First Scope & Astrophotography

[Penfold]

I'm after some advice on the purchase of my first Scope. Like everyone else seems to be doing at the moment.

My main interest is DSO and planets with the odd visit to the moon, my initial thoughts are for something like the skywatcher 200P or 250P either as a Dob or Explorer.

I initially thought of getting a Skywatcher HEQ5 SynTrek to be used for astrophotography but I'm wondering if that is the wrong way for me to go.

I have a Canon 7D/5D mkII plus a Canon 300mm f2.8 + converters, would I be better investing in Astrotrac for my camera kit and then spending less on the mount for a scope, I could then use the scope when I wanted and perhaps let the wife look through it occasionally whilst still having the option to take out my camera kit to darker sites for astrophotography.

So first things first would my lens be good enough to capture DSO's.

And if so any recommendations on Scopes that will last me a long time if not the above.

TIA

[E621Keith]

If you already have a the camera, lens and tripod, and only interested in DSO, then Astrotrac is a good choice. Add a teleconvter and stop down a few stops and you will be good to go. However, if you want to do planet as well, then you will need a telescope, a small sensor camera and the HEQ5.

A dob is strictly visual, even though some people take webcam planet image with them they are not ideal. Personally I would go for a Mak or an apo refractor for planets because the secondary supports on a reflector will reduce contrast.

What is your budget anyway?

[Penfold]

Hi Keith

I'm not that bothered about Planet photography that's more for viewing.

Thinking about it a bit more I might just get a scope for viewing with a budget of about £750 and then save up for an Astrotrac at a later date.

[E621Keith]

The mount is the most important component in DSO astrophotogrpahy, so I wouldn't spend too little on it. Since your lens is a 300mm f2.8, I'd assume it'd weight similar if not a bit more than a 4" refractor. In which case, I wouldn't get any mount smaller than an EQ5. My EQ5 just about manage 1 minute unguided exposure with my 80mm f6 (480mm) scope, so you should be ok with FL 300mm and with a 1.4 converter (420mm) if you keep individual exposure under 1 minute and stack. Longer exposure will require guiding.

A GOTO EQ5 cost around £450 and HEQ5 syntrek is £600. For planets, the ideal scope are maks and apo. Skymax 127 is around £230. A 150p or 200p will do better on deep sky but may lose a bit of contrast when compared to the Mak on planets. They cost £150 and £275 respectively.

While a 200p + EQ5 may fit in your budget, I'm worried EQ5 may be too small for a 200p when used for imaging. I think a EQ5 Synscan + 150p will be a good combination. It will also leave you some money for a good eyepiece, camera adapters, and other accessories.

If imaging is not your main concern, I might go for a Celestron Nexstar 6SE which I think is one of the finest GOTO scope in that price group. If you don't need GOTO or any imaging, a 12" Dob can send you to visual heaven.

[ollypenrice]

As ever the photography makes the compromise near impossible! A 300mm lens will need guiding for long exposure. I work regularly at 328mm with a focally reduced Takahashi scope and Tak mount with a PE of +/- 5 arcsecs, which is very accurate. But, alas, not accurate enough for AP. I would come back to AP later. An HEQ5 with 200P and guider is marginal in my view. HEQ6 would be my choice.

Olly

[Penfold]

The mount is the most important component in DSO astrophotogrpahy, so I wouldn't spend too little on it. Since your lens is a 300mm f2.8, I'd assume it'd weight similar if not a bit more than a 4" refractor. In which case, I wouldn't get any mount smaller than an EQ5. My EQ5 just about manage 1 minute unguided exposure with my 80mm f6 (480mm) scope, so you should be ok with FL 300mm and with a 1.4 converter (420mm) if you keep individual exposure under 1 minute and stack. Longer exposure will require guiding.

I've now seen some images taken with a Nikon 300mm + 1.7 converter using the same Tri-pod & Gear Head that I have with an astrotrac so this looks like my route for AP at a later date, I also have a 150 f2/8 lens as well so that's me sorted in this department.

A GOTO EQ5 cost around £450 and HEQ5 syntrek is £600. For planets, the ideal scope are maks and apo. Skymax 127 is around £230. A 150p or 200p will do better on deep sky but may lose a bit of contrast when compared to the Mak on planets. They cost £150 and £275 respectively.

While a 200p + EQ5 may fit in your budget, I'm worried EQ5 may be too small for a 200p when used for imaging. I think a EQ5 Synscan + 150p will be a good combination. It will also leave you some money for a good eyepiece, camera adapters, and other accessories.

See above I think I'm running before I can walk. I see FLO have the Skywatcher Skyliner 250P FlexTube AUTO at a good price which could be another option for just viewing.

If imaging is not your main concern, I might go for a Celestron Nexstar 6SE which I think is one of the finest GOTO scope in that price group. If you don't need GOTO or any imaging, a 12" Dob can send you to visual heaven.

I've seen the weight now of the 12" dob about 35kgs which I think is probably too heavy for the moment as I'd have to keep moving it from where ever it's stored into the garden.

However, that Celestron Nexstar 6SE looks a might fine piece of kit. A bit more investigation is required now.

Many thanks for your help.

As ever the photography makes the compromise near impossible! A 300mm lens will need guiding for long exposure. I work regularly at 328mm with a focally reduced Takahashi scope and Tak mount with a PE of +/- 5 arcsecs, which is very accurate. But, alas, not accurate enough for AP. I would come back to AP later. An HEQ5 with 200P and guider is marginal in my view. HEQ6 would be my choice.

Olly

Thanks Olly, I think I'm leaving the imaging as per above for the time being.

Cheers

Mark