Thoughts on widefield 'scope...

[akiil (Adam Kiil)]

Originally Posted by akiil

-------

I second the Samyang 24 F1.4 This is by far my favorite lens! Outstanding re. no coma.

---
This is a single 30 second unguided sub with my Samyang

[Retrograde (Pete)]

Originally Posted by Andy01

Wow, I googled the Borg and it does seem resistance is futile! Pricey though bet well worth further investigations. Cheers

Someone with much more experience than me mentioned that Peter Tan in Hong Kong would be a good place to source one. Check out his site if you are not already aware of it:
http://www.tan14.com/gears.htm

[Slawomir (Suavi)]

Originally Posted by gregbradley

Andy your best bet is to sell your existing scope and pick up an FSQ106ED.

It is the king of widefield scopes and is freely available. The reducer allows super wide imaging if you want to do that as well.

Nothing else really comes close except the TEC110 flourite F5.6.

I have used both. The TEC gives better colour, the Tak is more tanklike and strong. FSQ is probably the easier to use overall as its built specifically for imaging. A slight green bias could be corrected by flocking the interior if you wanted to go that route or just handle it in processing.

FSQ 106 can take any camera. Most of those smaller scopes lock you into small chips and don't have quality accessories and you could be setting yourself up for constant gear fiddle and eventual upset and selling at a loss to get one later anyway.

Greg.

Just out if interest, apparently Moonlite is now making 3.6" focusers (and optional rotators) for Tak scopes: http://www.focuser.com/media/Downloa...s/CXL%203.docx

[Octane (Humayun)]

Those focusers look absolutely stunning.

H

[Andy01 (Andy)]

Originally Posted by gregbradley

Andy your best bet is to sell your existing scope and pick up an FSQ106ED.

It is the king of widefield scopes and is freely available. The reducer allows super wide imaging if you want to do that as well.

Nothing else really comes close except the TEC110 flourite F5.6.

FSQ 106 can take any camera. Most of those smaller scopes lock you into small chips and don't have quality accessories and you could be setting yourself up for constant gear fiddle and eventual upset and selling at a loss to get one later anyway.

Greg.

Thanks Greg, good advice - yes I take the point and will probably buy a small 'scope to play with for season or two and then sell both and get an FSQ.

I've heard form a user that focus is super critical with those taks and as I use a mac and have to do everything manually, including focussing, it's unlikely to be a happy marriage at this point in time. Eventally I'll have to bite the bullet and go the PC route, but I'm not ready for that yet!

Wonderful report on camera lenses btw - may I recommend you post that in the Projects and Articles section for all to enjoy

Originally Posted by Octane

The FSQ-106N is even better than the ED with no colour casts.

How about a Takahashi FS-60CB? 60mm aperture, f/5.9 and 354mm focal length. Reasonably-affordable.

If you go any Takahashi route, be prepared for the nightmare that is the adapters.

H

mmm - was briefly tempted but was put off by the adapter thing. Doublet vs triplet, does it need a flattener? etc not sure

Originally Posted by Retrograde

Someone with much more experience than me mentioned that Peter Tan in Hong Kong would be a good place to source one. Check out his site if you are not already aware of it:
http://www.tan14.com/gears.htm

Thanks will email - Borg looks incredibly complicated though - wading through lots of different components, adapters, reducers, tubes, focussers etc.

So far the WO looks like the preferred complete package.

[Octane (Humayun)]

On a full frame camera, yeah, you'll need a flattener. On an APS-C chip, you might be OK.

H

[gregbradley]

I focused with an FSQ manually with an electronic focuser for years. I even used to do it manually using the microfocuser in the past.

Easy as Bro.

They are not hard to focus at all. What they are a little sensitive to is fast changing temperatures. That just means a refocus every now and then.

FSQ is king Bro (sorry for the Kiwi slang).

Greg.

[Octane (Humayun)]

Greg,

I got temperature compensated focusing working on my RoboFocus. It is a dream come true! I am now no longer wasting 10-15 minutes every hour in AcquireStar focusing routines.

It's not so bad with LRGB filters, but, once you start automating focus with narrowband filters, it takes ages.

I'm a happy camper.

H

[gregbradley]

I see FocusMax 4 has a temperature compensation feature. I was logging the focus positions of my Honders but it was hard to see an accurate difference per degree C. I think it was going in 75 steps out of 105000 on the Atlas. Not 100% sure. The temperature sensor on the Atlas seems slow to respond to the ambient temperature and I think that was throwing it off. Do you use an external temp sensor? That may be the key rather than one embedded in the focuser.

Sky X also has a temp compensation feature. It seems easy enough to use if you get the right temp data.

Greg.

[Octane (Humayun)]

FocusMax 3 has temperature compensation.

At the moment, the sensor is inside the RoboFocus control box.

I'll look at purchasing an external sensor in the near future.

H

[Slawomir (Suavi)]

I wholeheartedly recommend an external temperature probe. My Moonlites have internal probes and these are relatively slow to respond to temperature changes, while external probes are very sensitive and quick to respond to ambient temperature. It has made all the difference in my case.

[Andy01 (Andy)]

Ahem... Er, gents no disrespect but let's get back to the original topic.
So does anyone have hands on experience with a WO star71 or a Borg 77EDII and a CCD?

[Camelopardalis (Dunk)]

How about a SW Esprit 80? f/5 triplet, flattener in the box, plenty of field for your current CCD and available for under $2k should give you almost 4x the field area.

I have the Esprit 100 and the pixels on my 1100D are only a little smaller than your CCD, PM me if you're interested in some example data.

[rally]

I agree, but actually the best bet is the astrophotography model
FSQ106EDXIII
The captains wheel monstrosity is useless for any serious AP

You wont need a flattener for any FSQ either

Or pickup a secondhand FSQ106N

BTW The adapter thing isnt hard - you work out what you want in the image train and buy the custom length custom made adapter/s from Precise Parts.
The only thing to keep a track of is the total back focal distance.
I wonder those new Moonlite focussers have extra back focal distance built into them - that would make them invaluable - just 1-2 extra cms is all you need !

Cheers

Rally

Originally Posted by gregbradley

Andy your best bet is to sell your existing scope and pick up an FSQ106ED.

It is the king of widefield scopes and is freely available. The reducer allows super wide imaging if you want to do that as well.

Nothing else really comes close except the TEC110 flourite F5.6.

I have used both. The TEC gives better colour, the Tak is more tanklike and strong. FSQ is probably the easier to use overall as its built specifically for imaging. A slight green bias could be corrected by flocking the interior if you wanted to go that route or just handle it in processing.

FSQ 106 can take any camera. Most of those smaller scopes lock you into small chips and don't have quality accessories and you could be setting yourself up for constant gear fiddle and eventual upset and selling at a loss to get one later anyway.

Greg.

[gregbradley]

I'd ditch the FSQ focuser eventually and get one of these new FSQ ready models from Feathertouch 3.5 or Moonlite 3.6. They come ready to screw onto the FSQ apparently.

FSQ 106ED is a great scope but Tak messed up with the focuser. The FSQ106N focuser/focuser lock is better.

Greg.