MalcolmM

I can reach focus (Tak 100DC + WO Binoviewers) with the WO 1.6x GPC attached to the telescope end of my diagonal. To reach focus without any GPC I have to remove all the extensions from the scope, in effect reducing the OTA length by about 9 cm. Malcolm

Personally I would go for lighter as binoviewers are heavy to start with! The Morpheus are ~350g(?), and you'll need two so added to the weight of the Binoviewers you're talking maybe a kilogramme on the end of your scope. Much depends on how easily you can adjust the balance of your scope on your mount and what your mount is. I find my setup is definitely more shaky with the Binoviewers on. Malcolm

I sometimes have to loosen off the retaining screw of one of the eyepieces (usually the right hand eyepiece) in order to merge. Removing the tension must allow the eyepiece to centralise itself. Doing this has allowed me to merge even with 7.5mm eyepieces. I do find I can sometimes merge easily and sometimes it takes a bit of fiddling! Rotating an eyepiece can sometimes help merging. Making sure each eyepiece is in good focus is important too. Malcolm

This looks promising thanks, but I'll have to watch it slowed down despite his presentation being near the speed of light Malcolm

Thanks @andrew s, I had actually googled this quite recently and where I can understand it, I sort of feel the initial assumption takes you half way there. I will accept that there may simply not be a way of deriving it from first principles with my limited maths in the same way as length contraction and time dilation (though I guess even for these you have to make the assertion that c is constant for different observers!) Thanks again, Malcolm

I think the reason we buy so much equipment is 'because' of the bad weather. It's one way (all be it very expensive) of keeping engaged with the hobby So it really is a vicious circle! I haven't had the scope out for over 3 weeks ... but I've lots of goodies to play with when the clouds do clear Malcolm

I have been trying to understand the basics of Special Relativity with my very rusty 35 year old engineering maths. I can follow the derivations of time dilation and length contraction. I love that such weird concepts can so easily be 'proved' with a bit of trig and Pythagoras. However! Deriving E = mc^2 always seems to come down to approximating an expression as a series (Taylor?), where the first term is the rest energy, second term is the classical KE and subsequent terms are increasingly infinitesimal. I loosely understand approximating expressions as a series but I really struggle to understand how a particular term in the series (which is an approximation) can turn out to be so significant! Is there another way of deriving E = mc^2 using 'graduate engineering maths' that my head might understand and accept? Or maybe another way of looking at the Series approximation that would allow me to make the mental leap to accepting it? Thanks, Malcolm

Ha, I'm probably going to give my boat away, I'm too sore after sailing it and as far as I know they are no longer sailed in Ireland. You have 2 quite big scopes; I would be tempted to go for either a small refractor for ultimate grab n go and travel or something to do H alpha solar with (could be a dedicated scope or a quark or PST mod - I have a 50mm Lunt which is very good, but I know nothing about the other 2 options). Looking at the sun during a warm day in shorts and t-shirt is a lovely contrast to layered up in the cold and dark winter's nights! That being said, the N Ireland weather allows me to do that maybe 2 days a year Malcolm

Great report and I like the sketch! These days I can only vicariously enjoy this planet spectacle, I haven't seen a clear sky in 3 weeks! Malcolm

That was my conclusion from researching online! Though I do rate Ed Ting's reviews very highly. On the original topic; I can identify with back problems, ease of portability has always been one of my criteria. I have no experience with other similar scopes to the Mewlon but I do find it very easy to setup, the built in finder/handle is brilliant. Malcolm

All I can say to this is I have recently got a Mewlon 180 and the collimation was perfect straight out of the box, after having travelled half way round the world! Whether it stays that way or not remains to be seen but my experience with the Mewlon 180 so far is very very good! Malcolm

I really like the fact that they do not need extra in focus. I have done lots of tinkering in order to get my WO binoviewers working natively (no GPC) with my scopes in order to get low power and wide FOV. It has involved unscrewing bits of the OTA and adding Baader attachments. I can do it but it's a real faff changing from one setup to the other. My only reservation with these would be the 17mm internal field stop. If this were to give a smaller FOV than I can get with the WO I would probably not be tempted. I assume 17mm internal field stop will give a 15% smaller FOV than the 20mm(?) of the WO? Can anyone confirm this? I know most people use binoviewers for medium/high magnification for the moon and planets, but I find them great to use for low magnification too for open star clusters. Malcolm

Nice observation @Peter Drew. The detail sounds impressive. What setup are you using? I try to keep an eye on the sun looking for fast changing proms but I think I've only seen it once and nowhere near as impressive as your observation sounds. That being said, I'd be very excited just to see the sun these days! Gotta love the Northern Ireland summers Malcolm

Great report @Victor Boesen and fantastic pics! Malcolm

I really like the look of that Castor mount; it looks great! Malcolm

I'm envying that cloudless sky! How do you choose which of your telescopes to use? Malcolm

That's a really nice image! Malcolm

High time you sold those big heavy Pentax's If you like the 4mm TOE, you'll love the 2.5 and then you simply couldn't leave out the 3.3 Malcolm

@StarryEyed I got a quick session last night with the 180 and the 100DC after a night out! Moon was low and seeing very turbulent so not the best conditions for a comparison, let alone my wine impaired vision! 18 Abbe in the Mu and 7.5LE in the DC. What stood out for me was 1) despite its bulk, the Mu is just as easy to handle as the DC, arguably easier with the built in handle 2) the Mu gives much brighter views (as you would expect with ~3 times the light gathering power) 3) I can't say anything popped out in the Mu that I couldn't see in the DC (probably due to the poor seeing conditions) but fine rills for example were much easier to see and simply stood out better 4) no obvious difference in contrast between the scopes, I'm not sure what you would expect in this regard 4) the combination of Mu and DC on the Giro Ercole is really easy to use, even when I upped the power beyond what the seeing allowed, it was easy to track. A quick look at the Ring Nebula. Again despite the late hour it was virtually daylight! But much more obvious in the Mu and the donut shape visible. In the DC dimmer and no obvious donut shape. The stars, in particular Vega, didn't seem quite as sharp in the Mu. This was a very hurried observation as I was heading in. Not sure if this is a refractor/reflector thing or whether I need to double check collimation or whether I imagined it. By this time I had an Erfle 28mm in the DC (x26) and 25mm Abbe in the Mu (x86) so potentially an unfair comparison! Hope this is of some help! Malcolm

Those are great pics and in my experience, phone adapters are a bit of a faff, take a bit of getting used to but will allow you to get even better pics! Malcolm

I have a 100DC. I'll try and do a comparison sometime between it and the Mewlon. Malcolm

Ok, embarrassing moment! @Mr Spock you may have recommended me this one before, or maybe someone else on the forum. Turns out I have that app and was using it last night but simply missed the name of the valley. It may have been an effect of the wine! I was surrounded by a bunch of my partner's relatives oohing and aahing at the time, never having seen the moon through a telescope before. Not exactly outreach but really nice to see people's reactions when they see it for the first time. Thanks for replying. Malcolm

That one looks very good @Mr Spock, I'll take a look at it thanks. Malcolm

Great image @Laurieast; very detailed! Malcolm

Thanks @johninderby, that looks like it. That's a great looking chart, which one is it? Malcolm