Lunt LS50

[Tigger27]

Hi All,

This is my first post, but I felt compelled to pen my thoughts on the Lunt LS50 b600 that I bought a few weeks ago (to Help me get thru another Covid lockdown). A couple of important points first. I have been a night time astronomer for well over 10 years, but never tried Solar before. The other point is that I am strictly visual only. Tried astrophotography and hated it. I read quite a few useful threads before choosing the LS50. I wanted something half decent, but did not want to spend too much money because unlike night astronomy there is only one thing to look at.

I find the LS50 gives very good views of the Sun. I have it mounted on a light weight manual grab and go tripod, which works very well. The scope is very light and really easy to set up. The focuser works well and contrary to other posts I find it very easy to use and will not be changing it. I had to move the diagonal out about 15mm to get the eyepieces to focus, but no hassle. My focusing tip would be to set the focuser to notch 7 and then move the diagonal out until you get a reasonable focus then do the minor adjustments with the focuser.

 I am amazed that the Sun does not drift out of view as quickly as the Planets. Initially I used a Pentax 6-19mm zoom which was very easy to use and focus on the Sun. I thought this was the perfect eyepiece until I transferred it to look at Saturn and Jupiter on my little 4" SCT grab and go. This eyepiece was absolutely awful at night, so it was returned to the supplier.

I am a huge fan of Teleview eyepieces so decided to buy some secondhand Radians. I have always found these very comfortable to use and they are very sharp. I was lucky enough to pick up a set of 3, 5, 8 & 10mm. Of the four, I use the 5 & 3mm. The 5mm gives a lovely contrasty view of the whole disk (mag x70), so I use this to find  proms and spots. I then change to the 3mm (mag x116) , which gives a view of about a 1/4 of the disc but obviously at higher mag. The image is darker but not overly so. I have been observing the Sun during Sept - Nov so the Sun has been quite low in the sky. I expected a lot of atmospheric disturbance and thought the 3mm would be unusable but it has been fine. Much easier to observe the Sun rather than Mars!!!

Am I hooked on Solar? well not yet, probably because the solar activity is quite subdued at the moment but I must say it is good to observe something so dynamic. Every day is different and its lovely to do astronomy with the warm sun on your shoulders rather than freezing cold in the dark night. Its kind of like looking at Jupiter and its moons for the dynamism but in the warmth of the Sun 

To anyone who does night time astronomy and and like me has toyed with the idea of trying Solar, I would recommend it. Using the scope is different because of the pressure tuner. I have found this to be a bit of a fag and not sure that I have completely cracked it yet. What I do is get a good focus on the edge of the disc and then twiddle the PT until I can see some texture on the surface of the sun. It also helps to enhance the proms, but takes some getting used to.

Fianl word - Yes give it a go. the Lunt is very well built and inspires confidence.

 

[Floater]

Welcome. Glad you’re enjoying the Bright Side.

Hope you have lots of fun as Cycle 25 continues to build. 😎

[niallk]

Nice review!  I love my LS50.

I find the dual speed Moonlight focuser a fantastic addition - really allows that super fine focusing that reveals wonderfully fine detail.

You are pushing impressively high mag with it! 😎

Nice we're getting some activity now!!

[Luke]

Great first post! I am really fond of my Radian eyepieces for solar. I agree with you about how dynamic the sun is. You never know quite what you will get and sometimes it is worth popping back out several times on the same day as things sometimes change so quickly.

That's interesting about the focuser working fine for you. I'm very tempted to pick up a Lunt 50 at some point. I've looked through a few Lunt scopes and they have all given a beautiful view.

[Tigger27]

Hi Guys,

Many thanks for your comments. I am looking forward to seeing some decent activity and really must get some knowledge on what I'm looking at. I'm still at the wow! sunspots and proms stage. 

Luke - Thanks for the tip about popping out several times a day. I'll give that a try when dear old Blighty has some sunny days😎

[Merlin]

Lunt are good. I have a LS50f etalon attached to a small refractor. I can also double-stack it to the PST. I need a KG3 filter to replace the fogged one in the B600. I once bought a replacement from a British firm, but I can't remember who. They only charged £3 plus £2 postage. Can anyone recommend a UK supplier?

 

[Nigella Bryant]

Welcome to the bright side. I've been solar observing/imaging for over a year now and hooked, lol. I have a Lunt 60mm DS. My solar scope is the most used scope I own. Seeing during the day also seems better but no scientific proof of that. I've thought totally about going over to solar and selling off my night time scope's to get a bigger Lunt, lol. 

[Oldarn]

Hi All,

I am a keen Solar observer in the Southern Hemisphere. I ave an uninterrupted view of the Eastern horizon. I am close to investing in a Lunt 50mm and am not sure if it’s worth changing from the B600 to a B1200.

I want to make its use as easy as possible for daytime non astronomy visitors. Bono viewers are something I am considering too. 
 

I want to make the telescope a shared visitor experience - not just for me.

Any thoughts appreciated.

oldArn

[Peter Drew]

Always good to share equipment  with others.  Unless you wish to use the telescope for full disc imaging, the B600 will be adequate, a B1200 will provde a wider field of view but no change to the solar image.  Binoviewers are great with solar telescopes but most non astro users tend to have difficulty with them due to the varying adjustments needed for a good view.     🙂  

[Nigella Bryant]

I don't think the b1200 would be a wise investment on a 50mm Lunt but would be with a 60mm. You have to consider this if double stacking too. A 50mm b600 double stack would be better than a single stack 50mm b1200. The extra cost would be more or less the same. However the sun would be rather dim. It's surprising what an extra 10mm can do going to a 60mm Double Stack b1200. Perhaps look for a second hand Lunt 60mm double stack which is what I did rather than the Lunt 50mm. Just my preference really. Recent image taken with my second hand Lunt 60mm double stack pressure tuned scope. 

[Tigger27]

Hi Oldarn,

I recently purchased the Lunt 50 b600 and my rather poor review is above. I would think the b600 would be good enough for you (it certainly is for me). the 5 big points that I had not appreciated before I started were

1. Darkness affecting contrast - I thought you behaved just like night time astronomy ie pop the eyepiece in and away you go. Nope Solar is a bit different. Firstly you need to shield the eyepiece from the sun. It really makes a big difference. I know its a bit bonkers but I either drape a coat over my head or use a wide brimmed hat ( I have a Barmah squashy).

2. Twiddling the pressure tuner - You get the sun in focus with the eyepiece and then fine tune with the pressure tuner to bring out the granulation on the surface (nowhere near as good as the photo above) and the proms and loops on the edge of the disc. This is when you get the 'wow' moment.

3. Magnification - the higher the better I have found. I use a 5mm most of the time. Push it with a 3mm if the seeing is good. An 8 or 10mm will give a view of the whole disc

4. Binoviewer - I have a pair for my 14" Meade for nighttime stuff, but I dont think you need them for the sun. I find 10-30 mins is plenty of time for a solar session, whereas at night it can be many hours because there are so many objects to gaze at and binos really help my poor tired eyes for long sessions.

5. Sweet spot - I have found that the scope has a definite sweet spot in the centre and in order to make sure I see all the proms and loops very clearly, I use the 5mm and move the edge of the disc thru the sweet spot. It amazes me how much sharper you can see thru the sweet spot 

 

If you get hooked, you can always chop the 50 in for something bigger, so long as you have deep pockets! for me the 50 is fine and I cannot see myself splashing out on anything bigger. I have 10,8,5 & 3mm televue radians for the scope. 5mm is most used, 8mm not at all (will prob put is up for sale soon), 10mm is excellent for contrast but image is a bit small so a bit tricky to see the proms.

I dithered for a couple of years before getting the 50, but I am very pleased I have finally taken the plunge. 

 

[Tigger27]

Hello all,

An update after 6 months of use.

1. Totally hooked on the bright side! Every day it’s different, sometimes proms change by the hour.

2. Double Stack unit is ordered and will be shipped from Lunt within 2 weeks. I will update the chat on the difference between single and double stack and whether it’s worth the massive cash outlay.

3. I really have good feel for this scope now and have changed how I use it

4. Focusing - the standard one is ok, certainly not worth paying extra £250 - £450 for a feather lite. Why because the after market one give the same depth of focus and my main problem is lack of back focus using Televue Radians. My solution was to back out the diagonal, but this made me nervous so now I slide the EP in slowly and lock when the edge of the sun is in focus. Any fine focus use the focuser. No problem 

5. magnification vs seeing. I find that because the scope is only the 50mm, that it cuts thru the turbulence very well. I have only had a couple of days when the atmos has caused the view to be ‘swimmy’. I use 8mm to focus and see what’s going on. Then I change to 5mm for close ups. 3mm is really pushing it but occasionally the atmos is steady enough.

6 what can you see? Get the PT hooked up properly and the proms are glorious. You can even see the faint wispy ones. In fact, I have been checking photos of the sun taken by amateurs on the same days as I observe and I can say that I see fainter proms that are invisible to the AP guys. So proms 10/10

surface features - yes they are there but you cannot see much detail because of a lack of contrast. Hopefully the DS will improve the view. So surface features 1/10.

7. Would I recommend the LS50 - Yes it’s a lovely little scope that weighs a feather, is easy to set up and use.

8. How long do I send observing - it’s usually 15-30 mins at a time. After all theres only one star to look at. If Sol is dynamic, I leave the scope set up and come back from time to time during the day to see how the proms are evolving.

I have found a piece of blackout curtain for £3 off eBay really enhances the contrast. I have pinned it to a hat and use it all the time now. Score 10/10

9. What would I change - Aperture, you always want more!! Focuser because of the back focus. BUT ££££££

If I started from scratch, I would probably still buy the 50 because of cost. Solar is eye wateringly expensive! I will have a new double stacked 50 for £1,500 (imported from USA) UK dealers put a crazy mark up on. A double stacked 60 is going to be about £4,000. I asked myself if the extra light grab of the 60 was worth £2,500 and my answer was no.

10 what next - I get the DS in 2-3 weeks and cannot wait to try it out. IF it is as good as everyone says, then happy days! I will have a great scope and EPs; A nice tan and loads of vitamin D. What could be better than Astronomy in the warm sun supping a cold beer?

After that, sell one of the kids and buy a 80mm scope😀

clear skies and good seeing to you all

[niallk]

Great update

I'll be very interested to hear your thoughts on the DS.

Personally, I think it is extremely worth it - fantastic surface detail.  I did go for the dual speed Moonlight upgrade (never ending money, huh?!) and I find it pretty essential for getting that exquisitely fine detailed focus point.

Those 1x 'linear binoviewers' are tempting me - if they'd reach focus in an LS50, it would be fantastic to observe with two eyes....

Edited April 3, 2021 by niallk

[Merlin]

I have a Lunt LS50f etalon that I double-stack with the PST. I took a good image of the last Mercury transit using this arrangement. Lunt claims that it’s solar ware isn’t compatible with other systems, but it works in this case.

Alas, I’ve hit a snag. I decided to attach the LS50f to a 60mm refractor, which I do occasionally, although I don’t know why I  bother,  seeing that the PST double-stack gives superior results. A few days ago, I was screwing the Lunt onto the adaptor for the 60mm mode, except that this time the Lunt became cross threaded with the adaptor. It wouldn’t screw forwards nor unscrew. With care, I tried a strap wrench, but that didn’t work either. Heating the adaptor could be disasterous for the LS50f. Anyone any ideas?

[Roy Challen]

Well, if heating may cause damage, and no other option works, you could try cooling it. Pop the adaptor/Lunt in the freezer for a while and try again.

Don't know what to suggest if that fails.

[Luke]

Glad to hear you're having a blast!

I do like fancy focusers myself, though the SolarMax 60s' helical focuser* is not very well liked, mine had some backlash, but it was still usable and the scope served me very well.

It's a shame h-alpha is so expensive! I look forward to seeing what you make of your DS unit! I found it well worth it for the increased contrast on the disc, though perhaps it depends on the user's eyesight how much difference it makes. I used single and double stack over the same period for a good while (we had his and hers - I used the single for imaging plus visual and also observed a lot with my wife's DS) and you do pay a lot for the double stack and I am happy enough with a single stack but would always try to double stack myself when funds allow and if the bug really bites!

I really love the Radians for h-alpha and for white light.

Those Lunt 50's do look neat, I intend to replace my current filter as soon as funds allow and I think it will likely be with a Lunt.

I think you make a good point about returning later in the day to see how things have developed. I didn't know when I started out just how quickly things can change!

re: beer, the amount to consume is if my dodgy maths is right inversely proportional to the cost of the h-a filter. Maybe switch to Coke if you get a double stack 80 down the line?

@Merlin, I have no idea on mechanical things, strap wrench is the best thing I know. That's a horrible situation to be in with such a valuable unit. Hope you get it sorted. It might be worth asking on SolarChat: https://solarchatforum.com

* the helical focuser on my Tele Vue 60 is sweet!

Edited April 3, 2021 by Luke

[Solar B]

Ken , what about some very carefully applied lubrication , just enough so that 

it doesn't run onto the handheld areas ? I was under the impression that 

etalons could handle some heat but perhaps not too much either.

Brian 

[Peter Drew]

Whatever you do to try and release it, don't subject it to mechanical shock.  This could detach the etalon plates which are only kept together by molecular bonding.      😱

[Solar B]

Ken will be acutely aware of de contacting I'm sure Peter but many are not 

and I've just read a post about such !

We all try swapping round with HA filters and I did try an SM40 on a LS50 once 

on a old CN thread ... " Lunt still dissapoints "

Brian 

[Merlin]

 I find that the Lunt on its own isn’t as effective as the PST, but good when it’s stacked with the latter. I’ve long been aware of the problem of decontacting roughly treated etalons. In fact, I’d though of taking the Lunt to a local engineering firm to try to undo the cross-threading, but they might not fully appreciate the delicacy of etalons to shock.

lubrication of the adaptor presents its own risk, as lubricants tend to end up where we don’t want them.