Takahashi FSQ-106ED vs. FSQ-106N

[Moon]

What is the difference between these two versions? Does the 'New Q' have better optics for some reason? Or is it the other way around? :question:

James

[Omaroo]

Hi James

There's a bit of a chat about this in the archives: http://www.iceinspace.com.au/forum/archive/index.php/t-20319.html

[bert]

Greg Bradley's comparison between the 2 scopes.

http://www.iceinspace.com.au/forum/showthread.php?t=53735

[gregbradley]

Yeah I've used both (and still have the FSQ106ED).

Advantages of the 106ED:

can use a bino
more backfocus
better colour correction
minor vignetting of the 106N corrected
more compact
better sliding dewshield mechanism
makes very sharp images
fabulous microfocuser (better than my feathertouch microfocusers)

Disadvantages:
focuser flex reported by some users. I have used heavy cameras on both FSQ106ED and 106N and no troubles though apart from the focus shift on the 106ED focuser lock. The 106N has a screw down lock which is very strong, easy to use and no shift. I notice the FSQ85ED reverted to this more successful focuser lock so Tak knows this was a weak point.
captains wheel system is not as good as camera angle
rotator although you can have one of those as well.
focuser lock is defective- causes focus shift if you have it wide open and then lock the focuser. You have to have it partially engaged before
you lock it.
main disadvantage is the lense coatings. They are a mustard green and seem to rob the image of colour vibrancy. Check out the many fabulous Rob Gendler FSQ106N images for their wonderful colour vibrancy. Now see if you can find a single FSQ106ED image that matches it (admittedly Rob has fantastic processing skills but you'll see what I mean).
FSQ106ED images tend to lack colour for some reason. I put it down to the lens coatings. I could be wrong. But its noticeable.

106N:

Double fluorite lens - yum, fluorite still has some slight advantage over ED glass in my opinion.
great focuser lock, solid focuser, Tak microfocuser add on not the best around but works (a bit spongy maybe).
compact
has slight vignetting expressed as a dark bar through bright stars near the edges of the image (nowhere else). Not that noticeable but look at Gendlers 106N images and you'll see this effect.
slightly out of focus in blue and expressed as more blue halos around stars than a 106ED which shows none. Minor point really and not that bad.
Cheaper 2nd hand than the 106ED which is an extremely popular scope.

Bottom line is both are fantastic scopes. I have a slight leaning towards the 106N because of the better colour vibrancy in images from it but its close. The 106ED is super sharp but slightly colour dull. This may be the result of using ED glass over fluorite (probably not) or the coatings (what I suspect as no other scope I have has mustard green coatings they are usually bluish or grass green). As Roland Christen could tell you lens coatings can play a big part in the performance of the scope.

You'd be rapt with either however.

Apart from the above nit-pickiness the FSQ106ED is still probably one of the top 100mm imaging scopes around. Maybe an AP105mm Traveller with reducer or flattener would be better. Perhaps a TMB 105/F6.2 may be close as well, not sure about their focusers etc. I am hoping an upcoming TEC110mm fluorite triplet with flattener will beat it but that is yet to be produced and proven.

Greg.

[Moon]

Thanks :thumbsup:

[Moon]

Going to answer my own question (again)...
For anyone interested...

http://www.takahashi-europe.com/en/FSQ-106ED.optics.spots.htm

James

[gregbradley]

What do you make of that? It looks like the 106N has very slightly better spot sizes. It doesn't show the 106N with the extender.

Much the same spot diagrams though wouldn't you say?

Greg.

[Moon]

Yes they do look much the same.
The on axis spot for the ED looks a bit tighter to me.
James

[gregbradley]

Yes it does.

Having used both the main difference really is the vignetting of brighter stars along the edge in the 106N. The 106N is a bit out of focus in blue as well so 106N images tend to show bluish haze around some blue stars and a dark bar going through bright stars along the edges.

Otherwise much the same. I don't know you'd get an FSQ to use binos on as it wouldn't be my first choice for a visual scope.

The 106N as a visual scope is a bit like some Naglers. You have to look straight on otherwise you get a distortion. Not sure about the 106ED as I haven't looked through it (sad eh?).

For imaging purposes the big adavantage of the 106ED is the reducer which is fantastic. The big downside is the focuser lock which is quite poor and a bit embarassing to Tak who pride themselves on excellent focusers. You lock it down and it shifts the focus, the 106N lock is very firm and does not do that. The improved colour correction of the 106ED is also a plus and it is super sharp even more than the 106N which is extremely sharp.

They are both wonderful instruments and you'd be happy with either.

Greg.