What focal length?

[garymck (Gary)]

Hi,
want to buy a new scope for imaging wide field narrow band from my orange zone home in Geelong.

Looking to find the optimal size/focal length to frame a good number of narrow band objects. Hopefully want to find a scope that has a focuser adaptable to mechanising rotation to make mosaics easier.

Budget is up to 4K. Hope to find a scope no slower than F5.5

Will be used with a KAF8300 chip.

Esprit's look OK, but hate the focus rotation method, cludgy and rough on the one example I've seen in the flesh, and not automatable.

Suggestions?

TIA
cheers
Gary

[Alexborek (Alexandre)]

To be honest with you Gary, get a RASA. Amazingly fast and widefield. I'm not sure you can grab one of these for 4k... But you should give it a try. The Bintel's one is 11" aperture and 680mm FL, yet i'm pretty sure you can find some closer to RCs specs.

[Andy01 (Andy)]

I’m pretty happy with my Stellarvue SV70T & QSI 8300 combo.
Great bang for the buck.
I shoot widefield NB from the ‘burbs in Melbourne

[Atmos (Colin)]

Another option would be to get a Borg. They’re reasonably expensive but very good quality and umpteen combinations that can be achieved.

[garymck (Gary)]

Originally Posted by Alexborek

To be honest with you Gary, get a RASA. Amazingly fast and widefield. I'm not sure you can grab one of these for 4k... But you should give it a try. The Bintel's one is 11" aperture and 680mm FL, yet i'm pretty sure you can find some closer to RCs specs.

Unfortunately there is only 1 RASA and it's just shy of $10K !! Slightly out of budget I'm afraid...
cheers
Gary

[Slawomir (Suavi)]

Perhaps a telescope from TS would fit your criteria?

For example their Imaging Star 130 mm f/5 triplet should fit within your budget landed +taxes. I don't have any experience with this particular model, but I really liked their 102mm ED doublet that I used for a couple of years.

[traveller (Bo)]

Can you stretch your budget and aim for a second hand FSQ106?

[Atmos (Colin)]

Originally Posted by Slawomir

Perhaps a telescope from TS would fit your criteria?

For example their Imaging Star 130 mm f/5 triplet should fit within your budget landed +taxes. I don't have any experience with this particular model, but I really liked their 102mm ED doublet that I used for a couple of years.

This is virtually identical to the Sky Rover 130mm Sextuplet I’ve got, different focuser but that’s about it.

[Slawomir (Suavi)]

Originally Posted by Atmos

This is virtually identical to the Sky Rover 130mm Sextuplet I’ve got, different focuser but that’s about it.

Would you recommend your Sky Rover Colin? From your images and feedback I gather it is a nice telescope and a good performer

[glend (Glen)]

The Teleskop-Express Photoline series has several scopes that would suit within your budget, running at f5.5, and using FPL-53 objectives. While native f7 they reduce using the 3" screw on Photoline Reducer Corrector to f5.5. A triplet, running the four-element reducer is a great combination. The Image Star range with in built correctors are more costly and you lose the option of using them visually should you wish to do so.
I have the 115mm Photoline Triplet APO running at f5.5 and it is used for shooting narrowband. If you want even wider field options, the TS80 Triplet APO is a bargain, it reduces (using the same 3" Photoline reducer corrector, down to f5.5 (440mm fl).
You could look at Hyperstar options, say with a Celestron 8" SCT, or Edge HD, running the front mount camera but you need to use a camera like the ASI1600 to avoid increases on obstruction. This config wpuld be more expensive than the TS Photolime APOs but it is much faster at f2, however you may need to buy high speed narrowband filters.

[Atmos (Colin)]

Originally Posted by Slawomir

Would you recommend your Sky Rover Colin? From your images and feedback I gather it is a nice telescope and a good performer

Let’s just say that it’ll take the Nikon D810s quite small pixels at the edge of field with very little distortion

On the website it says it has a 55mm imaging circle of which is believe if you were to use something like the 16803 sensor with its 9 micron pixels.

I’ve just decided to go bigger and faster so mine will probably be up for sale soon enough

[garymck (Gary)]

Hi all,
thank you all for your suggestions:

Andy01: Stellavue look OK but perhaps a bit expensive for a "rebranded" scope, think there might be better value options.

Atmos: Had a look at Borg whilst on a recent trip to Japan, looked OK but very expensive for doublets that by some reports show a bit of color (short FL?) decided that for that money a Tak might be better :-)

Slawomir and Glend: I think the ultimate choice will come from TS, they seem to have a good rep, though I have seen the odd report of a dud scope. They have a nice looking 130mm FPL53 at around 1600 Euro - :-)

Traveller: and FSQ would be nice, but don't come up very often :-(

Decisions! Decisions!

cheers
Gary

[Andy01 (Andy)]

Originally Posted by garymck

Andy01: Stellavue look OK but perhaps a bit expensive for a "rebranded" scope, think there might be better value options.

Maybe so, but the two APOD’s I received for images taken with mine suggest it’s good value for money...

[garymck (Gary)]

Originally Posted by Andy01

Maybe so, but the two APOD’s I received for images taken with mine suggest it’s good value for money...

I think your skill in processing might have just as much to do with the APOD's as the scope

Gary

[Camelopardalis (Dunk)]

I know how much speed counts when it comes to narrowband, so in concert with a faster scope you might want to consider a camera with lower read noise also, since that is the major determining factor in getting sky limited subs.

[AstroApprentice (Jason)]

Hi Gary,
FYI, with the dedicated reducer/flattener for Borg 71FL or 90FL they are no longer doublets - 6 lens elements in 5 groups.

Atmos: Had a look at Borg whilst on a recent trip to Japan, looked OK but very expensive for doublets that by some reports show a bit of color (short FL?) decided that for that money a Tak might be better :-)