Imaging with the 130pds

[alacant]

5 minutes ago, mAnKiNd said:

right CC for the 130PDS

No, I can't say because I shouldn't be here as I don't have a 130pds. I just wanted to try and ease the confusion shared about ccs. I just know that the Chinese cc works fine on my 150/750 and 208/812. 

 

7 minutes ago, rotatux said:

collar prevents it from going deeper into the focuser.

The fit and protrusion is the same. The reason the sw protrudes into the tube is that it needs 20mm more inward focus. HTH

[Adam J]

3 hours ago, alacant said:

I have a 150mm and even with a proper 2 1/2" r&p focuser it flexed, especially noticeable at low dec near the horizon where the turning force is radial rather than longitudinal. But Louise confirms it's ok with a pds so that should be fine. Stars are superior when compared with the Baader too, but it magnifies the image which IMHO defeats the object of having a wide field telescope. In the end, I sent back the TS, got a Baader, sent that back -something about the elements being the wrong way making the coma worse- and got a cheap cc from aliexpress; perfect!

The elements the wrong way? Thats hard to imagine was it a MK1 or a MK3?

[mAnKiNd]

29 minutes ago, alacant said:

No, I can't say because I shouldn't be here as I don't have a 130pds. I just wanted to try and ease the confusion shared about ccs. I just know that the Chinese cc works fine on my 150/750 and 208/812. 

 

The fit and protrusion is the same. The reason the sw protrudes into the tube is that it needs 20mm more inward focus. HTH

Ok, thank you for all your input.

[Adam J]

Most people on here use the Baader and are very happy with it so it works well with the 130PDS.

Alacant: you are imaging at F4 so you may get different results compared to the 130PDS users at F5.

[Thalestris24]

Hi all

I'm afraid I can't confirm whether or not there were any issues at all with using the gso cc on a pds scope. It's been more than a year since I used a Newt having gone over to camera+lens and fracs, which have fewer issues generally . I don't think there is any advantage with using the gso unless you need the extra backfocus for something. Although I tried using a filter wheel at one time, the weight of it caused flex and I changed to using TS quick change filter drawers instead. They are much lighter and only take up 15mm so better (for me) in most cases.

Louise

[mAnKiNd]

18 minutes ago, Adam J said:

Most people on here use the Baader and are very happy with it so it works well with the 130PDS.

Alacant: you are imaging at F4 so you may get different results compared to the 130PDS users at F5.

Hi Adam, yes that seems to be the consensus, thank you for pointing that out.

18 minutes ago, Thalestris24 said:

Hi all

I'm afraid I can't confirm whether or not there were any issues at all with using the gso cc on a pds scope. It's been more than a year since I used a Newt having gone over to camera+lens and fracs, which have fewer issues generally . I don't think there is any advantage with using the gso unless you need the extra backfocus for something. Although I tried using a filter wheel at one time, the weight of it caused flex and I changed to using TS quick change filter drawers instead. They are much lighter and only take up 15mm so better (for me) in most cases.

Louise

Hi Louise, thanks again for replying, very useful feedback. It seems the PDS focuser can't cope with all that length and weight on it. I gather from your comment that the PDS focuser could cope with no flex when you used the TS quick change filter drawer plus DSLR?

It seems as though the GSO CC is more suitable for someone imaging with filters or narrowband for the provided extra backfocus, like you said. If one does not intend to though, then it seems the Baader/SW CC will better help avoid any potential flex issues. However, by the sounds of it, the weight of a DSLR alone will probably not flex a fully extended PDS focuser, rendering the potentially better optical quality of the GSO CC still a good candidate. May I ask Louise, did you notice any image quality difference between the GSO and Baader during any of your sessions? Apologies if you answered this elsewhere and I know you said it's been a while, I ask because you have used both.Also good to hear you are enjoying more success with your current setup

Thank you again for everyone's time, I feel positively overwhelmed by all of your replies.

Minos

Edited April 17, 2017 by mAnKiNd
clarity

[richyrich_one]

1 hour ago, alacant said:

Here it is. My telescope comet kit adaption connector eyepiece with 2".

Any chance of a link to it? 

[Thalestris24]

2 hours ago, mAnKiNd said:

Hi Adam, yes that seems to be the consensus, thank you for pointing that out.

Hi Louise, thanks again for replying, very useful feedback. It seems the PDS focuser can't cope with all that length and weight on it. I gather from your comment that the PDS focuser could cope with no flex when you used the TS quick change filter drawer plus DSLR?

It seems as though the GSO CC is more suitable for someone imaging with filters or narrowband for the provided extra backfocus, like you said. If one does not intend to though, then it seems the Baader/SW CC will better help avoid any potential flex issues. However, by the sounds of it, the weight of a DSLR alone will probably not flex a fully extended PDS focuser, rendering the potentially better optical quality of the GSO CC still a good candidate. May I ask Louise, did you notice any image quality difference between the GSO and Baader during any of your sessions? Apologies if you answered this elsewhere and I know you said it's been a while, I ask because you have used both.Also good to hear you are enjoying more success with your current setup

Thank you again for everyone's time, I feel positively overwhelmed by all of your replies.

Minos

Hi

Um, I honestly can't remember now as I mixed and matched so much! I started off with a 150pds (with Baader cc) then moved over to the lighter and easier to handle 130pds (with gso cc). The only problem I recall having with the 130pds was a tilt problem which seemed to be due to the focus tube rather than anything to do with coma correctors. I do remember using the gso cc with it as it increased the focal length but I didn't see that as a problem. However, I put the scope to one side intending to sort it out at some point.... I then spent a long time imaging with a camera and f4 200mm lens, then bought a 115mm frac which I've hardly used on account of the near permacloud here . My newts and their coma correctors are gathering dust...  

Louise

[mAnKiNd]

38 minutes ago, Thalestris24 said:

Hi

Um, I honestly can't remember now as I mixed and matched so much! I started off with a 150pds (with Baader cc) then moved over to the lighter and easier to handle 130pds (with gso cc). The only problem I recall having with the 130pds was a tilt problem which seemed to be due to the focus tube rather than anything to do with coma correctors. I do remember using the gso cc with it as it increased the focal length but I didn't see that as a problem. However, I put the scope to one side intending to sort it out at some point.... I then spent a long time imaging with a camera and f4 200mm lens, then bought a 115mm frac which I've hardly used on account of the near permacloud here . My newts and their coma correctors are gathering dust...  

Louise

Hi Louise, thank you for your reply and all the information you've shared. I lived in the UK for over a decade, so I know exactly what you mean by permacloud. I wish you clear skies and all the best. Thanks again.

Minos

Edited April 17, 2017 by mAnKiNd

[alacant]

3 hours ago, Adam J said:

you are imaging at F4

Hi. I am imaging at 150mm f5 and 208mm f3.9. I would be surprised if the cc does not work just as well with the pds. HTH.

[alacant]

1 hour ago, Thalestris24 said:

tilt problem which seemed to be due to the focus tube

pds + gso?

[Thalestris24]

1 hour ago, alacant said:

pds + gso?

Hi

Misalignment of the focus tube, I believe, but I never got around to trying to fix it.

Louise

[mAnKiNd]

7 hours ago, richyrich_one said:

Any chance of a link to it? 

Could it be this?

Edited April 17, 2017 by mAnKiNd

[Thalestris24]

I think this is the one I bought though I don't think it was called 'quattro' then....

[alacant]

9 hours ago, richyrich_one said:

link to it? 

3 hours ago, mAnKiNd said:

Could it be this?

Mi

If I do that, the price will rise overnight! There's not much to be saved anyway.

3 hours ago, mAnKiNd said:

Could it be this?

Dunno. Mine has no ID or markings; compare that description to how my seller described it. I think it's like all astro stuff. Wholesalers buy from China, mark up to retailers, they too mark up and we end up paying a fortune for it. It's worth scouring AliExpress though. There are still small outlets who still don't know what the rest of the world are paying. HTH.

[Thalestris24]

40 minutes ago, Thalestris24 said:

I think this is the one I bought though I don't think it was called 'quattro' then....

Same one here, I think

[mAnKiNd]

Order amended for 130PDS plus TS Quattro Coma Corrector. I decided that i'm going to go with what sounds like a slightly better image due to the 4-element design. As light pollution around me increases, I might be looking into narrowband for the future, so having the spacing to fit a filter drawer might come in handy. As for flex because of racking the focuser out too much with this CC, I think I'll be fine with a DSLR alone, but i'll report back if I experience any flexure with only that weight. A friend of mine has the SW CC 0.9x that I could borrow, and maybe I could even get my hands on a Baader MPCC. If I can, i'll be looking at doing a shootout in the near future and sharing the results with you here. No promises though, time will tell. I'm looking forward to receiving the scope and thank you to everyone for taking time to share their insights. Clear skies

Minos

[mAnKiNd]

..last minute change to the order..I sent an email to TS about comparing the TS GPU to the TS Quattro a few days ago and they only replied now saying: "the GPU performs way better than the Quattro. The stars are smaller and the colour correction is better at the GPU. The GPU is our choice for high quality imaging." Therefore, based on this new information, we swapped out the Quattro and ordered this instead.

[alacant]

5 minutes ago, mAnKiNd said:

ordered this instead

I'd put good money on a lot of users switching after you post images taken using that. TS stand to get rich!

[richyrich_one]

12 minutes ago, mAnKiNd said:

..last minute change to the order..I sent an email to TS about comparing the TS GPU to the TS Quattro a few days ago and they only replied now saying: "the GPU performs way better than the Quattro. The stars are smaller and the colour correction is better at the GPU. The GPU is our choice for high quality imaging." Therefore, based on this new information, we swapped out the Quattro and ordered this instead.

I'd only have one concern, how long is it? I'm guessing that would get mighty close to the secondary once inserted. Hope it works out, sounds excellent.

[mAnKiNd]

23 minutes ago, richyrich_one said:

I'd only have one concern, how long is it? I'm guessing that would get mighty close to the secondary once inserted. Hope it works out, sounds excellent.

It looks a bit long doesn't it? Might need to do some DIY..will return later when I have results, clear skies everyone ?

[alacant]

29 minutes ago, richyrich_one said:

how long is it?

The worse that can happen is 'D' shaped stars. It's not brilliant at f5 but still beats the competition hands down. Didn't realise your budget ran to it, otherwise we could have ended this many posts ago! HTH.

 

Edited April 19, 2017 by alacant

[mAnKiNd]

23 minutes ago, alacant said:

The worse that can happen is 'D' shaped stars. It's not brilliant at f5 but still beats the competition hands down. Didn't realise your budget ran to it, otherwise we could have ended this many posts ago! HTH.

 

Very useful photo, thank you for sharing it, it'll help me crunch some numbers to figure out spacings etc.. Yes, D-shaped stars are now a worry..we'll see how it goes. Hah! yes we could've ended it a while ago indeed.. Didn't really have this one so much in mind because i didn't come across much info about it, but it surely looks like a step up in quality from the others. Looking forward to it.

[alacant]

1 hour ago, mAnKiNd said:

but it surely looks like a step up in quality from the others

It's a good example of the price hike which I mentioned. Before it became public knowledge on another forum, the very same cc was a fraction the price it is now quoted.

**Edit. BTW, your working distance is going to be 52.5mm. I'd be cheeky and ask TS to include the required spacers for you, otherwise that's your next nightmare. HTH.

Edited April 19, 2017 by alacant

[mAnKiNd]

1 hour ago, alacant said:

*Edit. BTW, your working distance is going to be 52.5mm. I'd be cheeky and ask TS to include the required spacers for you, otherwise that's your next nightmare. HTH.

Thanks again for sharing this really useful information.

If you consider the focal flange distance of a Canon is 44mm, plus the 11mm from the Baader EOS locking ring I'm using, then that gives me 55mm total distance from lens to sensor.

However, since I use a IDAS LPS-D1 filter, which has a glass thickness of 2.2mm, then if I understand correctly, I can subtract that value from the total distance, giving me a "true" distance of 52.8mm, which is not a far cry from the recommended 52.5mm.

Considering the slight differences in each item due to manufacturing tolerances, I might just turn out lucky and that extra 0.3mm turns out fine, if anything, it might not even produce a significant difference between 52.8mm and 52.5mm.

The proof will be in the pudding though..soon

EDIT: looking at the graph you shared one more time, it looks like for 650mm focal length, it is around 52.6mm! Even closer to my distance..

Edited April 19, 2017 by mAnKiNd