just wanted to see how the collimation turned out. So for a next step I think I'll try a mosaic on M31 using the ASiAir's mosaic framing routine.  I'm just over the moon that the RASA is now collimated. 

Jim 

Sky is stunning tonight really clear and the air is still and not a cloud in sight. I took a break from using the telescope but couldn't resist a half hour just standing under the stars and enjoying the stillness of all.  

Jim 

I'm a big fan of the ASiAir, I'm running a plus and a pro version. Once you get up to speed with them  (the menu system is actually very intuitive) they just work, allowing you to get on with life. It would be great though if ZWO were to be a little more relaxed on what you can connect but I don't think that will happen any time soon despite some other more open arrivals to the market (Toup Tek's Astro Station ).  So all that said, I think I'd be quite interested in giving Indigo Sky a look. Even just as a nice Raspberry Pi project. Thanks for flagging it up Rory and for the useful instructions above, it's something that I hadn't came across before.  Off to find my Raspberry Pi now  

Jim 

1 hour ago, TiffsAndAstro said:

Is there any harm I could do testing say a 5.3kg scope on my sw SA GTi who's payload limit is 5kg?

I doubt you would do any harm as in structural failure. You may find battery drain is a little quicker and pending on the drive the slew rate may be slower. As per @Tomatobro comment I'd pay attention to balancing. Longer term you may find that gear teeth and bearing wear a little quicker than had been lifed by the design spec. That said, these mounts are not rotating at high rpm nor do they accumulate high "mileage".  So, on balance I think any additional wear on a 0.3 kg excess would be marginal.  Give it a go, see what happens  

Jim  

It is certainly easy enough to refit to other scopes. If swapping regularly I'd think about installing a bracket on each scope and perhaps even a flexible connector so you have them permanently on each scope. This means you would only ever need to swap out the focuser itself. As for magic bullet well I've been imaging mainly DSOs with mine in controlled with the ASiAir. Here the auto focus routine works a treat and it has been totally reliable. Not sure if there is much a difference when using it for planetary, hopefully somebody can comment. 

Jim

I wonder if using cosmetic correction within WBPP would help. It's an extra task to setup but may be worth a try. 

Jim

1 minute ago, ANTARES1_1 said:

I know that if you have been given the wavelength the you can use the formula E=hc(lambda). But I wanted to know what to do when f is not given in the above given formula

 

You determine f from the wavelength. If you do not have the wavelength then you simply divide the electron transition energy difference by Planck's constant as per @Zermelo post above and this will give you the frequency. 

Jim 

8 minutes ago, Mal22 said:

The first comment I heard (at this stage the entries were anonymous) was “well, someone has clearly just taken a photo of a photo at some space exhibition.”

I was delighted.

I was thinking that about the rock photograph, somebody probably visited a rock exhibition  

Jim

22 minutes ago, ANTARES1_1 said:

But what if you don't have the f?

What information do you have?

On 26/07/2024 at 11:23, LaurenceT said:

I know this has never been discussed here before😄 but........

I only have a dinky EQ mount now, the Star Adventurer GTi, and I'm not considering wildly overloading it but I would like to try my ancient refurb project of an Orion ED80 which just might (or maybe not) exceed the limit of 5kg.

Anyway, I've been reading quite a bit about the need to reduce the scope weight to some undefined percentage of the manufacturers stated limit because of various factors. I've had a search of Skywatchers mounts specifications and I can't see anything about reducing the limits of 

any of their EQ mounts, they just state the limit. Indeed on Astrobin a contributor anecdotally claims that a Skywatcher engineer confirmed that the load limit for my mount does not require reducing for imaging, I can't see why this should only apply to my little mount.

I'd just like to know whether there is any engineering or science based evidence ie with experimental data, to show if this load reduction is anything other than anecdotal.

As a mechanical engineer I’m pretty confident that these so called safety margins are all anecdotal if well intended. The main design limit is dictated by the holding torque provided by the drive and gearing and is not a structural limit as such. The proof is as always easy to ascertain, load your setup, image or view and look for any degradation in performance. There is no better evidence than gained by practical investigation.

Jim

Really good session last night (10 Sep) with clear sky all way through. Used the opportunity to carry on fettling my RASA 8 - I think I now have it properly collimated at last and producing decent images. Once I got collimation tied in I ran a 3 hour run on Andromeda as a test, hopefully do the processing today. Turned in a 3 am feeling very happy, my little observatory technician is looking a little tired today! I think she will perk up when we go for a walk  

Jim

Well done, a win is a win.  

Jim

On 10/09/2024 at 01:03, malc-c said:

 

Of course all this discussion is irrelevant for twelve days of the year as per the example shown above  

Now 12 days (nights) of clear sky each would be a thing. Wonder if there is an app for that  

Jim

Crikey. If from two separate cameras it would suggest some corruption or interference is being picked up from elsewhere in the setup as you say perhaps in the usb or maybe the connections.  It will be interesting to discover what you track this down to as the cause. 

Jim 

Brilliant, I love Orion's return to the night sky. 

Jim 

@jambouk, Here's the screenshot from the app I mentioned. It is called SynscanInit and was available on the android store, hopefully still available.  It is simple in that it presents a screen when you open it which gives you the parameters gps, time date etc all in the correct format to enter into the handset. I only use the handset very occasionally now but I find it useful as I can never remember the format and whether we are in DST or not! I don't know if that would help, assuming it is still available.  It would of course rely on each user having the app installed !

Jim 

On 07/09/2024 at 13:22, jambouk said:

It isn’t complicated for me either, but I am trying to simplify the process for other people who want to use the set up on an infrequent basis. I am going to explore using a WiFi dongle.

There an app available which when opened presents all the correct information in the correct format (BST ect) for the user to enter into the handset.  While it is not the automatic data push/pull that you are ideally looking for it really simplifies the task of initialising the handset. I believe it is available for android only I think.  I can post a screenshot tomorrow if it would help. 

Jim

Welcome to the forum, have fun.  

Jim

Best thing to do is a letter to the council asking if they can install a shield.  This is quite a common practice now. 

Jim

One or two useful upgrades there but nothing that sets the heather on fire for me. My ASiAirs are working perfectly at the moment so I'll delay updating for a while.  Good to see they are issuing these regular developments though despite their roll out issues. 

Jim 

Welcome to SGL, clear skies.  

Jim 

I've never used plastic weld before, here's hoping it worked. 

Jim 

@Scosmico That is a nice looking poster and a good idea to frame it. I'll need to have a search through my Sky At Night collection to see if I have kept any of the posters, you have got me thinking now.  

Jim 

2 minutes ago, Spad said:

Thanks Jim!

 

I have seen that rotator.... and it's price to!!! Until I gave a spare 500 quid. I don't mind fannying about manually!

Yep they are expensive, especially given that it is a relatively easy manual task. The only reason for showing the video though was to show you the Air's menu system and how you could use the information to do a manual rotation. I think the Air makes it a relatively easy task, 

Jim 

Yes it does. As you rotate the camera you would also call up another preview image which would of course show the new rotated framing and camera angle.  I know you didn't seek an automated solution but I thought it worthwhile to say that Deep Sky Dad now provides a camera rotator and a connection cable that will communicate with the ASiAir. It looks like quite a neat solution in the absence of any offering from ZWO.  If you watch the video you will get an idea of what the ASi menu/display will show re camera angle and how you could use the same information to do a manual rotation.

Jim