Toa 130 or Fsq 130 or

[Ken82]

So I’ve decided to get one of these scopes and I’d like some feedback if possible. 

I plan to use the toa at f7.7 for galaxies and with the reducer f5.3 for wider field. This is my first question - is anyone using this scope at f5.3? How is the field and correction ? Takahashi state an imaging circle of 40mm at this f ratio so not quite full frame. I’m using a 36mm sensor but don’t mind cropping 5-10% but is that realistic ??

with the Fsq 130 I could add the extender for galaxies at f7.5 fl 980mm imaging circle 44mm. This would be slightly better ?? But is it worth the price difference of 4-5k???

any alternatives ? 

If I got the toa I’d keep my Fsq 85 for widefield but if I got the Fsq 130 I could also get the reducer which would give me a similar fl to the baby Q. In which case I would sell the baby Q to part fund the price difference. 

Any thoughts ? Anyone using the toa at f5.3?? 

 

 

[Rodd]

Well--The FSQ and 1.6x extender makes it F8--slower than the TOA at F7.7--and the TOA is 1,000mm--so better for galaxies.  The image circle at F7.7 is 88mm! (or is it 90mm). It is not meaningful to compare the TOA with reducer to the FSQ with extender--you should compare the FSQ with extender to the TOA with 67 Flatner  for galaxies.  I would rather have the TOA for galaxies.  For wider field I would rather have the FSQ--because it can be reduced to F3 with the .6x reducer (I reduce the FSQ 106 in this way).  But, for the extra $7,000, using the TOA at F5.38 (.7x reducer) compares well enough to the FSQ 130 at F5.  Not worth $7,000 more --unless you want to reduce beyond native.  But then--you can get an FSQ 106 AND a TOA 130 for the cost of the FSQ 130.  The difference between the FSQ 106 and FSQ 130 is even less than the TOA 130--both can be reduced to F3, similar FL and FR.  1" less aperture--but The FSQ 106 at F3 produces some amazingly wide and highish resolution images--with a small pixel camera.

Then again the FSQ 130 cam be 2 scopes--taking the place of the TOA 130 and the FSQ 106.  Depends on what is more convenient for you.  Personally--even F7.7 is a bit much for my sky.  I would not want to go to F8 for a 5" scope.  My 11" Edge is F7 with reducer.  

Hope that helps

Rodd

[ollypenrice]

I would describe an imaging circle of 40mm not as 'not quite full frame' but as 'a million miles short of full frame.' Tak claim that the Baby Q with 44mm circle will cover full frame. Friends and I have tried it on two examples and all we can say is that they must be joking. It doesn't get anywhere near. On the long side the stars were like bananas at the ends of the chip. I love the Baby Q but it does not cover full frame or anything even close.

Why would you buy an FSQ 130 and extender for a paltry (and maybe questionable) 44mm circle when you could buy a TEC 140 and flattener which was designed to cover medium format film and certainly covers my full frame CCDs with virtually no light fall off in the corners? 

I would just keep the Baby Q for wide field and go for a TEC140 with flattener for high resolution. (Or an Esprit 150.) I've used my 140 with full frame at 1.8"PP  and with  smaller format at 0.9"PP where I find it competes with a 14 inch reflector I used to use. Indeed I'm such a fan of the TEC 140 that I've organized a gang to put a pair of them into a dual rig. (Second hand price for the pair, both with flatteners, 9000 euros. That's 5000 euros less than Optique Underlinden's price for one FSQ130. I'm sorry, the FSQ130 will be incomprehensible to me until somebody makes a camera which can exploit its gigantic corrected circle at native. When will that be? To me it's a scope without a camera.

Olly

[andrew s]

17 minutes ago, ollypenrice said:

 I'm sorry, the FSQ130 will be incomprehensible to me until somebody makes a camera which can exploit its gigantic corrected circle at native. When will that be? To me it's a scope without a camera.

Olly

Custom 4 CCD mosaic?

Regards Andrew 

[Alien 13]

57 minutes ago, andrew s said:

Custom 4 CCD mosaic?

Regards Andrew 

Or a nice piece of Kodak negative cut to size 

Alan

[Space Hopper]

If you are going down the Tec140 route (a new one) you are looking at 12 months ballpark wait time. Possibly longer.

[ollypenrice]

15 hours ago, andrew s said:

Custom 4 CCD mosaic?

Regards Andrew 

You buy this one, I'll get the next!

lly

[Ken82]

Thanks for the comments all !

ive actually decided to be sensible and get the Fsq 106 instead. A bit more adaptable with the reducers and extenders plus a lot cheaper. I’m going to pair that with a new zwo 071 and then in the autumn have a go at imaging narrowband with my Fsq 85 on a dual rig.