Jump to content

Narrowband

Eyepieces for SW 127 Mak


Recommended Posts

Ah, the agony of choice. Back when I was an amateur kid, we barely had any decent scopes, let alone eyepieces, as importing them from abroad was a major pain (and really expensive). Nowadays, just like with everything else, the problem is there is too much choice...just like when one goes to the shopping mall (feel exhausted after 30 mins already).

I've opted for a sw 127 mak on azgoto as my comeback scope for two reasons - one is portability, the other the light pollution (Belgrade is terrible, but the rest of Serbia is not too good either, just like everywhere else. Even in countryside there are unshielded lights everywhere). Plus, the kids like the Moon and the planets the most.

I know that it is more important to hone one's observation skills (and get them back actually in my case) more than to buy a gazillion of eyepieces, but I would appreciate some advice in order to better understand what might work in my Mak in the future. I've read Warthog's thread, and I understand that a Mak will not be that eyepiece-sensitive. Still, I would love to eventually get the best out of it for a reasonable price.

The two eyepieces supplied are MAs (10 and 25mm), one is generally good, the higher mag useless (by universal acclaim). FOV is, i believe, restricted to 1.1deg on 127 Mak, so it maxes out at 24 mm eyepiece at 68 deg or at 32 mm Plossl. Although a Mak is not a DSO beast, still it would be nice to get some low power, especially when in dark. Should I then add a 32mm plossl, or go for 24mm Hyperion which would provide the same FOV at a higher mag? I guess the lower the mag the brighter the objects, right?

Also, any recommendations for an eyepiece to replace 10mm supplied? I do not wear glasses, except for reading. Locally available choice includes GSO Plossls, Synta Golds, Magelan WA and Ortho Castell. A true dark site visit is coming soon, so a quick buy might pay off. In a month or so I would be able to resort to a much wider choice available at Teleskop Austria (Hyperions, Baader Orthos, Lacerta SPL, etc); , but that would be a long term purchase

I appreciate any and all advice you can give!

Link to comment
Share on other sites

  • Replies 26
  • Created
  • Last Reply

H BGazing,

Have a look at the BST Starguiders, they are c£50 and are well respected. Around the same cost are the Celestron X cel Lx range. You are correct that the Mak is forgiving on EP's  due to its long focal length. But  you get a lot of glass for your money with the BST range.

Link to comment
Share on other sites

The GSO plossl are usually reported as good, suppose 4 in total would be reasonable, total meaning wih or without the ones you have already, something to give say 150x and 120x at the shorter end then 30mm and one say 18mm area.

The BST's are sold in the UK by Alan at Skies the Limit for £49, they are also sold by TS at 94€ which is a fair increase over the UK price, comes to about £67 for what is £49 here. At TS they are branded TS NED eyepieces.

Cannot locate anyone else selling the same eyepieces - they exist under several names.

There is one company that have them at a good price however they only adverrtise the 18mm, also I know little (nothing) of the company.

Think you need someone like Alan to see this and he may be able to suggest a retailer as I think he is a bit closer to your bit of the planet then most of us are.

You could just email Alan at Skies the Limit and enquire about shipping BST's Starguiders to Serbia.

Link to comment
Share on other sites

I think it'll be best you try the stock eyepieces for a few sessions to start with.

You're right that lower magnification(=larger exit pupil) gives brighter image, for you f12 Mak, a 32mm eyepiece gives 78% ( (32/24)^^2) brighter image than a 24mm, 65% brighter than a 25mm. Therefore a 32mm is a clear better choice than a 24/25mm for your Mak.

10mm BCO should be a very good replacer for the stock 10mm, optically, it's better than any non-ortho eyepieces cost the same or twice as much, IMHO. Good luck with your choice.

Link to comment
Share on other sites

I think it'll be best you try the stock eyepieces for a few sessions to start with.

You're right that lower magnification(=larger exit pupil) gives brighter image, for you f12 Mak, a 32mm eyepiece gives 78% ( (32/24)^^2) brighter image than a 24mm, 65% brighter than a 25mm. Therefore a 32mm is a clear better choice than a 24/25mm for your Mak.

10mm BCO should be a very good replacer for the stock 10mm, optically, it's better than any non-ortho eyepieces cost the same or twice as much, IMHO. Good luck with your choice.

Thanks. What's 'BCO'?

Link to comment
Share on other sites

I think it'll be best you try the stock eyepieces for a few sessions to start with.

You're right that lower magnification(=larger exit pupil) gives brighter image, for you f12 Mak, a 32mm eyepiece gives 78% ( (32/24)^^2) brighter image than a 24mm, 65% brighter than a 25mm. Therefore a 32mm is a clear better choice than a 24/25mm for your Mak.

10mm BCO should be a very good replacer for the stock 10mm, optically, it's better than any non-ortho eyepieces cost the same or twice as much, IMHO. Good luck with your choice.

Also, and apologies for quoting twice, a 24mm will always have the same brightness, it is just that I will have a bigger FOV, and 32mm will always be brighter, hence advantage on DSOs, right?

Link to comment
Share on other sites

Sorry, BCO stands for Baader Classic Orthoscopic, very low scatter lights around bright stars/planets, and excellent throughput, 8mm eye relief for the 10mm BCO should work well none-glasswearer.

32mm eyepiece in your f12 Mak gives 2.6mm exit pupil size (32/12), about the brightest you can get for brighter DSOs (like many Messiers objects), and still small enough exit pupil the light-poluted sky will not look washed out.

Link to comment
Share on other sites

I have a seben/sw/cele 8mm - 24mm zoom, on my 127 mak the sun and moon fit perfectly at 24mm and look good right to the edge. I then have a couple of Barlows if I want to see detail on Jupiter. So far I've not found a need for other lenses, from my garden I won't see enough of larger DSO to make a 32mm worthwhile.

Link to comment
Share on other sites

Well I am still agonizing :-), its easier for you guys as xou have home delivery...

I was recommended pretty much everything, which would reflect that anything goes in a slow scope...

Is hyperion zoom a good option, or is it too heavy for the diagonal and the altaz goto mount?

Also, how good are all those SPLs with long relief...TAustria sells some by Lacerta, has anyone tried them? Can't find anything on the board re that particular clone...

Link to comment
Share on other sites

  • 6 months later...

Just to revisit this old one and thank everyone for their suggestions. I settled for combination of Hyperion III Zoom 8-24, and, to compliment small FOV on its upper end, I also bought a heavily discounted ES 24mm 68deg.
This pretty much covers all my needs at the moment...except for making me wonder if I should also have a 32mm plossl just to have M42 and the likes a bit brigher for the use with the filter...

Link to comment
Share on other sites

Mine is similar - 1500mm focal length Celestron Nexstar 127 Mak.

I have:

Celestron Omni Plossl 40mm and Revelation Plossl 32mm - both give similar performances,

Cel. XCel LX 18 and 12mm,

S/W UWA Planetary 9, 7, and 6mm.

These give x38, 47, 83, 125, 167, 214, 250 - a good, well-spaced spread.

Doug.

 

Link to comment
Share on other sites

11 hours ago, cloudsweeper said:

Mine is similar - 1500mm focal length Celestron Nexstar 127 Mak.

I have:

Celestron Omni Plossl 40mm and Revelation Plossl 32mm - both give similar performances,

Cel. XCel LX 18 and 12mm,

S/W UWA Planetary 9, 7, and 6mm.

These give x38, 47, 83, 125, 167, 214, 250 - a good, well-spaced spread.

Doug.

 

doesn't 40 mm in our rigs have the same true fov as the 32mm, thus producing simply lower power for the same true fov? doesn't 127 max out at 32mm plossl?

Link to comment
Share on other sites

Yes.  The 40mm gives a slightly smaller mag and a very slightly larger TFOV.  I just wanted to experiment with differences in brightness and contrast.  

So far, I've found that with the 40mm, the Moon looks a bit smaller of course, with a slightly wider view, framing it nicely.  I have not felt the view claustrophobic, or that there is too much barrel in view.  As for stars, I haven't noticed anything by way of differences in brightness or contrast, although the sky was not very dark at the time.  The experiment continues!

On balance, there is, I suppose, little point in having both EPs, although I do like the 40mm Omni, and now use it as my main "finder".

I'm thinking getting a 24mm wide angle (68 degrees) EP.  This would give a higher mag, but about the same TFOV as the 32mm.  The higher mag has the advantage of dimming the background somewhat, thus increasing contrast and compensating for light pollution.  The 24mm is, I think, the highest focal length you can get in a wide angle in a 1.25" focuser.

Finally, I did try a wide angle dual-fit EP, but the thing was huge and I couldn't take to it, so it went back!  

Doug.

 

 

Link to comment
Share on other sites

4 hours ago, cloudsweeper said:

Yes.  The 40mm gives a slightly smaller mag and a very slightly larger TFOV.  I just wanted to experiment with differences in brightness and contrast.  

So far, I've found that with the 40mm, the Moon looks a bit smaller of course, with a slightly wider view, framing it nicely.  I have not felt the view claustrophobic, or that there is too much barrel in view.  As for stars, I haven't noticed anything by way of differences in brightness or contrast, although the sky was not very dark at the time.  The experiment continues!

On balance, there is, I suppose, little point in having both EPs, although I do like the 40mm Omni, and now use it as my main "finder".

I'm thinking getting a 24mm wide angle (68 degrees) EP.  This would give a higher mag, but about the same TFOV as the 32mm.  The higher mag has the advantage of dimming the background somewhat, thus increasing contrast and compensating for light pollution.  The 24mm is, I think, the highest focal length you can get in a wide angle in a 1.25" focuser.

Finally, I did try a wide angle dual-fit EP, but the thing was huge and I couldn't take to it, so it went back!  

Doug.

 

 

Thanx, Doug. I really love my ES24mm, and having a higher mag improves contrast. Stock 25mm was bearable, but this is much better and has 10 degs more, handy for finding. I gave up on 32mm plossl because I was told that the ER on it is ginormous, and I wear only reading glasses. The only thing left that intrigues me is whether it might be better for use w/filter than 24mmES because it works with less magnification and therefore more light. But I guess it does not make much difference for anything but the biggest DSOs out there.

One day when I can afford a Dob and sneak it past the missus to compliment my Mak this willl be a moot point.

Link to comment
Share on other sites

I thought of a Dob, but am not sure about the bulk, so am considering a Celestron 8SE.  Angles not as wide, but a good aperture for DSOs.  I haven't found the Neodymnium filter makes much difference with faint objects, but again, it's been too cloudy to do a decent check.  The point about lower mag being brighter against higher mag giving more contrast is valid - something that needs checking out in practice!

 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.