'Upgrade' from 150P to 130P-DS...?

[Johnny666666]

This might seem like a weird thing to consider. I am a newbie and have a 150P and have had some encouraging results so far. I'm very happy with the scope's performance, which is limited mainly by my own experience.

However, one of the things I have considered as an upgrade is a 10:1 Crayford focuser as this will benefit me I believe. But... £100 for a replacement focuser for the 150P or ~£150 for a complete 130P-DS OTA with the 10:1 focuser and shortened tube for prime focus photography leaves me wondering which would be the better choice? I have seen some fabulous images taken with the 130P-DS so I know it is a capable scope. I already have the EQ3.2 mount with motors so I would just need the OTA.

At the moment I am very much learning and imaging most everything out there, and I'm aware that there is no 'one scope fits all' solution. However, I don't particularly want a scope that is too powerful because I would lose out on some of the wider field DSO's.

Any comments would be welcome - positive or negative. I'm just throwing the idea out there!

[ronin]

I suppose you cannot tell if the present focuser is made by Synta or made for Synta ?

If it is made for Synta by GSO there is an upgrade available for GSO focusers that cost 65€ from TS.

GSO Upgrade

[andyboy1970]

Positive - your mount will handle the smaller scope better.

I image with my 150p rather than my 200p for this very reason.

That will change when The beast is commissioned. (Meade 16ds mount with AWR goto)

[Alien 13]

The 130PDS would be a bit easier to control on the EQ3-2 with its shorter FL and lighter weight and imaging wise i dont think you would loose out too much.

Alan

[Johnny666666]

It's a Skywatcher 150P I have so I don't think the focuser will be much like those you mentioned. It's just a single wheel rack and pinion type.

[Johnny666666]

I think the mount is right on its limits, especially with a DSLR and other assorted gubbins chucked onto it as well. Both the 150P and 130PDS are f5, the shorter focal length of the 130 might mean I lose out a little on planets but gain on some DSO's (Pleiades doesn't fit in the 150P FOV!)

[Alien 13]

I think the mount is right on its limits, especially with a DSLR and other assorted gubbins chucked onto it as well. Both the 150P and 130PDS are f5, the shorter focal length of the 130 might mean I lose out a little on planets but gain on some DSO's (Pleiades doesn't fit in the 150P FOV!)

You have to have the Pleiades in the FOV but seriously the EQ3-2  gets a bad press at times but if its set up and loaded right it does work well enough to get some very decent images.

Alan

[Johnny666666]

You have to have the Pleiades in the FOV but seriously the EQ3-2  gets a bad press at times but if its set up and loaded right it does work well enough to get some very decent images.

Alan

I don't mind the EQ3.2 to be honest, but I know it's loaded up with the 150P etc. I wouldn't put anything heavier on it though.

I'm just wondering whether I would be disappointed with the performance of the 130 over the 150? It was simply the cost difference between either a focuser upgrade or a complete OTA (albeit slightly smaller) with the 10:1 focuser attached seemed so minimal as to hardly worth the question. but I thought I would ask anyway

[RikM]

The 130PDS would be more comfortable than the 150P on an EQ3-2 but the 130PDS requires a good deal of messing about to get it to work. With just a DSLR on board you might not have problems with balance and focuser slippage but just to keep in mind that it is not all plain sailing with the smaller scope. I found it really easy to get the 150P-SS to work okay. The focuser on the PDS has more inward focuser travel (which I didn't need anyway) but the single speed seems stronger and less prone to slippage / misalignment. Could also be that I simply had a duff PDS but I prefer the SS for imaging.

If you have a rack and pinion focuser, that is not normal for the current Explorer 150P. They come with a 2" Crayford single speed focuser (should be a smooth track rather than a toothed rack underneath). You might have a 150PL instead, so best to check because it will make quite a difference to the answers you get.

If you are up for the potential messing about, the 130PDS should be better on the smaller mount.

[Johnny666666]

The 130PDS would be more comfortable than the 150P on an EQ3-2 but the 130PDS requires a good deal of messing about to get it to work. With just a DSLR on board you might not have problems with balance and focuser slippage but just to keep in mind that it is not all plain sailing with the smaller scope. I found it really easy to get the 150P-SS to work okay. The focuser on the PDS has more inward focuser travel (which I didn't need anyway) but the single speed seems stronger and less prone to slippage / misalignment. Could also be that I simply had a duff PDS but I prefer the SS for imaging.

If you have a rack and pinion focuser, that is not normal for the current Explorer 150P. They come with a 2" Crayford single speed focuser (should be a smooth track rather than a toothed rack underneath). You might have a 150PL instead, so best to check because it will make quite a difference to the answers you get.

If you are up for the potential messing about, the 130PDS should be better on the smaller mount.

It's definitely a 150P not the PL, and fitted with the current focuser so it's probably my error. There is no mention of anywhere in the blurb that it is a Crayford focuser but it's single speed. I'm amazed that the dual speed Crayford appears to have caused you so many problems, I would've thought it would have been a better item than the single speed?

Don't get me wrong, I'm enjoying the 150P but focussing is so critical, especially in live view when waiting for the screen to update on long exposures. I seem to be constantly hunting between two 'slightly out of focus' positions!

[RikM]

I just use a Bahtinov mask and Bahtinov grabber software. This makes focussing much easier. I may fit a Lacerta DS upgrade from Modern Astronomy in the future though. They work well and are not expensive.

[Johnny666666]

I just use a Bahtinov mask and Bahtinov grabber software. This makes focussing much easier. I may fit a Lacerta DS upgrade from Modern Astronomy in the future though. They work well and are not expensive.

Yes, I have considered using a Bahtinov mask, although the grabber software would be of no use to me as I don't view anything on a laptop screen. So in effect what you're saying is using a Bahtinov mask on the stock SW single speed focuser will make my focusing as accurate as a 10:1 Crayford dual speed?

[RikM]

There is no inherent difference in the 'accuracy'of focus that can be achieved, it's more about the physical process of achieving it. Using a Bahtinov mask is way more accurate than eyeballing a star on the back of a DSLR screen. After that it just depends on how your focuser is adjusted and how confident you are of making tiny adjustments to focus. Since I always use a laptop screen and software aids, it makes no difference to me. For visual use or for planetary imaging, then a DS focuser would be a great help.

[happy-kat]

If you have a tablet you may be able to connect your canon to it, I connect my nexus and benefit from a large screen for focusing

[glowingturnip]

i got one of these to convert my focusser to a dual-speed - easy to fit and I'm very pleased with it - http://www.365astronomy.com/dual-speed-110-microfocus-upgrade-for-skywatcher-crayford-p-2484.html.  You should check it's compatible with your scope though.

And make yourself a bahtinov mask - http://astrojargon.net/MaskGen.aspx?AspxAutoDetectCookieSupport=1

I end up going through iterations of taking a photo to the laptop screen with the mask on, checking focus, and repeating till it's spot on.  a bit time consuming but becomes easier with practice.  I found I couldn't get good enough focus just on the dslr screen or through the eyepiece even with the bahtinov.

[Johnny666666]

That's an interesting upgrade, I've also spotted the dual speed motorised remote focuser attachment, which will help me greatly as I'm currently having to wait about 10 seconds for the scope to settle down after any touch. 

http://www.rothervalleyoptics.co.uk/skywatcher-auto-focuser.html

The RVO web page claims this focuser is suitable for the Explorer 150, which I assume is what I've got? However, I'm concerned again that adding even more weight is simply going to exacerbate any issues I have. As things stand both counterweights are at the very far end of the counterweight rod (any further and they'll drop off) and I can just achieve balance...

So again, I'm wondering about the 130P-DS, which is lighter and already has the 10:1 Crayford fitted

[Thalestris24]

Hi

I think you'd definitely find the 130pds easier to manage on your mount and that will be important if you plan to attempt some AP. Presumably you'll keep your 150p anyway? I have the 150pds with the same dual-speed Crayford. Never had any problems with it and it's happily taken my 1100d and now the qhy8l. I think there's an Astronomyshed video which looks at adjusting the focuser should you need to.

Cheers

Louise

[Johnny666666]

Hi

I think you'd definitely find the 130pds easier to manage on your mount and that will be important if you plan to attempt some AP. Presumably you'll keep your 150p anyway? I have the 150pds with the same dual-speed Crayford. Never had any problems with it and it's happily taken my 1100d and now the qhy8l. I think there's an Astronomyshed video which looks at adjusting the focuser should you need to.

Cheers

Louise

Hi Louise, yes if I went for a 130PDS I would still hang on to the 150P. I don't want to bodge a solution onto it when the 130PDS is not that much more expensive, and I can always sell one of them on at a later date. Some of the DSO photography in the 130PDS thread is simply breathtaking so I know what the scope is capable of. My camera is fairly lightweight but I feel I'm right at the limit of the mount already and this isn't helping, I'm sure. I've found I've been doing nothing but adding weight to it from the outset - adaptors, filters, better EPs, let alone potentially a Bahtinov mask, a 9x50 finder to upgrade the 6x30, and maybe a motorised focuser - and it's just getting heavier and heavier and I have nowhere to go...

[Thalestris24]

Hiya

Well everyone says the 130pds is quite a good imaging scope for DSOs. I've been happy with my 150pds but I have an Heq5 syntrek - obviously much sturdier for AP. But no reason why you shouldn't have a go! Be warned though - the forces of the dark art will drag you in! There is almost no limit to the expense! But it's as satisfying as it is frustrating. If only the weather here in Glasgow was more conducive. Sigh.

Cheers

Louise

[Johnny666666]

True! I have renamed my 'wants' list to the 'would really like if only I could afford it' list!

Unfortunately the 150PDS would not solve my problems due to the limitations of the mount, and for the expense of an 'almost identical' replacement to what I already have I would probably look at many more options because I would need to upgrade the mount as well. The 130PDS gives the same speed at a slightly wider field of view but is lighter so I can retain my current mount and get on with it, and I have less fear of adding a few bits and bobs for 'fine-tuning'

If only the weather would improve!

[Thalestris24]

Yeah - I wasn't recommending the 150pds for you - just saying that it's similar to the 130pds and I've had no problems with it. Not even collimated it - yet! It worked fine out of the box

Cheers

Louise

[Dodge]

Slightly off topic, where did you find a 130PDS for ~£150?  It's more like £170+ wherever I've looked.

[Uranium235]

I thought they were £165? (with auntie FLO)

With the 130, depending on how high you set the bar in the first place - will require a little fiddling to get it perfect. If like me, you are seeking perfect corners on a big(ish) chip - then you are forced to work with the pds focuser supplied since there are no 3rd party replacements for a 5" newt.

If you are familiar with drilling and tapping - when you get it, drill and tap another hole for third thumbscrew on the focuser (screw size M4). That will help to secure any cameras or correctors properly (avoid compression rings like the plague). There are a few little mods you can do while its cloudy (build a dewshield, an end cap for the bottom, blacken the drawtube etc..)

[Thalestris24]

Yep £165 - plus shipping, of course.

http://www.firstlightoptics.com/reflectors/skywatcher-explorer-130p-ds-ota.html

[Johnny666666]

I thought they were £165? (with auntie FLO)

With the 130, depending on how high you set the bar in the first place - will require a little fiddling to get it perfect. If like me, you are seeking perfect corners on a big(ish) chip - then you are forced to work with the pds focuser supplied since there are no 3rd party replacements for a 5" newt.

If you are familiar with drilling and tapping - when you get it, drill and tap another hole for third thumbscrew on the focuser (screw size M4). That will help to secure any cameras or correctors properly (avoid compression rings like the plague). There are a few little mods you can do while its cloudy (build a dewshield, an end cap for the bottom, blacken the drawtube etc..)

£159 from my local shop

However, I am a little 'lost' with these mods... I assume you mean a third hole and thumbscrew in the focussing tube and not somewhere on the Crayford mechanism? If so, where would be the most ideal place?

I have various adaptors including a 2" Lumicon extension tube which also has 2 thumbscrews and a 2" Twistlock Adaptor for 1.25" EPs or a T-Mount thread, both of which have 2" filter threads internally. I use these on the 150P because I want to standardise my filters to 2" across the board (I can also use them on my m43 camera system lenses, incidentally the system has a 'small-ish chip size of 17.3mm x 13mm). However, it remains to be seen what adaptors etc I can use on the 130PDS because the back focus is presumably in a different position?

Do you have any experience of the SW coma corrector?

As regards how high to set the bar - having looked at your images from the 130PDS I would be very pleased to even attain a fraction of the quality you have managed, although I realise I have a long way to go yet!