TAK FSQ Fluorite versions

[ollypenrice]

Ouch. For most nights that would mean focusing every frame for me!

ChrisH

This is also how it is for one of our guests with the TV NP101. It's as bad as the FSQ106N.

Olly

[Earl]

SGP which i use has a temp compensation routine built in which i need to train as it will automatically shift the trained ammount per calibrated drop over the sesion then with a focus check ever x number of subs.

On my todo list as well as the flats calibation wizard.

[kirkster501]

This is also how it is for one of our guests with the TV NP101. It's as bad as the FSQ106N.

Olly

To me that would be a complete PITA, especially from such a premium scope.  I can leave my FSQ85 running all night with maybe the slightest touch on the focuser for the blue filter.

[ollypenrice]

To me that would be a complete PITA, especially from such a premium scope.  I can leave my FSQ85 running all night with maybe the slightest touch on the focuser for the blue filter.

I don't disagree. I think that the ED 106 is a robotic focus instrument for many, though Velvet images under the same kind of skies as you (Derbyshire) and finds hers OK.

I find my fluorite quite tolerant. 

Tricky subject.

Olly

[Earl]

tbh, i click start and dont need to worry about, just catch some zzz's

[AnakChan]

Hi all, just bumping an old thread (sorry for necroposting).

All the posts here are very interesting. I'm looking at wide-field options but I'm into rather portable astronomy - i.e. no PC/laptops/notebooks. My astro camera is the the CDS Astro A7s, a full frame 12MP. Therefore it's approx 8.4 microns.

I've been looking at the FSQ-106 (fixed or N) vs the FSQ-106ED and although I was aware of the FSQ-106ED focus creep, I didn't expect it to be that quick. Since I have a no PC/laptop/notebook policy, and there are so many comments about the FSQ-106ED needing continuous focus check, it pretty much rules the ED out of my scope.

Similarly, seeing Olly's 3rd post of how the FSQ85 doesn't really suit such a large pitch sensor, would the FSQ-106 even cut it?

P.S. I'm looking at these scopes BTW for their large image circle.

[Herra Kuulapaa]

Similarly, seeing Olly's 3rd post of how the FSQ85 doesn't really suit such a large pitch sensor, would the FSQ-106 even cut it?

I've looked into TAKs too. Imaging the full frame monochromatic DSLR the image circle is very important. 85ED supports full frame sensor, but not anymore with the reducer. 106ED works on both options, but the I'm finding the sensor distance from reducer a bit too short to be able to add a filter wheel or even singe 2" filter there.

[Herra Kuulapaa]

And the specs:

85ED: http://www.takahashi-europe.com/en/FSQ-85ED.specifications.php

106ED: http://www.takahashi-europe.com/en/FSQ-106ED.specifications.php

Note especially the reducer and extender image circles.

[AnakChan]

I'm kinda more interested in how one determines (or calculates) the suitable pitch pixel size for a given focal length (or aperture?).

Does anyone have any links to that please?

[ollypenrice]

And the specs:

85ED: http://www.takahashi-europe.com/en/FSQ-85ED.specifications.php

106ED: http://www.takahashi-europe.com/en/FSQ-106ED.specifications.php

Note especially the reducer and extender image circles.

Whatever the spec sheet says for the FSQ85 image circle, I know from using two full format Kodak chips in two examples of the Baby Q at native focal length that it does not cover this chip. I does not even come all that close to doing so. On the internet there are several figures published for the true size of the Kodak 11 meg chip but it is slightly more than 35mm in most of them. Whether modern full format DSLRs are bang on 35mm or not I don't know. Personally I would be surprized if the Baby Q could cover a full format DSLR given that it was such a long way from doing so on the Kodak chips we tried. I wonder if anyone can show an image from the 85 with FF DSLR?

I'm kinda more interested in how one determines (or calculates) the suitable pitch pixel size for a given focal length (or aperture?).

Does anyone have any links to that please?

http://www.12dstring.me.uk/fov.htm

FLO now have a calculator as well.

I've worked between 3.5 arcsecs per pixel and 0.66.  At 3.5 (FSQ106/Atik 11000) you don't get the resolution you might like to have but the trade-off is field of view. Below 1" P/P you are going to need very good seeing and guiding. I guess my favourite compromise might be around 1.5 to 1.8 but I wouldn't want to feel hide bound by rules over this.

Olly

[mikeDnight]

Tak say 'mainly for environmental reasons...' That might be Japanese for 'money,' of course...  We must be fair to the ED versions of the 106; they are even better colour corrected than the fluorites and can take the focal reducer. The downside is just this infernal focus drift.

This was Baby Q and Atik 11000 at native 450mm FL. But get in close and the end distortions are quite severe. The 106 has a FL of 530 but no distortions.

(You can still do M78, Horse, Flame, Running Man and M42 in 2 panels, though...)

Olly

From what i understand, the decision to change from Fluorite to ED glàss had more to do with the nonfluorite elements containing too much lead, rather than the cost of producing fluorite crystal. I doubt cost would influence Tak too much, they'd just up the price and we'd pay it. Now Tak have found a complementary element to match the fluorite, they've started using true fluorite again rather than FPL53 in some of their scopes. The reason they give for doing this is that Tak claim true fluorite has light transmission many orders of magnitude greater than any ED glass. What this meàns for the future of the FSQ is anybody's guess, but if the current FSQs are in anyway superior, then grab one sooner rather than later.

[Starlight 1]

I just got the new Tak 106ed with a starlight 694 with filler wheel, Ian king sad it will work well . so far I had to get the Tak 2"auxillary extension ,and from the moon to Stars is only 3mm in.

and with my SWA 16mm meade wow.

[ollypenrice]

I just got the new Tak 106ed with a starlight 694 with filler wheel, Ian king sad it will work well . so far I had to get the Tak 2"auxillary extension ,and from the moon to Stars is only 3mm in.

and with my SWA 16mm meade wow.

It will. I helped process an image taken with a comparable setup very recently and it was an absolute peach. It would be nice to be able to use more of that expensive flat field but, at the moment, the cameras need to catch up with the FSQ.

Olly

[AnakChan]

I'm still in a dilemma in choosing between the FSQ-106N vs FSQ-106ED (and to further add to the complication EDX I/II/III). In reading CN, it seems it's not consistent that :-

1) every FSQ-106ED(X) suffers from the focus creep issue and therefore don't know if the issue is in the higher or lower percentile.  And for those that do is that on :-

  a) FSQ-106EDX-series

  FSQ-106ED (the one with the captain's wheel)

  c) both FSQ-106EDX and FSQ-106ED

2) every FSQ-106ED (with the captain's wheel) suffers from axis shift and therefore don't know if it's an issue with the higher or lower percentile

 

Also would something like the Starlite Instruments FTF351B-A or 3rd party focuser fix any (or both) of the issues above. And by using one, does one lose the ability to use reducers, extenders, etc.

The older fluorite FSQ-106's don't seem to have issues like the above however are harder to find accessories for since they're no longer in production.

[Herra Kuulapaa]

On 30.10.2015 at 08:51, Herra Kuulapaa said:

I've looked into TAKs too. Imaging the full frame monochromatic DSLR the image circle is very important. 85ED supports full frame sensor, but not anymore with the reducer. 106ED works on both options, but the I'm finding the sensor distance from reducer a bit too short to be able to add a filter wheel or even singe 2" filter there.

Well, it took some time to think things through, but: