Imaging with the 130pds

[alacant]

On 25/05/2020 at 01:17, matt_baker said:

The left side stars look pretty similar to me

Hi

 The effect is astigmatism and is common in the Baader cc. Centre field you're in focus. Left is due to inward focus error, right, outward focus error. Or vica versa. The in and out focus errors are because the camera's isn't held squarely in the light path. Even if it is, in my experience, there is still astigmatism.

Astigmatism causes the 90º rotation of star elongation you are seeing toward lateral extremities and is also responsible for the uneven cross shape in the astigmatic stars. 

If you can't live with it and correction in software isn't acceptable, either the 2 element sw or the 4 element gpu or GSO ccs would fix it. You could also try substituting the secondary mirror or using a camera with a smaller sensor.

HTH and good luck.

 

 

Edited May 28, 2020 by alacant

[spillage]

I have suffered from tilt for an age and can never be sure if is camera, focus tube or poor collimation or possibly all three adding up.

Not sure if anyone here has one or tried one but this adaptor might be of use. For only about £45 its worth a go but I think it will only work with the baader mpcc.

[lnlarxg]

3 hours ago, alacant said:

Hi

 The effect is astigmatism and is common in the Baader cc. Centre field you're in focus. Left is due to inward focus error, right, outward focus error. Or vica versa. The in and out focus errors are because the camera's isn't held squarely in the light path. Even if it is, in my experience, there is still astigmatism.

Astigmatism causes the 90º rotation of star elongation you are seeing toward lateral extremities and is also responsible for the uneven cross shape in the astigmatic stars. 

If you can't live with it and correction in software isn't acceptable, either the 2 element sw or the 4 element gpu or GSO ccs would fix it. You could also try substituting the secondary mirror or using a camera with a smaller sensor.

HTH and good luck.

 

 

Think the 4 element cc is same as sw’s own apalanatic cc, at least similar. Bit pricier but really great results. I got mine for the f4 imaging Newtonian, thought why not try it on the 130pds and am very happy I tested it

[alacant]

2 minutes ago, lnlarxg said:

4 element cc is same as sw’s own

Hi

Yes, the gpu and the sw have the same prescription, differing only in the fixed flange on the latter.

Cheers

[Stub Mandrel]

Don't forget you can adjust the tilt of the 130P-DS focuser tube

[spillage]

1 hour ago, Stub Mandrel said:

Don't forget you can adjust the tilt of the 130P-DS focuser tube

I didn't know you could do that. Are you able to explain how this is done and can it be done with everything attached?

Cheers

[Uranium235]

A bit of late night Ha imaging    NGC6820

Just 90min, I'll pick this up again in a few weeks when I wont have to wait so late for it to clear the tree.

 

[Dan13]

Fixed my issue, the tension needed tightening up thank you all

I have a project for a HARGB ( first time trying) this is my first 2 hours from 8 planned.( 4 HA 4 RGB) of the elephant nebula . Nothing but stacked just to see what it was like so far . Canon DSLR with the 130pds 

Edited May 29, 2020 by Dan13

[matt_baker]

How worth it would it be to get a moonlite focuser for the 130PDS vs buying a used 80mm triplet?

[spillage]

Thought I would post up this attempt.

Ha, Oiii, Oiii. About 10 hours over the last few days. ASI1600. I have some issues that need sorting but may end up adding some Sii. Tiff seemed to large so just a jpeg.

 

 

 

Edited May 31, 2020 by spillage

[Fieldsy]

How do you have your scopes rotated so the camera sits on top ,hangs on the side,or hangs underneath?

Thanks

[spillage]

I just let the balance of the third axis tell me where it needs to sit, but at the moment its happier sat underneath (more or less).

Edited June 1, 2020 by spillage

[Jamgood]

This is a great thread. I've been through it over the last week or so. Some fantastic images but sadly I can't join in with any as I'm unable to get a 130pds anywhere at the minute. These thing seem to be as rare as Rockin' Horse Thingy! I hope they haven't been discontinued.

[Dan13]

3 minutes ago, Jamgood said:

This is a great thread. I've been through it over the last week or so. Some fantastic images but sadly I can't join in with any as I'm unable to get a 130pds anywhere at the minute. These thing seem to be as rare as Rockin' Horse Thingy! I hope they haven't been discontinued.

I'm quite possibly selling mine with the CC and extras as soon as I can get hold of my next scope. Will bare you in mind mate . It's less the 5 months old 

Edited June 1, 2020 by Dan13

[Dan13]

37 minutes ago, Fieldsy said:

How do you have your scopes rotated so the camera sits on top ,hangs on the side,or hangs underneath?

Thanks

I have an ankle weight on the back end on the opposite side to the cam. Does wonders 

[Fieldsy]

8 minutes ago, Dan13 said:

I have an ankle weight on the back end on the opposite side to the cam. Does wonders 

I have a ankle weight wrapped around the back so that it isn't so front heavy ,but I like the idea of counter weighting the camera, filter wheel will try that.

[spillage]

To help with the DEC balance I have a sturdy flat steel bar with several holes drilled into it. This is bolted to top of the rings with a rear over hang. I use this to attach the guide scope and it allows me to bolt a sufficient weight to the rear. It's definitely a diy job but it has worked for a couple of years now.

[Stub Mandrel]

3 hours ago, Fieldsy said:

How do you have your scopes rotated so the camera sits on top ,hangs on the side,or hangs underneath?

Thanks

on the side to get the C of G as close to the mount as possible.

[Uranium235]

5 hours ago, Fieldsy said:

How do you have your scopes rotated so the camera sits on top ,hangs on the side,or hangs underneath?

Thanks

This way up 

[Piers]

5 hours ago, Jamgood said:

This is a great thread. I've been through it over the last week or so. Some fantastic images but sadly I can't join in with any as I'm unable to get a 130pds anywhere at the minute. These thing seem to be as rare as Rockin' Horse Thingy! I hope they haven't been discontinued.

I got one from FLO a couple of weeks ago, there's just about a 10day or so delay before delivery.

[Kenboy]

Hello, I'm just starting out and had a q  

I'm considering a SW 130PDS - has been popular for a number of years. 

Is there a consensus on what's the best budget mount for this scope?

I know the SW star adventurer is very popular, but it won't take this lvl of payload.

So is there any mounts that would go well with this scope - something cheaper than a HEQ5 😛

 

[Dan13]

39 minutes ago, Kenboy said:

Hello, I'm just starting out and had a q  

I'm considering a SW 130PDS - has been popular for a number of years. 

Is there a consensus on what's the best budget mount for this scope?

I know the SW star adventurer is very popular, but it won't take this lvl of payload.

So is there any mounts that would go well with this scope - something cheaper than a HEQ5 😛

 

If I'm being honest, the belt mod mount @Adam J is selling is a very sound investment for the long term. I'm went budget route with a mount before getting my HEQ5 and that is still my biggest regret yet. Just imo of course

[Adam J]

32 minutes ago, Dan13 said:

If I'm being honest, the belt mod mount @Adam J is selling is a very sound investment for the long term. I'm went budget route with a mount before getting my HEQ5 and that is still my biggest regret yet. Just imo of course

Yes it's the case for anything with a half decent aperture so 80mm refractors and over. You will want at least a HEQ5PRO. I used a 130pds on mine and I am sure a lesser mount would have been a massive pain in the bottom. The HEQ5PRO is the cheapest mount on the market that will provide consistent sub ascsecond guiding on such scopes. 

Adam 

[Dan13]

30 minutes ago, Adam J said:

Yes it's the case for anything with a half decent aperture so 80mm refractors and over. You will want at least a HEQ5PRO. I used a 130pds on mine and I am sure a lesser mount would have been a massive pain in the bottom. The HEQ5PRO is the cheapest mount on the market that will provide consistent sub ascsecond guiding on such scopes. 

Adam 

Fully agreed.  My pocket learned the hard way 🤣

[matt_baker]

4 hours ago, Adam J said:

Yes it's the case for anything with a half decent aperture so 80mm refractors and over. You will want at least a HEQ5PRO. I used a 130pds on mine and I am sure a lesser mount would have been a massive pain in the bottom. The HEQ5PRO is the cheapest mount on the market that will provide consistent sub ascsecond guiding on such scopes. 

Adam 

How do you deal with focuser sag with your FW + 1600MM?