1390 replies to this topic

[25585]

Are refractors the best optical design/type of scope for evaluating eyepieces? No collimation to possibly compromise accuracy, no optics obstructing, etc.

Edited by 25585, 12 September 2023 - 02:00 PM.

[SteveC]

So after playing around with the very cheap barlows, the LE 7.5mm and actually borrowing a friend's 2.5x powermate I can say a couple of things:

 

I don't like barlows or powermates. Too fiddly. Not fun. The powermates were definitely a major step up in quality but I very much dislike the whole process. Like I said, I have become a minimal glass snob, sorry!

I am really really disappointed with the LE 7.5mm eyepiece. It's got the build quality and the Takahashiness to it but it honestly does not hold a candle to the contrast of the TPL. I tried to like it, really I did but I always kept on going back to the TPL. Luckily for me it was really easy to pass on. Great eyepiece but not at TPL levels IMHO.

Finally I learned that even though there is a big gap between 12.5mm and 4mm I don't really need to fill it. Most of my observing today is done with the 12.5. I have the 25mm if I want to see big stuff and the 4mm for splitting doubles. 

 

I think the TPL 12.5mm have officially ruined me on other eyepieces. 

I use the Denk Powerswitch rather than a Barlow or powermate. It's easy to use, it introduces just one more piece of glass, and it doesn't take anything away from the view. Expensive though. 

[SandyHouTex]

I decided to get a case for my 6 TPLs from Harbor Freight.  I didn't want to go in their store so I ordered them online.  The Apache 2800 case was in stock in a store just 10 miles from me, so what did they do?  They shipped it from North Carolina and it's going to take 8 days.  Yoiks!

[Sarkikos]

Are refractors the best optical design/type of scope for evaluating eyepieces? No collimation to possibly compromise accuracy, no optics obstructing, etc.

Refractors do need to be in collimation to produce a good image.  Many don't have collimation screws at the objective, but they can still be collimated by manipulating the visual back.  (The holes on the OTA where the visual back is attached might need to be drilled into short slots to accommodate this.)   I hope my NP101is never needs recollimation.  I hear you pretty much have to send it back to Tele Vue.

 

Fast refractors will have obvious chromatic aberration unless they are APO's.  For reasons I've mentioned, well-corrected fast telescopes are better test beds for eyepieces than well-corrected slow ones.  

 

Refractors are also severely limited in aperture compared to Newtonians.  Larger aperture done well is a better test bed for eyepieces than smaller aperture done well.   A 10" Dob is a readily available instrument.  A 10" refractor, not so much.

 

So, at least depending on the object observed when testing eyepieces, the larger Newtonian could do a better job.  If I really want to see how an eyepiece performs when viewing bright planets, and thereby test the sharpness, scatter control and perceived contrast of the eyepiece, I think a good 10" f/5 Dob with Paracorr looking at Jupiter would be a better test of the eyepiece than an NP101is.  This has been my experience.

 

Mike

Edited by Sarkikos, 13 September 2023 - 05:14 AM.

[CrazyPanda]

Clouds cleared out for about 3 hours last night, and left me with excellent local seeing (jet stream was active though). I didn't spend the whole time doing eyepiece comparisons because good seeing is rare in my area and I wanted to actually spend time observing the planets at magnifications higher than ~150x.

 

Compared mostly the TPL against the DeLite, with some comparisons to the Docter and Nikon. These were done in the 14.7" scope with coma corrector giving me 158x in the 12.5mm eyepieces and 152x in the 13mm DeLite.

 

Sky was 21.06 mpsas, transparency was average to below average.

Targets included:

 

1. Albireo

2. Polaris

3. Stephan's Quintet

4. Saturn

5. Jupiter

 

When I did comparisons, I would compare the Docter and TPL directly, and the the DeLite and TPL directly, and then I would rotate all three or all four. I didn't have time to do DeLite vs Docter comparison and I felt this wasn't the purpose of this test anyway. I didn't compare the TPL directly to the Nikon.

 

All three eyepieces had been cleaned prior to this observing session.

 

For Albireo, my intent was to do color comparison between the eyepieces, but what I ended up focusing on more was scatter. There was definitely less scatter present in the TPL than the DeLite or Docter. I'd never really focused on this as much, but after several back and forth comparisons, and the use of averted vision, looking away from the eyepiece so my brain wouldn't ignore the scatter, it was clear that the space between Albireo's components was darker in the TPL, followed by the DeLite, followed by the Docter. Did not compare the Nikon for this test. I never got around to testing the colors.

 

I repeated this test against Polaris, same result. TPL showed less scatter.

 

I then swung over to Stephan's Quintet. For my skies, I can see all 5 members, but it takes a bit of effort. The magnification and exit pupil I was working with was not optimal for this target. All four eyepieces were much more alike than different. I did notice the 13 DeLite presented a brighter field, and NGC 7320 seemed to stand out better in averted vision, but the 13 DeLite was the odd one out given the slightly brighter exit pupil. It's also much easier to use averted vision in that eyepiece because of the longer eye relief. Following that was the Nikon NAV-HW. I've consistently seen how the Nikon's coatings keep things quite bright despite all the glass in it. The view seemed similar in brightness to the DeLite, but contrast wasn't quite as good. That's likely explained by the lack of observing hood and large eye lens catching light from the sky. The Docter and the TPL seemed about even and I could not really differentiate one over the other.

 

For Saturn, I only compared the TPL, DeLite, and Docter, with most comparisons back and forth between the TPL and DeLite. Saturn's moons were the first targets to compare. Tethys was about 3 arcseconds away from the disk getting farther as the observation went on and Mimas was about 8 arcseconds away from the rings getting closer. Both were challenging. Enceladus was about the same distance away from the rings as Mimas, but was easier. Dione, Rhea, and Titan were too easy to test against. In all three eyepieces, all the Moons were perfect little pinpoints. There was no sharpness differentiation. Enceladus was visible in all three with some mild averted vision, about an equal amount of time. Tethys was very challenging until it separated more from the planet. I first noticed it in the TPL after a decent amount of back and forth. Mimas was a real struggle. I first noticed it in the 13 DeLite, but that made me realize that Saturn was killing dark adaption, so before attempting to observe Mimas, I would take an eyepiece out, put the new one in, focus it, and then take a 60 second break. Each time I did that, Mimas was easier to see. However, it was *consistently* easier to see in the 13 DeLite. I could hold it about 80% of the time until Saturn clobbered my dark adaption. It was more like 50% of the time in the TPL, and less so in the Docter. The DeLite was showing the three faint moons better than the other three eyepieces.

 

For Saturn itself, I noticed there was some subtle tonal difference in the three eyepieces. The TPL showed Saturn as a brilliant off-white. The DeLite was more of a pale yellow. The Docter was similar to the DeLite, but a bit more brown. The darkest band on Saturn stood out best in the Docter, followed by the DeLite. Saturn felt a bit washed out in the TPL. Scatter around Saturn was lower in the TPL, followed closely by the DeLite, and worst in the Docter. Saturn was equally sharp in all three eyepieces. The jet stream was scrubbing away the absolute finest of details so I don't think there was sufficient definition present in Saturn to separate the three eyepieces.

 

Jupiter was similar, but showed even more pronounced differences. It seemed faded/pale in the TPL, warmer in the DeLite, and richer in the Docter. There was a fairly pronounced difference in scatter between the TPL and the Docter when comparing those two head-to-head. I'd observe with the TPL, and then put the Docter in and at one point I rubbed my observing eye when looking through the Docter thinking I had some junk I needed to clear out. Nope, it was just more scatter present in the Docter. DeLite was more similar to the TPL, but you could tell there was a bit more scatter.

 

The biggest differences came down to the details present. Without a doubt, the 13 DeLite stole the show on Jupiter. The faintest cloud bands in the North Temperate Belt and textures in the North and South Polar regions all stood out the best in the DeLite. They were there in the TPL but much harder to tease out. The Docter showed them as well but the scatter obscured them more than in the DeLite. The DeLite was the winner for detail on Jupiter. Again, sharpness was about the same for all three eyepieces, but I think the absolute finest details were scrubbed away by the jet stream and so maybe with more perfect seeing I would have seen some more differences in sharpness. The TPL's cool tone I think works against it for Jupiter and Saturn to a degree.

 

Supposedly I have a longer run of clear skies tonight with better transparency, and I will try again. If seeing is mucky I will stick to deep sky comparisons.

Edited by CrazyPanda, 14 September 2023 - 08:28 AM.

[payner]

Thank you for that good comparison. What I glean from it is the TPL excels at what one (I) primarily looks for in a "planetary" eyepiece and multiple star observation, minimal scatter. That one effect can often blur subtle details to an extent they are either not seen or not seen definitively, at least that is what I have found. Obviously the DeLite was not far behind and was better in your session in some instances.

 

The other attribute is tone. I look for cool tone eyepieces with this type of observing and find overall a "cleaner" presentation from them. What one may want to employ, particularly in planetary observing, are appropriate filters to highlight features one is concentrating on. I find the Baader Moon & Skyglow a good general filter for planets, but will use color filters or specialty filters (e.g., TV Mars Type A/B on that planet) when appropriate.

Edited by payner, 14 September 2023 - 08:44 AM.

[25585]

Is the TV Mars filter like the Baader Neodymium?

[Highburymark]

Clouds cleared out for about 3 hours last night, and left me with excellent local seeing (jet stream was active though). I didn't spend the whole time doing eyepiece comparisons because good seeing is rare in my area and I wanted to actually spend time observing the planets at magnifications higher than ~150x.

Compared mostly the TPL against the DeLite, with some comparisons to the Docter and Nikon. These were done in the 14.7" scope with coma corrector giving me 158x in the 12.5mm eyepieces and 152x in the 13mm DeLite.

Sky was 21.06 mpsas, transparency was average to below average.
Targets included:

1. Albireo
2. Polaris
3. Stephan's Quintet
4. Saturn
5. Jupiter

When I did comparisons, I would compare the Docter and TPL directly, and the the DeLite and TPL directly, and then I would rotate all three or all four. I didn't have time to do DeLite vs Docter comparison and I felt this wasn't the purpose of this test anyway. I didn't compare the TPL directly to the Nikon.

All three eyepieces had been cleaned prior to this observing session.

For Albireo, my intent was to do color comparison between the eyepieces, but what I ended up focusing on more was scatter. There was definitely less scatter present in the TPL than the DeLite or Docter. I'd never really focused on this as much, but after several back and forth comparisons, and the use of averted vision, looking away from the eyepiece so my brain wouldn't ignore the scatter, it was clear that the space between Albireo's components was darker in the TPL, followed by the DeLite, followed by the Docter. Did not compare the Nikon for this test. I never got around to testing the colors.

I repeated this test against Polaris, same result. TPL showed less scatter.

I then swung over to Stephan's Quintet. For my skies, I can see all 5 members, but it takes a bit of effort. The magnification and exit pupil I was working with was not optimal for this target. All four eyepieces were much more alike than different. I did notice the 13 DeLite presented a brighter field, and NGC 7320 seemed to stand out better in averted vision, but the 13 DeLite was the odd one out given the slightly brighter exit pupil. It's also much easier to use averted vision in that eyepiece because of the longer eye relief. Following that was the Nikon NAV-HW. I've consistently seen how the Nikon's coatings keep things quite bright despite all the glass in it. The view seemed similar in brightness to the DeLite, but contrast wasn't quite as good. That's likely explained by the lack of observing hood and large eye lens catching light from the sky. The Docter and the TPL seemed about even and I could not really differentiate one over the other.

For Saturn, I only compared the TPL, DeLite, and Docter, with most comparisons back and forth between the TPL and DeLite. Saturn's moons were the first targets to compare. Tethys was about 3 arcseconds away from the disk getting farther as the observation went on and Mimas was about 8 arcseconds away from the rings getting closer. Both were challenging. Enceladus was about the same distance away from the rings as Mimas, but was easier. Dione, Rhea, and Titan were too easy to test against. In all three eyepieces, all the Moons were perfect little pinpoints. There was no sharpness differentiation. Enceladus was visible in all three with some mild averted vision, about an equal amount of time. Tethys was very challenging until it separated more from the planet. I first noticed it in the TPL after a decent amount of back and forth. Mimas was a real struggle. I first noticed it in the 13 DeLite, but that made me realize that Saturn was killing dark adaption, so before attempting to observe Mimas, I would take an eyepiece out, put the new one in, focus it, and then take a 60 second break. Each time I did that, Mimas was easier to see. However, it was *consistently* easier to see in the 13 DeLite. I could hold it about 80% of the time until Saturn clobbered my dark adaption. It was more like 50% of the time in the TPL, and less so in the Docter. The DeLite was showing the three faint moons better than the other three eyepieces.

For Saturn itself, I noticed there was some subtle tonal difference in the three eyepieces. The TPL showed Saturn as a brilliant off-white. The DeLite was more of a pale yellow. The Docter was similar to the DeLite, but a bit more brown. The darkest band on Saturn stood out best in the Docter, followed by the DeLite. Saturn felt a bit washed out in the TPL. Scatter around Saturn was lower in the TPL, followed closely by the DeLite, and worst in the Docter. Saturn was equally sharp in all three eyepieces. The jet stream was scrubbing away the absolute finest of details so I don't think there was sufficient definition present in Saturn to separate the three eyepieces.

Jupiter was similar, but showed even more pronounced differences. It seemed faded/pale in the TPL, warmer in the DeLite, and richer in the Docter. There was a fairly pronounced difference in scatter between the TPL and the Docter when comparing those two head-to-head. I'd observe with the TPL, and then put the Docter in and at one point I rubbed my observing eye when looking through the Docter thinking I had some junk I needed to clear out. Nope, it was just more scatter present in the Docter. DeLite was more similar to the TPL, but you could tell there was a bit more scatter.

The biggest differences came down to the details present. Without a doubt, the 13 DeLite stole the show on Jupiter. The faintest cloud bands in the North Temperate Belt and textures in the North and South Polar regions all stood out the best in the DeLite. They were there in the TPL but much harder to tease out. The Docter showed them as well but the scatter obscured them more than in the DeLite. The DeLite was the winner for detail on Jupiter. Again, sharpness was about the same for all three eyepieces, but I think the absolute finest details were scrubbed away by the jet stream and so maybe with more perfect seeing I would have seen some more differences in sharpness. The TPL's cool tone I think works against it for Jupiter and Saturn to a degree.

Supposedly I have a longer run of clear skies tonight with better transparency, and I will try again. If seeing is mucky I will stick to deep sky comparisons.

Interesting feedback - thanks. Impressed by the TPL’s lack of scatter. But the comparatively improved detail offered by the Delite on Jupiter is particularly interesting. That’s a target on which the TOEs excel.
And maybe the Docter is not a planetary or double star eyepiece?

[Starman1]

Is the TV Mars filter like the Baader Neodymium?

No, it had a different emphasis.

Here is a spectrum of the TeleVue "Planetary" filter, which was formerly called the "Mars B":

https://www.cloudyni...ers/?p=10175470

Almost no output from 400-455nm.

It is closer to a couple other filters: Baader Contrast Booster (though not the same, of course), and the DGM GCE (but the GCE had blue and violet transmission).

 

I couldn't find a spectrum for their earlier "Mars A"

 

Here are the spectra for the Baader Moon & Sky Glow (neodymium) filter and the Baader Contrast Booster (neodymium with minus violet added):

https://www.cloudyni...ters/?p=7601587

 

And here is the spectrum of the TeleVue Mars B superimposed on the Baader M&SG:

Yellow is TeleVue, Brown is Baader

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[25585]

Many thanks. I find the Neodymium improves Mars and Jupiter generally, would the TV be better still?

[Starman1]

Many thanks. I find the Neodymium improves Mars and Jupiter generally, would the TV be better still?

The TeleVue was discontinued many years ago.

The Baader Contrast Booster is a bit better on Mars--extends into the red farther and chops off the violet--both good things for Mars observation.

[payner]

I’ve not used the Contrast Booster, but if it’s better than the two TV Mars filters it must be spectacular. Between those two filters, they are the best I’ve used for surface and cloud features. Each filter has different emphasis. 
I bought them around the 2012 apparition and did see them come up occasionally after they were discontinued (as I recall they were discontinued in the mid-2010s). It’s been some years now since I’ve seen them in the classifieds. Folks other than me must find them valuable to their Mars observations. 

Edited by payner, 15 September 2023 - 04:23 AM.

[CrazyPanda]

Interesting feedback - thanks. Impressed by the TPL’s lack of scatter. But the comparatively improved detail offered by the Delite on Jupiter is particularly interesting. That’s a target on which the TOEs excel.
And maybe the Docter is not a planetary or double star eyepiece?

I've always considered the Docter a superb planetary eyepiece, but I've never done a head to head against the 13 DeLite. I've always used the 13 DeLites in the binoviewer rather than monoviewing.

 

It's important to emphasize that none of these eyepieces are anything less than superb for these observations. You only start to pick out the differences when doing side-by-side comparisons and really nit picking the view.

Edited by CrazyPanda, 14 September 2023 - 10:06 PM.

[French astro]

Foa60q f15

TAO, TLE, TPL  

12,5mm Focal length 

Saturn, Jupiter, moon

Optimal viewing conditions.

 

I found that : 

 

The differences are marginal

 

The TAO, appeared to me the sharpest. 

Like a good Japanese chef, he cuts the strips like an itamae. 

 

The TLE reveals to me jupiter's polar regions better than its two other cousins. Its larger field sets it apart.

 

The TPL is the one that has better dispersion control. 

On the moon it literally acted like an OLED screen.The craters are drawn with vantablack. Absolute blacks. Impressive.

 

The abbe and the LE have nothing to be ashamed of, far from it. But the turret has chosen its winner, it can stop turning.

 

The TPL is remarkable 

Takahashi masters his business 

A revolution ? Certainly not

A success ? Absolutely

 

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[25585]

I've always considered the Docter a superb planetary eyepiece, but I've never done a head to head against the 13 DeLite. I've always used the 13 DeLites in the binoviewer rather than monoviewing.

 

It's important to emphasize that none of these eyepieces are anything less than superb for these observations. You only start to pick out the differences when doing side-by-side comparisons and really nit picking the view.

The Docter is ortho-like to my eye, especially on-axis, but off-axis it is still spectacular. I tried mine out with my new refractor, the 130mm F6 APM LZOS, breathtaking!

[CrazyPanda]

Every time I use the Docter, I say "This is what I want a full line of eyepieces of". I would sell all my other eyepieces in a flash. Keep the same optical quality, field of view, and exit pupil characteristics but with more focal length choices.

Edited by CrazyPanda, 15 September 2023 - 05:50 AM.

[French astro]

Sorry, i forgot to mention in the post above:

Note the green tint on the lens vs the caramel tint on the adde and LE.

The three are parafocals (almost parafocals according to the SarKikos definition of parafocality 😁).

So while waiting for the next HI TPL, TPL9, TOE5 or an other candy, the LE serie have broad shoulders to bridge the gap between the King TOE4 and the new TPL Prince

Edited by French astro, 15 September 2023 - 08:00 AM.

[Highburymark]

Foa60q f15
TAO, TLE, TPL
12,5mm Focal length
Saturn, Jupiter, moon
Optimal viewing conditions.

I found that :

The differences are marginal

The TAO, appeared to me the sharpest.
Like a good Japanese chef, he cuts the strips like an itamae.

The TLE reveals to me jupiter's polar regions better than its two other cousins. Its larger field sets it apart.

The TPL is the one that has better dispersion control.
On the moon it literally acted like an OLED screen.The craters are drawn with vantablack. Absolute blacks. Impressive.

The abbe and the LE have nothing to be ashamed of, far from it. But the turret has chosen its winner, it can stop turning.

The TPL is remarkable
Takahashi masters his business
A revolution ? Certainly not
A success ? Absolutely

Like your turret, the Tak sticker flew off mine 10 minutes into its first observing session. Thankfully, the quality of the mechanics and optics are better than the sticker glue. The little ‘made in US’ sticker on my TV85 also liberated itself from the parent scope in the first week of ownership. Shocking stuff.
Thanks for the interesting comparison. We’re building up a good impression of the TPLs’ qualities now.

[ji4m]

I am endlessly fascinated reading about the minimal glass count and barlow contribution.

 

Staying in refractor land, when do we start counting lens elements?  Singlet, doublet, triplet, Petzval?

 

Why is a properly executed barlow or Tak focal extender in the count?

 

I think they are all working on the "primary" image.  The eyepiece performs a different function making that image readily visible.

 

But, I have no doubt you critical observers see something important I miss, whether it's my acuity or skies prevent.  I really do believe it - I still listen to vacuum tubes and vinyl afterall.

[Paul Morow]

After CrazyPanda posted the picture of the baffles in the barrels of the new Takahashi TPLs I could not resist anymore.

 

I figured if the Takahashi folks engineered a fully new metal work containing baffles, then these new eyepieces are well thought out.

 

I ordered a pair of 18mm TPLs to evaluate against my other 18mm class eyepieces. I have been using this bino-viewing group for several years now, so I know how they all stack up against each other. I consider all of them low scatter eyepieces with great contrast for lunar & planetary observing. I consider the TAOs on top with the old TV Plossls very close behind and the LEs following a strong performing third place.

 

This early morning from 4:00 to 5:30 I observed Jupiter with my TEC140FL under good seeing conditions. Jupiter's GRS was visible during an Europa shadow transit and the new TPLs performed wonderfully. I was surprised by the TPLs impressive scatter control and wicked sharpness. The TAOs are great performers, but the light scatter in the TPLs is tapped down a little bit more like someone used a dimmer switch to dial down the light scatter. I would say the TPLs are about a half of a step better in scatter control and possibly 1/8 step sharper on axis compared to the impressive TAOs. The better sharpness was visible on Jupiter's outer limb edge and the moons focused tighter & cleaner showing obvious discs more easily. Overall on axis clarity, contrast and color tone appeared about the same between the TPLs and TAOs. Jupiter's low contrast features such as light gray garlands (loop festoons) under the NEB and white turbulence following behind the GRS were visible pretty similar between the eyepieces. I feel Takahashi has really raised the bar on these new eyepieces.

 

When comparing the TV DeLites to the old Radians I would consider the scatter control easily one a full step better in the DeLites. The Takahashi TPLs are much closer in performance to the TAOs, but the improvement is definitely there to see. Once you get to this level of performance these characteristics are pretty subtle overall. I will probably acquire a few more TPLs in the future, definitely hoping for a 32mm to be released. I will probably start a draft letter to my buddy Santa over the weekend.

 

Also, when the new Takahashi TPLs were delivered to my house, I had my Lunt solar telescope deployed in the backyard. The 18mm TPLs were compared to my personal favorite H-alpha observing eyepieces the Lunt Zoom and Takahashi LEs. Right out of the box I was surprised by the TPLs stunning sharpness and scatter control while observing the Sun in red light. The solar prominences showed subtle contrast and clarity improvement over my personal favorite LEs, I prefer the LEs over the TAOs slightly for H-alpha viewing. Yes, these new Takahashi TPLs are something special during the day and night!

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Edited by Paul Morow, 15 September 2023 - 11:58 AM.

[Mike B]

Like your turret, the Tak sticker flew off mine 10 minutes into its first observing session. Thankfully, the quality of the mechanics and optics are better than the sticker glue. The little ‘made in US’ sticker on my TV85 also liberated itself from the parent scope in the first week of ownership. Shocking stuff.
Thanks for the interesting comparison. We’re building up a good impression of the TPLs’ qualities now.

This must be what they call Astronomy’s “Sticker Shock”?   Loving my new old Edscorp VT Ortho!… That sticker is on fer keeps, man! I think mebbe Edmund Optics uses the same glue our ol’buddy Saito used?

[payner]

Paul: Another good, confirming report! If you do not have the three TOEs, they too are stunners in the short focal lengths.

[French astro]

After CrazyPanda posted the picture of the baffles in the barrels of the new Takahashi TLPs I could not resist anymore.

 

.......

 

Also, when the new Takahashi TLPs were delivered to my house, I had my Lunt solar telescope deployed in the backyard. The 18mm TLPs were compared to my personal favorite H-alpha observing eyepieces the Lunt Zoom and Takahashi LEs. Right out of the box I was surprised by the TLPs stunning sharpness and scatter control while observing the Sun in red light. The solar prominences showed subtle contrast and clarity improvement over my personal favorite LEs, I prefer the LEs over the TAOs slightly for H-alpha viewing. Yes, these new Takahashi TLPs are something special during the day and night!

 

Thank you and well done, very good report.

 

But who are these TLP what are you talking about ? 

Takahashi makes us stutter 🤣

Edited by French astro, 15 September 2023 - 11:44 AM.

[25585]

 

Takahashi makes us stutter 🤣

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[CrazyPanda]

Had some good conditions tonight after Hurricane Lee blew through. Left me with highly transparent 21.1 skies - better than average for my area.

 

The skies were very turbulent so I spent time doing deep sky observing and comparisons between the TPL, 12.5 Nikon NAV-HW, and Docter. I left the DeLite out because I wanted a consistent exit pupil.

 

Spent time on the Veil (unfiltered), M27, M33, NGC 891, NGC 7814 (good challenge is to spot the dust spine), various other galaxies in Andromeda, Triangulum, and Pegasus, as well as the Perseus cluster. I saw no advantage to the TPL in terms of what it could show over the Docter and Nikon. Similar observations held that the Nikon showed a slightly brighter field than the Docter or TPL and some galaxies in the Perseus cluster stood out a tiny bit more in the Nikon. Docter and TPL were identical in brightness, contrast, and how they presented objects.

 

In the past when I've done deep sky comparisons between the 20mm TV Plossl to the 21 Ethos or BHZ @ 20mm, and the 8mm TV Plossl to the 8 Ethos, I've been able to spot a very minor advantage in the TV Plossls. I was anticipating something similar here with the TPL vs the Docter and Nikon, but there was nothing that I could see which indicated it would reach deeper or provide better object-level contrast than more complex widefields.

 

To date, its primary advantage seems to be slightly lower scatter and ability to keep stray light well under control.

 

Sharpness is excellent but so far seems to be no better than other premium widefields. I need better conditions to fully determine if this is the case.

 

Despite better scatter control and overall excellent *field contrast*, planetary surface contrast seems worse in the TPL due to tonal differences that hide subtle shadings on Jupiter and appears to mute Saturn.

 

So far the 12.5 TPL seems like a very nice eyepiece, but not something that I'm blown away by. Maybe a larger scope or darker skies would be a better test for the eyepiece's deep sky capabilities.

 

The Moon will be an interesting target, as will trying to spot the Pup later this winter. I've fairly easily spotted the Pup in the Nikon, but with the TPL's superior scatter control, it should make for an interesting comparison.

Edited by CrazyPanda, 17 September 2023 - 01:21 AM.