New Product Alert - Heritage 150P

[Captain Scarlet]

Seriously though, my understanding is that any straight edge will produce a diffraction spike perpendicular to that edge: in fact one perpendicular spike for each "side" of the straight line within the aperture. So a straight spider vane, having 2 "sides" inside the aperture, will produce two spikes, one for each side of the vane. But a straight edge to the aperture itself will produce just one spike, as it has only one "side". Thus a circular aperture can be considered as an infinite number of small straight edges, each producing its own small perpendicular spike, thus manifesting as a ring: a diffraction ring.

Another example is the single straight edge that often appears on skywatcher (and others?) newtonian secondary mirrors, from where it's been held for silvering, which usually produces an annoying single spike slightly offset from one of the main spider-vane spikes.

Edited June 11, 2020 by Captain Magenta

[andrew s]

I do wonder if the light shield will stop sky flooding looks a bit small to me but maybe there are baffles in the focuser tube?

Regards Andrew 

[RobertI]

A nice addition to the range, I love my H130, so I'm sure this will sell really well. Being so light the OTA should sit nicely on smaller goto mounts like AZ-GTI too. Shame the OTA doesn't have similar decoration to the 130P, which I rather like as it makes it a little bit different.

6 minutes ago, andrew s said:

I do wonder if the light shield will stop sky flooding looks a bit small to me but maybe there are baffles in the focuser tube?

Unfortunately stray light does get into the focuser tube on the H130P if you're line of sight is towards an illuminated window or streetlight, so I imagine its the same for the H150. I've not worked out whether the stray light comes in via the front of the OTA or around the light shield, probably both. Not a huge problem if you are in a dark spot though or viewing bright objects like moon and planets. I have a simple homemade shroud and dew shield which has solved the stray light problem.

[JamesF]

In the case of spider vanes, a single support from the secondary to the tube will produce a diffraction spike either side of a star.  If there is a second support exactly 180 degrees from the first then there will also be two diffraction spikes in the same arrangement as for one support, but perhaps visibly brighter.

A three-vane spider with the vanes at 120 degrees to each other will therefore produce six diffraction spikes, whereas a four-vane spider will still only produce four.  In this latter case, each of the four vanes still produces a spike either side of a star, but they happen to overlap each other.  If you were to set four vanes so none was directly opposite another, you'd get eight spikes.

Recently I had a small straight piece of plastic swarf (I think) fall onto the lens of my ED80 in such a way that it reached inwards from the edge of the lens by about 5mm.  It caused a diffraction spike either side of bright stars, but only in one section of the image frame.  I assume that was because the light from other stars in the image that might have reached the piece of swarf wasn't also being refracted sufficiently by the lens to be part of the light cone that reached the sensor.

There are times when it is possible to get a single diffraction spike as Magnus points out.  I believe it depends on exactly where and by how much the obstruction intrudes into the light cone.

Magnus's point about considering the circular aperture as an infinite number of straight edges also has a relevance to imaging with a camera lens.  If the lens is stopped down, the blades that close down the aperture can each create a diffraction spike either side of a star.  For those who aren't keen on such spikes (holds hand up) the solution is to leave the lens wide open and cut an external stop from thin card or plastic, with a circular aperture, to fit to the front of the lens.

James

[JeremyS]

Going back to the original intent of this thread, this new offering looks like a great scope for beginners or for travelling. Moreover it is well priced. Makes it all very exciting. It's got to be worth a punt!

Edited June 11, 2020 by JeremyS

[DirkSteele]

2 hours ago, Stu said:

Looks fab! I can see one of these coming my way as a holiday scope, great stuff. 👍👍

That is what I was think as well.

[Barry-W-Fenner]

Well you do learn something new everyday! Thanks for the clarification folks!

 

Regards

Baz

[Chris]

Just ordered one to review for my Youtube channel. There's quite a few interesting aspects to this scope, and I want to put it through it's paces like I'm doing with the SW Starquest 102 R. 

 

[John]

34 minutes ago, Barry-W-Fenner said:

Well you do learn something new everyday! Thanks for the clarification folks!

 

Regards

Baz

[Mark at Beaufort]

39 minutes ago, Lockie said:

Just ordered one to review for my Youtube channel. There's quite a few interesting aspects to this scope, and I want to put it through it's paces like I'm doing with the SW Starquest 102 R. 

 

I look forward to your review Chris.

It would be nice if you could purchase an Astrozap light shroud to fit this 150 flextube OTA. 

The number of users that made their own light shroud for the Heritage 130P is quite large.

 

[Chris]

10 minutes ago, Mark at Beaufort said:

I look forward to your review Chris.

It would be nice if you could purchase an Astrozap light shroud to fit this 150 flextube OTA. 

The number of users that made their own light shroud for the Heritage 130P is quite large.

 

Hi Mark, hope you're well  Well this is the thing! There is so much 'scope' for different videos with this Heritage 150p, including a video about performing the usual mods (PTFE tape the helical focuser, home made shroud, and flocking)

As well as the usual setup and first impressions video I tend to do. I'm also keen to do an optical comparison with my 4" f/5 Achro to show prostective buyers the difference between the two types of scope. In particular I will be keen to Ronchi test the optics, and plug my little ZWO camera in the focuser to demonstrate what bight stars and planets look like with the 3 vane obstruction. 

Should be fun  

Of course, several months down the line you can probably expect this in the for sale section to make way for the next thing I want to test lol 

 

[RobertI]

26 minutes ago, Lockie said:

several months down the line

That long? 😂

[paulastro]

5 hours ago, FLO said:

We've just received our first stocks of the new Sky-Watcher Heritage-150P. This is sure to become the new best selling beginner telescope in the UK with the same great optics from the excellent Explorer 150P combined with the proven collapsible tabletop dobsonian mount of the Heritage-130P.

This is an excellent beginner scope with plenty of aperture to be genuinely useful and a lovely size to make it portable and easy to transport.

And, it's currently in stock!

 

I hesitate to ask this Steve in case I'm missing something, or I'm seen as some kind of party-pooper, but I have to ask 🙂

Why wouldn't most beginners be better off buying the Skyliner -150P Classic Parabolic Dobsonian which only costs £20 more? 

I know its bigger but other than portability I think the Classic dobsonian  has many obvious advantages - a more stable base  no need for something to stand it on, less susceptible to stray light, an optical finder, better focuser etc etc

 

 

[Ricochet]

@FLO Given that lots of people are looking at this as a travel scope, do you have a weight for the OTA? What size of mount is likely to be needed? (Assuming the dob base isn't wanted for travel.)

[Corncrake]

1 hour ago, Ricochet said:

@FLO Given that lots of people are looking at this as a travel scope, do you have a weight for the OTA? What size of mount is likely to be needed? (Assuming the dob base isn't wanted for travel.)

Good question ! I almost made the classic blunder of not reading and thinking and saying 7.5kg is in the spec., but that will be of the whole gubbins
( so that one can know if one's table is capable of supporting it
Not that I often carry a table onto my aircraft )

 

Re vanes/spiders : it isnt just the number of spikes, as John's pic illustrates, it is also about visibility. For (proportional to ) each LENGTH of edge an amount of brightness will be put into the view somewhere. A curved vane will put it into a fuzzy blob (John's 3 pic) round the star which can obscure a component of a binary (for example). 4 vanes (8 spikes in 4 overlapping pairs) on the other hand will carry that brightness into well defined regions which, with correct orientation, can leave a clear undisturbed region into which gap one can place the binary component ! Yes, I know, special pleading, but each spider has its purpose.

 

7 hours ago, FLO said:

same great optics from the excellent Explorer 150P

This is an excellent beginner scope

I fancy not just new beginners,

(how does the OTA weight compare with that the 150 ? I'm thinking tripod capability )

this beginner started with a diy 6" in 1960something and progressed to larger and larger beasts over time and, if honest, recently an inverse proportion of time actually out of my armchair by the fireside !!!

So, this could be a temptation

Edit PS I looked at the pic and thought two eyepieces, Naysmith nay cant be, how do they do that , , , doh ! focus stacking !!

 

Edited June 11, 2020 by Corncrake

[Chris]

31 minutes ago, Corncrake said:

Edit PS I looked at the pic and thought two eyepieces, Naysmith nay cant be, how do they do that , , , doh ! focus stacking !!

lol I thought the same at first glance. Also noticed FLO have started watermarking their product pictures. 

[Corncrake]

7 hours ago, Lockie said:

I reckon it could be partly weight saving. 

is the collimatable cell. SW's fixed primaries work really well

 

Oh, I only just realized it has two struts not three, I suppose they know what is needed, - but not triangulated so roll-on your review. Perhaps it needs to be collimatable whereas the fixed primary was in a (more rigid) tube ??

Edited June 11, 2020 by Corncrake

[Stu]

7 minutes ago, Corncrake said:

Oh, I only just realized it has two struts not three, I suppose they know what is needed, - but not triangulated so roll-on your review. Perhaps it needs to be collimatable whereas the fixed primary was in a (more rigid) tube ??

The 130P is the same and is very rigid, so I don’t think there is anything to worry about.

[Corncrake]

2 minutes ago, Stu said:

The 130P is the same and is very rigid, so I don’t think there is anything to worry about.

Thanks, I had been contemplating the 130 but roundtuits,,, then this comes into view lol ! Ok strike rigid and worry, sub repeatable and collimation holds no terrors, it was just a maybe observation.

[Stu]

5 minutes ago, Corncrake said:

Thanks, I had been contemplating the 130 but roundtuits,,, then this comes into view lol ! Ok strike rigid and worry, sub repeatable and collimation holds no terrors, it was just a maybe observation.

I think the focuser is the only negative point but having popped some PTFE tape on my 130P it is fine, actually very straightforward to use and allows accurate focussing. Not something you would want to image with but for observing with 1.25” eyepieces it is fine. It actually saves weight and cost so makes sense for this type of scope.

[Star101]

I was given a skywatcher heritage 76 mini dobsonian  (76mm Mirror and FL or 300mm ) about a year ago as the friend of my mothers found they couldn't use it. It did need collimating. Once I had collimated it I was very surprised at what a great image it produced from such a small scope. 

This scope, Sky Wathcer Heritage 150p Dob A 150mm mirror at 750mm FL will be a great scope to have around for friends parties etc. Just leave it out for everyone to use. It should give some great views of the Moon and other celestial objects. I'm sure its going to be a winner at that price.  

 

[Corncrake]

12 hours ago, Lockie said:

SW's fixed primaries work really well (I've tried several)

In my earlier comment I was thinking "Star Discovery" (another 6" f5) which caused some consternation at the time with its fixed primary, there have been (are?)  other fixed cell models ?

 

 

[Chris]

5 hours ago, Corncrake said:

In my earlier comment I was thinking "Star Discovery" (another 6" f5) which caused some consternation at the time with its fixed primary, there have been (are?)  other fixed cell models ?

 

 

Yes, I've owned a couple of Heritage 100p f/4's with fixed primaries, and reviewed the Starquest 130p which also had a fixed primary. Collimation stayed good out the box with all, even the f/4's! 

[John]

Can secondary adjustments be made with these scopes and those like them ?

 

[Stu]

10 minutes ago, John said:

Can secondary adjustments be made with these scopes and those like them ?

 

Yes, they both have secondary adjustment screws John. The stalk on the 130P can sometimes come loose but once tightened it seems to hold collimation well. The three vane approach on the 150p should be better though.

My 130P split Pi Aquilae so is clearly quite capable and well collimated.