Second telescope suggestions

[dannyboy]

I've owned an Explorer 130PM with EQ2 mount for about 7 years now, and have had a decent amount of enjoyment from it. I live in a relatively light-polluted  area, so have tended to stick to lunar and solar system planetary stuff, including some basic imaging using a cheap and cheerful NPC900 webcam. I'd love to be able to see a little more detail of Mars, Jupiter, etc. when observing though, and I've always struggled to get the webcam focused properly on the moon though - not sure if this is down to the webcam or the scope (or both). 

So, I'm considering treating myself to something slightly bigger and better, ideally with something better than the webcam for imaging too. My max. budget would probably be about £600, perhaps a touch more for the right scope (doesn't have to be new - second hand is fine). Are EQ mounts still preferable for imaging? Oh and I don't really tend to travel anywhere with the scope, so portability isn't a big factor for me.

Thanks for any suggestions.

Danny

[alan potts]

I would say for anything that gets close to serious an EQ mount is a must for imaging, there are many people on here whos mounts cost many times what their scopes cost, though of course some have dug deep for both. As for a scope I was wondering what you would think to a nice S/H Dob, could get something nice for 600 quid though imaging would be very limited

[Louis D]

I would suggest getting a second hand 10" or 12" Dob.  The additional details visible on planets will blow your mind.  Festoons and barges start to become visible on Jupiter, the Galilean moons begin to resolve as disks of different sizes and colors, the rings of Saturn show differing reflectivity and have sharp divisions, Saturn itself starts to show bands of differing reflectivity, nebula like Orion and Veil come alive with an OIII filter.  You can always add an equatorial platform later if you want tracking for short webcam exposures.

[vlaiv]

Depends what type of imaging do you have in mind.

I suppose that you might be talking about planetary imaging since you mention "cheerful NPC900 webcam". If that is the case, go for either motorized dob (SW 8" will cost a bit more than your budget), or go for 10" dob + equatorial platform.

If you plan for long exposure photography - then, for any serious stuff, you will need to spend at least that much money on the mount it self.

[Cosmic Geoff]

You need to define what sort of imaging you have in mind.  For planetary imaging you don't need an equatorial, as it can be done with an alt-azimuth GoTo mount, even the more lightweight variety (e.g. the 6/8SE).   Depends on whether you see yourself as a visual observer with occasional imaging, or a serious imager.  For visual, many now think that an equatorial mount is more trouble than it's worth.

Note that for planetary imaging the more expensive catadrioptic scopes have a built-in advantage over Newtonans - they have a large focal range which means that accommodating atmospheric dispersion correctors, filter wheels etc is no problem.

For deep space, it's a different ballgame altogether. And 600 pounds won't go far there.

[dannyboy]

Hi guys

Thanks for all the comments. Sorry for the late reply too, I'm subscribed to this thread but didn't get any email notifications for some reason.

Anyway, there's plenty of useful info there, which I really appreciate. It sounds like a pretty unanimous vote for a Dob then, although @Cosmic Geoff you mentioned catadioptrics too - would the main benefits of these be around the imaging side of things?

In answer to the questions around imaging, I only take the occasional shot of the Moon or Jupiter - pretty basic stuff and definitely no long exposure/deep sky etc. So I'd probably just go for something like this which I assume would be a small improvement on the SPC900, without costing a fortune. In terms of mount, it sounds like I could get away with an alt-az GOTO then - are these a bit cheaper than equatorial mounts?

thanks again

Danny

[Cosmic Geoff]

Once you get over the shock of the higher cost, catadrioptics are pretty much an all-round improvement on a Newtonian - as well as having some advantages for imaging they are much shorter and lighter, and the eyepiece stays at a convenient position (at the back) instead of moving around a lot. And collimation is less of an issue. They are also the instrument of choice for university astronomy departments...

One can't generalise on whether alt-az GoTos are cheaper - they are more commonly sold as a bundle with a scope. Several of the alt-az GoTo mounts are clearly designed with portability in mind, so if you don't want a lightweight one, shop with care.  You can also get combined EQ-alt-az goto mounts - at a price ?.

The Bresser camara might be OK but I know nothing about it.  A lot of planetary imagers use the ZWO  ASI120MC, which is a good camera - it used to cost over £220 but is now a lot cheaper.

[Louis D]

4 hours ago, Cosmic Geoff said:

Once you get over the shock of the higher cost, catadrioptics are pretty much an all-round improvement on a Newtonian

Not if you compare the view through a custom Dob versus a commercial SCT.  The much smaller central obstruction in a custom Dob (typically less than 20% compared to 35% to 40% for an SCT) combined with a very finely hand figured primary mirror lead to exquisitely sharp, high contrast views.  Aside from the EdgeHD series, every SCT I've looked through produces mushy star and planetary images aperture for aperture relative to custom Dobs.  Maks do seem to do a better job than SCTs, but become much heavier quite quickly as the aperture increases due to the thick meniscus corrector.

[Merlin66]

Louis,

My experience over the past twenty years with various SCT's is that they represent an acceptable compromise between performance and usability.

The C9.25 I used for a few years gave great views and is sadly missed.....

I use a C11 on an NEQ6pro mount ( a change driven by the limitations of a fork mount to accommodate the spectrograph) for spectroscopy. No issues, no drama.

 

[Stu]

Given the OPs budget, I think a decent sized Newt makes most sense. I have bought used Orion Optics VX10L and VX12L scopes with high quality optics for less than £600, they are there if you are a little patient. Much lighter than the Skywatcher alternatives.

I have used the Bresser Wi-fi camera, it worked ok but I think there are better wired options out there which put more emphasis on the sensor than the Wi-fi connection and will give better results.

You can also have fun and get decent results using a smart phone held at the eyepiece.

[Cosmic Geoff]

13 hours ago, Louis D said:

Not if you compare the view through a custom Dob versus a commercial SCT. 

That hardly seems like a fair comparison.  Custom Dob vs Edge HD sounds fairer.

[Louis D]

7 hours ago, Cosmic Geoff said:

That hardly seems like a fair comparison.  Custom Dob vs Edge HD sounds fairer.

Maybe not, but price wise new, they end up being similar.  In the states, a used 14" custom Dob often goes for less than a used 14" SCT.  That, and the statement was nearly absolute in its tone.  Perhaps if it had been phrased "Once you get over the shock of the higher cost, catadrioptics are pretty much an all-round improvement on a Newtonian except for absolute image quality."  I'd have been okay with it.

[Cosmic Geoff]

12 hours ago, Louis D said:

Maybe not, but price wise new, they end up being similar.  In the states, a used 14" custom Dob often goes for less than a used 14" SCT.  That, and the statement was nearly absolute in its tone.  Perhaps if it had been phrased "Once you get over the shock of the higher cost, catadrioptics are pretty much an all-round improvement on a Newtonian except for absolute image quality."  I'd have been okay with it.

I guess 'pretty much' was not sufficiently cautious wording for the purpose.

 I have seen praise for small-secondary Newtonians, but on a sample of 1+1, my 8" Newtonian does not seem to perform any better than my 8" SCT. So far as I can tell, of these two the SCT gives cleaner Airy disks under the right conditions. Overall, I am favorably impressed with the performance of my SCT (and the smaller Mak).

[dannyboy]

Thanks guys, some good info (and debate!) there. Probably a silly question, but is a Dob essentially just a reflector on an alt-az mount?

Anyway I'll do some reading on Dobs and SCT's to get a better idea of which would fit my budget best.

Cheers.

[Ricochet]

5 minutes ago, dannyboy said:

Thanks guys, some good info (and debate!) there. Probably a silly question, but is a Dob essentially just a reflector on an alt-az mount?

Anyway I'll do some reading on Dobs and SCT's to get a better idea of which would fit my budget best.

Cheers.

Technically the dobsonian is the mount itself and the type of telescope it is usually used with is a Newtonian reflector. The advantage of a dobsonian mount is that it is both relatively cheap and very stable.