Jump to content

SkySurveyBanner.jpg.21855908fce40597655603b6c9af720d.jpg

Can you see in 3D? With LOA-21s you can!


BillP

Recommended Posts

Just finished a review of a new eyepiece technology invented by Russ Lederman of Denkmeier Optical in the U.S.A.  IMO it is a game changer and now I can't imagine observing open clusters without them!

See attached PDF.

https://denkmeier.com/index.cfm?fuseaction=category.display&category_ID=33&CFID=46881394&CFTOKEN=37183053

The Denkmeier LOA21 3D Eyepieces v2.pdf

Link to comment
Share on other sites

  • Replies 31
  • Created
  • Last Reply

Thanks for sharing your experience, Bill :smiley:

I've been following the discussions on CN with great interest, this pair seems to be an essential kit for binoviewer.

Link to comment
Share on other sites

Forgive me if I am wrong but from what I gather bino viewers lose approx 1" off the aperture of the scope due to the splitting of the light and the unavoidable inefficiency of a prism. Then there is the fact that most scopes don't have the inward focus travel with out a barlow which again is adding more glass / light loss in the mix. Would not eyepieces of this complexity just go to exaggerate further loss ??

Link to comment
Share on other sites

Forgive me if I am wrong but from what I gather bino viewers lose approx 1" off the aperture of the scope due to the splitting of the light and the unavoidable inefficiency of a prism. Then there is the fact that most scopes don't have the inward focus travel with out a barlow which again is adding more glass / light loss in the mix. Would not eyepieces of this complexity just go to exaggerate further loss ??

From my understanding there should not be much loss of light.  The light absorbed by the glass path will not be all that much, and of course if the prism is multicoated then the interfaces will be 99.5% efficient.  Of course, the beam is split so each eye is only getting 50% of the available light from the main objective, but then your brain reintegrates them into one image.  So as example, my 4" Apo with binos feels like a 4" Apo or a fraction less, but not like my smaller 81mm Apo.  So I think the 1" loss claim is an fairly big over statement.

IME with binoviewing, for DSO perceptually they seem to be just a little less bright, but for planetary the gains are very much as more effective seeing details with two eyes (as we are designed) than with one eye.  So for me, when the seeing is tops and I am doing planetary observing, then binoviewing is a must.

In the past I have never been much of a fan for DSO viewing with binos and just used them for Moon and planets and white light solar as everything just looks more crisp.  But for DSO observing, other than providing more comfort since using both eyes, I found no advantage.  However, with this 3D development, that is all changed for me now.  DSO are orders of magnitude more interesting to observe now that they are in dimensional space.  Changes their whole character seeing the different stars at different depths and seeing larger nebula canted at angles in space, etc. 

Newts generally will need to use the OCA/GPC/Barlow that comes with binos to reach focus.  SCTs have enough focus travel to bino without addition of OCA/GPC/Barlow.  Refractors are a toss as some have enough back focus to not need the OCA/GPC/Barlow, like my TSA-102 and my Lunt/APM 152 ED Apo, and others will not like my Vixen 81S Apo.

Link to comment
Share on other sites

Bill,

It goes without saying coming from you, a great piece of work and very interesting to read. I was going to go down the road of bino viewing a few years back, whilst I was in England dealing with my Brothers sad death I got set up with the chosen eyepiece, 24 mm Panoptics. Though with my mind being on other things I forgot to buy the bino viewers. Since that I have taken the Ethos pill and swallowed a few Delos pills as well.

It will be interesting to see how much these cost when they hit the UK, so often we end with prices close to double that of the USA, though we will have to wait and see. This seems to be the next step forward.

Thanks for sharing this with us. 

Alan

Link to comment
Share on other sites

Bill,

It goes without saying coming from you, a great piece of work and very interesting to read. I was going to go down the road of bino viewing a few years back, whilst I was in England dealing with my Brothers sad death I got set up with the chosen eyepiece, 24 mm Panoptics. Though with my mind being on other things I forgot to buy the bino viewers. Since that I have taken the Ethos pill and swallowed a few Delos pills as well.

It will be interesting to see how much these cost when they hit the UK, so often we end with prices close to double that of the USA, though we will have to wait and see. This seems to be the next step forward.

Thanks for sharing this with us. 

Alan

a few years al ready. time flys alan :smiley:

Link to comment
Share on other sites

It will be interesting to see how much these cost when they hit the UK, so often we end with prices close to double that of the USA, though we will have to wait and see. This seems to be the next step forward.

You would think with a "world economy" we will ever get around to "world pricing" as well?  Should be the vendor price of the item, shipping, then whatever the import tax is...period.  Actually there should be no such thing as an import  tax IMO but guess that is another discussion.

Link to comment
Share on other sites

Hi Bill,

i understand that your review was done based on use of these Ep`s in Russ`s 20" dob.I would be more interested to read up a review based on using these Ep`s in your 4" APO or the 6" ed as that will bring us closer to the "truth". I binoview 99.9% of my observation time and due to relatively light polluted area, my targets are only planetary,doubles,variables and bright clusters.

I am not currently interested to change my set up,as i am very happy with what i have,but i would love to hear and read the review of these new Ep`s from Russ,same goes for the new TV De-lites and Baader`s Morpheus. ;)

Clear skies

Link to comment
Share on other sites

i understand that your review was done based on use of these Ep`s in Russ`s 20" dob.I would be more interested to read up a review based on using these Ep`s in your 4" APO or the 6" ed as that will bring us closer to the "truth".

Actually, most of the descriptions of various targets are with my smaller Apos.  So only 3 or 4 of the observations I mention are with the large Dob.  The rest with the Apos.   If you look at the paragraph which stars talking about moving to less dark site and then starting with M29, from that point forward it is all with my 3", 4" and 6" Apos...primarily my little 3" actually!  Frankly I preferred the viewing with the LOAs through the smaller instruments...that 20" just could not show a lot of TFOV.

With small apertures open clusters, any nebula or glob or close double set in a rich star field, or any wide double are really where these EPs shine.  With larger apertures it is any object that fills half the FOV or more can be very interesting even if not set in a rich background.

I actually prefer them in my smaller aperture scopes.  I found that operating around 40x-60x is really a nice spot with these for the myriad of open clusters and wider doubles and just rich field scanning.  Given how spectacular the observing is with them with a richer field instrument, like my little 81mm Vixen, I am considering building a special setup just for these.  So I am thinking of maybe something like a 120mm f/5 Achromat with WO binos with 1.6x OCA and the LOA-21s as a permanent fixture.  This will give me about a 1.3 deg TFOV and 46x.  Alternatively thinking of a C6 with a reducer and WO binos without the OCA.  This will give me a little more aperture in a smaller and lighter package and give me the same 1.3 deg TFOV and 46x so perfect for all the small and large open clusters up there.  Just thinking about which setup will give me the best star points as I don't always have a lot of luck getting SCTs to behave well thermally.

I am thinking of doing this fixed setup idea because binos do add some complication to the process and not as free and easy as monoviewing.  So will reduce hassle if I just build a special setup.

ps - I will have some DeLites and Morpheus EPs in my hands next week...so will have some reviews posted a few weeks from now on all these.

Link to comment
Share on other sites

I have just got some gear from the States, it cost me about $90 for postage and the cost of the Import and VAT is about 25% on top of that.

So ($ 600 + 90) * 1.25 = $ 862

Or in UK £ 552 at todays exchange rates.

Derek

Link to comment
Share on other sites

my apologies Bill,i missed that part as i was reading your review whilst at work and must off skipped that :) definitively interesting eye pieces ,but as most of us living in UK the issue is the importation tax and shipping costs what will make these eye pieces relatively costly.

I think for time being i will stay with my 2 sets of Meade research grades + a pair of Baaders 35mm eudiascopics and combo of 4x and 2x powermates.This gives me all possible magnifications i require.

Still looking forward to your review of De-lites and Morpheus as you never know :D

Link to comment
Share on other sites

Very exciting! However i do have a pair of denki 21mm and tbh i think they are awful compared to my other lens sets (baader zooms and 24mm tv pans). So im sceptical atm.

But im a huge 3D movie fan so will be watching this thread closely

Sent from my SM-N910U using Tapatalk

Link to comment
Share on other sites

Very exciting! However i do have a pair of denki 21mm and tbh i think they are awful compared to my other lens sets (baader zooms and 24mm tv pans). 

Would you like to explain in detail what you meant? Transmission? lateral color? edge sharpness? what scope and binoviewer you're using? etc?

Link to comment
Share on other sites

Its been a long time since i used them so i have to go from memory. But i remember these lens are awful and put them away to never use again. I got them with my denki 2 super system. I also have a paire of williams optics and a baader mrk5 bino. Tried the eyepieces in all three binos. As far as i can remember they have a slight colour to them. When looking at planets and the moon about 50% out from the fov the circular objects distort into ovals very disturbingly. Hence stars outside the middle flare awfully.

Sent from my SM-N910U using Tapatalk

Link to comment
Share on other sites

Thanks for the info. Have you looked at the Moon with the 24mm Pan in the same way? I would expect that Pan should oval the Moon more than the 21mm Denk does, since Pan is known to have most pincushion distortion of eyepieces with around 70 degree FOV.

Link to comment
Share on other sites

Again I am off topic, sorry Bill, Yong I guess the Pcush is the cost of being about the sharpest 24mm EP I have ever seen.

I think the 21mm eyepieces from Pingster may well be just like stock EP's, not that that makes the problems right, Bill is a very experienced observer and would be too sharp to get caught out by poor eyepieces.

Alan 

Link to comment
Share on other sites

Thanks for the info. Have you looked at the Moon with the 24mm Pan in the same way? I would expect that Pan should oval the Moon more than the 21mm Denk does, since Pan is known to have most pincushion distortion of eyepieces with around 70 degree FOV.

I love viewing the moon in the 24pans. And yes theres some distortion. But in the denki i was unacceptable distortion . Plus if my memory serves right on the moon and planets you would see a colour fringe on those targets with the denki.

Sent from my SM-N910U using Tapatalk

Link to comment
Share on other sites

Thanks Pinster.

Alan, I know that the extra pincushion in Pan is for minimizing astigmatism for a sharp edge, but, pincushion is a distortion, and it ovals the Moon.

Sorry for being off topic Bill.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.