A low power eyepiece quality upgrade?

[N3ptune]

Hello Dave

I still have my LET 28mm Eyepiece,  but I am kind of sceptical about more surprises.. I know it has a lots of distortions with my current F5.. I could be good with another telescope maybe.. with this one, I am not sure.

[Dave In Vermont]

Admittedly I didn't try it in such a fast scope. So I'll add: "Your mileage may vary."

But I'm still saying they aren't half bad! I'm sure someone will find it a decent EP in their gear!

Enjoy & Thanks -

Dave

[DHEB]

3 hours ago, N3ptune said:

Hello Dave

I still have my LET 28mm Eyepiece,  but I am kind of sceptical about more surprises.. I know it has a lots of distortions with my current F5.. I could be good with another telescope maybe.. with this one, I am not sure.

I have that same eyepiece and the same telescope as you have. The eyepiece is far from perfect, but a large portion of the aberrations are due to coma, not the eyepiece. With a coma corrector that eyepiece becomes quite decent.

I believe an important aspect that has been discussed in this thread is that no matter which eyepiece you decide to settle with, for such a fast telescope you will need a coma corrector if you aim at a wide angle and aberration free field.

Good luck choosing!

[N3ptune]

7 hours ago, Cinco Sauces said:

I have that same eyepiece and the same telescope as you have. The eyepiece is far from perfect, but a large portion of the aberrations are due to coma, not the eyepiece. With a coma corrector that eyepiece becomes quite decent.

I believe an important aspect that has been discussed in this thread is that no matter which eyepiece you decide to settle with, for such a fast telescope you will need a coma corrector if you aim at a wide angle and aberration free field.

Good luck choosing!

It's a great telescope! ((; I am so glad I bought it even if people say the equatorial mount is confusing to use with odd eyepiece position, etc. For me it's a truly great instrument and not really expensive also to get a good RA tracking option, to sketch. 

@Cinco Sauces

I understand you use this coma corrector bellow with the LET 28mm eyepiece and you get good result out of it? If you could put a % on how much better you notice the LET is with this coma corrector, how much would it be?

http://www.telescope.com/Astrophotography/Astrophotography-Accessories/Baader-MPCC-Mark-III-Multi-Purpose-Coma-Corrector/c/4/sc/61/p/102815.uts

Is it possible to use a corrector like that with a 1.25" eyepiece also? it's not clear how to use it.

[John]

My advice would be to save your money by not buying a coma corrector and put it towards a well corrected wide field eyepiece such as an ES 68.

Your Q70 will be at least as well corrected as the 28mm LET is (the latter is a 3 element design based on the Kellner). The coma corrector will remove a good proportion of the coma but the astigmatism that these eyepieces produce will still be there.

 

 

[TheLookingGlass]

I agree with the above statement. Pass on the others and get a 34mm or 28mm ES 68, you'll be glad you did it. 

FYI, I am betting that those ES 62's are just re-hashed Meade 5000 Plossls. All of the focal lengths match. The Meade 5000 plossls were complete DUDS, especially in fast scopes.

[N3ptune]

@John

I am not forgetting about the Q70 has Astigmatism   all this discussion is to test different things. It's settled for the 62mm series, I am not getting that. But also i am unsatisfied with the dimensions of the 68d series, my 32mm is already putting much brightness. It's a psychological stop for me, to go beyond 32mm

But there is another contestant believe it or not:

This massive beast! The 82d series mastodon 30mm 1001g . But now, can my telescope support 82d AFOV without inducing too much aberration, or will it bend my focuser? I am scared of the 82d series.

 

 

[Mr Spock]

I used to have a 250mm Skywatcher and the best match for me was the 22mm Nagler. It got even better when I attached a Baader coma corrector to it - pin sharp right to the edge.

[N3ptune]

@Mr Spock

Ok.

I am sure the Naglers are at the top of the line, but I need to remain in a certain price range too. I can't buy an eyepiece and a coma corrector it's too much.  Mr Spock would agree with me I am sure.

He would say keep your Q70 and enjoy it. But I never know, if a 30mm 82d can be a good improvement by itself with no coma corrector over the Q70..

 

 

 

 

[DHEB]

6 hours ago, N3ptune said:

It's a great telescope! ((; I am so glad I bought it even if people say the equatorial mount is confusing to use with odd eyepiece position, etc. For me it's a truly great instrument and not really expensive also to get a good RA tracking option, to sketch. 

@Cinco Sauces

I understand you use this coma corrector bellow with the LET 28mm eyepiece and you get good result out of it? If you could put a % on how much better you notice the LET is with this coma corrector, how much would it be?

http://www.telescope.com/Astrophotography/Astrophotography-Accessories/Baader-MPCC-Mark-III-Multi-Purpose-Coma-Corrector/c/4/sc/61/p/102815.uts

Is it possible to use a corrector like that with a 1.25" eyepiece also? it's not clear how to use it.

My point was to illustrate the importance of a coma corrector. The eyepiece is indeed mediocre.

You will fare well by following the advice of investing at first in a good eyepiece and not in the CC. However, my impression is that once you go wide field you will notice the coma and will wish a CC.

Good luck !

[Moonshane]

What are your skies like? If you have any light pollution I'd stick to no more than approx 5mm exit pupil. My recommendation would be a 27mm Panoptic but used. It's superb.  At f5 I think you'd get away without a coma corrector but a cc would optimise the system.

 

 

[N3ptune]

5mm is good I agree, but I would not say better or a complete substitute to 6.4 because I already think my current 32mm eyepiece is a definite standard in my eyepiece box. There is no perfect match to get a perfect results (in theory) with ES and the prices are not exactly economic.

ES 28mm 68d 2" would be a good choice but it's too close to 25mm, I don't see the point. (ill be annoyed to swap between 2" and 1.25" too often to get almost the same result, one EP will be wasted)

ES 34mm 68d 2" will have more brightness then my current 32mm (which is not something I don't wish), and maybe a loss because of a small excess of exit pupil.

ES 32mm 62d 2" the optic might not cut it, and 62d is not really enough.

ES 30mm 82d 2" By itself, might not perform has well has 34mm 68d for correction, and it's huge, heavy and expensive.

Televues are too expensive.

All of the above would need Coma corrector to perform even better. But the price of the duo is killing my motivation. 

 

--> Maybe it's not my time to upgrade, I have to feel a perfect deal for me. Perhaps in the use market I could find something.

 

 

 

 

[TheLookingGlass]

55 minutes ago, N3ptune said:

5mm is good I agree, but I would not say better or a complete substitute to 6.4 because I already think my current 32mm eyepiece is a definite standard in my eyepiece box. There is no perfect match to get a perfect results (in theory) with ES and the prices are not exactly economic.

ES 28mm 68d 2" would be a good choice but it's too close to 25mm, I don't see the point. (ill be annoyed to swap between 2" and 1.25" too often to get almost the same result, one EP will be wasted)

ES 34mm 68d 2" will have more brightness then my current 32mm (which is not something I don't wish), and maybe a loss because of a small excess of exit pupil.

ES 32mm 62d 2" the optic might not cut it, and 62d is not really enough.

ES 30mm 82d 2" By itself, might not perform has well has 34mm 68d for correction, and it's huge, heavy and expensive.

Televues are too expensive.

All of the above would need Coma corrector to perform even better. But the price of the duo is killing my motivation. 

 

--> Maybe it's not my time to upgrade, I have to feel a perfect deal for me. Perhaps in the use market I could find something.

 

 

 

 

Your best bet is to get rid of the 25mm 1.25" EP and replace it with the 28mm ES 68, or get rid of the 25mm 1.25" EP for the 30mm ES 82. Correction without a coma corrector on the 30mm ES 82 is quite acceptable, and even with the 28mm ES 68.

It depends on how much "tolerance" you have for coma from the mirror. 

PS: You will always have a bigger field with 2 inch EP's over 1.25" eyepieces.

[N3ptune]

Note: Just to be clear, whatever I do, i need to go try to see by myself before I buy.

@TheLookingGlass

For exemple, if I get a 30mm ES82d there is no need to get rid of the 25mm really, 30mm at the limit, is an addition to my current collection.  I mean, a 30mm with 82 degrees AFOV 2" is something else then a 25mm with 60 AFOV 1.25"

If the correction might be good by itself, what about the weight stress on the focuser?

[TheLookingGlass]

[TheLookingGlass]

Well that's just great. I just typed a huge explanation about these eyepieces above and my comment went out the window, but the pictures remained.   Grrrrrr......LOL !

I've owned quite a few widefield EP's and I recommend 2" eyepieces over 1.25" EP's, unless you ONLY have a 1.25" focuser. Out of all of the ones I owned, my faves are the 28mm ES 68 and 34mm ES 68. The 28mm will be better in light polluted skies, as the views will be less washed out because of the smaller exit pupil. The 34mm was better in darker skies even though the exit pupil was rather large.

I actually prefer the 34mm ES 68 over the 35mm TV Panoptic, because the 35mm Pan has really weird eye placement in a large, short FL reflector. It works a lot better in a long focus refractor. I also prefer the 28mm ES 68 over the 27mm Pan in my 10" reflector, and you will save heaps if you grab a 28mm ES 68 over the 27mm Pan.

I also owned the 30mm ES 82, and I sold it because the top lens is recessed so far in that I can't sketch and use my reading glasses with it. Correction without a coma corrector in the 30mm ES 82 is acceptable to my eyes. Same goes for the 28mm ES 68. The 30mm ES 82 has better correction than the 28mm or 34mm ES 68's, but the ES 68's have excellent eye relief if you need to wear specs. The 30mm ES 82 is also a very heavy EP as well.

The 34mm Meade 5000 SWA has the exact same types of glass used in the ES 68's. Scott Roberts from ES used to work for Meade, and he was responsible for copying the older Meade 5000 designs over to the ES eyepieces. So, you won't see any difference from the Meade 5000 SWA's to the ES 68's, or much of a difference from the Meade 5000 UWA's to the ES 82's either, except for outer design.

I owned a 2 " GSO coma corrector at one time and it does make the views a lot better IMO, but once you add a barlow into the mix, you have this LONG cantilever hanging off your scope, which put me off always having it in there, plus, I like to use 2 inch extension tubes with 2 " filters on them because I detest screwing filters to my eyepieces in the dark and in the cold and I have to REMOVE the coma corrector in order to reach focus using the ext tube / filter combo.

Here's some widefields I have owned and tried, (with pics above... and some I did not include in pics), with a rating from 1-10: (Most are 2 " and some are 1.25").

40mm ES 68 - 8/10

38mm Orion Q70 - 5/10

35mm Panoptic - 7/10

34mm ES 68 - 9/10

32mm Orion Q70 - 5/10

31mm Nagler - 10/10

30mm ES 82 - 8/10

27mm Panoptic - 7/10

26mm Orion Q70 - 5/10

24mm ES 68 - 7/10

22mm Vixen / Orion LVW - 10/10

21mm Pentax XL - 8/10

20mm Pentax XW - 8/10

 

 

[TheLookingGlass]

5 hours ago, N3ptune said:

Note: Just to be clear, whatever I do, i need to go try to see by myself before I buy.

@TheLookingGlass

For exemple, if I get a 30mm ES82d there is no need to get rid of the 25mm really, 30mm at the limit, is an addition to my current collection.  I mean, a 30mm with 82 degrees AFOV 2" is something else then a 25mm with 60 AFOV 1.25"

If the correction might be good by itself, what about the weight stress on the focuser?

Well, the only thing about that is that there isn't enough of a magnification jump to keep both IMO, but if you want to keep both, that's entirely up to you.

 

 

[N3ptune]

10 hours ago, TheLookingGlass said:

Well that's just great. I just typed a huge explanation about these eyepieces above and my comment went out the window, but the pictures remained.   Grrrrrr......LOL !

I've owned quite a few widefield EP's and I recommend 2" eyepieces over 1.25" EP's, unless you ONLY have a 1.25" focuser. Out of all of the ones I owned, my faves are the 28mm ES 68 and 34mm ES 68. The 28mm will be better in light polluted skies, as the views will be less washed out because of the smaller exit pupil. The 34mm was better in darker skies even though the exit pupil was rather large.

I actually prefer the 34mm ES 68 over the 35mm TV Panoptic, because the 35mm Pan has really weird eye placement in a large, short FL reflector. It works a lot better in a long focus refractor. I also prefer the 28mm ES 68 over the 27mm Pan in my 10" reflector, and you will save heaps if you grab a 28mm ES 68 over the 27mm Pan.

I also owned the 30mm ES 82, and I sold it because the top lens is recessed so far in that I can't sketch and use my reading glasses with it. Correction without a coma corrector in the 30mm ES 82 is acceptable to my eyes. Same goes for the 28mm ES 68. The 30mm ES 82 has better correction than the 28mm or 34mm ES 68's, but the ES 68's have excellent eye relief if you need to wear specs. The 30mm ES 82 is also a very heavy EP as well.

The 34mm Meade 5000 SWA has the exact same types of glass used in the ES 68's. Scott Roberts from ES used to work for Meade, and he was responsible for copying the older Meade 5000 designs over to the ES eyepieces. So, you won't see any difference from the Meade 5000 SWA's to the ES 68's, or much of a difference from the Meade 5000 UWA's to the ES 82's either, except for outer design.

I owned a 2 " GSO coma corrector at one time and it does make the views a lot better IMO, but once you add a barlow into the mix, you have this LONG cantilever hanging off your scope, which put me off always having it in there, plus, I like to use 2 inch extension tubes with 2 " filters on them because I detest screwing filters to my eyepieces in the dark and in the cold and I have to REMOVE the coma corrector in order to reach focus using the ext tube / filter combo.

Here's some widefields I have owned and tried, (with pics above... and some I did not include in pics), with a rating from 1-10: (Most are 2 " and some are 1.25").

40mm ES 68 - 8/10

38mm Orion Q70 - 5/10

35mm Panoptic - 7/10

34mm ES 68 - 9/10

32mm Orion Q70 - 5/10

31mm Nagler - 10/10

30mm ES 82 - 8/10

27mm Panoptic - 7/10

26mm Orion Q70 - 5/10

24mm ES 68 - 7/10

22mm Vixen / Orion LVW - 10/10

21mm Pentax XL - 8/10

20mm Pentax XW - 8/10

 

 

Thanks for all this relevant information, really interesting.(the things in red). Your ratings of the Orion Q70 are far bellow the ES. did you tried the Q70 with a Coma corrector to rate it at 5/10? 34mm ES 68 seems to be champion.

--> Right now between 25mm and 32mm, I like the difference of magnification, I think it's a good gap.  My goal is not to replace my good Xcel-LX 25mm, it's to replace the Q70. If I can't replace the Q70 that's it, nothing is happening.  

My level of motivation is low. but it's interesting, I am learning things.

 

[N3ptune]

I have reach a verdict, this discussion was instructing for me, lots of informations and various advices. But, I am pretty sure it's not worth it to spend money upgrading.

I officially let this project go..

Thanks for your patience also and good advices.

[TheLookingGlass]

2 hours ago, N3ptune said:

Thanks for all this relevant information, really interesting.(the things in red). Your ratings of the Orion Q70 are far bellow the ES. did you tried the Q70 with a Coma corrector to rate it at 5/10? 34mm ES 68 seems to be champion.

--> Right now between 25mm and 32mm, I like the difference of magnification, I think it's a good gap.  My goal is not to replace my good Xcel-LX 25mm, it's to replace the Q70. If I can't replace the Q70 that's it, nothing is happening.  

My level of motivation is low. but it's interesting, I am learning things.

 

The Q70 won't be any better in a coma corrector, Lots of astigmatism in that EP.

[TheLookingGlass]

37 minutes ago, N3ptune said:

I have reach a verdict, this discussion was instructing for me, lots of informations and various advices. But, I am pretty sure it's not worth it to spend money upgrading.

I officially let this project go..

Thanks for your patience also and good advices.

Oh it is worth it upgrading......I used to use the Q70's as well, but after upgrading to the ES 68's I wouldn't go back to the Q70's.....ever again. HUGE difference.

[N3ptune]

it's a great power to be able to settle for less too. In fact, I could spend the rest of my life looking at the sky with my Q70 and see many many interesting things, even if it's not the top quality.  I have to refocus on astronomy before shopping, now there are clouds in the sky since I don't even remember when... it's affecting my lucidity and my common sense.

This is 20 minutes ago, I was waiting for improvement but the contrary happened, it got worse.

http://imgur.com/QgaQWo0

[N3ptune]

@TheLookingGlass

This is really funny, I stumbled upon that bellow: lol 

 

[John]

The trouble is that it's a slippery slope when you get a really nice eyepiece amongst more regular (but still competant) ones. You find you keep going back to the really nice one and the others just don't seem quite as satisfying any more

Either that or the experience confirms that your current ones are rather nice after all !

Thats the great thing about having an active used equipment market. You can buy, try and then, if it does not "float your boat" sell on at either no, or very little loss. Virtually all my eyepieces have been secured through this approach.

 

 

[TheLookingGlass]

10 hours ago, N3ptune said:

it's a great power to be able to settle for less too. In fact, I could spend the rest of my life looking at the sky with my Q70 and see many many interesting things, even if it's not the top quality.  I have to refocus on astronomy before shopping, now there are clouds in the sky since I don't even remember when... it's affecting my lucidity and my common sense.

This is 20 minutes ago, I was waiting for improvement but the contrary happened, it got worse.

http://imgur.com/QgaQWo0

No worries. You asked, and I gave you my opinion from an observers perspective of 30+ years.

Cheers.