Imaging with the 130pds

[richyrich_one]

11 hours ago, sagramore said:

Hi everyone. Two more photos to add to the 130-PDS party  I have posted them "properly" with the respective write-ups in the threads linked under each image, but both were taken with the 130-PDS on an NEQ6 mount, unguided, with an unmodified Canon EOS 550D.

 

M97 Owl Nebula and M108 - full thread here: https://stargazerslounge.com/topic/265499-messiers-97-owl-nebula-and-108-galaxy/

 

M101 Pinwheel Galaxy - full thread here: https://stargazerslounge.com/topic/265501-m101-my-first-48-minutes-of-the-pinwheel-galaxy/

 

The Pinwheel certainly needs more data, it's a deceptively dim subject! I think I should wait until I get autoguiding set up though first.

Thanks for looking!

 

Hamish / sagramore

Impressed you're getting this kind of result unguided. I can't do 10 sec unguided without trailing with supposedly good PA.

[sagramore]

22 minutes ago, richyrich_one said:

Impressed you're getting this kind of result unguided. I can't do 10 sec unguided without trailing with supposedly good PA.

Thanks - I'm pretty surprised too! It helps when you look for targets near polaris of course

I think I'm really pushing it with 2 minutes as I do not drift align and I do lose some subs to vibrations and stuff - perhaps it's periodic? I am hoping to get an ASI camera to start guiding with soon to try and fix some of those issues.

[StamosP]

Hello again, 

I've done some calculations about the size of the secondary (i think it's 47mm) and i'm thinking of replacing it with a 58mm one to illuminate better the aps size chip of my canon. The central obstruction will go from 13% to 20% but i also want to remove 2cm from the focuser's tube or push the primary up to protrude less in the ota (more light and no D shaped stars).

In this way i think the amount of light hitting the primary will be slightly more so there will be no decrease in contrast.

What do you think? Is there something wrong in my calculations?

[Uranium235]

You just need to be aware that a larger secondary may give rise to unwanted diffraction effects. But give it a try, you have nothing to lose!

[StamosP]

16 hours ago, Uranium235 said:

You just need to be aware that a larger secondary may give rise to unwanted diffraction effects. But give it a try, you have nothing to lose!

I'll probably remove the secondary with its holder from my 200pds (58mm secondary), throw it to the 130 and see how it goes before proceeding to a more permanent solution.

How much is the focuser extended when using a ccd? If i remove  2cm will it reach focus without the need of an additional extender-adapter? (i use a canon dslr)

[Uranium235]

It will be roughly the same distance as a DSLR since the spacing from the CC is exactly the same.

[StamosP]

My latest image...

My plan was to collect more than 3hours worth of data but clouds had a different opinion, so i managed to capture 72min total.

Furthermore there was an enormous Saharian dust cloud all over Greece making the sky brighter than usual so my subs were rather short, 90s each at iso1600. From the site i'm shooting under normal conditions i can easily manage 3+minute long exposures, same iso.

130Pds+SW x0.9 CC, Canon 600d Baader astro mod, HEQ5pro, ZWO Asi120mc+9x50 Finder scope

Phd2, BYEOS, DSS, Pixinsight

48x90s Lights iso1600 (dithered every 3images), 20 flats, 10 darks, 40 bias

[Dbswales]

Hi everyone. This is my first image on my 130pds. I didn't manage to get many subs as I was trying to image it before it went behind next doors tree! 

Hopefully it's recognizable to you as M42 but I had so much pleasure seeing 'something' when it went through DSS and Pixinsight.

I know it's not the best but I can't help feeling totally chuffed to bits with it.

 

[StamosP]

Hello everyone

Does anybody here use a hutech idas lps d1 filter?

I'm thinking of getting one but i wonder if there are any reflections with this combo since i've read reports about reflections with this filter (even though it does a pretty good job supressing lp...)

[Uranium235]

Pimping up the 130pds ready for short summer nights:

 

Before flocking: (scattered light all over the shop)

 

Flocked: (now blacker than a miners black bits!) apart from the strip up the middle where the tube seam is.

 

 

[Marky1973]

Not even light can escape.....

[StamosP]

On 11/4/2016 at 23:47, Uranium235 said:

Pimping up the 130pds ready for short summer nights:

Before flocking: (scattered light all over the shop)

Flocked: (now blacker than a miners black bits!) apart from the strip up the middle where the tube seam is.

 

Details please! 

What material did you use? Was it difficult removing and reinstalling the primary mirror cell?

I can source easily this sticky velour paper (is this what you used?) but i'm a little bit concerned about dust and moisture issues...

[Uranium235]

9 hours ago, StamosP said:

Details please! 

What material did you use? Was it difficult removing and reinstalling the primary mirror cell?

I can source easily this sticky velour paper (is this what you used?) but i'm a little bit concerned about dust and moisture issues...

This is the stuff I used:

https://www.firstlightoptics.com/misc/black-velour-telescope-flocking-material.html

The primary mirror is probably the easiest thing to remove (I gave mine a good clean too). The focuser also needs to come off, as well as the finder shoe  - but the biggest concern are the spider vanes as you need to find a method of re-centreing them when you put them back. What I did was to get a piece of card and make a circle exactly the same circumfrence as the OTA inside, then punch a hole in the middle  - and once re-installed all I needed to do was line the centre screw up with the hole in the card.

Other difficulties are actually getting your arm in there to smooth down the flocking, 5" doesnt give you a lot of room to move about so take it easy and get as many air bubbles out along the way as you can. The last half an hour was spent shifting air bubbles and using spare flocking to make a new bottom cover for the telescope.

Other new parts include a T2-2" dovetail adaptor which includes an M48 thread. I thought I would give it a go so I can see if its any better than my exisiting all threaded connection. Inital tests show that it rivals the holding power, thanks to the dovetail connection  - as when the three thumbscrews are tightened up - if forces the adaptor downwards (and therefore tight against the pushfit adaptor).... no slipping or slop. The advantage being that I can adjust the camera angle with ease (which isnt the case with my current setup).

One other thing of note was while I cleaned the primary I took a look at the mirror clips - they seemed to be gripping the mirror (maybe) a little too tightly so I back off one or two of the screws. First thought was "blimey.... how tight are these?!!" - they were done up as far at they will go! So i got a few rizla papers and backed off the clips until I could get a paper in, after which I gave each a tiny tighten up just enough so its enough to hold it without any danger of movement.... whether it improves the performance (or not), I wont know until its tested.

Hoping for some clear sky this weekend so I can give it a go - running at 580mm / f4.4... nice

[StamosP]

Thanks for the info Uranium!

I'm looking forward to see your opinion after the tests. 

Is the flocking material paper like or rubbery-elastic? I have seen in a local book store rolls of self adhesive black velour but it doesn't have any elasticity, it's basically  a sheet of paper with adhesive on one side, velour on the other...

One other thing, if i remember correctly you have a Baader MPCC, what have you done and your focal length is shorter than native?

I own a SW coma corrector but i'm not pleased at all, the only thing that makes me keep it is that it acts as a reducer... If i can make my system run at 580mm with a Baader cc i'll order it immediately!

[Uranium235]

Yep, its got a sort of rubber flexibility about it. I used up a bit more tonight and made a new dewshiield, looks pretty good now

I have two correctors for this telescope, the Baader MkIII - and the SWCC, which also acts as a 0.89x reducer (+/- .2 depending on spacing). My SWCC has been butchered (lol) with a hacksaw to remove the stop collar, it now happily sits within the drawtube so I actually gain backfocus. As long as I've got the spacing right and dont point it at any bright stars it should be ok - especially in Ha (where bright stars pose no problem).

[Uranium235]

130pds back out of (temporary) retirement!

 

[Owmuchonomy]

Excellent Rob. As a Mod can you move my post from here ...

.... To this thread. I must have messed up.

[Uranium235]

No need to move it, just post the image in this thread

[Owmuchonomy]

In preparation for May 9th and because I am panicking as my Lunt is not here yet I made a white light filter for the 130PDS.  I set up this morning in Alt-Az mode to do some visual and of course was taken aback by the shear size of AR2529.  I wondered if my ASI 120MM would work so I stuck that on too.  Here is the result from a 60 second SER file this morning.  I feel a bit more confident for May 9th for Mercury and April 20th for the ISS solar transit.

[happy-kat]

In really sorry but I can't read your post at all, even the normal trick of highlighting the text doesn't make it legible. It is black rows with dark grey text.

[StamosP]

Uranium did you notice any improvement after flocking?

I found a local hardware store that sells DC-fix black velour, i think it's the same with the one you used. Have you noticed any shedding?

[Uranium235]

7 minutes ago, StamosP said:

Uranium did you notice any improvement after flocking?

I found a local hardware store that sells DC-fix black velour, i think it's the same with the one you used. Have you noticed any shedding?

Its been a while since I last used the 130, but yes it does appear to improve the contrast and seems to have made my flats more accurate since light isnt bouncing around inside the OTA and bypassing the mirrors. No shedding either.

[Robp]

I also took my 130pds out to do some solar imaging (Remember the solar filter people!)

This is a single frame taken from my canon 1100D and colourised using this guide:

 

[Uranium235]

Darn it...  I missed that monster sunspot, probably because I was working or otherwise engaged.

[Jonk]

If anyone's looking for a used 130PDS, one has just popped up on ABS -> http://www.astrobuysell.com/uk/propview.php?view=111748