Commanderfish

Grab and go set up: Manfrotto 405 head and 055 tripod weighing 4.6kg. FC76 DCU clamshell, dovetail, diagonal.and eyepiece weighing 2.8kg. About 400g heavier with the Ethos SX which does cause the vertical axis to shift but is parfocal with the Panoptic 24. Nagler Zoom and Baader 2" connection coming tomorrow; I'll experiment with bringing the EPs to focus with a 2" diagonal tomorrow.

Oh dear, do you think this might be undermounted?

Yeah sorry about that... And it's going to get worse. Manfrotto tripod coming tomorrow, Nagler Zoom and 2" Baader clicklock coming on Friday. Silver tube rings and dovetail at some point...

I haven't installed the Starlight yet as the adaptor is out of stock. I am impressed with the current focuser and have a Baader clicklock 2" coming on Friday along with a Nagler Zoom. As you know, the current focuser is only 30mm travel but Im sure I can make it work to.some degree. Feathertouch may go on the CC8, we'll see...

Oh look, wall to wall cloud! Tak FC-76DCU, as new in triple box with clamshell, Feathertouch 2015 (not installed), RDF and 1.25" diagonal and EPs. This set up needed the 20mm(?) extension with the stock focuser. Cloud will be prolonged as tomorrow brings a Manfrotto Tripod and Friday brings a Nagler Zoom 3-6mm and a Baader 2" Clicklock. Silver tube rings and dovetail also ordered. Note: using my kitchen scales, the stock focuser weighed 450g and the FTF2015 weighed 540g, so only 90g more. The FTF 2025 is listed as the same weight on Starlight's website.

Alert all stations: Prepare for heavy sustained cloud

I have a 4.7mm Ethos SX so getting the 2-4mm makes more sense than the 3-6mm provided the exit pupil doesn't get silly, which I suppose isn't a concern on the moon.

Thanks Jeremy. Do you feel like the scope is being pushed at 3mm/x190? I gather they can go very high on the moon. Ever feel like 2mm/x285 would work?

The info about parfocal-ness is very useful!

I've noticed people use prisms on these scopes sometimes rather than mirrors, is there any particular reason for this? Low light path distance? Also how do you rate the Nagler zoom? I'm thinking about getting the 2-4mm for the DCU although I imagine it would only be useful on the moon and planets. Also, I am tempering my expectations for first light, as I don't live on a farm with dark skies!

Thanks Holly I appreciate your help and I am glad to be joining both the Tak club and the DCU club! Whilst extra aperture is hard to turn down (FC100, if there were actually any available), I do currently lack a true grab and go scope, my lightest currently being the CC6 at about 5.5kg without EPs and my shortest FL being the 115mm 800FL Apo triplet. The DCU is only 1.8kg plus EPs, bracket and and finders. I think the DCU will get a lot of use and as lockdown is being eased I might well take this further afield from time to time. Yes I'm very interested in whether your Ethos come to focus, my maths suggest that the weighty 21mm would give a great view at x27 and 3.7 degrees, though the 17mm weighs 300g less and would still give 3 degrees field. I'm fully expecting heavy cloud from tomorrow and expect first light to be some time away...

My classical cassegrain dual speedp focusers (basically the same as refractors) have 37mm focus travel which is enough for all my 2" EPs without changing extensions. One of my refractors has 100mm travel but it doesn't get used as all of the eyepieces used are 2-inch. I think the benefit of long travel probably comes when you use a mixture of 1.25 inch, 2 inch and cameras. But I don't do astrophotography and I stick to 2" (including dual fit 1.25"/2").

Right, so slight change of plans, the guy selling me the Feathertouch was thinking about listing a few more scopes. I was offered (inter alia) a nearly new 2020 FC-76DCU, it looks like its been out of the box maybe twice. So a 76 DCU and a Tak clamshell are on its way to me now! Expect heavy cloud in SW London/Surrey tomorrow! I've ordered nice tube rings, so the Tak 80mm clamshell (in the new Tak light blue) will be up for sale soon, let me know if interested... Really excited about this, I know it doesn't have the aperture of the FC100 but it's going to be so portable. If anything it's an excuse to keep the 115 triplet, we'll see... I just need to choose which 2" EP solution to go for; I had ordered the Baader Click lock but Baader are on holiday till next week apparently. I will have the 1.5" Feathertouch shortly, but I was thinking of putting that on my CC8 as I'll have the correct adapter. I had a good session yesterday with the CC8 and it's stock dual speed focuser; I think I underestimated the cooling time on the scope and last night it wasn't as hard to reach sharp focus after 45mins cooling, although I still feel the main focus wheel is geared a little too low (takes too many turns for my preference). If I want to use the Feathertouch with the FC76 I'll need to order an adapter. I've been reading good things about the standard FC76 DCU focuser, that it can handle a 2" diagonal and Nagler/ES grenade, but that the travel is limited. Hmm what to do? Anyone been using the stock 76DCU focuser with multiple 2" EPs? How many could you bring to focus? My calculations suggest not all will focus with 30mm travel!

😄😄😁 I'm sure that's a lovely 127 your friend had. My 127 ED Apo triplet must be my most used scope of all time. A real keeper 👍

Slight hitch in the plan - the guy who is selling me the Feathertouch 2015 is including and adapter for my CC 6 and CC8, and the CC8 focuser in particular winds me up, not that it is in any way bad, in fact it's very good for a stock focuser, but because it is geared too low; it moves too slowly and somehow this makes it harder for me to get to perfect focus. Remember what I was saying earlier about me not using the microfocus wheel?! So once it's arrived and installed, if I like it I'm back to square one on the Tak focuser 😄

Yep this scope woild.maimly be for wide field and grab and go. Generally speaking there's a balance between aperture and portability/cool down time. Big scopes need time to cool and are harder to move about during the session (dodging terrestrial objects). I think 4" scopes have a great balance of this, whilst CCs give a lot of aperture in a portable package.

Yep I always have a CC6 or 8 alongside a frac for.aperture, the CC8 is.great on M42. My 10" dob has a slightly brighter view than the CC8 but less contrast, and seems more suscepitble to lght pollution. However I find it much harder to find objects in the dob. Or rather, it's so much easier to.find objects in a wide field frac mounted coaxially with a big scope like the the CC8, which then gives the aperture.

I do have an 8" CC and a 10" dob but they do take time to cool. The dob doesn't have the contrast of a CC or a frac, even when cooled.

Now here's a question for you; does M42 Orion Neb look better in an FC76 or an FC100? I'd have assumed the 100, but reading reviews, am I wrong?

I think I'd prefer the slightly shorter FL of the DC over the DZ as the fields are that little bit wider. I do prefer the look and feel of the feather touch too. So I think these scopes are all good solutions but I'll probably go for the DC and Feathertouch. I also suspect the DC and FT is going to be a little lighter and slightly easier to mount stably. Really for portability they should have made a 100dcu!

That is super helpful Stu! So, the DC model will be available in a few weeks but the DF won't.be available til June. I am probably in the minority but I really don't like the Tak light green or even the new light blue, so a feathertouch is quite appealing. I do like the silver rings though. I can currently pick up a used FTF 2015 at a more reasonable price though that only has 1.5"/ 38mm travel. Still better than stock. I've done some calculations using one of my exisiting fracs which shows I need 30mm travel to get all of my 2" EPs to focus (except one Kitakaru 45mm which I would be very unlikely to use with a 740mm FL scope anyway. This means that with 38mm travel and the right amount of extensions, I can get all of my 2" EPs to focus with an FTF2015. The FTF 2025 is the recommended focuser for Taks but as far as I can tell the FTF 2015 should have the same fitment as it seems Starlight only have one range of adapters for all the FTF20xx focusers - does that make sense? Should work with an A20-302/304? So the DF would be the most economical way to use all 2" EPs but I'd have to wait 3 months and I don't like the colours, the stock DC wouldn't quite have enough travel for all 2"EPs, the DC plus used FTF2015 would do the job but the DC with new FTF2025 would be most versatile at the highest price. I'm tempted to get the DC and used FTF 2015. Thoughts?

That is marvelous info Stu! I like the silver ring and am going for silver OTA tube rings too. Sounds like the 304 adapter might give slightly more in focus than the 302 - does anyone know if using the 302 still gives enough in focus for most 2" EPs with a 2" diagonal?

Is one of the solutions to insufficient infocus on the DC with 2" diag to install a Feathertouch? Because that's the way I'm leaning...

It's 1.2" for the DC and 2.5" for the DF and DZ with stock focusers