Mounting a Telescope to an ASTROTRAC, Help Please!

[Specman]

Hi,

I'm already thinking I need a big lens on my SLR, say 200mm to get some decent astro pics using my Astrotrac. So I started looking then saw the price! I then thought I could buy a nice little refractor with that kind of dosh and it would be more useful..

First Light Optics - William Optics Megrez 72 FD DDG APO

So my shopping basket is growing again

Apart from this:

Astrophotography Made Easy - Home

What else do I need to make it happen? How can I attach the Williams to the head? What do you recommend?

I'm currently running the holiday package and a Canon 1000D SLR so I guess somebody will say pier and wedge also. I am trying to keep it simple and thought a small refractor instead of a big lens would be a better way to go.

This leads to my final question what would be the best set up for guiding through the port, guess I need one of these:

First Light Optics - ADM Vixen-type Dual Mounting Bar

use a 50mm finder scope or similar as a guider???

Not much info about on the net except the manufacturers blurb so would appreciate a look and info from anybody running a setup already, pic appreciated. Thanks

[m.tweedy]

This

First Light Optics - Vixen-type saddle for Astrotrac TH3010 Head

to go on the head and it can then accept the vixen type saddle on the Megrez72

Do you really need to guide? it is complicating what should be a simple set up. If you polar align accurately then there should be no need for guiding.

[m.tweedy]

You can use a normal (sturdy) photographic tripod. I used my Manfrotto before the pier and also the 410 head before i got the wedge. Both of which were more than adequate. The Megrez72 is not a heavy scope even with the slr slung on it and both of the above will cope easily.

[Specman]

Thanks for the reply

So i now have the following:

• 1 x NEW AstroTrac TT320X-AG
  
• 1 x AstroTrac Polar Scope
  
• 1 x Manfrotto 055XPROB Tripod
  
• 1 x Manfrotto 496 RC2 Ball Head
  
• 1 x Manfrotto 410 Junior Geared Head
  
• 1 x AstroTrac 8xAA Battery Holder & Lead
  

And purchased today:

• 1 x Astrotrac TH3010 Head Package
  
• 1 x Vixen-type saddle for Astrotrac TH3010 head
  

So as a small portable refractor for Astro photography / viewing I'm thinking of the following:

WO Megrez 72 FD DDG APO

First Light Optics - William Optics Megrez 72 FD DDG APO

with

WO x0.8 Reducer

First Light Optics - William Optics 0.8x Reducer III (2011)

Any thoughts?

A Canon 200mm prime has been considered but I think that the little WO scope will be more useful maybe. Anything else I might consider

Cheers

Mark

[m.tweedy]

have you considered this

IKHAROS 80mm F7 ED APO refractor

or this

Skywatcher Evostar ED80 DS-PRO Package

Refractors from Ian King Imaging

Just giving you options

[Specman]

Thanks Michael,

I already have the Sky-Watcher Evostar-80ED DS-PRO f/7.5 APO, 0.85x focal reducer / corrector, but its quite a beast and thought it would a) be quite heavy for the mount and not as protable for a quick grab and go.

I have the boxed kit,

Package Includes

Evostar DS-PRO 80mm F/7.5 optical tube assembly (OTA).

Optics made in FPL-53 glass.

2" (50.8mm) Di-Electric Star Diagonal.

2" Eyepiece 28mm LET.

9x50 Finderscope.

Dual speed 11:1 2" Crayford focuser.

Tube rings and mounting plate.

Aluminium carrying and storage case.

Its a bit of a beast in its box.

I liked the idea that the WO 72 was barely a foot long colapsed.

[m.tweedy]

I agree however I am a bit concerned you may be disappointed with the views after the DS-PRO. Also I do not know how robust the DDG focuser is for astrophotography. Maybe some 72 owners will chip in here.

I have the WO66 and WO90 and have not considered the 72 as I feel it is too close to what I already have.

[Specman]

The Megrez 72 is advertised as an astrograph and I've seen some good reviews. I want it mainly for imaging. Check out these reviews:

First Light Optics - William Optics Megrez 72 FD DDG APO

It has a 432mm focal length and with the flattener/reducer on can get down to f4.8. I'm thinking it would be more useful and get me better images of DSO's than a 200mm DSLR lens. At least that's what I'm hoping. But of course I want to spend wisely.

[m.tweedy]

Looks a good little scope. I hope the L bracket fits into the saddle on the Astrotrac. I am sure it will because the 66 fits in mine.

Let us know how it all goes together (with pictures of course).

Good luck and clear skies.

Michael

[Star Gazer]

I have a Megrez 72. Which is a doublet refractor. I don't know who is advertising it as an astrograph but if they are, I think they then they are wrong. For the Megrez 72 to be an astrograph it should at least have a field flattener included in its design; it doesn't, you have to add one. You especially need one if you are using a DSLR.

As regard to the DDG; a lot of nonsense is written about this. It is nothing more than a handy readout. If it goes wrong or the batteries die then no problem just use it like any other focuser.

I also have an Astrotrac and I reckon without a shadow of doubt you need to replace the ball head with another 410 geared head or better still get the wedge. I doubt you will be able to control the scope just using the ball head. The Megrez plus flattener plus DSLR is quite a weight for all but the most expensive ball heads.

I took this recently with the Megrez and my 7D if you're interested.

[Specman]

Thanks Stargazer!

Cool image by the way

Its good to see an example of what the WO72 can do.

My aim is to put together a light weight grab and go that doesn't take up half the room in the car when I go on holiday, hence the Astrotrac, I agree about the ball head and have just ordered the Astrotrac TH3010 Head Package and Vixen-type saddle to enable me to fit a small scope securely. The head is counter-balanced.

Deciding the best options to spend my hard earn't dosh is the difficult bit. I hate buying something and regreting it later!

[m.tweedy]

I agree with your comments Star Gazer. The only (small) weak point in the setup that I can see that Specman has bought is the 410 geared head instead of the wedge. He has got the Astrotrac head and vixen saddle for the head which includes counterweights so the setup should balance quite nicely.

I have mounted my WO 90 without issue.

As I do not own a 72 I know nothing about them so cannot give any useful info. The 90 I have does not have a DDG as it came to me with a Moonlite attached instead.

[m.tweedy]

Oops looks like the post crossed.

[Specman]

I took this recently with the Megrez and my 7D if you're interested.

I'snt the Canon 7D a bit of a 'beast' for hanging off the back of the telescope? I considered upgrading to a 5D but I'm now thinking 550 or 600D. The 5, 6 & 7D series have bigger, full sized chips don't they? Don't they also have a monster battery pack and aren't they bigger and generally heavier?

How do you get on with it?

Cheers

Mark

[Specman]

The only (small) weak point in the setup that I can see that Specman has bought is the 410 geared head instead of the wedge. He has got the Astrotrac head and vixen saddle for the head which includes counterweights so the setup should balance quite nicely.

I thought that the geared head looked a well made beefy bit of kit, but have you had problems with it Michael? I agree that the wedge and pier is the best way to go, but that start to bring me back to tons of kit so I may as well use the HEQ5 & the DS Pro 80.

Can you mount the wedge on the tripod?

The tripod seems the weakest link, I should have beefed up a bit!

I have mounted my WO 90 without issue.

As I do not own a 72 I know nothing about them so cannot give any useful info. The 90 I have does not have a DDG as it came to me with a Moonlite attached instead.

You mount the WO 90 on the Astrotrac? How does it cope? Is it a big scope?

Cheers

Mark

[m.tweedy]

I thought that the geared head looked a well made beefy bit of kit, but have you had problems with it Michael?

No I just thought the Astrotrac wedge flipped over into the pier and made the whole thing easier to transport. My suggestion is to try the head-lots of people use it without problem

I agree that the wedge and pier is the best way to go, but that start to bring me back to tons of kit so I may as well use the HEQ5 & the DS Pro 80.

Can you mount the wedge on the tripod?

Yes you can. Looks a bit strange though-you will know what I mean if you try it.

The tripod seems the weakest link, I should have beefed up a bit!

That can come later. Again try it out. If necessary hang a bag filled with sand/stones heq5 counterweight (well anything really)

You mount the WO 90 on the Astrotrac? How does it cope? Is it a big scope?

It is a lot heavier than the 72 and I would prefer a geared head on top but there does not seem to be anything on the market that is geared with a vixen saddle on top.

Cheers

Mark

why not join the astrotrac yahoo group. They will have come across everything (and more) that concerns you.

[m.tweedy]

:icon_scratch:I have replied but the reply seems to have been included in your quote

[Star Gazer]

I'snt the Canon 7D a bit of a 'beast' for hanging off the back of the telescope? I considered upgrading to a 5D but I'm now thinking 550 or 600D. The 5, 6 & 7D series have bigger, full sized chips don't they? Don't they also have a monster battery pack and aren't they bigger and generally heavier?

How do you get on with it?

Cheers

Mark

Hi Specman,

The 7D size wise is much like the 5D bit has a 1.6b crop sensor. The 5D is a full frame sensor. I don't run mine with a battery pack that would make things too unwieldy. The 7D is a bit bigger than the 550/600 DSLRs and it does have a magnesium alloy body rather than plastic, so it's a bit heavier. I wouldn't want to put anything much heavier on the Megrez as the stock focuser is not the best you will find. Of course you must use the focus lock. This not only stops the focuser slipping but also adds some rigidity to the draw tube mechanism.

[Specman]

Hi Specman,

I wouldn't want to put anything much heavier on the Megrez as the stock focuser is not the best you will find. Of course you must use the focus lock. This not only stops the focuser slipping but also adds some rigidity to the draw tube mechanism.

Have they not upgraded the focuser on the new model? I thought the WO stuff was supposed to be one of the best? At nearly £500 it should be! Or am I being naive here?

Seriously, how does this compare to the top end Skywatcher Crayfords?....

You got me worried now...

[JonH]

Can you mount the wedge on the tripod?

The tripod seems the weakest link, I should have beefed up a bit!

Mark

I use the wedge on a light weight carbon fibre tripod with no problem whatsoever despite using a hefty full-frame DSLR and 70-200 f2.8 zoom.

The Astrotrac was bought to take on foreign photo trips and the wedge chosen over the geared head because it's lighter. The wedge is a great piece of kit and one that I can thoroughly recommend.

[Specman]

Thanks Jon,

Good to know!

The wedge is on the shopping list.

[JonH]

Nice one Mark, you won't regret it.

[m.tweedy]

Thanks Jon,

Good to know!

The wedge is on the shopping list.

If you get the wedge then you may not need the 410 head. If that is the case can you return it and get your money back.

[Star Gazer]

Don't get rid of the 410!

Here's what I would do. Put the wedge between the Astrotrac and the tripod. May be its obvious to you but you use this for Polar alignment. Then you put the 410 on top of the Astrotrac under the camera/telescope. This mean you can do away with the uncontrollable ball head.

With the weight of Megrez and DSLR, you will find a ball head is just uncontrollable. At least with a 410 you can wind the different axes to compose the shot your after.

[m.tweedy]

I would agree but Spec man has bought the Astrotrac head and vixen saddle to go on top of the Astrotrac instead of the ball head. I have still got my 410 head but find it is now being used for other things now as I also have the head. The vixen saddle will hold the scope more securely than using the camera screw attached to the 410 (in my personal opinion only).