Is my new Mak 127 dead??

[SCOOB_81]

Hi All,

I was hoping that someone could help me with an issue that I have with my new scope, a Skywatcher Mak 127 Supatrak auto, please?

I’m really enjoying astrophotography with the SPC900 webcam and started out with a Skywatcher 130p. I’m no expert, but managed some decent shots of the planets using a Tal X3 barlow – and loads of patience! I was looking at ways to upgrade the 130p, but figured the money would be better spent on a scope that has a proven track record with imaging. I know what the Mak 127 is capable of from some of the excellent shots on this forum.

I’ve used the scope a handful of times with Jupiter and at low magnification all seems well with crisp images. Use the included X2 barlow and you’re pushing it, unable to get a really clear image (Is that right that 10mm & the included barlow pushes the scope beyond it’s limits??).

The issue that I have is with imaging. I’ve tried imaging with my Tal X3 and the images were shocking whilst recording. I was completely unable to focus, despite an hour of trying. The stacked images were as bad as when I first started out with the 130p, worse in fact. I figured the Tal may be too strong for the scope and so I tried the included X2 barlow today. I’ve seen shots taken with my exact setup (including an extension tube on the Barlow) and they’re fantastic – again, I couldn’t focus and the final stacked images were terrible.

I’ve given plenty of cool down time, seeing was good, no dew on the lens, camera filter is spotless – I’m stumped!

Anyone had any similar experiences with the Mak??

Thanks,

Sean.

[nightfisher]

Im gonna guess here and say that due to the long focal length of the mak, using a barlow will take it way over the limit if using a webcam the x3 barlow will give you x750 mag with the webcam, try it without the barlow, how is the mak for visual work

[malc-c]

Sean,

The Mak will have a focal length of 1500mm, if you use the 3x barlow that equates to 4500mm. With an aperture of 127mm that equates to a focal ratio of approx F34. The result would be a very dim image, which (assuming you could focus within the range of the focuser) would have a very very small depth of field. Factor in the typical atmospheric conditions and it would be impossible to get a sharp image.

The best I've managed is stacking two 2x barlows through an 8" f5 (thus having an effective focal ration of F20), and that was under very good seeing conditions, but it was extremely hard to focus, and on the edge of the limit for the webcam

[RikM]

I struggle to get any kind of decent image with the Skymax and even a 2x Barlow. Good for the moon but that's about it. That said, lunar / planetary imaging doesn't really interest me so I haven't put much effort into it.

Here is the best I achieved:

[JamesF]

The usual rule for maximum magnification is twice the aperture, so 250x (near as makes no odds) with the 127 Mak. The focal length is 1500mm, a 2x barlow doubles that to 3000mm and with a 10mm ep that would give you magnification of 300x, which is not only probably more than you can reasonably expect from the scope, but also more than you're likely to get in anything other than exceptional seeing. The same rules don't necessarily apply when you're using a camera though.

The included barlow is rubbish. I'd take the lens out and just use it as an extension tube. The Revelation or Celestron Ultima barlows are incomparably better.

If you're having trouble focusing then you might want to look at a Bahtinov mask. It may help (or it may not It might also be worth looking at motorised control of the focuser, because there's a fair bit of wobble when moving the focus knob that makes it very difficult to get right.

The 127 Mak is a good imaging scope, but it's far more demanding than the 130P and may take a lot of practice to get right. You're seeing far less sky by the time you have a 2x or 3x barlow in, so every little quiver of the scope or flicker of atmospheric distortion is going to look so much worse. For the latter reason it's also worth trying to do some imaging when the target is as high in the sky as possible.

James

[SCOOB_81]

Thanks for the replies, gents! Some really useful comments there and a big help.

I have to agree and think that with the X3 Tal that I’m pushing it way too far. As you say, even the X2 will be too much on all but the clearest nights. Thanks for the suggestions on alternative barlows, I can imagine that they will be a big improvement over the standard, and it is something I’ve thought about upgrading. Same with the motorised focuser! I’d look at modifying my 130p to take the Skywatcher autofocusser, but also read a thread on the same thing with the Skymax. It is difficult to focus, a bit more of an art that the 130p.

Visually it seems ok at around 150X, but stepping up with the X2 barlow is just too far, as you all said. I’ll give it another go tonight. The weather isn’t looking to bad out of the office window at the moment, so perhaps the gods will smile for tonight!

Those images are great, Rik. Your deep sky shots are fantastic!! Can I ask if you use a light pollution filter, please?

Thanks!

Sean.

[SCOOB_81]

Oh, just one more thing! Does anyone know what just using the X2 barlow as an extension tube will give as a rough focal ratio, please??

Cheers.

[Jove]

Hi,

Focussing is hard - and the longer the focal length the harder it gets - the 'sweet spot' gets narrower and narrower and finding it takes practice. What doesn't help is that the focusser on the 127 is not that good for doing really fine focussing, and if your mount is like mine the image bounces around a lot when you so much as brush the focussing knob. Things that may help:

- adding some ballast to the mount so that vibrations are dampened more quickly

- some people stick a jam jar lid onto the focusser, the idea that the larger radius makes it easier to do small adjustments of focus

- use a Bahtinov mask

You don't say what you are trying to image, but I found Jupiter a good target to practice on, and easier to bring to focus that Saturn or Mars.

I'd also practice without a barlow and a 2x barlow before going to 3x.

Good luck!

[bigal1]

I always use a 2x barlow and an extention tube (skywatcher 2x barlow with lens section removed ) placed into my diagonal with my 127 mak and webcam but this does require good conditions , i have had what you describe happen more times than i care to remember and always it is down to bad conditions . Them few lucky times when i'm out and its good the images can be totally different and you know for sure when you have hit focus , maybe just keep getting out as many times as you can and at some point i rekon you will get lucky and see the difference ( maybe also just stick with the 2x barlow for now ) good luck with it

[Baffa]

I'd say skip the barlow, you need really good sky to get a decent pictures with that focal lenght.

I have tried using barlows with my scope but even if I have stable sky conditions it's too dim to bring out the details. And the mount, well, not stable enough either...

[SCOOB_81]

Thanks for the replies everyone – luck is definitely needed here……..

Again, some great advice and I’m going to work through everything mentioned over the next few days if the skies keep as clear as they are now.

I’ve just tried as many of the suggestions above observing/ videoing Jupiter; no Barlow, Skywatcher X2 Barlow with and without lens (just as an extension tube), including all of those without the diagonal. I’m not blessed with surgeons hands, but am fairly shake-free with focusing and I can usually get fairly lucky with the ‘sweet spot’. Unfortunately, after an hour outside and contorting my neck in ways that will be familiar to those who have seen the exorcist (the finder scope is the work of Lucifer himself), focusing for imaging is verging on impossible……. I couldn’t even manage to image Jupiter with no Barlow, with it always appearing slightly out of focus. I’ve also tried messing around with the camera settings in WcCtrl too, just to see if a new scope needs new settings, but nothing improved.

Basically, I can observe to roughly the magnifications and clarity of my 130p (which is slightly out of collimation), but imaging with the Mak is not a lot of fun at the moment.

Sorry it’s not exactly ‘polished’, but I’ve included the best I’ve been able to get out of the Mak along with a fairly standard one from the 130p. The Mak is using the SW X2 barlow (I know its not great) and the 130p is a X3 Tal. Both are approx 750/1500 frames @ 10fps over 3 mins in WXAstro Capture.

The jam jar lid is a really great idea, and I’ll try that next.

At the moment though I’m fairly demoralised.

Thanks again

Sean.

Mak 127

SW 130p

[malc-c]

Don't put yourself down, both images are very good, and you should be proud of them, especially as Jupiter is not at it's best position now. I've seen worse taken with far larger scopes.

The image from the 130 will be brighter as the effective focal ratio is f15 (650 x 3 /130) where as the Mak will be almost f24 (1500 x 2 /127). The only way to compensate is to lower the frame rate, increase the gain and balance with the exposure. Try downloading Sharpcap, it is (IMO) easier to tweak the settings. Try to get a bright image with the gain 40 - 60%

[Dunkster]

Demoralised Sean ?!?

Could you teach me how to process images like that because mine don't come close

[SCOOB_81]

Apologies that this thread is a little old. I’ve been away with work and not had a chance to say thanks again for the support, folks.

Cheers!

Sean