Imaging with the 130pds

[D33P]

10 hours ago, bottletopburly said:

Did you sample stars for colour? Core showing Green try sampling a selection of the core for colour then press sample  m31 works quite well this way and use the rgb sample to see if green channel is dominant then knock green channel down until you see green almost disappear  that a nice image well done .

Thanks for the advice. I'll be honest, I don't if I used the stars for colour or not. I'm very much still at the 'randomly click stuff until stuff looks better' stage. I have a lot to learn. I'll have another go at Startools later in the week when I have a bit of time to spare.

[AstroMuni]

On 07/09/2021 at 18:25, Maho said:

This is no way as good as most of the images put on here but this is my first ever picture after processing in GIMP. I could only take 29x30sec subs from my Bortle 8 location. I also took flats, bias and darks too. Taken on a CEM25P

Its a nice picture. What camera have you used and what software did you use for stacking?

On 07/09/2021 at 18:25, Maho said:

For some reason, top left of the frame is a lot darker than the right. The stacked image had no differences in lighting and only happened as I tried processing it in GIMP.

Take a look at your darks. If there is amp glow then during processing its cancelled out leaving a dark area.

 

Edited September 27, 2021 by AstroMuni

[Andyy]

Is it possible to use the SW Aplanatic coma corrector on the 130PDS?

[Jamgood]

1 hour ago, Andyy said:

Is it possible to use the SW Aplanatic coma corrector on the 130PDS?

Yes. It's identical to the TS-Optics GPU CC that I use with my 130PDS. Only the name is different I think. Probably a rebrand but from the same factory.(I'm actually using it as I type. Excellent CC's. Less fiddling around with back spacing, etc, like with the Baader. Mine worked straight out the box. 

The really good thing about it is it pushes the focus point out by 20mm so little to no focuser protrusion in the OTA.

Edited September 27, 2021 by Jamgood

[Jamgood]

Oops, double post.

Edited September 27, 2021 by Jamgood

[Mycro]

Hello everyone! New Owner of a 130pds here. I am reading as much as I can from this topic, and I hope to tweek some things in my scope in the future. For now I am still learning how to guide my EQM-35pro (with a moded Xbox livecam), and still without the comma corrector. Here is my first light with this telescope between clouds, while learning to guide, in a 10th flor flat at a bortle 9 location.

48x60s subs ISO400 with a EOS2000d, Mount - EQM35-pro. Guiding SV165 and Xbox Livecam. Half the subs where unguided. Processed in DSS and GIMP (learning also).

[Laurieast]

Very nice! 

[barbulo]

Good one! 

The coma corrector and a precise guiding will boost the quality (even more) 😉

[Andyy]

21 hours ago, Jamgood said:

Yes. It's identical to the TS-Optics GPU CC that I use with my 130PDS. Only the name is different I think. Probably a rebrand but from the same factory.(I'm actually using it as I type. Excellent CC's. Less fiddling around with back spacing, etc, like with the Baader. Mine worked straight out the box. 

The really good thing about it is it pushes the focus point out by 20mm so little to no focuser protrusion in the OTA.

Sounds good!

[Andyy]

Is it neccessary to cut the drawtube to avoid pacman stars when using MPCC and ASI1600MM?

[Jamgood]

1 hour ago, Andyy said:

Is it neccessary to cut the drawtube to avoid pacman stars when using MPCC and ASI1600MM?

Not necessarily. With the MPCC you might have some focuser protrusion into the OTA but it doesn't always cause pacman shaped stars. I never noticed any at all when using my old MPCC. 

The nightmare I found with the MPCC was trying to get it to sit straight in the focuser tube. There's a bevel on the MPCC that makes it nigh on impossible to get it nice and flush. One corner of my images always had elongated stars. Obviously camera weight (I had a Canon 60Da at the time) added to the problem too. I found that filling the bevel with two layers of electrical tape helped to sit the MPCC a bit more flush and combat the issue. It wasn't perfect but it helped. YMMV, others seem to be completely happy with the MPCC. Best thing I did was sell it on.

[Andyy]

8 hours ago, Jamgood said:

Not necessarily. With the MPCC you might have some focuser protrusion into the OTA but it doesn't always cause pacman shaped stars. I never noticed any at all when using my old MPCC. 

The nightmare I found with the MPCC was trying to get it to sit straight in the focuser tube. There's a bevel on the MPCC that makes it nigh on impossible to get it nice and flush. One corner of my images always had elongated stars. Obviously camera weight (I had a Canon 60Da at the time) added to the problem too. I found that filling the bevel with two layers of electrical tape helped to sit the MPCC a bit more flush and combat the issue. It wasn't perfect but it helped. YMMV, others seem to be completely happy with the MPCC. Best thing I did was sell it on.

Star shape problems only apply for 130PDS right, not the 150PDS? 

[Whistlin Bob]

21 minutes ago, Andyy said:

Star shape problems only apply for 130PDS right, not the 150PDS? 

Not sure- but I use the SW CC and I've also had the problem on a 200p that I use for imaging, so I wouldn't be surprised if it affected the 150pds as well.

[Andyy]

8 minutes ago, Whistlin Bob said:

Not sure- but I use the SW CC and I've also had the problem on a 200p that I use for imaging, so I wouldn't be surprised if it affected the 150pds as well.

Guess it apply for the PDS-line of scopes then. Hate to make drastic changes like cutting the drawtube to get  things right. I think I’ll takena closer look at the GSO-line of newts. Or maybe refractor is the way to go for me…

 

[barbulo]

10 hours ago, Jamgood said:

One corner of my images always had elongated stars. Obviously camera weight (I had a Canon 60Da at the time) added to the problem too. I found that filling the bevel with two layers of electrical tape helped to sit the MPCC a bit more flush and combat the issue.

Same issue in a 200PDS with a 600D. Tape helped but I ordered a Baader Clicklock to fix it properly. We'll see.

[alacant]

1 hour ago, Andyy said:

it apply for the PDS-line of scopes

If you want a cc and leave the focuser intact on a pds, then the answer is to use the gso cc. This cc moves the focus position away from the tube. Whilst the Baader and GPU leave the focus position intact, the sw 0.9 moves the focus position toward the tube. All three of the latter will give 'D' shaped stars unless focuser modifications are made, the sw being the worse culprit.

An alternative would be to move the main mirror up the tube say 1.5cm and fit a larger secondary.

[Len1257]

On my 150PDS I had to move the mirror up slightly after fitting the Baader clicklock. All because of the MPCC bevel.

 

[Jamgood]

3 hours ago, Andyy said:

Star shape problems only apply for 130PDS right, not the 150PDS? 

I think the problem applies to all Newts, with different margins of error/pacman shapes, with different CCs.

With the MPCC and SWCC, the focuser is cranked right in.

With the TS-Opticd GPU, the focuser is pushed out 20mm. Here's where mine sits. 

 

[Andyy]

21 minutes ago, Jamgood said:

I think the problem applies to all Newts, with different margins of error/pacman shapes, with different CCs.

With the MPCC and SWCC, the focuser is cranked right in.

With the TS-Opticd GPU, the focuser is pushed out 20mm. Here's where mine sits. 

 

Thanks! I plan to use my ASI1600 with the 130PDS and I already have the MPCC. I’m looking at the TS FUFmpcc adapter for a more secure connection. Will this adapter make the «pacman star» problem even worse?

[Jamgood]

13 minutes ago, Andyy said:

Thanks! I plan to use my ASI1600 with the 130PDS and I already have the MPCC. I’m looking at the TS FUFmpcc adapter for a more secure connection. Will this adapter make the «pacman star» problem even worse?

I had one of those for a short time. (It came with the used MPCC I bought) I found it next to useless personally. It was an awkward faff around with the locking ring for rotation and I was still having issues with the 55mm+ back spacing at the time so I abandoned it. Bear in mind that I was using a DSLR at the time though and there was less room for manoeuvre around the connection. 

I went for this Compression Ring in the end and I had the more success with that and the MPCC with the bevel taped. I'm still using it now with the TS-Optics GPU. 

My conclusion though is the best thing I ever did was get shot of the MPCC. However, I know it's not a cheap hobby and we work with what we have.

[rotatux]

Can't be sure about the MPCC because I have the SWCC (which collar can't be removed -- softly), but from what I see you could use some small M48 extension (3-5mm ring or filter) camera side, so that it would be locked above the bevel.

It's quite cheap and would also make it sunk deeper in the focuser, and so would reduce the "protruding focuser tube" problem.

[Eruliaf]

First proper attempt at imaging for (too) many months due to house move, short nights, too much work and of course, clouds. However I am very happy with the progress from my first DSLR images (refer to embarrassingly over manipulated avatar image) to this, the first with my ZWO cam and ASIAir set up. The ASIAir really is a wonderful box of tricks which makes taking quality images so much easier. Even an idiot like me can do it!

Being stubborn, I didn't want to wait for the moon to drop, so had to remove quite a gradient from this image as well, but it did help being such a small target allowing me to crop a lot out.

Exhibit A - The Cocoon nebula

ZWO ASI 071 MC colour camera with 7 hours 15 mins of 5 min subs - 20 flats, 5 darks and 20 bias. Stacked with deepskystacker and processed in Gimp.

Only removed a single sub, where the ISS photobombed with a very bright white streak across the middle of the field.

Edited September 29, 2021 by Eruliaf

[Stub Mandrel]

I've been quiet for a while. It's ggod to see lots of great new images with teh 120P-DS

Here are some of my latest images with mine.

 

 

 

[rotatux]

Nice M33 !

Loving its natural colors ... maybe raise low reds a bit for more nebulosities in the galaxy.

[Andyy]

130PDS came in today and looking good! Collimation is slighty off, but the collimation screws on the secondary are extremely tight (all three)!

Any tips to loosen them? Thanks!