Advice on getting started in AP

[m-r-c (Mark)]

Hi all,

I'm planning to start down the AP rabbit hole, and I'd like some advice before I start buying stuff. I'm more interested in DSOs than planets, and I understand that there are different requirements for nebula vs planetaries & galaxies (widefield vs longer FL?), but widefield sounds like the more sensible (and common) starting point. I currently have a manual 10in SW dob (solid tube, f4.7, 1200mm FL) for visual, but it's obviously not suitable for AP. So I'm thinking about the following setup - the goal is a fairly minimal kit that does not skimp on quality (but doesn't bankrupt me either), portable, and something that I'm not going to need to upgrade after just a few months of playing around:

* Mount: SW AZ-EQ6 GT (prices seem to be around $2500 +/-)
* Scope: SWED80 f7.5 600mm FL (~$870)
* Field Flattener: SW 0.85x Focal Reducer Corrector for ED80 (~$330)
* Power supply: no idea yet
* Camera: Canon 1300d DSLR (just because I already own one)


Now some newbie questions:

1) Obvious one first: is this a good starting setup that will last a while, and am I missing anything that is really worth getting up front? From what I've read, the FF/FR is pretty much essential. I know autoguiding is highly recommended, but I was thinking that I could (should?) do without while I learn the ropes.

2) Would the AZ-EQ6 handle my 10in newt OTA (15kg + rings) in EQ mode for AP and/or in AZ mode for visual with goto (the specs say yes, but what about in practice)? The AZ-EQ5 is a lot cheaper and sounds like it would be fine for the ED80, but not for my newt - is the AZ-EQ6 worth the extra $? (I assume so if for no other reason than that I'd be less likely to need to upgrade the mount in future - plus everyone says not to skimp on the mount)

2b) If the mount can handle the newt OTA in EQ mode, is it really worth getting the ED80 as well? That might be a dumb (or dumbER ) question, but I'm not sure how to compare the two for AP, and I'd rather ask a dumb question than make a dumb assumption.

3) Is the only difference between the SWED80 and the SW Black Diamond ED80 the diagonal and dual speed focuser? Is the BD worth the extra ~$400? I'm not sure if I would use it much for visual given I have the dob (never used one, so don't know). How do they compare in performance? I read somewhere that they both use the same fl-53 glass, so the main difference would seem to just be the focuser?

4) An ED80 seems to be the default entry level choice for widefield AP...what would be a good 'next step' if I wanted to get tighter shots of planetaries & galaxies (not to buy now, just planning ahead)?

5) What is a good option for power supply? I will mostly be using this in my back yard, so have access to mains, but I would need some sort of adaptor at least, and I would like something portable, too. I've had trouble finding good info on this...

6) How big an issue is street lighting for AP (close street lights on both sides of my house )? If it's a problem, what's the best solution - filters? Post-processing? Move ?

Thanks.

(that turned out a bit longer than expected...sorry)

[Atmos (Colin)]

Welcome to the forums Mark and yes, it certainly is a rabbit hole that you never come back out of

I'll start with the most pressing first, your 10" newt with patience and understanding will work on an EQ6 but it really is working at its limit there. Disregarding the pains that come with working at that extra focal length, pushing so close to the EQ6 payload limit can make it a bit of a nightmare to get working right.

So, not that that is out of the way, I'd say you're on the right path Whether you'd want to start with the EQ6 or the EQ5 is up to you depending on where you see yourself moving. The EQ6 does have a larger payload limit so does future proof yourself a lot more, the EQ5 is a brilliant beginners mount and both will be just as capable starting with an EQ80.

The Black Diamond and standard ED80 are identical telescopes yes. They may come with different accessories and even potentially be a different colour but they are identical telescopes. As to which one to pick, if you're only looking at doing astrophotography with it, which ever one has the better focuser!

If you are happy to limit yourself to 60-90s exposures then you don't need to auto guide, as long as you get a good polar alignment that is. For most DSLR photography in a light polluted place, you're not likely to be able to go past that anyway. Guiding is of course preferred for a number of reasons but you don't have to jump into that straight away if you don't want to. Just remember that it IS where you are going to end up

In time, you may find yourself wanting to upgrade from an ED80. Being a doublet refractor it will exhibit some star bloat as the blue/violet part of the spectrum isn't being corrected for but there are a lot of 80-120mm triplets that will sit on an EQ5 or up to 140mm on a EQ6 (some use a Sky Watcher Esprit 150 on them, very close to the weight limit there).

An 8" newt will work fine on an EQ5 but there is a significant increase from 8" to 10", then again from 10" to 12"! The lighter carbon fibre 10" F/4 newts are fine on an EQ6 but they're a lot more expensive than more standard 10" models.

[thegableguy (Chris)]

Hi Mark,

I'm also playing at the shallow end of the AP pool, perhaps a few months along from where you are now. I started with a Dob and struggled to take decent photos of anything beyond planets, so I bought an NEQ6 and ED80 (and 0.85 flattener) which I used a DSLR with. I've been shooting unguided and have managed a couple of decent shots with 90 second subs.

After 3-4 months of that I started hungering for more focal length, so I've recently picked up an elderly second hand 8" f/5 reflector. First light was a success, even unguided; the far larger aperture allows shorter subs and my polar alignment was good enough for 45-second subs.

I haven't had any chance to use it since as I've taken it completely apart to clean & collimate it and Sydney's weather has been hideous.

Guiding is the next step. I'm a bit intimidated by it all actually but there's only so much one can do without it.

But yeah as Colin said below I think you're on the right track with your current plans. Let me know what you decide, look forward to seeing the results!

[Atmos (Colin)]

Chris is therefore the perfect example as to why you're starting down the right path
Where Chris and I differ is that I am not hungering for more focal length (at 660mm right now) but then again I am more interested in imaging wider fields than galaxies. Chris (and potentially yourself) at shooting at ~510mm.

[glend (Glen)]

Patience is a virtue, so the old saying goes. You are going to make mistakes, get frustrated, lose a nights data, and all sorts of things will go wrong, such is the learning curve. As the guys suggest, keep it simple at first. Good luck.

[gregbradley]

Sounds like a good starting setup the ED80 and a DSLR.

I would add that you will want to modify your DSLR or pick up one already modified (the APS sized Canon modded DSLRs are often quite cheap) to pick up nebula.

A standard DSLR will not pick up the Hydrogen Alpha light that well.

Also if you are imaging in the suburbs with bad light pollution you will need a light pollution filter.

Alternatively you can get a one shot colour SBIG camera with self guiding 2nd hand for reasonable cost. It may be too much costwise but it will mean you can do 10 minute exposures. 2nd hand one shot colour astronomy cameras often are relatively cheap as owners decide to upgrade to a mono camera later on and sell their one shot colour. But starting out a one shot colour is easier to use. The new ASI1600C is not that expensive for what it is. Quite an advanced camera.

Unguided it will be challenging to get round stars even at only 90 second exposures. A bit frustrating really. But fun too. Autoguiding is something to add fairly early on. You can also whack a 50mm lens on your Canon and put it on your mount and now you can get good looking images at 90 seconds.

Greg.