Imaging with the 130pds

[8472]

4 minutes ago, cmanley134 said:

Great, thanks! Any special tools needed, or just hacksaw and sand down any rough edges?

Not really, a hacksaw should do it and yes, you don't want to leave any burrs to lacerate your or any future owner's hands.

Upon re-assembly, I covered any exposed metal with black self adhesive flocking material.

Just be wary of how much of the drawtube you remove.

Take too much off and the tube will come off the rollers in the focuser when you wind it fully out.

Additionally, I shifted the primary up the OTA, so I wouldn't have to saw too much of the drawtube off.

Good luck!

[sagramore]

Can confirm - I shifted my primary up the tube and didn't modify the focus tube at all. Protrusion is negligible now and the mod is reversible. Although I would guess a combination of both, as suggested by 8472, is in fact the optimum final result.

[cmanley134]

On 19/01/2024 at 17:50, 8472 said:

Not really, a hacksaw should do it and yes, you don't want to leave any burrs to lacerate your or any future owner's hands.

Upon re-assembly, I covered any exposed metal with black self adhesive flocking material.

Just be wary of how much of the drawtube you remove.

Take too much off and the tube will come off the rollers in the focuser when you wind it fully out.

Additionally, I shifted the primary up the OTA, so I wouldn't have to saw too much of the drawtube off.

Good luck!

1 hour ago, sagramore said:

Can confirm - I shifted my primary up the tube and didn't modify the focus tube at all. Protrusion is negligible now and the mod is reversible. Although I would guess a combination of both, as suggested by 8472, is in fact the optimum final result.

Thanks all - ended up taking 13mm off of the end, based on the difference between my focus point and the point at which the tube protrusion was no longer visible. Just need to finish painting the end and reinstall. I'm not a visual guy but I did see some reports that this mod can cause the tube to fall out when fully extended - I still have another 10+ mm on the end before the flat spot where the focuser makes contact starts, so I think I should be okay. 

[AstroMuni]

On 19/01/2024 at 17:16, cmanley134 said:

I'm using a reducing corrector and want to chop my drawtube.

I wanted to do the same when I purchased my Baader MPCC but then I realised that if I push the CC into the focuser tube, the tube no longer peeps out into the OTA when I achieve focus. So (if you havent already done so) check if this type of arrangement will help.

EDIT: Looks like this is too late now 🙂 so good luck with your setup

Edited January 22 by AstroMuni

[Bibabutzemann]

On 22/01/2024 at 12:30, AstroMuni said:

I wanted to do the same when I purchased my Baader MPCC but then I realised that if I push the CC into the focuser tube, the tube no longer peeps out into the OTA when I achieve focus. So (if you havent already done so) check if this type of arrangement will help.

I also found that chopping the draw tube is not necessary, even with my Canon. It doesnt protrude enough to cause any issues. I had to unscrew the stop ring of the CC and push it further in along with my extension tube. This only works with my thin 1mm M48 to EOS adapter, not with the standard 11mm EOS T Ring.

 

Tried new processing techniques on Bubble Nebula and Sorroundings captured last autumn. Roughly 19 hours integration with the l-extreme and 1 hour for RGB Stars

HEQ 5 + EOS 2000D + 130PDS

 

[woldsman]

First image with the 130pds paired with a zwo asi183 mono camera. NGC 7789: L 100 x 30", RGB @20 x 60"  plus darks, flats, dark flats. Imaged during an almost Full Moon but weather has been so dire  lately just happy to get a test session. The scope has had various mods: mirror clip mask, Monorail focuser, CNC spider being the main ones. Coma corrector is the Baader MPCC with back distance of 55mm measured from the T2 thread. Collimation not exact as I had to travel away from home & did this a few days before the session. There's also a bit of tilt which I think I'll have to live with as the focuser upgrade and associated 3d printed base for the focuser introduces this risk. Not sure about the MPCC spacing as there are some eggy stars to the left. Would be grateful for any observations that will help improve things. Have included a screenshot of ASTAP's abberation inspector and a single Luminance sub. Comments welcome!

 

 

Edited January 27 by woldsman

[edarter]

On 26/01/2024 at 01:26, Bibabutzemann said:

I also found that chopping the draw tube is not necessary, even with my Canon. It doesnt protrude enough to cause any issues. I had to unscrew the stop ring of the CC and push it further in along with my extension tube. This only works with my thin 1mm M48 to EOS adapter, not with the standard 11mm EOS T Ring.

 

 

 

Exactly what I did, certainly with a Canon camera there is no need to chop the focus tube in order to reduce protrusion, though you do need to spend £20-£30 instead.

1  Low profile camera adaptor (1mm rather than 11mm)
2  Spacer between CC and camera to suit (width of which fits inside the FT) so all the spacer & the CC are inside the FT. In the case of the Baader this also moves that annoying shoulder out of the way of the locking screws, thus also helping CC and camera tilt!
3  Move the primary mirror up the OTA (10mm spacing from the rear plate leaves plenty of thread on the adjusters on mine)

Result is a protrusion of approx 5mm in to the OTA at focus (mine was originally 25mm+) and completely reversible. No more pacman stars

 

Thanks
Ed

[Bibabutzemann]

On 27/01/2024 at 19:01, woldsman said:

 There's also a bit of tilt which I think I'll have to live with as the focuser upgrade and associated 3d printed base for the focuser introduces this risk

During Collimation Primary mirror, secondary mirror and focuser getting alligned. So if the focuser isnt pefectly square to the tube, it shouldn't cause issues.

For final adjustments of the primary mirror, i use my main camera+CC and i take images of a star rich field with a bright star at the center.

Then in live view i adjust the primary mirror, so that the bright star moves in the opposite direction of the worst corner. 

Then i move the scope to recenter the bright star. Refocus and repeat the procedure until all corners are equal.

When all corners are equally bad, you can worry about correct spacing

[woldsman]

9 minutes ago, Bibabutzemann said:

During Collimation Primary mirror, secondary mirror and focuser getting alligned. So if the focuser isnt pefectly square to the tube, it shouldn't cause issues.

For final adjustments of the primary mirror, i use my main camera+CC and i take images of a star rich field with a bright star at the center.

Then in live view i adjust the primary mirror, so that the bright star moves in the opposite direction of the worst corner. 

Then i move the scope to recenter the bright star. Refocus and repeat the procedure until all corners are equal.

When all corners are equally bad, you can worry about correct spacing

Thanks, Patrick. I use an electronic Ocal for collimation along with visual tools (collimation EP, Cheshire, & Concenter EP). The secondary mirror collimation was not quite exact & I think this is the area I need to nail first.  I re-did collimation during a cloudy weekend on Saturday. Secondary circle again not quite aligned & I think because the distance of the secondary is off very slightly. As a result the primary centre spot not quite lined up either. But very interesting technique - doing final collimation of the primary with CC in place. 

Edited January 30 by woldsman

[cmanley134]

First image with the modified drawtube - this does have BXT stellar correction, but the change has definitely helped. Stars are nice and round and I've even seen a ~10% decrease in FWHM. Also tried a narrowband/broadband mix here which I quite like. Next up, secondary spider! I've received my CNC spider from Backyard Universe and just need to get it installed.

[woldsman]

M13 with the 130pds & an Atik 414ex camera. Imaged during an almost Full Moon & not great seeing.
 

Edited March 27 by woldsman

[woldsman]

Another session with the 130pds & Atik 414ex. M64 (Black Eye Galaxy). There is some detail in the arms & dust lane but a bigger aperture is probably needed for this target. 

 

 

 

 

 

 

Edited 1 hour ago by woldsman

[lrosellpardo]

Beautfiul orion nebula taken in Feb '24

 

[Bibabutzemann]

Anyone have an idea what this asymmetric artefact around bright stars could be?

Equipment: 130pds, Baader MPCC, EOS2000D

Never seen this before

 

Edit: Nvm, it was some weird smudge on my CC 😅 Sometimes i overthink..

CS

Edited April 12 by Bibabutzemann

[woldsman]

M106 imaged with an Atik 414ex mono camera. 5 hours integration.

 

 

 

 

 

 

Edited 4 hours ago by woldsman

[lrosellpardo]

I love 130pds and I'm thinking to buy second hand 200pds.

The autofocuser was a big improvement in my images + BlurXterminator in pixsinght I think gives decent results.

 

[lrosellpardo]

On 11/04/2024 at 05:00, Bibabutzemann said:

Anyone have an idea what this asymmetric artefact around bright stars could be?

Equipment: 130pds, Baader MPCC, EOS2000D

Never seen this before

 

Edit: Nvm, it was some weird smudge on my CC 😅 Sometimes i overthink..

CS

I have baader mpcc too, but I don't get this artifacts, in my case with brightest stars appears a secondary reflection.

Is your DSLR full spectrum mod?Are you using UV/IR CUT?

 

[Bibabutzemann]

6 hours ago, lrosellpardo said:

I have baader mpcc too, but I don't get this artifacts, in my case with brightest stars appears a secondary reflection.

Is your DSLR full spectrum mod?Are you using UV/IR CUT?

 

You might have missed my edit of that post. It was just a smudge on the CC  

[lrosellpardo]

3 minutes ago, Bibabutzemann said:

You might have missed my edit of that post. It was just a smudge on the CC  

sorry, I didn't read it.

[cmanley134]

Has anyone 3D-printed a dew shield for their scope? I have one of the floppy adjustable ones and I'd prefer something a little more secure with a consistent/repeatable fit. I don't have any 3D printing equipment myself but if anyone has the file I know someone who could do the printing for me. Thanks!