Ricochet

On 18/04/2021 at 17:31, Lotinsh said:

@Ricochet Thanks for the advice, I already made a thread about barlows that work with my telescope, so far got 1 response and I can't find that barlow in Europe, the link was US, could you maybe recommend me an barlow lens that would work? Also how much would better 10mm eyepiece would be?

The thread that I can see has links to the sponsor of this forum, FLO, which is a UK supplier who will deliver to Europe.

Of the two barlows suggested in that thread one is a generic barlow sold under the astro essentials brand. If you search on eBay for a 2x barlow you will find many listings for the exact same barlow shipped directly from China to whichever country you live in. 

The second suggested barlow is sold by Baader. Searching for Baader products on the websites of more local European suppliers should allow you to find it. 

With regards to eyepieces it is possible that almost any eyepiece would be an improvement. The cheapest option would be a decent Plossl eyepiece, but at 10mm the eye relief will be getting a bit tight so the slightly more expensive generic eyepieces sold as "Planetary" eyepieces would be better. Beyond this, it depends how much you are willing/able to spend on an upgrade. My suggestions for an upgrade would be one of: 

• 8/12mm BST Starguider (sold under different names outside of the UK)
• 10mm Baader Classic Ortho
• 9mm Vixen SLV
• 8.8mm Explore Scientific 82°
• 9mm Baader Morpheus

On 19/04/2021 at 00:24, Lotinsh said:

@Ricochet Did what you told me, shortened telescope's tube by 1 cm and could easily could get focus on everything! So, should I still return my barlow and get one that fits my telescope or just not pull out my telescope fully?

Routinely changing the extension of the telescope during a session will become tiresome quite quickly. My choice would be to find a barlow that comes to focus without the need to change the extension of the telescope. 

2 hours ago, phattanglo said:

The only thing altered is the addition of a Revelation Astro centring adaptor to replace the standard 1.25 holder but I seem to think it was about the same height.

This will be your problem, they are quite different heights I think. You need to put the 2" extension in the focuser and then put the self centring adaptor into that. If you put the self centring adaptor straight into the slightly larger than 2" hole at the top of the draw tube your eyepiece will be too close to focus. 

10 hours ago, TRACEY 1409 said:

Hi, I am a complete beginner and an independent site has recommended the celestron starsense explorer 114lt telescope. I have watched videos of this and it looks really easy to set up and I like the fact you can use an app to pinpoint stars and planets that you want to view but how good is this really. I have up to £200 to spend but have seen sites that say a good set of astro binoculars are just as good if not better for a beginner due to the increased field of vision? 

The Skysense app and phone cradle are supposed to be good and there are a few people here who have bought one of these sets just to get the app and cradle so that they can reuse it on a different telescope. The LT 114 telescope however, is definitely one to avoid. It has a cheap barlow lens built into the focuser to try to reduce the aberrations from the fast spherical primary mirror. Reviews of this type of telescope typically use the word "blurry". The DX 130 in the same range is probably a much better telescope to observe with and additionally, the DX mount is probably a bit nicer to use than the LT mount. Other telescopes are available, but with a relatively low budget you have to choose between spending the money on the telescope and spending the money on electronic aids to find things.

The usual recommended starter binoculars to learn the sky are 10x50, and if you decide to buy some of these the ones I would go for are the Opticron Adventurer T, but looking at the light pollution map for your listed location, I think they might be a bit of a disappointment. What I think you need is a telescope with a large aperture to gather the light from faint stars so that you can then observe star clusters at relatively high magnification to dim the background sky. This time last year the Skywatcher Skyliner 150p would have been ideal for about £200, but covid supply issues have pushed prices up and availability of all telescopes is very patchy. If you are prepared to wait until covid is "over" then maybe the price will come down again, but in the meantime I would definitely keep an eye on the second hand market.

On 13/04/2021 at 19:48, Pondus said:

May I suggest you leave the tube ~1cm from fully extended, when using the barlow. You might achieve focus then.

Try it using 25mm barlowed.

 

Rune

I think this advice may have been misunderstood. The advice in this post is that as the Heritage 130p is a collapsible dobsonian. the telescope itself can be shortened by about 1cm when the barlow is going to be used. 

On 14/04/2021 at 03:01, Neil H said:

Hi your missing the point if you remove the lens section of the Barlow then put this aside you don't need it at the moment now use the rest of the Barlow which is the tube part as an extension to see if you can focus the eyepieces if you can then you do need an extension

Sorry, Neil, but it is actually you who is missing the point. The eyepieces focus when placed directly into the focuser. Putting an extension tube between eyepiece and focuser is completely unnecessary and will do nothing but push the eyepieces out too far so that they cannot be focused.

@Lotinsh: What you need to do is to send this barlow back as it does not work with your telescope and look for one in which the upper section is physically shorter as this should mean that the lenses in the nose don't have to be pushed as far beneath the focal plane, or as advised earlier, get advice from other owners of this telescope about barlows which definitely work with it. However, given that you only have the starter eyepieces supplied with the telescope, my first upgrade choice would be to replace those (or at least the 10mm) with something better first.

8 hours ago, StuartT said:

Is a monopod stable enough? (With only one leg)

Yes, I think so. Obviously, it is not as stable as a top end tripod as you are still providing some support but what the monopod does do is to take the weight of the binocular so that you can easily hold them and observe even high altitude targets without (much) strain. Additionally, with only one leg coming down to the ground, you can easily pan around without the risk of tripping over the splayed legs of a tripod. The disadvantages are that you won't be able to share the views with someone else as you can't pass the binocular to someone else without loosing the target, or stop to consult a map half way through a star hop. 

8 hours ago, StuartT said:

also, don’t monopods already have heads? I’m interested in why you recommend a head from a tripod instead?

That particular head is a trigger grip ball head that has an almost unique design that means that the trigger grip doesn't get in the way (of your face) when you mount binoculars on top of it. It has been available for years under a variety of brands but currently the only place I know you can get it is bundled with the Amazon basics video tripod.

The trigger grip ball head design allows you to squeeze the trigger to move the head and then locks in position when you release the trigger. With a standard ball head or monopod mount you will find that for any single tension setting you have something that is either too tight for smooth movement or is unable to support the binocular at high altitudes. 

I think the best combination for this size binocular is the head from the Amazon basics video tripod and a good monopod that extends high enough to hold the binoculars above your head. 

54 minutes ago, Don Pensack said:

The world's best lens pen is only clean on its first use and since it is not used with a fluid, merely scoots the grit around.

There should not be any grit on the lens by the time you use the "pen" end. The pad is for removal of oils after any solids have been removed. 

36 minutes ago, amaury said:

That seems sensible if you are observing from a bortle 6 backyard.

I observe from a Bortle 4 area, I believe I can stretch that recommendation to 5mm exit pupil for my low power EP in that context.

In practice you probably wouldn't really notice the difference between exit pupils of 4.5mm and 5mm and either is fine. I think that really you want an eyepiece that will maximise the field of view so it is a case of choosing between: 

• 20mm 100°
• 30mm 82°
• 40mm 68°

In my 8" f6 dob my mono view set is 28mm, 14mm, 10mm and then a 2x telextender to give me 7 and 5. The "missing" 20mm (or 28mm) is the one you can probably skip, the rest I get regular use from. You might find a zoom or more closely spaced fix eyepieces are useful for the higher magnifications where you are hitting atmospheric limits. 

Given that the problem appears to be finding objects and a RACI finder is wanted for the new scope to help find objects, I would suggest just buying a RACI finder and shoe for the current scope. This will give you the ability to determine whether the RACI helps or whether a go-to system is required before spending hundreds of pounds on a new set up. 

Additionally, I would suggest getting an eyepiece around the 18mm mark for observing DSOs that you do find as there is a big gap between the 9 and 32mm eyepieces already owned. 

I don't think there is something that is "too advanced", but the problem I think you will most likely encounter is that the telescope is too big. Binoculars are the most grab and go instrument that you can have. If you have the urge to go out, you just pick up the binoculars, go outside and start observing. On the other hand, an 11" SCT requires significant planning before a session. The mount must be carried out and set up, then the OTA must be taken out and put on the mount. Given the weight and bulk of the OTA, lifting it on to the mount is potentially a two person job. Once set up the telescope will need to acclimatise for perhaps a couple of hours before use. An SCT will also require active dew control to prevent the front corrector dewing over. Ideally, an 11" SCT would be permanently mounted in an observatory rather than set up and packed away each time. It is possible that this telescope is your wife's dream scope, but I think that this would have to be something that you discuss with your wife, rather than something that appears to be a surprise gift. 

Assuming that your wife's interest does lie with the moon and planets, rather than deep space, then I would be more inclined to look at a 5"/127mm Maksutov as a first telescope. The Skywatcher Skymax 127 AZGTi bundle would probably be my personal choice, although the current worldwide stock situation means that you need to find out which telescopes are currently available and adjust your selection accordingly. 

5 hours ago, toofaruphill said:

I had decided to replace my fungal  achro with a Bresser 127 quad f9 (ish) achromat but have just seen very similar Opticstar  127. I would nt expect it be as good as its about £100 less but thought I d ask for anyone on here who has experience of it. 

Thank you

Jonathon

The Opticstar scopes are rebranded Bresser scopes so optically they should be the same. However, the Opticstar models appear to be using an old, much inferior, focuser. I would definitely spend the extra £100 on the Bresser. 

Also, the f9 variants are doublets, only the f5 are quads. 

3 hours ago, dbuzz said:

 

If your collimation looks like this then your collimation is perfect. The shadow of the secondary must be offset towards the primary mirror, which can make the reflection of the cap look off centre when it isn't. 

This is a picture I took of the collimation of my 8" f6 dob. Yours should look similar. 

37 minutes ago, amaury said:

would you say that your clicklock experience is tilt-free? I am pretty sure it'll be wobble-free, not so sure about the tilt consistency of the clicklock. Thanks for the feedback.

I am visual only so I haven't attached a camera and used any inspection software to 100% guarantee it, but as far as I can tell there is no tilt. The clamping of the clicklock is absolutely consistent so if there is a tiny bit of tilt it will be the same each time. If you fit clicklocks then the weaknesses in your optical train will be the focuser and even flex in the OTA tube wall.

12 hours ago, amaury said:

The question is: does the Baader Clicklock also achieve the same level of tilt-free/wobble-free experience as the HG Parallizer?

I've not owned the HG to compare, but my clicklocks have always held every eyepiece that I have tried perfectly so far as I am aware. However, the 2"-1.25" reducer clicklock has an undercut, so there is the possibility that your 2" eyepiece clamp will tilt the clicklock, so then all your eyepieces will be tilted by the same amount, in which case you will want to change the 2" clamp for a clicklock as well.

7 hours ago, Fenton said:

You can even see a nebula smudge.

I believe you have actually captured M35 there.

With regards to phones, I haven't owned one that was accurate enough to use by holding it up to the sky. I just use mine as a map to compare to what I see in the sky, so I would definitely go for the RDF solution in your position.

43 minutes ago, Astro_Dad said:

coma - assume not really an issue visually unless using say the 30mm or other low power for sky sweeping?

It will depend on how sensitive your eyes are to it and the apparent field of view of the eyepiece. The wider the apparent field, the more you will see coma towards the edges. 

45 minutes ago, Astro_Dad said:

When it is suggested that the longer focal length Starguiders are not as well corrected for short focal ratio scopes, does that mean in terms of coma and/ or field curvature? 

The 18 has a combination of field curvature and astigmatism(?), the 25mm has astigmatism. 

The Bresser site describes the design as "achromatic refractor", which is a shame. 

If you already have the parasol, give it a go. Anything that you can do to block light will be an improvement. I would also consider anything that you can do to make things darker on an even more local scale. Buy or make a dew shield to help block stray light from entering the telescope, buy a patch for your non-observing eye and a spot bandit to stop stray light entering around the top of the eyepiece. I would also use some sort of observing hood. You can buy a specialist astronomy hood or you might have a coat with a suitably large hood already, or simply drape a towel over you head to block light. Once you have found an object and have your stray light blocking devices in place, make sure that you observe that object for an extended period of time so that your night vision can improve.

Of the two a 2.5x is more likely to be useful, but personally I would be more inclined to buy a 2X barlow than anything more powerful. However, I don't think a barlow has much value with your current eyepieces. If you barlow the Plossl you will probably end up with too high a magnification, and the kit eyepieces aren't that great, particularly the 10mm. I would upgrade at least the 10mm before adding a barlow. An 8 and/or 12mm BST Starguider is a good quality and ergonomically nice eyepiece to use and often chosen as a first upgrade.

1 hour ago, AllanK said:

SVbony SV134 and Omegon A-Z Baby

Of the two I would choose the Omegon as the side mount means that the telescope can rotate around its centre of mass. With the "over the top" style mount, the friction required to hold a telescope changes with the altitude it is pointed at, and at high altitudes the mount may not be able to cope.

1 hour ago, AllanK said:

Sky Rover 2inch Follow-up AZ Pan&Tilt Telescope Mount

That is not the same mount as the Omegon, it is actually a bigger, probably more stable (i.e better), mount. I've actually got one (branded as the Altair Astro Starwave Mini-Az). It's a reasonable travel mount for small telescopes but you might want something more stable for high power viewing. As the C5 is quite a short telescope it might fare ok on this mount.

1 hour ago, AllanK said:

Cullman Mundo 525M

I've got a Zomei 818C, which looks very much like it is the carbon fibre version of your tripod and almost certainly came out of the same factory. More accurately, I've got the pieces of it, because one day it came apart in my hands. The "stopper" inside the central shaft that the 3/8" screw screws into is only glued in place and this is where it failed. I would not trust it with a telescope attached having seen this. In addition, the tripod itself is nowhere near rigid enough for astronomical use. If you turn a mount head on top of the tripod, the whole thing flexes at the joints and then springs back a little when you let go. 

If I was in your position I would look at the Skywatcher AZ5 mount as I believe it is more stable than those previously discussed and use it with your existing tripod only while saving up for the Skywatcher 3/8" stainless steel tripod. 

3 hours ago, mincam said:

if the planet never sees the moon's shadow

I think that you are considering the planet as "stationary", with the same pole always facing the sun rather than considering the change in direction of sunlight over the "year". At one time, one of the poles will be facing the sun, as in the edited picture, and the moons will not cast a shadow. A quarter of a year later, the equator is facing the sun, so all the moons pass between planet and sun and both cast shadows on the planet and see the dark side of the planet. Another quarter of a year, and the other pole is facing the sun, so you are back to no shadows.

No. Any aberration from the objective already exists by the time it gets to the eyepiece and so the eyepiece will show that aberration, plus any aberrations from the eyepiece itself. The only real exception to this is field curvature, where the curvature from a particular eyepiece may counteract the curvature from the telescope. 

13 hours ago, MathewRimmington said:

8mm/2, so 250x magnification on my scope.

The standard Dobsonian Skyliner 200p has a focal length of 1200mm so a 4mm eyepiece will yield a magnification of 1200/4 = 300X. If you have bought an Explorer 200p that has been converted to a Dobsonian then that would have a focal length of 1000mm so a 4mm eyepiece would then give you 250X.

For a telescope with an aperture of 200mm the optimum planetary magnification lies in the region of 1 to 1.2X aperture, which is 200 - 240X, however the atmosphere in the UK often limits useable magnification to the 150-200X range. This would indicate that the 2X barlow will suffice and allow you to use the zoom in the range in which the apparent field of view is largest. For Uranus and Neptune (sometimes Mars when it is far away) you may find it useful to push the magnification to an equivalent of 4mm to increase the disk size but diffraction will be scrubbing detail and beyond this is unlikely to be of use.

If you get into double star splitting then the standard 2-2.4X aperture limit applies (if/when allowed by the atmosphere) and you could use the full range of the zoom and a 3X barlow, but if this were to happen I suspect you would be looking for a sharper eyepiece than the Celestron 8-24mm.

Buying a 24mm Panoptic is definitely not a waste. At the high focal length part of the zoom range the field is very narrow and so a wide field 24mm is more a necessity rather than an extravagance. The panoptic is an excellent eyepiece, possibly the best option for maximising the field from a 1.25" eyepiece. 

On 06/03/2021 at 14:53, KP82 said:

There is a BST 12mm in the Sales/Trade section atm. It's one of the best budget eyepieces.

1 hour ago, HollyHound said:

Never ever... ever... look at Tele Vue Ethos... just don't 😬🤣

Classic SGL budget inflation 🤣