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Franklin

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Posts posted by Franklin

  1. 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.

  2. 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.

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  3. 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?

  4. 20 minutes ago, Alysha said:

     Would a 32mm eye piece be better than a 25mm for wide viewing? (I know this probably sounds like a dumb question) 

    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.  

  5. 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.

  6. 17 hours ago, vlaiv said:

    It means that this central section can be removed. Remove it and place cover on the scope. This will create aperture mask. It will let less light in scope - and is there fore very bad for general observing of faint things, but it will sharpen up view on high magnifications. You want to achieve this effect:

    image.png.d8d797384c157cf8cd99d291bddd9ce0.png

    (people make aperture masks out of various bits)

    What's that Vlaiv? 

    Is it a Frankenstein scope?

  7. 2 hours ago, wesdon1 said:

    I have now decided to scrap the EQ5 mount idea and just DOB mount it and then next spring buy an EQ6.

    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.

    • Thanks 1
  8. 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.

  9. On 11/10/2021 at 14:20, wookie1965 said:

    Just a quick one would binos work in my refractors and would I get any benefit please.

    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.

    • Like 1
  10. Just now, F15Rules said:

    It will be interesting to see by how much they will have gone up in price

    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!

    • Haha 1
  11. On 11/10/2021 at 08:49, Deadlake said:

    However try buying either new or on the second hand market....

     

    On 11/10/2021 at 10:26, F15Rules said:

    I hope at some point to get a Baader Maxbright MkII when they reappear on the market😊.

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

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  12. 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!

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