• BirdForum is the net's largest birding community dedicated to wild birds and birding, and is absolutely FREE!

    Register for an account to take part in lively discussions in the forum, post your pictures in the gallery and more.

The Baader Hyperion Mk IV Universal 8-24 Zoom,..A small review and open thread. (1 Viewer)


Well-known member
Hello..I want to make a small review of this eyepiece,and use the thread to keep all the comments that users want to add about this eyepiece, its use in different scopes and its performance.

I have had this eyepiece for a bit over a month, as a loaner that Baader sent me, upon request ,to clarify its use and compatibility with different optics.
I mentioned to Baader that I had experience adapting the Mk III to my Kowa scope and that always praised,in all honestly,the qualities of this zoom in the forum. I was very happy when some member mentioned that the Mk IV was able to be attached directly to the Kowa 823,but other members claimed that it would not attach or reach focus,so I offered myself to test and clarify the use with this model,and perhaps other models If I had the chance. It turns out that Baader had tested many of the current models and are quite aware of what does and does not work, but there is always room to some more experiments.

Anyway ,as far as performance goes this new version MkIV of the Hyperion Zoom is very close optically to the previous version. At first Glance Coatings have been changed in both ends of the eyepiece, as advertised by the manufacturer.
Improved coatings are in the list of changes ; Improvement to the already excellent Phantom coatings featured by this series of oculars.The new coatings are green and a bit deeper versus the bluish hue of the mkIII

The Mk III has excellent coatings already .Contrast ,color rendition as well as glare control are very good. Colours are natural yet vivid with the best possible contrast. Internal reflections (or external on the lens surface) are virtually non-existent, and same with glare ..I don't think other changes have been made to the optics so I wont go on evaluating the view,because there are lots of comments over the internet about this Zoom views.
It offers a wide field of view ,excellent contrast and a sharp image at all magnifications..All I can say is that since I placed the Baader zoom on my 823 I have sold some of my Kowa wide eyepieces ,The 21X WA ,the 32X and the 50x and those are VERY good eyepieces that I felt I didn't need anymore.

For me a wide zoom is a big deal. To Have an old fluorite scope like my 823 ,that lacked a good zoom ,meant to carry a couple of wide field eyepieces with me ,and change back and forth .Even if I didn't change a lot .I rather to zoom. and keep the wide field.
I modified the threads of the mkIII but now they were wearing off,due to a bad measurement in my modification, thats why I was excited about the MkIV, and sad when I read some reports of it not working on the 823!!!
As it turned out IT DOES WORK as a charm.. The eyepiece fits the Kowa threads and as expected allows for a less tight infinity focus point...more on that later..

The other changes that are visible and tangible are the physical dimensions and the operation of the zoom. The Size and weight of this zoom had been reduced considerably.The mark III had a quite massive presence and hefty weight. People using Binoviewers wanted thinner eyepieces to have room for the right interpupillary distance. The Mk IV is much slimmer and lighter.The reduction in weight helps with balance .This I feel a lot when using the Mk IV vs MkIII..with the MkIK I don't have the scope moving backwards all the time, specially if I do phonescoping or digiscoping .I think we talk 6 Oz in weight reduction.
Then comes the operation of the zoom...the other improvement..also very evident is the now super smooth zoom operation with the same distinctive click stops . The mark III was a bit stiffer ,specially in cold weather,and baader redesigned the whole internal rail system to deliver a much more easy to move zoom action. Ultra smooth is the feeling.

And to finalize the account of changes ,another quite important one is the Universality (Hyperion Universal zoom eyepiece)..The eyepiece now is much easier to adapt to a number of spotting scopes and telescopes..
Up to the MkIII the zoom had a fixed rotatory collar to fit the 1 1/4 ,2 inch barrels and the SCT adapter. Many spotting scopes using astronomy eyepieces , had problems reaching focus with this eyepiece because it sat high on the adapter.
So another redesigned feature here..A new removable collar is now fitted to the Zoom,.This collar fits directly 2 inch astro barrels,SCT telescopes and lucky for me Kowa 823 external threads with a great ,secure fit. Two adapters are provided to fit 1 1/4 barrels..one for telescopes and one ,with a lower profile,to fit spotting scopes allowing not for 4 extra mm back focus ,often needed to reach infinity.
Baader makes now a number of adapters and step down rings to different models. A larger diameter ring has been produced to fit Kowa 88/77 series and adapters to fit Zeiss, Leica ,opticron and other Kowa models are also made,among many other accessories for photography .

My intention was to keep testing different models with the zoom and create a list of compatibility...I will add to the thread personal experiences as well as links to others experiences shared in this or other forums...


New member
Kowa TSN-823

Hi mayoayo,

I have just purchased a used 823 and 32xW eyepiece. I am intrigued by the Baader Hyperion Mk IV and appreciate your thorough review.

I just want to put my mind at rest and confirm that the MkIV is definitely compatible with my 823 without the need for an adapter.

Would you recommend the MkIV over the 20-60 zoom for the 820 series?

Thank you!

Users who are viewing this thread