Uranium235

A good start, not sure whats going on in the bottom right (caused by off focus or misalignment in stacking?). But I do need to mention that you have to be pretty good with your focus to get the best out of the 130, especially if its coming out "hot" - you cant get a reliable focus for about 30min. But, once its settled, focused and locked you dont need to touch it again until you change filter (ive been able to do three nights straight without touching the focus).

Btw, did you get a CC?

I'd almost say thats your best image yet!

You've set the bar now, no going backwards  

An update on the HH-M42 (full image in deepsky section):

I know that Uranium has actually sawn of the ridge of the skywatcher coma corrector in order to put the whole camera setup further inside the focuser and thus reduce the length the focuser sticks into the actual tube. Would there be another coma corrector fitting the 130 pds where you wouldn't need to do that? Anyone has one?

The Baader MkIII will fit the bill. It all screws apart so you can break it down to an M48 thread, it offers no redcution factor - but the field is good.

Excellent work Olly, a "zoomify" version of this would be great!

Igwiz, on 11 Feb 2015 - 06:49 AM, said:

Cheers Uranium.  Yep, I have already abandoned the idea of piggybacking the 130 and the LX together. Just the 130 solo with the ST80 (thanks for the advice on that) on an alteq6.  Only thing I am still grappling with is how the ST80 sits on the 130 (do I need to be anything extra to do that?) and whether my Atik 314L will find focus or whether I need an extension tube of some variety?  Want "Night 1" to be as painless as poss!! Nearly there!

Take a look at the post linked by happy-kat, it goes into the question of whether you really need an ST80 to guide a 130pds. Which in reality, is a bit of overkill - not unless you plan to use it with the LX200 as well.

To mount the ST80, you can either get a dual vixen saddle and guidescope rings. Or to go the cheap route you can just bolt another dovetail and the tube rings directly to the top of your 130pds tube rings. Theyre an M6 thread if im not mistaken. The aforementioned method means you have no adjustment because its fixed, but they should be aligned well enough to guide off. Another downside is that you have made your rig quite "tall", so as it tracks the sky - gravity will have more of an effect on the balance.

If the 130 is going to be your primary imaging telescope, and you have a spare 9x50 finder - then I'd just go with that. All you need then is a half decent guide cam with an on camera st4 port - that will plug straight into your EQ6 st4, and youre up and running! (barring a little configuration of PHD). 

The ST80 would be a better choice for a guidescope if you want to use it with both the LX or the 130pds. Normally a finderguider is good enough, but that probably wouldnt cut it with the focal length of the LX200 (finders can only guide you up to about 1000mm FL). Having said that, the 130pds would happily guide the 200LX.

But.... hang on a mo - the alarm bells are ringing in the weight department. If you combine a 10" SCT with a newt (on a dual saddle), with all the imaging gubbins... and then chuck on an ST80 - thats going to be quite a lump (even for an NEQ6). Plus there is the downside that if mounted, there is no way of adjusting the LX/130 to match, not unless you invest in a quite expensive (and heavy) adjustable saddle. So in conclusion, its probably best to only use one - not both. Using both will just over complicate things when really, all you want is to be up and running as soon as possible.

As for whether the 80ED is better than the 130? Well I have both, and while the 80ED can yield some fantastic, sharp images (if given time) - its just nowhere near as fast as the 130pds (especially when reduced). In the last 12 months I think the 80ED has been out only twice, but it didnt take long for me to get the thirst for speed again. But I still wont sell the 80ED, I still have plans for it (would be nice to turn it into a solar scope with a quark ep) - plus its always good to have a reliable backup telescope should anything go horribly wrong.

Igwiz, on 09 Feb 2015 - 2:24 PM, said:

Inspirational thread guys! Thank you!

A question if I may:  I am about to defork my 10" LX200 and put it on an ALT EQ6 using a losmandy plate.   My idea is to then piggyback a 103PDS onto the LX.  I was then thinking that when imaging with the 103 I could use the LX as a guidescope and vice versa.  Is this completely bonkers? (And what is the easiest way to piggyback the 103 on the LX). Just bought a 314L+ in anticipation!

Many thanks

Ig

Not sure the LX will make a good guide scope since its a far longer FL than the 130pds. And with it being a longer FL, comes the problem of the star "jumping about" a bit too much, meaning that your autoguiding will respond accordingly (by jumping about). Perhaps a way to get it to work would be to adjust some of the PHD settings so its less sensitive. A better solution perhaps would be a separate, short focal length frac that will happily do both (ST80?) - you might even get away with a finderguider.

Hard to say, ive never looked through mine during the daytime. It shouldnt be a problem once you get a camera on it.

Surprisingly light these little newts are eh? Well, they are until you load them up with kit... I think mine doubled in weight when the imaging gear and legweights were attached (feels like it anyway!).

Thanks guys, hopefully if I can get another night or two (with no Moon) I can finish it off and present a full resolution version. Whether I get that night between now and the end of Feb is another matter! Something tells me I might still be doing this one at SGLX

Just a preview of what im working on at the mo, its not ready yet so its just a cut-down version (quite a bit of moon damage on the top strip to be fixed):

On balance it will work out quicker than the 200p for larger stuff, slower FR yes - but youre grabbing a lot more sky so youre cutting down on mosaics. Im currenty trying to finish a 6 pane mosaic - which seems to have taken forever! January wasnt a kind month for AP.

thanks for the info rob but i went the other way and got the 80ED with and FF so now i can get some Wider shots (when the cloud clears) 

the only filter i needed to refocus with is the blue all others seem to be fine but then that was with the 200p ds and the skywatcher cc not sure if that makes a difference.

thanks again

No prob mate

Youre using the 383 with the 80ED reduced yes? Then i might suggest 900s subs as a benchmark, but certainly not below 600s as f6.38 does the 383 no favours.

hi Rob 

do you have a focal reducer on your 130 pds and if so where did you get it, i find myself wanting to do a bit wider field shots than my 200 pds will allow.

Yes I do use a FR (of sorts), its just the Skywater coma corrector. As well as fixing the coma (but not as good as the Baader in that aspect), it has the odd side effect of being a 0.9x reducer. And that reduction factor is tuneable (ie: more distance = more reduction, but more coma). Ive managed to get mine running about 0.87x(ish), which translates to f4.4.

Though its great for NB, its not really apochromatic - so you need to refocus between filters (something you dont need to do with the Baader). If I were to do some RGB work, id probably switch to the other corrector.

Yarrr.... it be another blast from the 130

Fullsize with info can be found in the deepsky subforum.

Oh ok. I have some Velcro though it's of the heavy duty type - the stick-on is really hard to get off! Insulation tape is easy enough to remove. It's, um, just a metal tube! As long as it's functional, I don't much care!  I've left the scope in the box in my bedroom this afternoon - too cold for messing about in there. Will have a go with it tomorrow

Louise

I just need to add, the velcro isnt actually stuck to the scope, I used it to extend the leg strap of the ankle weight so it fits the circumference of the OTA.... a bit like having a really big leg...lol.

Thalestris24, on 22 Jan 2015 - 1:28 PM, said:

Hi Rob

Well I did say a while ago I was thinking of getting one . It's actually not that much smaller than my 150pds - unsurprisingly! I'll probably only be putting a dslr on - plus maybe a filter wheel and definitely the autofocuser, of course. I actually do have some ankle weights though they are 1kg ones. I don't see an easy way of fitting one to the tube except by maybe using tape?

Louise

My leg weights are held on with a combination of velcro straps (to hold it roughly in place), then backed up with a load of elastic bands to make it a snug fit. That makes it easier to remove if you need to... tape would be a bit of a one-way process (and leaves residue on you nice new shiny OTA if left for too long).

Blimey, got a few people jumping on the bandwagon now

Just be prepared to find a way of balancing out the primary (I used 0.5kg leg weights), these little newts hardly weigh anything so they end up going camera heavy.

Thanks! What do I do with the measured gain?

Is the gain camera or chip dependent?

You can use that figure to work out how much time you need for each sub, I find that 600s binned @ f4.4 gives a signal three times cleaner than 600s on my 80ED. So, I can get away with using less - ie: 2 hours binned is normally enough for a clean(ish) pic, and to do it unbinned would take roughly double the time (4 hours).

Im not sure whether the binning gain is chip or camera electronics based (probably both), and will more than likely differ from camera to camera. Thats why you need to check it out for yourself, but theres probably someone better qualified than me to give stats on the internal gubbins of CCD cameras. I just go on real-world observations (which dont always follow whats on paper).

2.97" p/p aint bad! I usually reserve binning for mosaics, as it allows me to quickly build something under tricky conditions - albeit at the price of resolution. Think of it this way, its like transforming your 750mm of focal length into 375mm, except without the increase in FOV. Which is only 25mm less than Espirit 80 (2.78" p/p), and 25 more than the Star71 (3.18" p/p)  - but im just comparing resolution here nothing else.

Its probably worth measuring your gain between 1x1 and 2x2 first. Take some flats at 2x2 (using a Ha filter) and achieve a target ADU of something like 24000 - make a note of the time, now switch to 1x1 and see how long it takes to get the same level, then divide one by the other to get your (rough) gain.

Thanks for confirming that, I thought it might not work.

Jonk, on 14 Jan 2015 - 4:16 PM, said:Jonk, on 14 Jan 2015 - 4:16 PM, said:

Very interesting info on the 130PDS.

Does anyone have any images taken using the longer 130/900?

We're in the process of butchering one that had a broken focuser, to see what can be achieved using a 450D on a motorised EQ2.

Im not sure if a DSLR will come to focus on the 130/900, the only images i've found are taken with a modified webcam (google search).... but type "skywatcher 130pds" into google, and you get a torrent of images

Oh dear.... ive found my first image, taken Jan 2010:

DaveS, on 31 Dec 2014 - 2:01 PM, said:

Well, I've been to FLO and ordered a 130 PDS, a MPCC and two Bahtinov masks (For the 130 and Meg 90). I already have a Premium Cheshire collimator, so fingers crossed!

Welcome to the club!

Good news is that you have the MPCC, which maintains the parfocal nature of the 130. So no need to refocus between Ha and OIII (done it for myself).

It will require more cooldown time than your frac, about 30min until its settled down enough to get good feedback from the b-mask. If you do it hot, the pattern jumps about all over the place making it difficult to judge.

Two things you need, the spacing for the MPCC:

From bottom of T2 thread: 55 (quoted), 57 (actual)

From bottom of M48 thread: 57.5 (quoted), 59.5 (actual)

The numbers marked as actual are what I needed to do in order for it to cover the 8300 chip.

I can definitely echo the above statement in that lasers by themselves (unless its a glatter with attachments) are pretty useless. But when used in combination with a cheshire/sight tube, they do start to prove their worth. Cheshire first, laser second (then repeat if need be).

But it is still possible to get a (very) duff laser. I was given a Seben laser with one of my telescopes and bloomin' awful it was. It couldnt hit the side of a bus, never mind my primary spot!