6" or 8" Newtonian F/5 for astrophotography

[laser_jock99]

I don't think so! I guess you mean the F4. Very difficult to get these to perform properly and they hardly ever do so out of the box. 

Olly

Bizarrely enough my new 10" F4 arrived perfectly collimated literally 'out of the box'- possibly a coincidence? But considering the battered box & the postal journey I think the collimation locking screws held it pretty well. 

There's a lot of nonsense talked about collimation- with the right tools it should only take a couple minutes.

The big Newtonian astrographs aren't really suitable for beginners- though they are a joy to use when everything's working properly.

[Uranium235]

Thank you all for your prompt response and support .... :-)

Uranium235 ,

Wow, I got blown away with your image of the Rosette nebula, never thought it could be achieved with a 130mm Newt scope.

Even though I have deep passion in the universe through research and those documentaries on Bluray, but I have not ever ventured out of my comfortable couch into the dark cold night to explore the wonder of the universe    Therefore, I'm very consciously investing my money in my first scope ... not to little to kill my passion, and at the same time not too much if it turned out it wasn't what I want !!

So after more than 2 months of research, with a lots of help from this forum, I'm planning for an average package of around $2,000, if it's close to $3,000 it triggers the guilt

Celestron CG-5 GOTO mount

6" OTAW - is this the same one as PDS?    http://www.skywatcheraustralia.com.au/?wpsc-product=bkp150-otaw-dual-speed-d-150mm-f-750mm

Baader 21mm & 8mm with FineTuning Rings 14mm & 28mm

Baader T-ring/adapter 

Baader UHC-S filter

Baader 2.25x Barlow

Lumicon 4 planetary + moon filters

Collimator:

I'll be doing drift alignment in the first few months to learn the rope, if I still survive the Melbourne winter   , I'll be looking into Orion mini-autoguider package. (I do feel ashamed comparing our winter in Australia to other places in Europe or US   )

The tube weight is 6kg, my DSLR body is 0.65kg + ~0.5kg (for barlow or EP) ..... so it's just over 7kg without autoguiding scope/camera, or about to 7.5kg with Orion autoguiding

Could you please give me your thought on this? .... and no.... I wouldn't dream of producing the images like you guys did with 130PDS, but if they are reasonable to convince my wife for the upgrade .... I would be very happy 

Thanks heaps.

 (my brother's $100 department store telescope killed the idea of having my own telescope 10 years ago   )

Thanks for the positive comments on my images from the 130pds. But I do have to add that those were hard-won images, depending on how high you set the bar in the first place. The biggest challenge (as with any reflector telescope) is getting round stars in all four corners of a big chip. All too often its 3 good corners and one duff one, so the focus point has to be moved in order to balance the field.

Today I ordered the parts to construct the ultimate M54 Skywatcher focuser mod (threaded - rotateable - tiltable). In a couple of days I will fetch the bench drill and get to work on it.

In regard to your choice of equipment, if you can get your hands on an HEQ5 - get it. I used to own a CG5 and while it was capable, it definitely isnt "set up and walk away" like a HEQ5 would be - it will be good for 450s subs on a regular basis (anything more decreases your hit rate). But If youre definitely getting the CG5, make sure it has a polar scope too. You should be fine with just the OTA, camera + Corrector, plus a lightweight finderguider (mounted on top of tube rings). Also, to keep weight down, you can remove your 2nd finderscope once mount calibration is complete. Your collimation tool should be a Cheshire, no need for lasers.

You might want to figure in a coma corrector too, in case you want to capure any DSO stuff - otherwise coma starts to take over as you move away from the centre of the image.

[ozboyz1]

I can't thank you guys enough for the valuable advice. Since the idea of getting the scope is to reward my 9 yr old son, who has developed passion in astronomy .... and to give him an opportunity that I did not have when I was at his age.

So I guess, I'm going to shelf my astrophotography  idea for now, and go for the HEQ5 Pro & 8" Skywatcher PDS, mainly for visual observation. Because if I go for 6" to satisfy both observation and AP, I would always be wondering what I'd miss out with the 8" ..... unless you insist on the 6" since there is little gain in observation.

If the scope still gets used on regular basis after 6 months, I'll be looking into APO ED 80 or 100 for AP. Would you kindly suggest a good scope at reasonable price, say under $AUD1,000 (I know the 2 don't get along very well  )

Many thanks again !!!

[Uranium235]

Wise choice, getting a HEQ sorted out now will put you on the same playing field as many other imagers. If you are thinking about an 80ED or 100 further down the line, I'd get the 80ED as it also doubles up as an excellent imaging scope - plus it will offer a much wider FOV than the 200pds will (and its more "grab and go").

Very few people can afford to get the bits all in one go for a half-decent setup. Take your time, the stars will still be there next year

[GuillermoBarrancos]

If the scope still gets used on regular basis after 6 months, I'll be looking into APO ED 80 or 100 for AP. Would you kindly suggest a good scope at reasonable price, say under $AUD1,000 (I know the 2 don't get along very well  )

Many thanks again !!!

For pure imaging purposes don´t pay more than you have to and go for the 80ED. It´s the most popular used scope in Astrophotography.

I don´t know how the Australian dollar translates into scope prices, but here in europe you can get a good 80ED doublet for around 500-600 Euro and a triplet 80ED APO for around 900-1200 euro.

When it comes to ED doublets, the Skywatcher Equinox 80ED Pro is among the most popular ones, with the Skywatcher Evostar 80ED Pro as cheaper option. 

When it comes to Triplet APO, you have the William Optics GT81, AltAir Astro Wave 80ED, Skywatcher Esprit 80ED Pro as recommended examples.

Side note:

In the "affordable" range, the 100ED like the Skywatcher 100ED is a bit of a "strange duck in the pond", in that it´s more of a visual scope due to it´s F/9 focal ratio.

The 80ED and 120ED are more dedicated towards imaging due to their faster focal ratio.

[Astrosurf]

I've got an HEQ5 Pro and a SW200P, As has been said, imaging is tricky as it needs no wind and no vibration. I do image with it pretty successfully, though, for my low-ish standard! Here's my Astrobin site (note, I also use a WO Megrez 72mm):

http://www.astrobin.com/users/Astrosurf/

Good luck!

Alexxx

[ozboyz1]

That's very encouraging Alex, thanks .... I'm going trying my luck as well .... now it's time to get off the couch to buy that mount and scope   Thank you all !!!

By the way Olly, I've been to your website and hope one day my family can pay you a visit 

[ryandsimmons]

I have a CG5 mount, and have a C8 telescope on it.  Not done much with it yet thanks to the weather, but I did do a fair bit of research beforehand and an 8 inch scope is fine with it.  An SCT at least, which is not the best for photography, I am not sure about other OTA.

[Astrosurf]

Good luck ozboyz1. Let us know how you get on.

[Evie]

Thanks for this topic - I was already thinking about 6" SW and HEQ-5, but now decided firmly on it. Now only put away some money for it and HEQ-5 GoTo. Imaging is more important for me, as my eyes are not the best.... The weight and the dimensions also gives their point.

Good luck with your choice