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Imaging with the 130pds


Russe

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I had first light with my 130 P-DS last night, but nothing to write home about, just getting focus and stuff. Did get an image of the moon, but so near full it's not worth posting.

May have another go tonight if it holds clear.

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Real First Light!

After much faffing around I managed 12 x 240 sec subs of M42 through 3 nm Ha

post-3064-0-81074700-1425586681_thumb.jp

Unfortunately the focus was a bit off, probably in my haste as my imaging time was slipping away and didn't take time to slew to Betelgeuse and refine focus with the Bahtinov mask. The stars are a bit soft and I see some doubled diffraction spikes.

When the moon moves out of the way I'll be having a go at some of the brighter galaxies, ones that I might stand a chance of imaging through this horrid orange murk.

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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?

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Yes, I'm using a Baader MPCC. I think part of the problem was down to my haste and, yes, laziness. I'd been using the Baader L filter for my first trials the previous night, then switched to the Astrodon Ha for this image. The first trial exposure had looked OK so I went ahead with this run. In hindsight I should have slewed to Betelgeuse and touched up the focus with my Bahtinov mask, but I'd been faffing around so much and I wanted to get this run in and the kit put away before turning in myself that I skimped the final touch.

I set up not long after I got home from work about 5.30 or so but it was turned 9 o/c before I had M42 in the field and was ready to start imaging. Most of this delay was due to actually finding my target what with meridian reversals and not having any kind of finder on the 'scope. I think a few more adjustments need to be made, along with fitting a finder. If I do fit a finder I'll also need to add some counterweights to the tube to balance the camera and filterwheel.

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Blimey, you need a finder! :)

Im using the Baader sky surfer (RDF), it came with the telescope as a freebie and it helps a lot with those initial calibration stars that have you doing a limbo dance under the telescope. But normally, after the first star is done, the following two always land fairly close to the centre of the CCD chip (I use the crosshairs in Artemis to calibrate the mount).

For your next test, try to find something in a good starfield and take a few subs for inspection of the corners. Youre using a nice camera, so you want to make sure you can use every last pixel (just in case you start getting into mosaics).

To get better balance, leg weights are pretty good.

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Yeah, got a lot of work to do. I've a RDF on my Megrez but it won't fit the 130 unfortunately, something more to buy. I'd hoped to get away without adding counterweights, but I guess I'll just have to bite the bullet and put some lead on the rig. Something like M44 has a nice field of stars and is well placed ATM so might make a good target for testing flatness of field.

The PA could do with a tweak I think as the guide graph looked pretty horrible.

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I very much endorse the Astrotortilla/Eqmod solution: no need for finder. Getting the focus tight is the key with 130pds: I agree with Rob, need at least 30m

to cool down and stabilize. Fitting the inexpensive skywatcher motor focuser is one very efficient way to get the focus tight remotly from a warm room,

cheers

E.

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I very much endorse the Astrotortilla/Eqmod solution: no need for finder. Getting the focus tight is the key with 130pds: I agree with Rob, need at least 30m

to cool down and stabilize. Fitting the inexpensive skywatcher motor focuser is one very efficient way to get the focus tight remotly from a warm room,

cheers

E.

Hmm... wonder how the 130pds compares to the 150pds. I fitted a SW 'autofocuser' to the 150pds not so long ago. It's made focusing much easier and once focused, keeps it quite well. I'm going to do the same with the 130pds once I have it set up properly :)

Louise

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I very much endorse the Astrotortilla/Eqmod solution: no need for finder. Getting the focus tight is the key with 130pds: I agree with Rob, need at least 30m

to cool down and stabilize. Fitting the inexpensive skywatcher motor focuser is one very efficient way to get the focus tight remotly from a warm room,

cheers

E.

Im still a bit old-skool when it comes to calibration and pointing, prefering to separate tasks out (netbook imaging, mount pointing). However, I do use Stellarium mount control from time to time (depends if I have a USB socket free), especially if im going off the beaten track. To take images over subsquent nights, I use the markers function in Artemis - which always gets me quite close. Low tech, but it works :)

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Hmm... wonder how the 130pds compares to the 150pds. I fitted a SW 'autofocuser' to the 150pds not so long ago. It's made focusing much easier and once focused, keeps it quite well. I'm going to do the same with the 130pds once I have it set up properly :)

Louise

Hi Louise,

It should be quite similar to fitting it to the 150pds, and as you say it holds focus pretty well for a few hours,

E.

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Hi Louise,

It should be quite similar to fitting it to the 150pds, and as you say it holds focus pretty well for a few hours,

E.

Hi

Oh, yes, fitting the autofocuser won't be a problem. I was just wondering how critical the 130pds focus will be, as people were saying... Of course I'll find out - eventually! Coma corrector (and filter drawer) are on their way! :)

Louise

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  • 2 weeks later...

Can i join this club, yes i own a 130p ds  :grin:

Right, i am NOT a deep sky imager but the plan is........i can see you all wincing at this,...........130p ds, 1000d un modded and ...............8SE alt az mount  (runs for cover)

The main reason i got the 130 is to use as a widefield visual scope on the goto se mount but nothing wrong with putting the camera on it and shooting some rough and ready images of things like the ring neb, M42, M45 and maybe a few brighter globs, if this does not work i will still have a good visual scope on goto, oh and i can image the moon with it, my fav subject :cool:

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Welcome to club 130 :)

Ok, the mount isnt ideal, but there is still stuff to be had - plenty of givers (M27, globs etc). Im not sure how long your max sub length will be before field rotation kicks in, but just give it a go and find the limit.

Ive got a couple more snaps to process from SGLX, but its just clouded over so im going to take the kit apart now.

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Welcome to club 130 :)

Ok, the mount isnt ideal, but there is still stuff to be had - plenty of givers (M27, globs etc). Im not sure how long your max sub length will be before field rotation kicks in, but just give it a go and find the limit.

Ive got a couple more snaps to process from SGLX, but its just clouded over so im going to take the kit apart now.

Cheers Rob, subs will be 30 secs to 1 minute max, im thinking 1000d with 2" nose piece direct into focuser and 2" lp filter. No point in even trying for  few weeks till i move to new house. By the way your images are top notch, very good indeed

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Jules,

Here it is

attachicon.gifIMG_20150322_135923251_HDR.jpg

Is yours different?

Cheers for the picture, i bought mine used and its ended up with a very low profile generic 1.25 reducer, i strongly feel i will struggle to get focus with 1.25 ep`s, i have sourced a higher profile reducer that slips into the 2" focuser and should be about right height

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I gave the scope a try today with a nearby mountain here but i couldn't focus with the supplied 28mm 2" eyepiece

With the 1.25" eyepieces i had i was able to focus easily, could it be because of the distance of be subject?

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