Lunt Ls50THa

[Pete Presland]

Looks like a nice edition, better than a thumb screw.

[Moonshane]

this one is a bit cheaper, a bit shorter and also has a built in helical for fine focus. might be a decent solution.

https://www.firstlightoptics.com/adapters/baader-t-thread-to-125-helical-focuser.html

 

[DRT]

Thanks, guys. Might pop over to RVO to try these as I'm a bit doubtful about them matching up well with the Ethos 2" skirt.

[Highburymark]

I have the baader with the fine focuser - like all clicklocks it works really well. There's a much cheaper low profile telescop service adapter (T2-1.25") that 365 has - fine for a TV plossl but just the thought of introducing it to an Ethos sends a shiver down the spine

[garryblueboy]

I've also got the Baader works really well also I'm very pleased with the moonlite focuser also quality bit of kit 

[andre2]

On 4 januari 2015 at 02:06, Qualia said:

Excellent review, Jabe and thank you for putting this together. Indeed, I think it is the first proper review I've read on the web since the Lunt 50mm has come out and I'm really happy everything things seems sorted out of the box without any quality control issues to contend with. The Lunt 50mm really sounds a great scope and all things considered, for H-alpha viewing is very reasonably priced.

I've seen some images of the 50mm double stacked and it has provided quite stunning views and now reading through your review, I wonder if the pressure tuner is also making a significant improvement on the more traditional tilt design? If this were so, might not the 50mm give the 60mm entry scope a good run for its money? 

Thanks again for your time and effort

Hi i want to order the lunt 50 mm 400BF and a 25 mm vixen NPT €41 eyepiece to use it with a simple trypod for now. Do you think it is worth the €300 more then the PST?

 

[andre2]

On 3 januari 2015 at 22:45, jabeoo1 said:

Lunt LS50THa Review

 

The Lunt LS50THa telescope is my first solar scope. It is also my first refractor. I am using it on the older model 'Vixen Porta 2' mount via a Lunt dovetail plate. The scope has the addition of a Televue sol finder.

From Transit

The package arrived well protected. The outer box contained a second box surrounded by loose foam infill. The inner box contained firm foam which was shaped to hold the contents very securely. Both boxes were tape sealed with Lunt logo tape. I assume it was factory sealed in the USA and remained untouched until arrival. This firm foam could easily be removed and if slightly cut (1cm off either side) it could fit into a 'standard' hard case for a cheap long term solution for transport and safe storage.  So far I am not aware of an official Lunt case for the 50mm model.

First Impressions & Setup

Read the instructions first ! There is a useful piece of information advising that you check the diagonal is secure by checking if the screw on the side of the focuser is finger tight before removing the scope. The risk of the B400 or B600 blocking filter falling off and breaking does not bear thinking about. Do not get too excited and make this mistake !

The scope feels compact but substantial and weighs 2.15 Kg without an eyepiece. The helical focuser moves with a nice resistance as does the pressure tuner (a tiny amount of play on the helical focuser is present but this does not cause any issue in use). The heavy metal dust cap that covers the front lens has a long thread and feels reassuring to take off and replace. All glass surfaces were spotless on inspection after removal from the box.

I realized pretty quickly I would have to loosen the clamshell and turn it 90 degrees to allow correct orientation to the mount. This was easy to do, as was attaching the dovetail plate and sol finder.

In Use

I have done around 4-5 hours observation time so far with the following eyepieces:

 

Televue 25mm Plossl (x14)

Televue 15mm Plossl (x23.3)

Televue 11mm Plossl (31.8)

Takahashi LE 7.5mm (x46.6)

I noticed that to get sharp focus with the TV eyepieces, adding the supplied adapter between the focuser and B600 filter achieved it perfectly.

The scope is very intuitive to use with the information from the short instruction manual.

The sol finder was exactly aligned on first attempt and captured the sun in the 25mm EP, no tinkering needed. The helical focuser when turned produced a sharp limbed disc. The pressure tuner then bought out extensive detail of both disk and prominences, and a quick fine tune back on the helical focuser produced a sharp and pleasantly detailed image.

 

Seeing a hedgerow prominence for the first time was an outstanding start, and I was very satisfied with the ability to get a very sharp contrasted view. Different levels of density were really obvious, as was the changing state of the prominence. As the sun moved across the FOV I noticed that the prominence had the tendency to fade. With higher magnification this phenomenon is less obvious and is not present at all in the 7.5 mm @ x 46.6. Major features at lower power seem to benefit from placement within a 'sweet spot' in the field of view, especially if your aim is to tease out every last detail of that particular feature. This is in no way distracting and is no doubt part of the systems characteristics. Part of the charm is learning the knack of keeping the focus, the pressure tuner and FOV parameters in check to the feature/s you are trying to observe.

 

Scanning the solar limb once tuned to any prominence is great fun, especially as many more become apparent that may have been overseen completely. The pressure tuned etalon in use here is rewarding at bringing out the fullest potential of the morphology of the prominences.

 

With both the pressure tuner and focuser set, I found the 15mm did a lovely job of presenting a nice view of both limb and disc features at the same time. Only a little tweaking of the slow motion controls on the tripod to maintain the view or vary it slightly was needed. Quiet filament regions are presented well along with the sometimes subtle but lighter associated filament channels. Active regions also feature well. Sunspots appear very dark and sharp. With patience all features become more evident in complexity. The only thing I can compare the views to is to imagine viewing a very dynamic Jupiter on steroids in excellent seeing. All this said with the Sun currently in winter placement I have not yet had the opportunity to release the instruments full potential.

Is the lunt 400 BF is woth it over the now €300 cheeper PST!?

[alanjgreen]

Lunt 35 was better than a PST.

Lunt 50 will be miles better than a PST

Go with Lunt, you will not be dissapointed. If you can stretch to the 600 BF then that will be money worth spending. The 400 has a 4mm exit hole to your eyepiece and the 600 has a 6mm exit hole to the eyepiece. Makes for a brighter view and a wider FOV.

I wouldn't buy a PST.

Go for an eyepiece around 14-15mm as a nice starting point. The 25mm will not give much magnification.

 

[Merlin66]

Alan,

Sorry to disagree....

The PST was designed for visual not imaging and unfortunately the available back focus will limit most cameras.

The tilt tuning of both the PST and some Lunt etalons does in fact allow "full doppler tuning" the initial design position (zero tilt) is well into the red wing of Ha and the tilt tuning takes the CWL down, through Ha to the blue wing and beyond.

Bang per buck it's still a solid 40mm performer, with a 5mm blocking filter. (A larger blocking filter only increases the field of view)

 

 

[DRT]

9 hours ago, Merlin66 said:

A larger blocking filter only increases the field of view

I find this very hard to believe. Of what possible use is a larger FOV on a scope that already delivers full disk views of the only object it is useful for?

[Merlin66]

Exactly!

Larger BF diameters are designed for longer focal length systems to maintain full solar disk coverage, when used on shorter focal length systems, the additional FOV can be useful to ensure large faint proms are well recorded.

 

[Moonshane]

I have managed to increase the field of view by using binoviewers. Not sure how but it works. I get full disk with 100mm aperture resolution at 85x with my BF5 and PST mod. I suspect it is because of the placement of the BF closer to the etalon. That said, it seems a bit counter-intuitive. Using cyclops, I get about 2/3rds of the disk with the same detail, resolution and brightness, albeit everything is easier for solar with BVs.

 

 

[Live_Steam_Mad]

On 10/08/2016 at 13:46, FLO said:

Starlight Instruments and Moonlite will be launching new focusers to fit Lunt solar scopes, we intend to stock them both.

Currently we are expecting the Moonlite models to arrive first but I will post an update as soon as we have a price and ETA. Promise  

HTH, 

Steve 

For those that would like motorised focusing, Starlight told me that their dual speed Feathertouch focuser was needed as the single speed model has no provision for adding a motor. I am referring to a factory fitted remote controlled motorised focuser for the LS50. Hopefully someone (maybe FLO) will import this focuser so we can buy them in UK.

I also bought a LS50 brand new recently, and they are excellent, plenty of surface detail and prom detail, with very good contrast, I like mostly to use my TeleVue Radian 8mm eyepiece, and often with a 2x Barlow element on the end of the eyepiece with a UV/IR filter acting as a spacer to make the barlow magnification factor suitable for bringing my LS50 to focus. Wonderful views. Pressure tuner holds pressure for a long time. Very pleased with mine.

Regards,

Alistair G.

[DRT]

54 minutes ago, Live_Steam_Mad said:

Hopefully someone (maybe FLO) will import this focuser so we can buy them in UK.

https://www.firstlightoptics.com/specialist-focusers-borg-tele-vue-lunt-gso-rc/feathertouch-125-focuser-for-lunt-50mm-solar-telescopes.html

[Merlin66]

Derek,

that appears to be a single speed unit, not the double speed mentioned above....

[Anne S]

On 22/08/2017 at 22:51, Live_Steam_Mad said:

For those that would like motorised focusing, Starlight told me that their dual speed Feathertouch focuser was needed as the single speed model has no provision for adding a motor. I am referring to a factory fitted remote controlled motorised focuser for the LS50. Hopefully someone (maybe FLO) will import this focuser so we can buy them in UK.

I also bought a LS50 brand new recently, and they are excellent, plenty of surface detail and prom detail, with very good contrast, I like mostly to use my TeleVue Radian 8mm eyepiece, and often with a 2x Barlow element on the end of the eyepiece with a UV/IR filter acting as a spacer to make the barlow magnification factor suitable for bringing my LS50 to focus. Wonderful views. Pressure tuner holds pressure for a long time. Very pleased with mine.

Regards,

Alistair G.

I've always sourced my focus motor from Lakeside Astro via Ian King Imaging. They design a bracket between them to hold the motor. I've had to send photos of my RC6 focuser to enable them to design it. Given there's no advantage in a 2 speed focuser when motorising, it may be worth finding out if they can sort something out. I've just invested in a second hand Feathertouch for my Lunt 50 and will probably try to motorise it at a later date.

Anne

[DRT]

On 23/08/2017 at 00:13, Merlin66 said:

Derek,

that appears to be a single speed unit, not the double speed mentioned above....

Oops, sorry, I didn't pick up the reference to the dual speed version