1487 replies to this topic

[Tom S.]

There is a separate endless thread about the Takahashi TPL eyepieces…

 

New Takahashi eyepieces announced!

 

…started on 7/14/23, reaching 1275 posts over 51 pages by 9/25/23.

 

It contains all kinds of interesting commentary, and a few widely scattered user reports.

 

In post #1275, user “25585” wrote “How about a new thread since the eps are actually being used now?”

 

Not a bad idea. 

 

To start such a thread, I combed through the above-mentioned topic for actual user reports of TPL eyepieces.

Here they are, to date.  (Sorry if I missed any.  Please add their link to this thread).

 

If you go out and actually use a TPL, please add to this thread.

 

 

https://www.cloudyni...ced/?p=12858380

 

https://www.cloudyni...ced/?p=12879085

 

https://www.cloudyni...ced/?p=12886662

 

https://www.cloudyni...ced/?p=12886701

 

https://www.cloudyni...ced/?p=12910340

 

https://www.cloudyni...ced/?p=12931944

 

https://www.cloudyni...ced/?p=12941966

 

https://www.cloudyni...ced/?p=12963833

Edited by Tom S., 25 September 2023 - 01:43 PM.

[CrazyPanda]

I'll add another observation.

 

Tonight I had good seeing conditions but decided to just stick with the ETX 90 for my observations. The ETX 90 doesn't have the greatest of optics. Relatively strong SA and zonal issues are present.

 

However, the seeing was steady enough that Jupiter's moons presented as clean diffraction patterns in the 12.5 TPL and 13 DeLite.

 

What I found interesting was the 12.5 TPL presented those diffraction patterns a smidge more cleanly than the 13 DeLite. The space between the spurious disk and the first diffraction ring was more pronounced. The first diffraction ring was also a bit brighter and easier to see in the TPL. The spurious disk itself was a wee bit sharper.

 

In general I felt the TPL seemed to show a bit of a brighter view than the 13 DeLite.

 

It would seem when you're really aperture starved, and at the actual diffraction limit for the optics and conditions, the TPL has a bit of an advantage. These differences were exceptionally subtle, but I was able to repeat this observation several times over the course of 90 minutes or so.

 

In my previous tests in my big dob, I was obviously not at the diffraction limit since I was resolving more air turbulence than the diffraction limit of the scope, and the view in general was bright enough that it's not so easy to spot differences in brightness between the eyepieces. Stop the aperture way down though, and it's a different story.

 

I think I have to repeat my planetary observations with some off-axis aperture masks on the dob. Optical quality is considerably better than the ETX, and the longer focal length will give me more magnification. 130mm off-axis mask for F/13.2 would be a pretty good objective to compare the TPL to the DeLite more closely.

Edited by CrazyPanda, 26 September 2023 - 01:23 AM.

[Paul Morow]

However, the seeing was steady enough that Jupiter's moons presented as clean diffraction patterns in the 12.5 TPL and 13 DeLite.

 

What I found interesting was the 12.5 TPL presented those diffraction patterns a smidge more cleanly than the 13 DeLite. The space between the spurious disk and the first diffraction ring was more pronounced. The first diffraction ring was also a bit brighter and easier to see in the TPL. The spurious disk itself was a wee bit sharper.

 

In general I felt the TPL seemed to show a bit of a brighter view than the 13 DeLite.

 

Obviously the DeLites and TAOs are wicked sharp eyepieces, but the new TPLs are wicked sharper!

 

I have seen this in my TEC140FL.

[jrazz]

IMHO the TPL 12.5 are the real jewels.

 

I compared the 12.5mm and the 25mm on the Whirlpool and Andromeda Galaxies last night. The 12.5mm held an edge in contrast despite the exit pupil benefit of the 25mm. I truly expected the 25mm to show more because of it's brightness but that wasn't the case. DGMW, the 25mm is fantastic but the 12.5mm is truly special.

[SandyHouTex]

IMHO the TPL 12.5 are the real jewels.

 

I compared the 12.5mm and the 25mm on the Whirlpool and Andromeda Galaxies last night. The 12.5mm held an edge in contrast despite the exit pupil benefit of the 25mm. I truly expected the 25mm to show more because of it's brightness but that wasn't the case. DGMW, the 25mm is fantastic but the 12.5mm is truly special.

DGMW stand for?

[csrlice12]

Does Good on Milky Way?

Don't Go My Way?

Doesn't Get Much Worse?

Edited by csrlice12, 26 September 2023 - 09:49 AM.

[jrazz]

DGMW stand for?

https://www.urbandic...e.php?term=dgmw

[Alan S]

IMHO the TPL 12.5 are the real jewels.

 

I compared the 12.5mm and the 25mm on the Whirlpool and Andromeda Galaxies last night. The 12.5mm held an edge in contrast despite the exit pupil benefit of the 25mm. I truly expected the 25mm to show more because of it's brightness but that wasn't the case. DGMW, the 25mm is fantastic but the 12.5mm is truly special.

In my experience using differing magnifications like this on galaxies...I feel it gets complicated...I do the same as you quite often, switching and comparing eyepieces to find the best view.  I often find the mid-focal length eyepieces do best on galaxies as far as detail, as they provide a nice balance of a darker sky background and magnification, over the lower power eyepieces.  The lower power eyepieces certainly can provide a more contextual view that is stunning in its own right.  In my case, I have a hard time saying the contrast is better in one or another when it is a complicated game of surface brightness, sky brightness, eyepiece FL...and how tired I am 

[Mike B]

Does Good on Milky Way?

Don't Go My Way?

Doesn't Get Much Worse?

Too much time spent with college kids….

[VA3DSO]

DGMW stand for?

I always hear a Pretenders song in my head when I see that acronym.

 

Rick

[Mike B]

In my experience using differing magnifications like this on galaxies...I feel it gets complicated...I do the same as you quite often, switching and comparing eyepieces to find the best view.  I often find the mid-focal length eyepieces do best on galaxies as far as detail, as they provide a nice balance of a darker sky background and magnification, over the lower power eyepieces.  The lower power eyepieces certainly can provide a more contextual view that is stunning in its own right.  In my case, I have a hard time saying the contrast is better in one or another when it is a complicated game of surface brightness, sky brightness, eyepiece FL...and how tired I am 

Well stated, sir!

 

Okay, at the risk of wearing down the needle, I’ll play my worn LP again: Here is the place for a hi-Q zoom!… you can literally dial-in the exit.pupil your eye likes best in REAL TIME, and watch as the sky background darkens to the ideal level for contrast, or even too far & watch faint stuff vanish!  Zooms are typically challenged at the upper extent of their TFoV range, but for digging in down deep & pulling subtle stuff out of the grey, they are a powerful tool!

 

As a rejoinder to the above, once your zoomer gets you the FL & exit your eye likes, you can always pull the zoom out & stick the corresponding fixed-FL EP in for further viewing, if you wish. Yet I always found the zoomer, once down in the 9-12mm range, had such a nice view, and at 70-80* wide to boot, why would I wanna swap in a 45* EP?

[Scott99]

It would seem when you're really aperture starved, and at the actual diffraction limit for the optics and conditions, the TPL has a bit of an advantage. These differences were exceptionally subtle, but I was able to repeat this observation several times over the course of 90 minutes or so.

 

I think you're onto something here......I think this is why refractor users get more excited about minimum glass ep's than big Newt or SCT users.
 

[Sarkikos]

I'll add another observation.

 

Tonight I had good seeing conditions but decided to just stick with the ETX 90 for my observations. The ETX 90 doesn't have the greatest of optics. Relatively strong SA and zonal issues are present.

 

However, the seeing was steady enough that Jupiter's moons presented as clean diffraction patterns in the 12.5 TPL and 13 DeLite.

 

What I found interesting was the 12.5 TPL presented those diffraction patterns a smidge more cleanly than the 13 DeLite. The space between the spurious disk and the first diffraction ring was more pronounced. The first diffraction ring was also a bit brighter and easier to see in the TPL. The spurious disk itself was a wee bit sharper.

 

In general I felt the TPL seemed to show a bit of a brighter view than the 13 DeLite.

 

It would seem when you're really aperture starved, and at the actual diffraction limit for the optics and conditions, the TPL has a bit of an advantage. These differences were exceptionally subtle, but I was able to repeat this observation several times over the course of 90 minutes or so.

 

In my previous tests in my big dob, I was obviously not at the diffraction limit since I was resolving more air turbulence than the diffraction limit of the scope, and the view in general was bright enough that it's not so easy to spot differences in brightness between the eyepieces. Stop the aperture way down though, and it's a different story.

 

I think I have to repeat my planetary observations with some off-axis aperture masks on the dob. Optical quality is considerably better than the ETX, and the longer focal length will give me more magnification. 130mm off-axis mask for F/13.2 would be a pretty good objective to compare the TPL to the DeLite more closely.

I see here a reasonable rationale for the preference some observers have for comparing eyepieces in smaller rather than larger aperture.   But it doesn't really match my experience in the field, especially when using Jupiter as the test object.  I see differences of sharpness and perceived contrast more easily when comparing eyepieces in larger telescopes.  Though maybe a 14" or even a 12" Dob might be problematical except in excellent seeing.  I don't have extended experience with Dobs that large.  My largest aperture is a 10" f/4.8 Dob.  That scope seems a good test bed for comparing eyepieces, as long as the seeing is moderately good.  Excellent seeing isn't necessary.

 

Mike

[CrazyPanda]

I see differences of sharpness and perceived contrast more easily when comparing eyepieces in larger telescopes.

 

Rationally I agree this should be the case, but I think it's probably only applicable if you have seeing that is better than mine.

 

To me the biggest limiting factor of small aperture comparisons is contrast. At the ~1mm exit pupil and ~100x magnification of last night's observations in the ETX 90, contrast on Jupiter was so low that it was just hard to see the minutia defining features that would let you separate one eyepiece from another.

 

And to clarify, I could spot NO difference on Jupiter's disk between those eyepieces in last night's test. I was using only the diffraction patterns of the Moons as a proxy for sharpness and definition. The subtle differences I noticed did not translate to any difference on the planet (again, because contrast was so poor compared to a bigger scope that Jupiter was just not presenting enough definition to separate the eyepieces).

 

A bigger scope at modest magnifications presents a rich, vivid, well-defined planet which feeds the eye enough signal to make good judgements about differences between eyepieces. The only difference I can see being harder to judge is a difference in brightness. I bet there's probably no more than a 4-5% difference in transmission between the TPL and the DeLite, and that's being REAL generous in the TPL's favor. If you have a bright subject, you're not going to notice it. But if you're starved for light (like the eye is at planetary mags in a 90mm Mak), then you might notice a brightness difference more easily.

 

But everything else (contrast, detail) is going to be compressed badly enough that a comparison won't lead to much, as was the case for Jupiter's planetary disk in last night's observations.

Edited by CrazyPanda, 26 September 2023 - 02:22 PM.

[EboO]

Is there somebody who tried it on solar view ?

[CrazyPanda]

Is there somebody who tried it on solar view ?

White light solar observing report here:
 
https://www.cloudyni...4#entry12931944

Edited by CrazyPanda, 26 September 2023 - 02:50 PM.

[EboO]

I missed it, thanks.

[Tom S.]

Is there somebody who tried it on solar view ?

And here:

 

https://www.cloudyni...ced/?p=12858380

[Tom S.]

TPL 12.5mm / 2.5x Powermate    vs.    Pentax XW 5mm  -    comparison on JUPITER
 
A) Takahashi TPL 12.5mm combined with a TeleVue 2.5x Powermate, giving 208x in my scope.
 
B) Pentax XW 5mm (by itself).  Also 208x.
 
Scope:  Tak FS-128  (128mm f/8 refractor).   Tracking mount.   No filters.  No eyeglasses.  WO dielectric diagonal (mirror, not prism).
 
Seeing: a little above average.   Many instants where the Galilean satellites were rendered as small discs.
 
Swapped back and forth between A and B repeatedly over about 45 minutes total.
 
Conclusion: both showed a lot of detail, but the Pentax XW 5mm was better
 
It was a good time to look at Jupiter because Io and the GRS were transiting, and there were some white ovals adjacent to the GRS.
 
The TPL/PW combination, and the PXW, were equally sharp, and Io crossing in front of Jupiter stood out equally well.
 
But with surface features (GRS, belts, some white ovals, etc) there was more contrast with the PXW, and details just popped out more impressively.  Views with the TPL/PW combination seemed ever so slightly pale and washed out in comparison, not a huge difference but the effect was definite.  The GRS doesn't currently have much color, but I thought I saw a little more saturation with the PXW.

 

These findings regarding contrast on Jupiter are similar to what I found when comparing A) and B) on the moon a few nights ago, as reported here: https://www.cloudyni...ced/?p=12963833

 
This is not an evaluation of purely the 12.5 TPL, because the 4-element Powermate was in front of it, but I believe it's still a relevant comparison.  I suspect a lot of people would use this eyepiece in combination with a Barlow or Powermate in scopes that have ~1200mm or less focal length (i.e. most refractors and many Newts) in order to reach ~ 200x to observe planets and the moon.

Edited by Tom S., 27 September 2023 - 07:12 AM.

[SandyHouTex]

https://www.urbandic...e.php?term=dgmw

I can't go there on my work computer.  Besides you do know to spell out an acronym before using it, yes?

Edited by SandyHouTex, 27 September 2023 - 10:43 AM.

[SandyHouTex]

Too much time spent with college kids….

 

TPL 12.5mm / 2.5x Powermate    vs.    Pentax XW 5mm  -    comparison on JUPITER
 
A) Takahashi TPL 12.5mm combined with a TeleVue 2.5x Powermate, giving 208x in my scope.
 
B) Pentax XW 5mm (by itself).  Also 208x.
 
Scope:  Tak FS-128  (128mm f/8 refractor).   Tracking mount.   No filters.  No eyeglasses.  WO dielectric diagonal (mirror, not prism).
 
Seeing: a little above average.   Many instants where the Galilean satellites were rendered as small discs.
 
Swapped back and forth between A and B repeatedly over about 45 minutes total.
 
Conclusion: both showed a lot of detail, but the Pentax XW 5mm was better
 
It was a good time to look at Jupiter because Io and the GRS were transiting, and there were some white ovals adjacent to the GRS.
 
The TPL/PW combination, and the PXW, were equally sharp, and Io crossing in front of Jupiter stood out equally well.
 
But with surface features (GRS, belts, some white ovals, etc) there was more contrast with the PXW, and details just popped out more impressively.  Views with the TPL/PW combination seemed ever so slightly pale and washed out in comparison, not a huge difference but the effect was definite.  The GRS doesn't currently have much color, but I thought I saw a little more saturation with the PXW.

 

These findings regarding contrast on Jupiter are similar to what I found when comparing A) and B) on the moon a few nights ago, as reported here: https://www.cloudyni...ced/?p=12963833

 
This is not an evaluation of purely the 12.5 TPL, because the 4-element Powermate was in front of it, but I believe it's still a relevant comparison.  I suspect a lot of people would use this eyepiece in combination with a Barlow or Powermate in scopes that have ~1200mm or less focal length (i.e. most refractors and many Newts) in order to reach ~ 200x to observe planets and the moon.

Using the power mate, I think, invalidates the comparison.  From what I know of TV, their optics are only polished to a 60/40 scratch/dig, which would damage the view with the TPL.

[Nippon]

I can't go there on my work computer.  Besides you do know to spell out an acronym before using it, yes?

Yeah, it seems even journalists have forgotten the spell it out on first reference rule.

[SteveC]

Obviously the DeLites and TAOs are wicked sharp eyepieces, but the new TPLs are wicked sharper!

 

I have seen this in my TEC140FL.

As a resident of New England,  I support your use of "wicked" as an eyepiece quality benchmark. 

Edited by SteveC, 27 September 2023 - 11:21 AM.

[norvegicus]

Using the power mate, I think, invalidates the comparison.  From what I know of TV, their optics are only polished to a 60/40 scratch/dig, which would damage the view with the TPL.

Which was my exact experience.  I am disappointed with the PowerMate now, but it took the superior polish of the Tak TPL to make me notice.

 

Very much looking forward to a 5 and/or 7.5mm and/or ~10mm eyepiece from Takahashi of this quality.  

Edited by norvegicus, 27 September 2023 - 11:24 AM.

[alnitak22]

Using the power mate, I think, invalidates the comparison.  From what I know of TV, their optics are only polished to a 60/40 scratch/dig, which would damage the view with the TPL.

“From what I know of TV….”….that about sums it up. And there are TONS of testimonials from experienced observers attesting to the fact that the Powermates are invisible in use. So there’s that.