Still looking for a replacement for my 16mm, 68 deg MaxVision ep…

[kev100]

Hiya,

I’ve posted before on this issue. The 16mm MV is probably my most used ep - the mag is good, it’s a reasonably flat view, but I find the 68 deg field of view and the eye relief a bit tight. Ideally, I’d be looking for a 16mm 82 degree ep, suitable for an f4.7 scope (funds prevent TVs and the like, such as the 16mm Nagler). I was looking at the 14mm Explore Scientific 82 deg, but I feel that the increased mag offsets the wider fov. The only advantages that I see are increased eye relief and a smaller exit pupil, so better contrast. Just wondered if anyone has any thoughts?

Cheers,

Kev

 

 

Edited April 15, 2022 by kev100
typo

[Zermelo]

Did you consider this one already?

https://www.firstlightoptics.com/ovl-eyepieces/ovl-nirvana-es-uwa-82-ultrawide-eyepieces.html

[kev100]

6 minutes ago, Zermelo said:

Did you consider this one already?

https://www.firstlightoptics.com/ovl-eyepieces/ovl-nirvana-es-uwa-82-ultrawide-eyepieces.html

I had considered the 16mm nirvana, but the reviews I've seen weren't great with faster scopes ...

[Ricochet]

I've got the same focal length scope and I go from a 21 Ethos to a 14XW. I can't think of any object where I think that I could do with something with a TFoV between the two. 20 to 14mm is also the ideal step in terms of exit pupil. However, if you can afford the 14mm ES82 then you can afford the Baader Morpheus and based on everything that I've read about them, that is the one I would go for. However, the 14mm Morpheus only makes sense if that is going to be the only Morpheus that you're going to buy, so say you end up with an eyepiece set of 20 Myriad, 14 Morpheus, 10mm and shorter XWs. If you're going to end up with multiple Morpheuses then you want to skip the 14, so I would go for the 12.5mm. The exit pupil is right where you want it for extended DSOs both unfiltered and with a UHC filter if the transmission of the Morpheus is as good as their reputation suggests. You could then see if you still find yourself using the 16mm ES68 or if you just skip right over it because at the moment I think your problem is the gap between the 16 and 8.8mm.

[kev100]

1 hour ago, Ricochet said:

I've got the same focal length scope and I go from a 21 Ethos to a 14XW. I can't think of any object where I think that I could do with something with a TFoV between the two. 20 to 14mm is also the ideal step in terms of exit pupil. However, if you can afford the 14mm ES82 then you can afford the Baader Morpheus and based on everything that I've read about them, that is the one I would go for. However, the 14mm Morpheus only makes sense if that is going to be the only Morpheus that you're going to buy, so say you end up with an eyepiece set of 20 Myriad, 14 Morpheus, 10mm and shorter XWs. If you're going to end up with multiple Morpheuses then you want to skip the 14, so I would go for the 12.5mm. The exit pupil is right where you want it for extended DSOs both unfiltered and with a UHC filter if the transmission of the Morpheus is as good as their reputation suggests. You could then see if you still find yourself using the 16mm ES68 or if you just skip right over it because at the moment I think your problem is the gap between the 16 and 8.8mm.

That’s very interesting, that you see the gap as being between 16 and 8.8, when I’m seeing the need for a wider field of view between the 20 and the 8.8 … a 16 being the mid point for me. Already a fan of the ES 82 range, and at nearly 50 quid cheaper than the Morpheus, the 14mm ES would be my preference, I just wish there was a 16mm 82 degree version. Given that there isn’t, the question comes down to whether the better eye relief and smaller exit pupil are enough to justify replacing the 16 MV …

[Ricochet]

14 minutes ago, kev100 said:

That’s very interesting, that you see the gap as being between 16 and 8.8, when I’m seeing the need for a wider field of view between the 20 and the 8.8 … a 16 being the mid point for me

1.4X rule, equating to a doubling or halving of exit pupil (~brightness of extended objects/background sky) with each step. In my opinion exit pupil is the most important factor in choosing eyepiece steps until you start hitting atmospheric limits.

16 minutes ago, kev100 said:

at nearly 50 quid cheaper than the Morpheus, the 14mm ES would be my preference

FLO have the 14mm ES82 at £174 (out of stock for 90 days) and the Morpheus at £188 (in stock). Morpheus were over £200 but appear to have come back down again.

[PeterC65]

I have the ES82 14mm and I like it. It is my second most used eyepiece after the ES68 24mm and offers a distinctly different field of view. At the higher magnification end I've had the ES82 6.7mm and ES82 4.7mm for a while and recently added the ES82 8.8mm to fill the gap (I managed to convince myself that there was a gap to be filled!). If I was buying again I would probably choose the ES68 16mm instead of the ES82 14mm because I think the 16mm would be a better fit, magnification wise, between the 24mm and the 8.8mm and because, while I like the 82 degree apparent field of view, I can only really take in 68 degrees without rolling my eye around.

I don't have any Morpheus eyepieces but do have the Baader Hyperion Zoom. I find this gets less and less use these days because I prefer the ES eyepieces. I also find it a bit clunky because of the way it comes apart. The ES eyepieces or the other hand are as solid as a brick and feel bomb proof.

 

[kev100]

Hi all, and thanks for the thoughts. Although still unsure about the 14mm ES, I think I might go for it anyway, keeping the 16mm MV in reserve just in case. I just saw a 16mm Nagler on ABS, but as the only reason that I'm in the market for an EP at the moment is the fact that I have a voucher with a particular retailer, this rules out spending elsewhere. The 14mm's better ER (stated to be 20mm) and smaller exit pupil should give better views than the 16, albeit will little or no change to the fov, which is what I really wanted ...

Really want to like the Nirvana 16, but just can't ...  

[Don Pensack]

7 hours ago, kev100 said:

I had considered the 16mm nirvana, but the reviews I've seen weren't great with faster scopes ...

Neither is the 14mm Explore Scientific.

[kev100]

7 minutes ago, Don Pensack said:

Neither is the 14mm Explore Scientific.

Interesting ... This is what I've read ...

https://stargazerslounge.com/topic/183154-explore-scientifc-82-degree-eyepiece-range-first-light-report/#comment-1900802

[Don Pensack]

8 hours ago, kev100 said:

Hiya,

I’ve posted before on this issue. The 16mm MV is probably my most used ep - the mag is good, it’s a reasonably flat view, but I find the 68 deg field of view and the eye relief a bit tight. Ideally, I’d be looking for a 16mm 82 degree ep, suitable for an f4.7 scope (funds prevent TVs and the like, such as the 16mm Nagler). I was looking at the 14mm Explore Scientific 82 deg, but I feel that the increased mag offsets the wider fov. The only advantages that I see are increased eye relief and a smaller exit pupil, so better contrast. Just wondered if anyone has any thoughts?

Cheers,

Kev

 

 

The magnification half way between a 20mm and a 8.8mm is a 12.2mm eyepiece.

The 12.5mm Morpheus is very close (it measures at 78°)

And the APM Hi-FW 12.5mm is 84°, another possibility.

 

Now, if you want 2 eyepieces, equally-spaced, in between the 20mm and 8.8mm, they should be 14mm and 10.2mm to keep magnification gaps equal.

 

[Don Pensack]

12 minutes ago, kev100 said:

Interesting ... This is what I've read ...

https://stargazerslounge.com/topic/183154-explore-scientifc-82-degree-eyepiece-range-first-light-report/#comment-1900802

I've used the eyepiece in an f/5 dob with coma correction, and I can see astigmatism in the outer roughly 10° of field.

Your scope is f/5 I believe, so you'd see the astigmatism added to coma if you're not using a coma corrector.

Coma is more visible the wider the apparent field, so an 82° replacement for your 16x68 (the best in that series, though a small eye relief, as you mention) would show more coma.

Center sharpness and contrast is good in the 14x82, but your 16mm is sharper farther out in its field than the 14x82.

If you truly want sharpness to the edge and contrast equivalent to your 16mm, the Morpheus and APM I mentioned above would work.

As would the APM XWA 13mm, or the StellaLyra 14mm 80° (good buy!), or TeleVue Nagler 13mm T6, just to name a few.

Edited April 15, 2022 by Don Pensack

[kev100]

Thank you 👍 I'll take a proper look at the EPs you mentioned. I'm not after perfection in the field of view, and can put up with the coma/astigmatism. I do though like a bit of context to the object being viewed, that comes with the wider fov...

Kev

[cajen2]

If it's any help, I've just bought a Morpheus 12.5mm and very slightly prefer it to my 14mm Pentax XW. It gives a FOV which I find perfect for my tastes: wide enough to be involving and as you say, to give context but not so wide that you are forced to peer into 'corners'.