Ricochet

Similar-ish looking bandpass to the Astronomik CLS, which I think does help a small amount on some (but not all) galaxies. However, LED lights will pollute the wavelengths both of these allow to pass as well as the range that is cut. In that scenario perhaps the Astronomik is preferable as it has a chance of cutting some of the blue spike at about 450mn that a cool white LED produces. I'll have to re-test now that the motorway near my house has been "upgraded" from sodium to LED.

You need more spacers. The manual states you need 75mm between the flattener and CCD. The optical length of the camera is 12.5mm and the Baader parts 19mm. This means that unless you have spacers to make up the 43.5mm required, you will need more or different spacers. Buying the Baader spacers will stop the spacer you do have from fouling on the filter slider.

For visual you increase the brightness by observing with a larger exit pupil (= lower magnification) than without the filter. For a UHC you probably want to be looking at an exit pupil of around 3mm or more, depending on framing, whereas you would be aiming for an exit pupil around 2mm for an unfiltered view.

No, you would have to buy the Baader UFC spacers that have the same dovetail and clamping system as part B. Alternatively, if the field flattener and part B have M48 threads then M48 threaded adaptors could be placed between the flattener and B.

Let me see if I can help. Here is a labelled version of the original photo. @hubble space telescope, please confirm if the following are correct: A is the part which came with your telescope. If you unscrew the eyepiece clamp from the end of the focuser, the wider end M68 of this screws to the focuser. The smaller side is probably M48. B is the M48 adaptor. You should be able to screw the smaller side of part A into the hole in the middle of part B. C is the filter slider. It is not important for figuring out how everything is assembled so put it to the side. D is the main filter chamber with the M42 camera adaptor already attached. E is some sort of spacer ring. Perhaps it is supposed to be placed in A before you screw it to B to prevent the two becoming seized. If A screws to B correctly, then B is the correct part. We know that D is correct because you have screwed it to the camera already. The difficulty is connecting B to D. As @MarkAR has just said, B should drop into the open side of D, and then you can use the grub screws around the edge of D to lock B in place. If you already have the field flattener, this will go between parts A and B. However, in order to get the correct spacing between the flattener and your camera, or just to reach focus, you may need to buy additional extension tubes to fit between B and D.

Once the finderscope is aligned with the main telescope, it will remain aligned so long as you leave the finder attached. If the finder gets knocked between sessions then it may need realigning but over the course of an evening it should remain aligned.

I think, until they just touch. It's difficult to remember now as I just do it naturally.

I'm not sure what you mean? Do you mean wind the focuser in? You want the focuser approximately in the same position as when you are using an eyepiece.

No, any direction is fine, I meant just to choose a direction and stick with it. It shouldn't make much (if any) difference at all, so it is not a comment worth worrying over.

Stars are so far away that they will always be point sources through a telescope. What you will see is more stars in any given area of the sky than with the naked eye. The only star that is an exception and can be seen in any detail is the Sun, but this requires specialist solar filters or solar telescopes. The moon, planets, nebulae and galaxies will appear larger through a telescope than with the naked eye.

If you have the adaptor in the focuser so that the locking screw is on the right, always have it on the right. Don't have it sometimes on the left or on top for example.

With my Bresser, I check collimation each time I get the scope out, but I haven't had to touch anything for quite a few sessions. If the collimation moves when you lift the scope from one point in the garden to another or from house/shed to garden then you might need to tighten the collimation bolts a touch more. For the secondary that would just be doing the bolts up more tightly, but for the primary I would tighten all three collimation (not locking) knobs a full turn or more so that the springs are more tightly compressed, and then recollimate.

Yes, tighten the clamp on any collimation tool in exactly the same way that you would do on an eyepiece. I would also always orient the 1.25" to 2" adaptor in the same direction to allow for any offset. (But offset is very minor, it's a lot more important to make sure things aren't being tilted. ) Those do look good. Getting one is on my list but I've not got around to it yet.

If you get a laser, I would recommend just getting a cheap one with an angled face and a 2x barlow so that you can use the barlowed laser technique to collimate the primary. These days I have reverted to just using a cheshire for the secondary and a short cheshire with the crosshairs removed for the primary.

Is this in the day time on terrestrial objects? The closer an object is, the further out the eyepiece will need to be in order to focus. If you are trying to focus on terrestrial targets (which the scope is not designed to do), then you will need some sort of extension tube (i.e. an additional adaptor) in order to focus. This means you are way out of focus. Assuming my earlier assumption was correct, remove the additional eyepiece adaptor so that you only have either the 1.25" or 2" adaptor in the focuser. This should allow the telescope to focus properly. When you turn the focuser wheel, which way does the focuser move to make the circle of light smaller? This is the direction you need to continue to go to achieve focus. Absolutely not.

For £2000, possible, for £200 I would forget the idea. For strictly visual use have a look at the Skywatcher Skyliner 150p. It will be better all round than something from the Astromaster line.

You might have just sold me on the FT there, John.

If I was looking for a zoom I would look around for the cheapest available clone of the Lunt/OVL/Skywatcher/etc 7.2-21.5mm zoom, as it is well reviewed by people whose opinions I would trust. I looked through one of the 8-24mm zoom clones and the most accurate description I could give it is "blurry". Perhaps it was a poor example, but it wasn't something that I would choose to use.

The diffraction patterns would be different as all three have different secondary spiders, but the mirrors are the same and so the visuals would be very similar aside from that. Choosing between them based on the mounts will probably be a more important decision.

My advice would be that you don't buy any telescope from the "Powerseeker" line. Some models may be better than others but generally, they have issues due to the way they have all been built to a very cheap cost. With reference to the 70/700 you are looking at, you should also avoid any telescope where the mount has the additional bar pictured below between the mount and telescope, which is a clear indication that the mount isn't up to the job and compromises have been made. With respect to your binocular choices I think two are worth consideration: The Olympus DPS-1 10x50, if you plan to hand hold The Omegon 15x70, if you plan to get a monopod for them. Once you go up to 20x you're going to be at the stage where you need a good tripod, and a red dot finder + bracket in order to find anything in the sky. I had some Celestron Skymaster 25x70, and that was certainly the case there. The field is too small for the binocular to be its own finder and the magnification too great to be hand held. I believe the Omegons are the same as the 15x70 Skymaster so unless the 15x hides the optical deficiencies of the 25x Skymaster, I would rate the Olympus DPS-1 as better both optically and mechanically so that is the one I would look at first. However, to me binoculars seem like a bit of a specialist instrument and personally, I would be disappointed with a pair of binoculars as a sole instrument. I think that a decent telescope would be a much better, and more satisfying, all round instrument. I would advise you to save up some more so that you can increase your budget in order to afford the Skywatcher Heritage 130p as a first instrument.

Ok, so a fine focus model for sure. How does the quality of the moonlight compare to the feather touch on the dob? Is there a significant difference?

I'm considering upgrading the stock helical focuser on my Lunt LS50. I don't really have to refocus that much to it isn't really the focusing that bothers me, more the fact that it "wobbles" on the back of the telescope if you touch it and I'm hoping that an upgraded focuser will solve this issue. As far as i can see I have the following options: Moonlight LS50 focuser (fine focus) Feather Touch LS50 focuser (coarse focus) Feather Touch LS50 focuser (fine focus) Has anyone compared the Moonlite to the Feather touch in the flesh? Is it worth the extra £150 for the Feather touch version? If the quality is actually pretty equal then the Moonlite seems the way to go but if the Feather Touch is clearly better then, relative to the cost of the scope, an extra £150 isn't that much. If you haven't compared the two side by side, but chose between the two for your scope, what was it that swayed you one way or the other?

I had the 7mm X-Cell LX, and it was a good eyepiece. Unfortunately, I don't have it to go back and assess the quality of the coatings now that my eye is more critical. At the time I thought it was better than the 8mm Starguider I also owned. However, with both Starguider and X-Cell LX, the longer focal lengths are generally weaker than the shorter ones, but at f10 they might both be ok in terms of correction.

Personally, I would start my eyepiece collection by choosing something in the region of 2-2.5X the focal ratio, so a 20-25mm eyepiece. Then I would move in steps of ~1.41, which will lead to a doubling or halving of brightness depending on which way you go and is what your brain notices as "steps" in brightness. This would give you something in the region of 14-18mm for your second eyepiece and then 10-12.5 for the next. Where this falls down is for Lunar/Planetary where you will want a whole range of focal lengths so that you can adjust for what the atmosphere will allow on any given night. As you've already got the 25mm you could keep that for now and consider that maybe in future you replace it with a 24,, 68° eyepiece (i.e the Explore Scientific or TeleVue). That would mean you're looking for roughly 17.5mm and 12.5mm eyepieces as your next steps up, both of which are available in the Baader Morpheus range if you do decide you want to spend your budget at this time on a single eyepiece. Optically, these are better than the cheaper ones you are considering and they also have a bit more eye relief, which will make them more comfortable if you do have to wear your glasses. I've tried my 25mm BSTs with glasses and they're just about usable, but my glasses touch the rubber eyecup in its lowest position so a touch more eye relief is preferable if you do wear glasses.

Possibly too much magnification. a 6mm will yield a 1mm exit pupil so you're at the point where the airy disk will start dimming stars.