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C8 EdgeHD eyepiece change up

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#1 mikee

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Posted 22 January 2020 - 09:16 AM

Hi all - 

Last summer I bought a 31mm Nagler for use in my NP101 which is simply sublime in the summer sky.    I also have an EdgeHD C8 and bought a Baader 2" diagonal that attaches directly to the back of the scope and two nights ago I popped my 31mm Nagler in the scope for the first time and pointed it at M42 and was blown away with the amount of detail as well as the nice apparent FOV.     I must have spent an 45 minutes just on M42 and this from a pretty light polluted back yard.

 

After that I popped in my Delos 17.3 and my Delos 14 to compare and while the views were sharp and pleasing the weight difference caused me to have to fiddle for a while with the balance of the mount.  I started wondering if maybe I'd be better of selling them and getting either a 13 or 17mm Ethos in place?  I have a 24mm Pan that I love but again the balance between these is significant (maybe the TV Brass EP holder would help?).      

 

I also think the Ethos would be great in my NP101 too but if go that route I am not sure which one is better.   Light pollution/seeing in the northeast is troublesome at best although I summer up in Maine and my skies are very dark (but seeing can still be troublesome as it's on the coast).    I also have an 8mm Delos that I use for planets/moon in the NP101 but it's usually a bit much in the C8.    

 

So wondering now if  a 17 vs 13 ethos for my scopes is worth the change or should I just stick with the Delos?      I do find that the for my viewing habits the 17.3 Delos and 14mm Delos are two close to be useful regularly so I had been planning on selling one of them (probably the 17.3).   I think the 13mm Ethos would be fantastic in the NP101 but I wonder if it would be too much power for regular use in the C8.  Also it's a big jump from 31mm to 13mm and my lowly 24Pan weight issue comes into play..

 

Thanks!


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#2 Janco

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Posted 22 January 2020 - 09:28 AM

The 13mm Ethos will make your 14mm delos redundant and probably also the 17mm, but to a lesser extent.

Balancing is really not that important when it comes to visual work to be perfectly honest with you it shouldn't be a reason for spending so much more money on eyepieces which will honestly be equal in optical quality.

If you like the larger FOV I would get rid of both Delos eyepieces and get the Ethos. Optically though they are all on par.

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#3 gfstallin

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Posted 22 January 2020 - 06:44 PM

This is a great question. I usually balance for one eyepiece and that's it. My heaviest eyepiece is a Delos 17.3 (my 36mm Hyperion actually weighs less). Most mounts are fine with a 1 lbs. or so of imbalance, perhaps a little more. I've never noticed a problem, but I've also never used a 2 lbs. eyepiece on my SCTs. My hunch is that balance for eyepieces on a SCT on an equatorial mount probably isn't that important for visual, but something more definitive than a hunch based on 1 part hope, 1 part "that's the way I've always done it," and 2 parts guesswork would be appreciated. 

 

Even if it turns out the imbalance is harmful to your mount (which mount is it?), there are less drastic measures than eliminating excellent eyepieces. Sure, you are replacing them with other excellent eyepieces, but that is not the point. The TV brass equalizer you mention is certainly one elegant option worth exploring (balance with Nagler, add equalizer when using Delos and other 1.25" eyepieces). ADM makes a small counterweight for dovetails that might work, but that seems like too much of a hassle for strictly visual.

 

George


Edited by gfstallin, 22 January 2020 - 06:45 PM.


#4 junomike

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Posted 22 January 2020 - 08:42 PM

I'm a fan for the Ethos however when I had the Delos and 31T5 I found using the TeleVue Equalizer with the Delos  was close enough (in weight) to the 31T5 kept the balance in check



#5 mikee

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Posted 23 January 2020 - 07:10 AM

Thanks everyone.  I just realized I didn’t clarify that this situation is for an Alt/Az mount I have.   I use an AVX as well but started testing out the C8 on my M2C mount and it’s surprisingly stable and vibration free with isolation pucks under the AVX tripod.  Anyway the balance is problematic when using heavy to not so heavy EP’s.   Part of it is When using the Nagler 31mm it means I have to clamp the vixen rail down near the back of the tube and sliding a C8 on the mount to adjust balance is awkward at best.  
 


Edited by mikee, 23 January 2020 - 07:10 AM.


#6 junomike

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Posted 23 January 2020 - 04:49 PM

Thanks everyone.  I just realized I didn’t clarify that this situation is for an Alt/Az mount I have.   I use an AVX as well but started testing out the C8 on my M2C mount and it’s surprisingly stable and vibration free with isolation pucks under the AVX tripod.  Anyway the balance is problematic when using heavy to not so heavy EP’s.   Part of it is When using the Nagler 31mm it means I have to clamp the vixen rail down near the back of the tube and sliding a C8 on the mount to adjust balance is awkward at best.  
 

This is exactly what the TV Equalizer is for (using with the lighter 1.25" eyepieces) and swapping to and from a 31T5



#7 MrRoberts

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Posted 24 January 2020 - 10:28 AM

Used the 31N with my now sold 15" dob. It was so immersive. My C-8/E with FR loves the 17E with my 2" Baader diagonal and the 13E with the Baader 1.25 prism diagonal.

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#8 Sarkikos

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Posted 27 January 2020 - 11:17 AM

Thanks everyone.  I just realized I didn’t clarify that this situation is for an Alt/Az mount I have.   I use an AVX as well but started testing out the C8 on my M2C mount and it’s surprisingly stable and vibration free with isolation pucks under the AVX tripod.  Anyway the balance is problematic when using heavy to not so heavy EP’s.   Part of it is When using the Nagler 31mm it means I have to clamp the vixen rail down near the back of the tube and sliding a C8 on the mount to adjust balance is awkward at best.  
 

The M2, the earlier version, has the same advantages and disadvantages as you mention.  But then most mounts (heads) shift when switching between eyepieces of substantially different weight, or just when removing a heavy eyepiece.  You can clamp down really hard on the altitude knob, but that can damage the mount over time.  And often that's not good enough to keep the load from shifting.  This is the fatal flaw of many, many mounts.

 

I have a DM6 on Avalon T-Pod 110.  I can set the DM6 to stay put when switching between eyepieces or removing/adding heavy eyepieces.  And the T-Pod 110 is a light but sturdy tripod.  But the combo is expensive.

 

Mike


Edited by Sarkikos, 27 January 2020 - 11:18 AM.


#9 Sarkikos

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Posted 27 January 2020 - 11:24 AM

The EdgeHD 8" has a flat, well-corrected field.  It really needs eyepieces with flat, well-corrected fields.  If the eyepiece has a very wide, flat, well-corrected field, that's even better:  Ethos.   

 

Mike


Edited by Sarkikos, 27 January 2020 - 11:26 AM.


#10 Astrojedi

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Posted 31 January 2020 - 01:40 PM

Thanks everyone.  I just realized I didn’t clarify that this situation is for an Alt/Az mount I have.   I use an AVX as well but started testing out the C8 on my M2C mount and it’s surprisingly stable and vibration free with isolation pucks under the AVX tripod.  Anyway the balance is problematic when using heavy to not so heavy EP’s.   Part of it is When using the Nagler 31mm it means I have to clamp the vixen rail down near the back of the tube and sliding a C8 on the mount to adjust balance is awkward at best.  
 

 

Getting new EPs will not help (unless you are looking for an excuse to get shiny new EPs) as the OTA will go swinging while you are trying to change EPs.

 

I use my EdgeHD 8 with my M2C mount with no issues when changing from light to heavy EPs or vice versa and no mount friction adjustment required while changing the EPs.

 

Setup is important to a pleasant experience. Here is what I do. You need to do this only once. Then just mark the balance point on the dovetail.

 

When I put it on the OTA on the mount I will balance the OTA with the heaviest EP with the OTA pointing at a 45 deg angle i.e. up at the sky. Then I will tighten the alt friction to where I can move the OTA smoothly and the OTA does not move when I take the EP out. Don't leave the axis too loose.

 

This will take some experimentation the first time but you figure this out it will be on autopilot.



#11 SeattleScott

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Posted 31 January 2020 - 01:59 PM

I just went the route of 42lvw so there are no balance issues relative to the 1.25” LVWs. But the TV equalizer is cheaper than a 42lvw, and it would be a little bit of a shame to not utilize the 31T5 (obviously you could still use it in the Apo).

Like the previous poster, I set the tension once and am basically done, although I might have to snug it up a little for targets low in the sky. That’s the advantage of not using 2.5lb eyepieces.

Scott


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