What observers say about the Houdini 20 Eyepiece

"As far as correction is concerned, this eyepiece lives up to its spec: no coma right up to the edge. It's quite impressive, in fact. I spent a good while comparing it with the Nagler 22 (in the Paracor) and the correction is at least as good as in the corrected 22. The field of view of the Houdini is the same as that of the naked Nagler 22; used with the Paracorr, the Nagler 22 therefore gives a smaller field of view.

So, duly noted, it works like a charm!

I didn't see any noticeable difference between the Houdini 20 and Nagler 22 in terms of sharpness, transparency, or sky background.

I'm quite impressed with the performance of this eyepiece, with its impeccable coma correction (at F4 in any case), all of which is quite light and for a very reasonable price."

JDGall@astrosurf, France, 500 mm F/4 telescope

"Zero edge of field brightening, and zero vignetting/edge of field darkening. The field is remarkably uniformly illuminated. The 21 Ethos and 28 UWA (and 31N and 17 NAV-HW) all vignette with the Paracorr. Only the 17ES92 seems to be spared the vignetting caused by the Paracorr.

When I use those eyepieces WITHOUT the Paracorr, they all exhibit nicely uniform field as well. Seems the Houdini 20 saves you from the ill effects of the Paracorr's tendency to vignette low power ultra and hyperwides - a win for the Houdini.

The Houdini 20 is a wonderfully easy eyepiece to look through without glasses. It's workable with glasses but still not what I would consider glasses-friendly. Field illumination is superb. It's light weight and the safety kerfs on the barrel are much nicer than an undercut.

The coma correction clearly works well, and it's strongly preferable to using UWAs and hyperwides without a coma corrector.

With better conditions for M3, I tested the central sharpness of each eyepiece. No question that the 20 Houdini was every bit as sharp in the center as the 21 Ethos. Very, very crisp rendition of M3."

CrazyPanda@cloudynights, USA, 14.7" F/4.6 telescope

"Pentax XW23 85° + Paracorr Type 2 vs Houdini 20 mm 86°.

With the Pentax XW23 behind the coma corrector, I get 60x magnification. With the Houdini 20, I have a magnification of (drum roll...) 60x too !!!!

It's quite amazing, the field of view is exactly the same. You'd have to smoke super-thick carpet to see any difference. The coma correction is identical. Sharpness to match. Perhaps at the extreme edge of the field (like around 5% of the distance from the edge to the center...) the shape of the corrected stars changes a little, but is not at all degraded. But that's just looking for lice on the head of an Ourang-outan.

Conclusion: the Houdini 20 does the job superbly. The Houdini is a lot lighter... I'll have to rethink the balance of my instrument, even if it'll do."

maire@astrosurf, France, 300 mm F/4 telescope

"Stars remain stars out to the edge of the field at f/5 - imaging quality is excellent including field curvature correction. And there is no edge of field brightening from distortion (something I know from the Nikon NAV SW).
The Pentax XW 20 in comparison feels like tunnel vision and develops bad stars from ~70% of the field on. So here is a clear winner."

doppio@cloudynights, Germany, 10" F/5 binoscope

"I just received the 20mm eyepiece yesterday and I love it!  Tried it on my 10" f/3.6 scope and it works beautifully. No distortion while panning across the sky, sharp to the edge.  Very comfortable to view with. I think the 86-deg AFOV is perfect. I'm the optical designer at Starizona and I thought this was such a cool idea and wanted to try it out. Well done! Looking forward to using it more any trying it on more telescopes."

Scott Tucker, USA, 10" F/3.6 telescope

"The Houdini works while presenting a very nice, high-quality field of view. It maintains sharply defined stars very nearly all the way out to the field stop of its generous FOV.  Granted, f/6 is not an acid test. However, all of the TeleVues, as sharp as they were near the center (especially the 20T5 and E21), started showing coma around 2/3 the way out.

Houdini kept up with the 20T5 and the Ethos in terms of sharpness; the latter two did better than the 22T4 as one looked farther off-center, and the Houdini did noticeably better. I thought the 86° AFOV of the Houdini presented a nice middle ground between the Naglers' 82° and the Ethos' 100°. It felt more immersive than the 20T5; about the same as the Ethos and the 22T4.

Where the Houdini earned its keep was in viewing multiple objects in the same FOV, where those objects - or parts of them - fell outside ~ the center 50% FOV. For example, M104 and Jaws. With M104 nicely framed on one side of the FOV, all of Jaws' stars remained sharp and tight even near-ish to the opposite edge of the Houdini. Not quite so in the 20T5 and Ethos; and definitely not in the 22T4. I had to look for the coma in the TeleVues - might not consciously notice in a casual view - but again, no unseeing it once noticed. I expect this nice characteristic of the Houdini will hold true for other wide or multiple objects, e.g. Markarian's Chain (covered by crud tonight), the Double Cluster, Kemble's Cascade, M31, etc."

astrophile@cloudynights, USA, 10" F/6 telescope

"I received the eyepiece yesterday. I was really impressed with the fit and finish quality of the eyepiece. Pictures don't do it justice. It feels great to handle this eyepiece. I have had other eyepieces from that factory and exterior quality of the Houdini definitely feels like a step above. Not that it's necessarily important to me, but the box it came in was really nice as well. It has a magnetic flip lid like the old explore scientific boxes and really nice custom formed foam."

buckingham_hoo@cloudynights, USA

"Results were surprisingly good. Images were sharp over nearly the entire field, other than the expected (large) field curvature of this scope. In other words, re-focusing for the field edge gave sharp images free from coma or astigmatism.

I also tried the Nagler 20 Type 2, Nagler 20 Type 5, and Nagler 22 Type 4 eyepieces in the same configuration, but none were as sharp as the Houdini 20. The Naglers all showed some combination of off-axis coma and / or off-axis astigmatism. The coma seen in the Naglers was no doubt from the scope, whereas Houdini seemed to correct it.

Houdini is "plug and play" which is a huge advantage.  With the coma correctors I probably spent an hour total looking up eyepiece focal plane positions, Paracorr settings, reading manuals, crunching numbers, converting inches to mm, finding my extension tubes, trying different tubes, etc.  With the Houdini you just drop it in and observe... yea!"

ngc7319_20@cloudynights, USA, 72 mm" F/6 refractor

"In the 16", Houdini 20 provides fantastic views compared to other eyepieces available to me at this time (SW bundled 28mm LET Kellner, a 32mm SWA, and an almost full set of Hyperions). With my spectacles, I did not find it too hard to see the edge of the field. I do have to press the eyeglass to the folded rubber cup, which makes it a bit hard to shift my eye laterally to reach the edge. However, after an hour or two of getting accustomed, I seemed not to notice this problem anymore."

Vostok@cloudynights, Finland, 16" F/4.5 telescope