Stu

Thanks Piero, I actually meant 40mm 68 degree, a TMB eyepiece. My apologies, my fingers are clearly getting more sausage-like every day!!

Still envious of your long dangly remote control cables Nick Lovely scope.

I use a BBHS but in the T2 design. Good enough for all but the biggest 2". I don't really notice vignetting even on a 50mm 67 degree. Shorter optical path and lighter.

Well, I could see a place for the AZ5 for the frac in that case. At low and medium power the tracking would be easy and setup would be very quick.

For your kind of observing, which I think is still mainly lunar with a bit of planetary and other higher power viewing, I think the EQ5 is probably the best bet Jules. If you were star hopping or doing lower power viewing then an AltAz may be better, but for simple tracking at high power a driven EQ5 is very stable and convenient.

There seem to be plenty of people using the AZ5 with similar sized scopes who are quite happy with it.

Just rewound and watched that from launch, all went well. Thought the interview was very informative too.

Not a screw on cap, but it should be possible to find a push fit cover for the lens cell.

Those are great set ups Mike, have done similar things many times with little Taks and larger Taks, plus numerous other variations of widefield and higher power. Great fun

They look like the rings I have with mine. As I recall they were a cheaper option but seem very good to me. I have recently bought a heated Astrozap dewshield for my scope. Had to check with them which was best to buy and they recommended the AZ-804 and it fits very well. I have even thought of taking it instead of the fixed one if traveling.

Just stick the EQ5 on the pier Jules, wouldn't that work?

Agreed. Not a great actress though, a bit wooden..... Sorry. It's Friday...

Especially big ones!!!

I am a long way from being an expert, but I do read up on stuff when I need to refresh my memory. As you acknowledge, there is a difference between a synthetically grown Fluorite crystal, which is still a crystal vs a glass which contains a high level of fluorides but is still a super cooled liquid not a crystal. To say that FPL-53 is synthetic Fluorite is incorrect I believe, but it does have an Abbe number close to Fluorite. As an aside, synthetically grown Fluorite is favourable because natural Fluorite has too many flaws. Actually, it is not a case of Fluorite scope good, fpl scope bad, far from it. Many factors are important, the mating element material, the design, figure and polish of the elements, the cell design and manufacture etc etc. A number of high end manufacturers get this right. I happen to enjoy doublet scopes for observing, and in this case I believe that Fluorite allows for better colour correction and reduced scatter/increased contrast. I have had better views of Jupiter in the Tak than I had with a very good FPL-53 triplet so that satisfies me. This article may be of interest if you haven't already seen it. http://scopeviews.co.uk/What is Fluorite.htm

The CoC is surprisingly vague on this subject.....

I think you are confusing a synthetically grown crystal with synthetic Fluorite FPL-53 which is a glass not a crystal.

Canon as far as I'm aware. Why the devil icon?

Certainly not the opposite. My understanding is that for doublets, using Fluorite makes a difference to the colour correction and contrast. It is certainly my experience from using my Tak that it performs better than previous scopes I've had so I'm happy with what I've got. For triplets I don't think it makes as much difference. None of this is to say that FPL-53 ED scopes are bad, they are not. The 100ED is still an excellent scope.

Synthetic being the operative word... Fluorite crystal does not scatter any light so a laser does not show when it passes through the Fluorite element. Not the same with FPL53 glass. https://www.cloudynights.com/topic/331900-fpl-53-green-laser-test/

Is that where you 'hope' the target is in view?

Exit pupil is the measure I was referring to. With, say, an f12 Mak, a 32mm Plossl gives a 2.6mm EP and a 40mm gives 3.3mm. The same exit pupil should give the same brightness regardless of the scope, the difference being the magnification achieveable with varying aperture. For example, an 80mm f5 frac and a 300mm f5 Dob will both give 6mm exit pupils with a 30mm eyepiece, resulting in the same image brightness, but the mag with the 80mm will be x13.3 and with the 300mm it will be x50.

No wonder it was late. Even so, how did he get it back so quickly?

I've said previously (hopefully not in this thread! ) that the 40mm probably only makes sense in a Mak or SCT with a 1.25" visual back in order to get maximum exit pupil for narrowband filters.

I reckon the FC-100 (sorry, I'll put 50p in the swear box ) has been a bit of a game changer John. It's such a good visual scope, and relatively affordable, I think it has raised Tak's profile outside imaging quite a lot. Back to Vixen... had two of these, very nice