SW 150 follow my Heart or my Brain?

[Enceladus Dan]

Hello, 

 

I’m new to both Astronomy and Photography so this is going to be a steep learning curve for me, I’ve been reading lots of articles and forum posts which have changed my mindset considerably over the past 3-4 months I’ve been trying to find my ideal first (hopefully last me 3-4 years before I seek better) telescope set up. 

 

It started with looking at an celestron EQ114 for £167 which I soon left behind and found the SW 130 which came in 3 variants, 130, the shorter 130p with a parabolic mirror or the motorised 130m. I settled on the 130p on a EQ2 mount at £195 with intensions of mainly visual but maybe some photography. 

 

After some reading I discovered back focus and the problems with prime focus so started looking for ways round it. Focuser mods or what I planned on was getting a mirrorless camera and get a slim t-ring to reduce the back focus. After using only my phone (HTC U11) to take 16 second exposures at iso 100 I was amazed at how many stars it picked up and then the bug had bitten. Since I have purchased a canon EOS M3 camera with a 18-55 kit lens to practice with while I seek out my first telescope. 

 

Seeking the best way to use a camera on the 130p I learned that the 150p has. Duel fit focuser with direct camera attachment by removing the eye piece extension which appears to be at least 20mm removed. I read of people using DSLR cameras perfectly on the 150p but also others saying it does not and AP requires the PDS version. 

 

I’m certain I want the SW 150 but I’m torn between models. The 150 P claims to be direct DSLR so my M3 having 26mm less back-focus should be fine, the 150 PDS comes with less accessories but has a duel-speed focuser.  I also have debating thoughts on the mount. The EQ 3-2 that comes with both has been reported on several posts as not adequate for AP but people say they have managed fine with it. 

 

My heart says go all out and get the 150 PDS OTA and a separate EQ5 Deluxe knowing it meets my needs. My Brain is saying hold back as £495 is a big leap and I would need to get the Barlow and another eye piece on top. Below are my thoughts on what options I have. 

 

Option 1 

As above buying the 150 PDS OTA, EQ5 Deluxe, 2x Barlow and BST 8mm coming to £570 

 

Option 2 

Buying the 150 PDS EQ3-2 kit, 2x Barlow and BST 8mm coming to £475 

 

Option 3

Buying the 150 P EQ3-2 kit coming to £320 

 

The 150P seems to offer a better kit price as PDS OTA versions are £40 more than the P but as a kit the PDS is £80 more, so I’m saving £40 on the mount in theory. This means I can get going and if the EQ3-2 is no good I can sell it later to put towards buying the EQ5 deluxe. Obviously this route would mean waiting to get a tracking motor until I’m either certain on the mount or upgrade. 

 

If anyone can 100% say the 150p with the direct DSLR attachment is able to get prime focus I think this is my way to go. Also the duel-fit focuser vs the duel Speed focuser I could mod later if needed as I’m confused where both state a speed ratio of 1:10. 

 

Many thanks for any advice, especially those with the 150P that use it for AP. 

[vlaiv]

Imagine you want to split scope use between visual and astrophotography and express that split in percents.

If those two are equally important to you, you would assign 50% to each. Just imagine any numbers that come to mind. If astrophotography has more than 5% - get EQ5 mount.

I know that people say that you can image with EQ3 but just because something can be done (by few people) - does not mean you want to do it on regular basis.

Even for purely visual - EQ5 mount is better choice for 150P/PDS type scope.

If you decided on EQ5 because of AP being more than 5% - then get 150PDS.

I think that you will be able to reach focus with DSLR and regular 150P, however 150PDS is astrophotography oriented version for a reason. It is not just position of the focus plane, it is also - dual speed focuser. At F/5 ability to focus precisely is important.

Quality of focuser is also important - you don't want wobbly focuser where camera will tilt under its own weight and will change tilt depending where the scope is pointing (gravity always points down regardless of the pointing of the tube).

Do keep in mind that EQ5 deluxe version is manual tracking mount and you want to add tracking motor to it, so that is not the final cost of the mount for imaging. You'll also want to add coma corrector at some point - factor that into account.

In any case - I think your choice is very good one - probably one of few telescopes that will do it all - enable both visual and AP, for both planets and deep sky objects, but do seriously consider bigger mount.

[Enceladus Dan]

On 28/12/2020 at 17:32, vlaiv said:Imagine you want to split scope use between visual and astrophotography and express that split in percents.

If those two are equally important to you, you would assign 50% to each. Just imagine any numbers that come to mind. If astrophotography has more than 5% - get EQ5 mount.

I know that people say that you can image with EQ3 but just because something can be done (by few people) - does not mean you want to do it on regular basis.

Even for purely visual - EQ5 mount is better choice for 150P/PDS type scope.

If you decided on EQ5 because of AP being more than 5% - then get 150PDS.

I think that you will be able to reach focus with DSLR and regular 150P, however 150PDS is astrophotography oriented version for a reason. It is not just position of the focus plane, it is also - dual speed focuser. At F/5 ability to focus precisely is important.

Quality of focuser is also important - you don't want wobbly focuser where camera will tilt under its own weight and will change tilt depending where the scope is pointing (gravity always points down regardless of the pointing of the tube).

Do keep in mind that EQ5 deluxe version is manual tracking mount and you want to add tracking motor to it, so that is not the final cost of the mount for imaging. You'll also want to add coma corrector at some point - factor that into account.

In any case - I think your choice is very good one - probably one of few telescopes that will do it all - enable both visual and AP, for both planets and deep sky objects, but do seriously consider bigger mount.

Thank you for the quick reply, 

I plan on getting the enhanced dual axis motors, I thought it was worth the little extra money for the options of sidereal, lunar and solar speeds. I think I’ve worked out my confusion over the dual-fit to dual-speed. Flo describes the dual-fit as also being 1:10 in the kit but not on the OTA so I think it’s a typo in the kits description. Therefore if I go for the 150p I would most likely fit the dual speed upgrade kit. 
 

As for the mount I do agree the EQ5 is my best choice I’m just debating getting the 150p kit with EQ3-2 to start with while utilising the £40 saving to offset the loss when I sell and upgrade to the EQ5. This meaning I can play sooner as I just spent £300 on a camera lol. 
 

I know either way I’m looking at not much change from £1000 buy the time I’m set, then I will probably be looking for my next piece of equipment to compliment it. 
 

it’s reassuring you also think my M3 will achieve prime focus on the 150p. 
 

thanks.