Imaging with the 130pds

[Marky1973]

Here is the latest image from the 130.... might be the last for a little bit as the WO71 gets a good run:

I'll find a way to incorporate both telescopes into the setup, but im trying to avoid guidescope rings on the frac... maybe some sort of adjustable saddle is in order, would prefer to make it because buying one is pretty expensive.

Actually... just thought, I do have some other data to process from the 130... totally forgot I had that! (got an M45 kicking around somewhere)

Just catching up with this thread and that is an amazing image Rob....

[Uranium235]

Cheers Mark & Chris, the 130 will probably ride again tonight - another clear night so I might have a very belated stab at the Veil. Still not yet worth doing any OIII as I will barely get an hour before Mr Moon comes along to spoil the party.

[happy-kat]

I love following this thread lots of cracking images to look at.

[JimFR]

Cheers Mark & Chris, the 130 will probably ride again tonight - another clear night so I might have a very belated stab at the Veil. Still not yet worth doing any OIII as I will barely get an hour before Mr Moon comes along to spoil the party.

Ahh yes! Sometimes the solar system is just grit that gets in the way! ;-)

[JimFR]

While you're all here, I'm getting a bit frustrated with some images - I managed to find M15 and M71 photographically (and with a bit of luck and educated guessing!)

but I may have misguessed the exposure required.

What would you suggest for a DSLR on a 130PdS for these two?

14x30s @ ISO1600 is probably not enough, I'm guessing...

Edited October 4, 2015 by JimFR

[Uranium235]

While you're all here, I'm getting a bit frustrated with some images - I managed to find M15 and M71 photographically (and with a bit of luck and educated guessing!)

but I may have misguessed the exposure required.

What would you suggest for a DSLR on a 130PdS for these two?

14x30s @ ISO1600 is probably not enough, I'm guessing...

The exposure time might be enough becuase theyre only point sources, but both are going to appear pretty small on your chip. I guess you could crop the image dimensions so it diplays at pixel scale (ie:100%).

[JimFR]

The exposure time might be enough becuase theyre only point sources, but both are going to appear pretty small on your chip. I guess you could crop the image dimensions so it diplays at pixel scale (ie:100%).

They do come up small, yes. The sky isnt great, nor's the chip resolution either, but I did figure out flats (a bit ;-) )

[Uranium235]

Pelican unbinned:

3.5hr 2x panes, 1x1bin (1.7" p/p), taken earlier this week

Fullsize:

https://farm6.staticflickr.com/5713/21762453009_5419866149_o.jpg

[HenryW]

Fantastic! What is  "Unbinned" ?

[Uranium235]

The majority of mosaics I do with the 130 are with the CCD in 2x2bin mode (binned), this has the effect of summing a group of 4pixels into one big pixel (eg: instead of pixel size of 5microns, it is now 10) - that summing of pixels improves the signal/noise ratio (giving cleaner images, quicker).

However, because I have effectively doubled the size of my pixels, it cuts the resolution and image scale in half (a bit like using a 325mm FL telescope - instead of 650mm). The resolution of binned 130/383L is 3.4" p/p (image dimensions 1677x1264) - unbinned, that improves to 1.7" p/p (3354x2529).

So basically I went 1x1 for more detail and a much larger image  but, 1x1 takes more exposure to get over the noise.

[Thalestris24]

That's a fruity one, Rob!

Louise

[simmo39]

Another little experiment! went out the other night to try a few things and had a quick shoot at M 31. I have bee playing around with Gimp, Pixlr and the trial version of Pixlnsight. All have advantages for me, Free for the first 2 lol. But Pixlnsight is amazing. The only problem is that there is so much on there that I havent got a clue or time to work out how to use!. Anyway here is my latest effort.

Edited October 5, 2015 by simmo39

[Ishan Mair]

I got some time off work and since I have a Baader MPIII waiting for me, I tried to collimate my scope first time in over an year. BUT A collimation question : Should the 130PDS have secondary offset when seen under the focuser? I mean when I put the collimation cap on and see though the hole, I see that secondary leaves a larger space below it than above. The circle of the drawtube and secondary mirror are not concentric. The orientation of scope is parallel to ground and focuser extended vertically away from ground.

Ishan.

[sidelight]

As far as I am aware the secondary should be centred and concentric in the cap.  The offset comes in later when you align the primary with the secondary.

Cheers

Ross

[Interstellarshaw88]

some fantastic images on here people,

uranium hats off to you mate, most of your images are simply amazing.

[miafey]

Amazing results from a 130!

Can't wait to get my 150 now!

[Uranium235]

some fantastic images on here people,

uranium hats off to you mate, most of your images are simply amazing.

Thanks

But I'd say they're within reach of everybody, given a bit of practice, patience and tinkering (same as any newtonian really).... oh, and a half decent mount & camera after all, the optics are only 3rd on the list of considerations when it comes to narrowband AP (#1 being the mount, and #2 being the camera).

[Interstellarshaw88]

Don't pull your self down, fantastic images mate something I will be looking forward to learning how to do that's for sure

[simmo39]

my latest go       Cocoon Neb.

Edited October 10, 2015 by simmo39

[Ishan Mair]

Nice image that !! Which coma corrector do you use?

[Ishan Mair]

As far as I am aware the secondary should be centred and concentric in the cap.  The offset comes in later when you align the primary with the secondary.

Cheers

Ross

Thanks Ross. Collimation has got me worried after getting squarish stars in Baader MPCC III. The secondary holder itself looked a slight displaced from the centre when seen with the cap (not up-down the telescope tube..but the other direction). I rotated the secondary, it looks ok now. How tolerant is collimation in this scope?

Ishan.

[simmo39]

Nice image that !! Which coma corrector do you use?

Hi,thanks,  i use the Sky watcher one. not sure if its the best but seems to do the job.

[sidelight]

Thanks Ross. Collimation has got me worried after getting squarish stars in Baader MPCC III. The secondary holder itself looked a slight displaced from the centre when seen with the cap (not up-down the telescope tube..but the other direction). I rotated the secondary, it looks ok now. How tolerant is collimation in this scope?

Ishan.

Its a fastish scope and will benefit from being right.  In the end, after trying several times, I ended up stripping mine right down squaring the focuser, resetting the spider etc.  Now its right....

If its all out, it may be as well to at least start nearer the beginning and check your secondary is central in the spider.  

As well as astro babys fantastic guide http://www.astro-baby.com/collimation/astro%20babys%20collimation%20guide.htm I recommend watching these videos which take you end to end - https://www.youtube.com/watch?v=zd-fl9SEYHw

Collimation is not as bad as you fear, you just need to get each stage correct and it all falls into place.  If you rush a stage and assume its "good enough" you will end up going round in circles, as I did, trying to correct an error should have been corrected before.  Allow yourself plenty of time the first time, and know its going to be frustrating.  Once done it takes a couple of minutes when you set up just to tweak things back to where they should be.  

Cheers

Ross

[Ishan Mair]

Astronomyshed is the place to go !! Thanks for the links.

I dont think I will strip anything after bad experience with my mount.

So I'll start with resetting the spider. Following astro-baby's guide, I'll make a circular sheet, put a hole to it and check spider position. I agree collimation is not as bad as it seems. I have had good experience collimating my XT8.

Its just this sideways shift of secondary that got me worried. Infact, despite this problem I can do the rest of the process to get exactly the view through the collimation cap as shown in this image by astro-baby. ( Mel, I hope its okay to use the image for this purpose.)

[StevieO]

Here's one from last night, NGC7000 in Hubble pallet with my recently acquired AtiK 383L. 12 x 10min Ha, 6x10min for OIII and SII, stacked in DSS and combined in Photoshop, using the excellent Annie's Actions plug-ins. 

Looks well at first sight but I keep getting slight misalignment of the channels towards the edges, which I assume is down to tracking/rotation errors. Any suggestions or comments welcome.

Cheers

StevieO