Can't decide which one for AP....

[Welrod50]

OK folks, I'm after some considered views please and although this has most likely been raised before now, I thought I would create a new post to see what new ideas folks may have, and hopefully generate some renewed interest amongst the ranks

I currently have an EQ2 mounted SW Explorer 130 (non parabolic) onto which I mount a Pentax Kx via a T adapter on a SW 8-24mm zoom EP (with LP filter fitted).

I have another thread here which details some recent results I've had with still image RAW capture and Registax converted video, so wont go over old ground...

Having been bitten by the bug for AP, I know I will struggle to do any serious DSO imaging with my current set up. I would like to do some more successful capture of Jupiter, Saturn, Moon et al (be it with still image or DSLR video) and also be in a position to capture the brighter DSO's (M42, M31, M13 and the like) and am aware I will need to potentially take numerous stills of several seconds each and stack them. I am also aware of the limitations of SynScan/GO-TO alt/az tracking mounts compared to EQ tracking mounts, but I have a budget which must be adhered to

My questions are listed simply here:

1. Which would be best for this - SW Skymax 127 SynScan GO-TO or the SW Startravel 102 SynScan (or equivalent Celestron/Meade in similar price range). I have gone for SW based purely on my current fondness for the brand, but I'm open to opinion.

2. Will the 127 Mak be significantly less successful than the 102 refractor at DSO work, given that exposures will run into numerous seconds. Will the refractor be considerably softer than the Mak at planetary imaging?

3. I know that AltAz will track my object of choice enough to allow exposures of several seconds and beyond without worrying about star trailing. However, will these set-ups take the weight of a small DSLR without putting too much stress on the motors?

Your thoughts and examples please folks, as ever will be much appreciated!!

Oh and one final thing, does anyone know the difference between the Skymax 127 SynScan GO-TO and the same scope with a SupaTrak Auto mount? I know this may sound a daft Q, but to my amateurish mind, they perform the same function. Is one better than the other??

Cheers and clear skies for tonight!!!!!

Scott.

[steppenwolf]

There is no 'one size fits all' solution for deep sky and solar system imaging. Forgetting about the mount for a second (although this is actually the most important part of the whole equation!), for Lunar and planetary imaging, the 127 would be the better bet because of its focal length. However, for deep sky work (with the exception of galaxies) a shorter focal length is more desirable as the majority of objects are relatively large in field of view terms. So, that is dilemma number one, if you have only one telescope, you've really got to make a bit of a decision here, deep sky or solar system.

...... and now the mount. For fast frame imaging such as that required for Lunar and planetary imaging, you can get great results from an Altazimuth mount because total exposure time is seconds. However, for deep sky objects, you will realistically be looking at minutes of exposure and an Altazimuth mount will not be suitable. I have the exact mount that you are looking at and I love it, in fact I have only very recently bought it BUT I have got it for visual use. That is not going to stop me trying some very wide field imaging of objects like the Milky Way using a wide angle (28mm) camera lens but I will be expecting my exposures to be in the sub 30 second region - a telescope would not be suitable here.

The SW Skymax 127 is a Maksutov so it will perform well with respect to chromatic aberration, the SW Startravel 102 will not fare so well in this regard.

In your situation, I'd say get the SW Skymax 127 SynScan GO-TO for imaging solar system objects and to give an alternative view to that obtained with your SW Explorer 130 and also use the AZ mount with your DSLR camera and a wide angle lens for an interesting foray into wide field deep sky imaging.

........ and start saving for substantial EQ mount for the next stage of deep sky imaging.

[dmahon]

For DSO photography you really want:

A short focal length ED refractor

A motorised, sturdy EQ mount

GOTO is advisable

An ED80 on an HEQ5 pro would be ideal. You can just about get away with an EQ5.

[rowan46]

To be frank none of those combinations is close to the real package the skymax 127 on either mount will give decent planetary images with a webcam but will be useless on either mount for all but the brightest dso's (and getting those will at the very least be difficult). the startravel will give you some very bloated stars.

What about the 130p ds with a celestron cg4 or skywatcher eq3 and then get dual axis or syncan upgrades at a later date if you want to image dso' you need an eq. The eq3 is not a great imaging mount but it is still better than any alt az mount for imaging dso's. I seem to recall that eq3 with just ra drive took some halfway decent pics of the larger brighter dso's

[kirkster501]

I had the same question a few months back and the HEQ5/ED80 combo was recommended to me by the experts on this forum. And what a good recommendation it was too. Superb for DSO. For Planetary I use my CPC.

[steppenwolf]

I had the same question a few months back and the HEQ5/ED80 combo was recommended to me by the experts on this forum.

Absolutely agree - but we have to work within Scott's budget as he has made it clear that he has to stick with this! I'm pleased that the recommendation has worked out well for you though.

[Welrod50]

Thanks for the input guys. I am typical in that I am greedy and want the best of both. I suppose that is why I chose the SW 130 as my first telescope (discounting my old Tasco refractor I had off Santa when I was about 5 yrs old) as it offered a good focal length for planets with a reasonable aperture to allow enough light for DSO viewing. That said, I was a little disappointed with how faint and fuzzy M31 proved to be last night. I have to say, I am rather leaning towards the 127 Mak as I do enjoy planetary viewing and therefore imaging.

I do not want to sell the SW 130 though as I do expect that it will give better views when I next visit a dark sky area (only had the bino's last time) although I'm not expecting a vast improvement, and it's size and weight is restrictive.

I want to invest in something smaller, lighter, more transportable and that has the added bonus of being able to track objects better than I can with my eyes and hands! I'm thinking of the 127 Mak and maybe a 40mm EP to provide a wider field view, so long as I can still actually see M42 say, even if I can't image it. I think I could live with that.

Any thoughts?

Scott

ps - will the 127 Mak take a small DSLR weight wise without stressing the motors?? If not, this all becomes slightly redundant

Keep the input coming please folks........

[steppenwolf]

I want to invest in something smaller, lighter, more transportable and that has the added bonus of being able to track objects better than I can with my eyes and hands!

That's why I bought the SW AZ GoTo mount.

will the 127 Mak take a small DSLR weight wise without stressing the motors?? If not, this all becomes slightly redundant

The key here is to ensure that you have an accurate balance in the altitude axis - I bolted the 'shoe' on my Megrez 72D refractor to a Vixen dovetail bar so that I could adjust the balance point with a large eyepiece in place so you could do something similar to ensure that your system is balanced with the DSLR in place if necessary.

[Welrod50]

OK folks, update (followed by some final advice hopefully please)............

Have managed to get out twice this week (somehow )

I have done some serious viewing with my SW 130 f900 Newt on its original standard EQ mount, and also engaged in further AP, some via eyepiece with attached Pentax Kx and some wide field with a Sony R1 with remote release mounted atop the OTA. Will be spending much of today going through the pictures and video from this. Anyway, I have come to the considered view that I cannot expect shutter speeds of much beyond 10 seconds before stars begin to stretch. It is very subtle until you go beyond 15-20 seconds, but all the same, I am something of a perfectionist.

My original posting still stands, that I would like something much more portable with the potential to do some wide field and possibly DSO photography and along those lines, I have done much research and spoken to both FLO and Sherwoods to gain further input. I have decided to move away from upgrading my mount, based on size and weight and the fact that it would be equally difficult to transport as my basic EQ. I live within 20 minutes drive of the Roaches and intend to do some serious DSO observing/AP.

I have been recommended a Celestron Nexstar 4se Mak or Celestron Nexstar 102 SLT refractor (based upon budget). My decision therefore is this:

Nexstar 102 SLT, with Baader Semi APO filter!

My thoughts being that it gives away a lot of focal length to the 4se, but gains serious aperture and even though it is less optically capable than my current SW 130, a good deep sky site will negate this (and more so!) hence I can justify this move. I am acutely aware that the 4se has EQ wedge, albeit it will not be as capable as a HEQ5 or similar, so this is a bit of a mute point in my eyes. I am therefore after your thoughts on this choice and realistically, what type of shutter speed can I expect before field rotation becomes too much for DeepSky Stacker to overcome. Will the SLT track accurately when I have set it up (meticulously!) and what are the views of those who own it? Keep in mind, I will be doing mostly viewing with it, but the capacity to do AP for some 40% of the time is a bonus.

Apologies for rambling, but I have tried to include all my thoughts, and hopefully generate interest for others in a similar 'spot' to me

Clear skies!!

Scott.

[Welrod50]

Rather than start a new thread, further to the above post, I obtained this last night:

Taken with video on the Kx via EP adapter. EP being a SW 8-24mm zoom @ 12mm with std (low quality) SW x2 Barlow lens. Virtual Dub and Registax then taken into PS Elements 8 for final tweaks and cropping in. Original image was about half the size. Can I expect similar with the Celestron 102 SLT GO TO (albeit a little smaller due to the 30% less focal length)?

Any help/thoughts would be brill

Scott.