DeLite 1st Light Review

[Profiler (Profiler)]

Originally Posted by N1

Bill, while I quite like your review and would consider it valuable to anyone considering these EPs, I respectfully disagree with your chair/stool analogy. I can't see how ER and AFOV could possibly be of the same importance as optical performance. Rather, I'd class the latter as the legs and seat of the chair, with eye relief and apparent field of view corresponding to things like armrests, padding, heating coils in the seat, social media connectivity of the seat and so on - you get the idea. Omit optical performance and the whole thing is all but useless. The same is not true for the other two things.

Not that I want to get into any debates but I tend to agree with this metaphor as a better depiction of the differing variables relevance. Additionally, factors such as AFOV and ER are not purely related to eyepieces. Barlows improve ER on some EPS and fov is also dependent on the fl of your instrument. The Takahashi FS-60 and Televue-TV60 give fantastic widefield views with simple plossls due to their short focal lengths

[N1 (Mirko)]

Originally Posted by Profiler

Not that I want to get into any debates but I tend to agree with this metaphor as a better depiction of the differing variables relevance. Additionally, factors such as AFOV and ER are not purely related to eyepieces. Barlows improve ER on some EPS and fov is also dependent on the fl of your instrument. The Takahashi FS-60 and Televue-TV60 give fantastic widefield views with simple plossls due to their short focal lengths

Yes, but how do you metaphorise the fact that a decent ortho will be just as good or better than most Televue eyepieces, at about a third of the cost?

Note also that I was referring to AFOV, not TFOV.

[ausastronomer (John Bambury)]

Originally Posted by N1

Bill, while I quite like your review and would consider it valuable to anyone considering these EPs, I respectfully disagree with your chair/stool analogy. I can't see how ER and AFOV could possibly be of the same importance as optical performance. Rather, I'd class the latter as the legs and seat of the chair, with eye relief and apparent field of view corresponding to things like armrests, padding, heating coils in the seat, social media connectivity of the seat and so on - you get the idea. Omit optical performance - the legs and the seat - and the whole thing is all but useless. The same is not true for the other two things.

Hi Mirko,

This is the exact point that Bill is making, that the whole thing is highly subjective and entirely dependant on end user preferences. To some, AFOV is the most important. To others on axis performance and form factor is paramount. To others it is comfort and AFOV, to others its off axis performance. There's no right answer. To me its an eyepiece that offers the best balance of most of those things. From someone that owns TV Ethos, TV Delos, TV Nagler T4, TV Radian, TV Panoptic, Pentax XW, Pentax XF, Pentax XO and UO HD orthos, the PENTAX XW's come closest to satisfying me as a closest to "keep me happy" eyepiece. Others will choose other eyepieces because some criteria which are important to me are less important to them and vice versa.

Cheers
John B

[N1 (Mirko)]

Originally Posted by ausastronomer

Hi Mirko,

This is the exact point that Bill is making, that the whole thing is highly subjective and entirely dependant on end user preferences. To some, AFOV is the most important. To others on axis performance and form factor is paramount. To others it is comfort and AFOV, to others its off axis performance. There's no right answer. To me its an eyepiece that offers the best balance of most of those things. From someone that owns TV Ethos, TV Delos, TV Nagler T4, TV Radian, TV Panoptic, Pentax XW, Pentax XF, Pentax XO and UO HD orthos, the PENTAX XW's come closest to satisfying me as a closest to "keep me happy" eyepiece. Others will choose other eyepieces because some criteria which are important to me are less important to them and vice versa.

Cheers
John B

John, I totally agree that it's subjective and different people prefer different things. However, how would you answer this: Which of the following: - 1. eye relief, 2. AFOV, 3. optical performance - shows the least variance between all those eyepieces you own? Or in other words, what do they all tend to have in common. What I'm saying is that the three variables above are not equal. So much so that one of them might be regarded as a must-have (within reason), unlike the other two.

+1 on the XOs!
And yes, I do like wide fields too.

[WilliamPaolini]

Originally Posted by N1

Bill, while I quite like your review and would consider it valuable to anyone considering these EPs, I respectfully disagree with your chair/stool analogy. I can't see how ER and AFOV could possibly be of the same importance as optical performance.

Hi Mirko,

I see it in action all the time with my observing as well as with others. With all the eyepieces I have used and own, which has been hundreds, bar none the absolute best for the best (contrast, crispness, details) lunar performance has been the TMB Supermonocentric. Not much comes close at all as the views are stunningly detailed. However, 9 times out of 10 I will not use my Supermonocentrics for lunar observing even though it without a doubt for me puts up the most optically precise and detailed view in my preferred telescopes. Why? Because for lunar observing I am willing to forgo a best optical performance in trade for a little more ER and a lot more AFOV.

Actually, I can also say based on my experiences that nothing beats the Supermono or the Zeiss Abbes on pulling in the most stars the most authoritatively in a Glob Core. Yet again, I prefer to trade that for more AFOV.

Now on a planet I will trade AFOV and ER for the best view I can muster.

So my weighting of ER, AFOV, and Optical Precision very much varies based on the target or task at hand, and sometime on the scope as well. I think it is probably this way for a great many observers.

-Bill

[Don Pensack]

Originally Posted by Wavytone

Sorry I laughed out loud when I saw the image of shingles and Paolini claimed distortion was "minimal". The amount of pincushion distortion was shocking for a 62 degree eyepiece, and frankly the rest of Paoloni's review is superficial unquantified rubbish, ie worthless.


At least a side by side comparison with established premium eyepieces should have been provided that looks into th following with actual measurements from an optical bench:

A) sharpness off axis as a result of field curvature, spherical, coma and astigmatism, given the field curvature and distortion of the test telescope which also matters; Paolini didn't bother to mention the scope used;

B) lateral chromatic error near the edge of the field of view,

C) spherical aberration at the exit pupil, aka the "jellybean" or blackout problem affected certain eyepieces, notably Naglers;

D) eye relief as measured on an optical bench; Paolini clearly just takes the Televue data without any attempt to verify it by direct measurements.


Anyone with XW's, LVW's or nikons should keep them. No reason to switch.

I don't believe either TeleVue or BillP claimed these eyepieces were orthoscopic, just sharp.
At 62 degrees of field, there will either be rectilinear distortion (RD) or Angular magnification distortion (AMD) at field edge, or both. TeleVue produces eyepieces with as little AMD as possible, which guarantees there would be RD at the edge of the field.
Perhaps that makes these less than ideal for purely daylight use, but it has very little bearing on how they perform at night.
Had they solved for RD instead of AMD, they wouldn't have been as good at night.
"Ya pays yer money, and ya makes yer choice" when it comes to distortion.
If what you want is an eyepiece as close to distortion free as possible, don't go much over a 40 degree apparent field.

[Steffen]

Originally Posted by Don Pensack

If what you want is an eyepiece as close to distortion free as possible, don't go much over a 40 degree apparent field.

That's the crucial point. Eyepieces used to be great and affordable until the super-panavision craze befell the market. This was likely driven by marketing (if you want to keep charging more and more you have to offer something extra) as well as a shift from observing to sightseeing (IMHO).

For my type of observing there is nothing wrong with a 40-50 degree apparent field. I'd be loathe to go beyond 70, because I'd either be wasting a lot of money or I'd be compromising on quality in order to gain something I don't need.

I would rather (in fact, I do) spend the extra money for the ability to zoom.

EDIT In that regard I see the DeLites as a step in the right direction.

[Don Pensack]

And you would be the customer at whom they are aimed.
It's ironic. I bought some Clave Plossls in the late '70s, which, taking only inflation into account, translate into the prices of the DeLites today.
And who would pay that price for a Plossl today?
We are spoiled, you and I, by having such good eyepieces available today.
You prefer the narrower fields and I the widest possible, and we can both get what we want. That wasn't true back then. We are so lucky.

[Steffen]

Originally Posted by Don Pensack

We are so lucky.

We are indeed. I suppose a little less angst and a lot more appreciation would do us all well