Franklin

I bought a Porta II hoping to mount a 4" refractor on, weighing around 5.5kg, but it was a no go. It was great for the ED80 at around 3.5kg though. Maybe it was the longer tube of the 4"?

Is the AZ5 heavier duty than the Porta II ? or are they pretty much the same in payload capacity?

Clear here but seeing in and out. Io shadow transit prominent and Io egress seen. Barge in NEB as above. 4" ED refractor @ 140x with Baader CB filter. Seeing better earlier at twilight, Cassini Division and EQ band on Saturn @ 187x with Baader Orange longpass. Copernicus showing great detail, nice shadow.

Prism diagonals have the same image as mirror diagonals. Correct, Mirror fast and Prism slow. About the same price really. Baader do a 32mm prism for around £80 which is really good but it's part of the T2 system so you need nosepiece and eyepiece holder on top. The best 1.25" prism diagonal is the Takahashi for around £99. The 2" Zeiss prisms begin to get quite expensive but so are high end 2" mirror ones.

That's one heck of an eyepiece!

Seems a bit silly to me. They are all top-notch scopes. What does a point on the scale represent?

It's just the rubber eyecup that needs removing to expose the retaining ring which needs tightening up. The collar which rotates up and down with the eyecup on is seperate from the lens assembly. Most of the BST's (not sure about the 25mm) have a barlow element at the field end which can be accessed by unscrewing the nosepiece. The field lens side also has a retaining ring if memory serves so the rattle could be coming from that rather than the top eye lens?

RotherValleyOptics are doing optical maintenance now.

I had a rattling BST. Rubber eyecup pulls off and then tighten up the retaining ring, not too tight though. Lens spanner helps.

Wow, I've never seen that before. It must have an in-built mirror/prism. I thought you had made it by putting a spider and secondary into the back of Bresser 102.😀

The 32mm will give you the widest fov in a 1.25" focuser and slightly less magnification. You would see a greater area of the sky. Not much greater I may add. There are some very wide eyepiece designs but they are also very expensive.

Your scope is a short focal length refractor and is more suited to low power widefield viewing such as star clusters and the brighter Messier objects in general. So I would go the other way and get a longer focal length eyepiece such as a 32mm Plossl which would perform very well for this kind of observing. As Vlaiv has noted above you already have a 10mm and a barlow for high power.

What's that Vlaiv? Is it a Frankenstein scope?

That is the correct decision, you will not be disappointed with the performance of the 10" newt on a dob and the EQ6 will handle it fine. A big scope like that on an EQ5 would be like a jelly in the slightest breeze and when focusing or even coughing in the direction of the tripod. Big scope=Big mount.

Totally agree with the above and they come up on the used market at very good prices.

Achromatics can't quite focus all the wavelengths of light at the same point, so the violet/blue light is a little blurred when the other wavelengths are in focus, even more so in faster scopes. Having a longer focal length helps control this aberration, that's why all the old classic refractors were so long and awkward to mount. A simple Wratten yellow filter works by cutting out the blue light all together, but of course it also turns everything yellow. Though it will sharpen up the contrast as it will remove the unfocused violet/blue light. I've observed with achros for 40 years and have now just got an entry level ED that uses FPL51 glass and the improvement is very noticeable. Saving up for some proper fancy glass now.

I tried an eyepatch and didn't get on with it really, elastic kept twanging my ear! I now have a pair of Roy Orbison style sunglasses with the left lens knocked out, Jack Duckworth style. The neighbours must think I'm a right weirdo! 😃

They would work with a barlow Paul. The longest fl eyepiece to use without vignetting would be about 20mm, so with a 2x barlow your low power would be 10mm fl equivalent eyepiece, around 100x assuming 1000fl scope. Benefits are, much more comfortable viewing, greater definition of details and the Moon just looks awesome in 3D.

Yes Dave, I don't think there will be much change from £400. I still want a set though. The WO's were great but I would prefer the non-rotating dioptre adjustments of the Maxbrights, as I've got a doubled up set of BCO's with the winged eyecups just sat waiting! Bill.P points this out in his excellent review, as well as the greater clear aperture. Best start saving!

Maxbright II should be available in Jan 22 according to the Baader UK rep.

Stick with the 4". The planets are not very high up at the moment and the atmosphere plays havoc with the seeing, like looking through boiling water!. If Saturn and Jupiter were up higher in the sky your scope should easily show the Cassini Division and plenty of detail on Jove. As far as Mag goes the 142x is fine for Jupiter with its larger disc but Saturn could benefit from 200x. Again it all boils down to conditions. Low elevation, bad seeing and maybe even collimation? The Bresser achros usually have decent optics, I've owned several in the past, but if chromatic aberration is visible then that will lower contrast as well. You could try a yellow filter to control this or a more expensive Contrast Booster filter which I would recommend to use with all achros when used at high mags. Having said all of that I can say that the upgrade to ED glass DOES make a huge improvement over traditional achromatics and also binoviewing just makes everything stand out more again. I've always had achros and recently got a 100ED and binoviewers and the improvements have just blown me away! Saving up for a Fluorite now, when will it ever end!

Watched the ingress at 140x and a CB filter. Lovely view but clouds have rolled in now and spoilt the party, as usual.

That's the Hex focuser, looks like it could do with a clean up.

Providing it's all in good order it's a good deal, 1/2 price in fact, if that's the kind of scope you're after. You already have a 130mm reflector, so the 127mm refractor is pretty similar, aperture wise. The scope and mount are a definate upgrade on the Astromaster though.

£1k telescope outfit for £500. Looks new, so it's a good deal, as long as the goto all works and the optics haven't been coloured in with felt-tip pen by some toddler!😄 Don't see the tripod spreader plate in the pics? Widefield views of star clusters will be amazing through that thing.