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Hmmmm, what's this????

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#1 Eddgie

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Posted 22 July 2013 - 01:00 PM

Looks like a Binotron connected to a T2 Prism!

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#2 REC

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Posted 22 July 2013 - 01:14 PM

So that sure looks nice! Not much light path loss with that! How long will the OTA be from the back of your SCT? Are you going to test it out in your C8 as well?

Bob

#3 johnnyha

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Posted 22 July 2013 - 01:36 PM

Very nice! I actually have something similar although I have not connected it yet, mine was an adapter made by Precise Parts and I added the Quickchanger dovetail. The top in the photo threads into the Denk PowerXSwitch. The one that Ed has posted is even a bit shorter though!

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#4 swampdog

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Posted 22 July 2013 - 01:54 PM

Ha! Ha!..That bino likes to play!

#5 Eddgie

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Posted 22 July 2013 - 04:00 PM

This is the prototype from Denkmeier. It needs a few minor changes, and Russ is going to cut a new one and send it to me for evaluation.

Of course this idea is that he will put them into production soon and sell them as an option for those that want to utilize short light path diagonals like the T2 Prism.

I was so excited though that I could not wait and asked Russ if I could show pictures and he agreed, so I think he is committed to going ahead with production!!!!

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#6 herrointment

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Posted 22 July 2013 - 05:51 PM

Three cheers for Mr. Moreno!!!

Reason and persistence are a winning combination....thanks, Eddgie!

#7 REC

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Posted 22 July 2013 - 05:59 PM

Wow, that looks awesome! Is this a better solution than using a diagonal that screws directly into a SCT to keep a short light path?

Bob

#8 Eddgie

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Posted 22 July 2013 - 06:26 PM

Honestly, I don't know. I think you may be talking about the Baader Clicklock, which when used with the locking ring can have the nose removed and be screwed directly to the rear of the SCT port?

The configuration I am using is the Televue Short SCT/2" adapter. This is as short as you can get in a normal 2" adapter, but it is still about 30mm!!!

The Maxbright mirror though is ZERO! The diagonal body literally screws right on to the rear port. Can't get shorter than that.

But this means that you have the light path through the diagonal and this is still about 65mm for a standard 2" diagonal. The T2 Prsim is only 38mm, so add 38mm to that and you are at about 76mm, but the binoviewers don't screw on to the top of this diagonal so if you were using it with binoviewers, you would need to put the 2" nose on them and this adds 30mm or so.

I think Denkmeier has a dovetail that will allow you to mount directly to the top though, and this would only add a bit to the light path.

The Baader Clicklock though is going to be the shortest 2" configuration for monoviewing though.

For binoviewing, if Denk has the adapter that lets you screw right to the top and not use the eyepiece holder, it may actually be a bit shorter than the T2.

But you also need the Lock Ring.

Could be an expensive way to save a few millimeters.

I would personally go with the T2 Prism and the Televue short SCT/2" but I am trying to go 100% binoviewer.

If you are going to continue to use 2" eyepeices and have to buy a 2" diagonal anyway, the Baader Clicklock with locking ring may make more sense (again, this assumes that Denk makes a mating ring which I believe is available). Then you could screw off the eyeppeice holder and put on your binoviewer.

There could be clearance issues to. I have not had any serious clearance issues with the Televue Short adapter but with smaller SCTs, the Clicklock solution is not going to clear the focuser, and on the EdgeHD 8" may not clear the mirror lock knobs.

Complicated, isn't it...

#9 Sorny

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Posted 22 July 2013 - 06:30 PM

Nice! I just got my Binotron-27 "a-la carte" and the unit itself is VERY nice. The Bino/Power Switch hooked to the T2 looks quite slick.

Maybe Russ will temp you to the dark side and you'll embrace the power switch. :bigshock:

You should be able to use an adapter straight to the binotron body as well. The power switch should just thread to the body of the binoviewer. It's worth a shot for experimentation's sake. ;)


#10 Eddgie

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Posted 22 July 2013 - 08:30 PM

Yes, I have used it with the dovetail on both the powerswitch and directly on the bino body, but only today while testing on the C5 (solar).

I have been making measurements of the difference in aperture reduction when comparing the 2" diagonal configuration to the T2 prism.

I am not really going to share the data here, but I can say that in general, the result is consistent with my ongoing messaging on the forum which is that the shorter the light path, the better off you usually are, and the Baader Prism is much shorter than a standard 2" diagonal and so far, my measurements are 100% consistent with my message.

Am testing with the C14 tonight.

It is tedious though because for every configuration, I have to unmounts the scope to make the measurement. Was easy with the C5, but I am dreading it with the C14.

#11 Sorny

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Posted 22 July 2013 - 08:38 PM

I can't say I envy you that task with the C14...

Wind picked up for me, and clouds moving in. Apparently the new gear curse is alive & well.

#12 Eddgie

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Posted 22 July 2013 - 08:54 PM

By the way.. This is not my Binotron. Denkmeier sent it to me to test the T2 adapter prototype and to provide data on the difference the light path changes make vs a 2" diagonal.

I have to return it when I am done.

#13 Astrojensen

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Posted 23 July 2013 - 01:25 AM

I though the Binotron 27 looked quite interesting, mostly because of the big prisms and the collimating, but wrote it off, because it wasn't compatible with the T2 system and Denk didn't have anything similar. This changes things drastically.


Clear skies!
Thomas, Denmark

#14 Eddgie

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Posted 23 July 2013 - 07:50 AM

Yes, I am happy to see that Denkmeier is interested in offering this option.

My message has been that for SCTs, light path length can be very important, and this addition will allow compatibility with the T2 Prism which is about as short as one can get.

Perhaps when Denk realizes how profitable it would be having their own short light path option for a diagonal, maybe they will produce one.

To me, the perfect diagonal would eliminate even the quick change connector and simply thread directly on to the binoveiwer with maybe an O'Ring between them for resistence.

This was my goal when I made my own "T2 Prism". I really wanted to find a short adapter that was threaded for the prism hosing on one end and the Binoviewer on the other end to eliminate the 8mm in between the bino body and prism.

This is the best I could do:

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#15 Eddgie

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Posted 23 July 2013 - 07:53 AM

And I am only 11mm of light path length away from getting full aperture out of the C5 using the setup above.

I have very seriously considered cutting the front and rear of the TV SCT to 2" adapter and further shortening the 2" to 1.25" adapter in the picture, but the gain of 3mm is not worth it I suppose.

From where I started though, I have improved the brightness of the C5 by 25%. Not bad.

#16 bcuddihee

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Posted 23 July 2013 - 08:26 AM

Actually Russ does make this connector..its called the special dovetail connector. T screws on to the bino where the nose piece attaches and then directly to the diagonal body sans the eyepiece connector. With the denk system the eyepiece connector does not screw on as in many other diagonals but rather it attaches with two thumbscrews. I have one on order and I'll post pics when I receive it.

#17 Eddgie

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Posted 23 July 2013 - 08:48 AM

That is the part for the 2" diagonal though, yes?


I don't think that adapter works with the T2 threads on the Maxbright Prism, T2 Zeiss Prism, or Maxbright mirror.

These have much shorter light path than the 2" diagonal an that is why I think some people are interested in this particular adapter. It allows you to use these smaller diagonals.

After all, if he did already have this solution, then I would not be testing a prototype for him it would seem, yes?

I am testing this because he contacted me after becoming aware of my on-going posts about light path length.

I think he became concerned because perhaps he thought I was picking on Denkmeier (I was not, but rather highlighting the compromises of any long light path approach with an SCT). Anyway, during the dialog, he asked what he could do, and I said "Get T2 compatible."

He listened and is now acting.

I have provided him with many different actual measurements showing the difference between a best case 2" diagonal system (and most people do not have best case... Far from it usually) and the T2 prism.

Even as compared to the best case 2" scenario (Standard 2" diagonal), the T2 Prism easily came out ahead on every telescope I tested on, reducing the focal length and in many cases increasing the aperture by enough to make a 25% difference in brightness (vs a "Typical" 2" system where no particular attention was paid to keeping light path short).

Removing the eyepiece holder on a 2" diagonal is an improvement though, and for someone that wanted to stay with 2" diagonals on their SCT for binoviewing, it would of course be great as long as they followed though and also went to the AP visual back or the TV short SCT to 2" adapter. Using it with something like a Clicklock visual back does falls short of optimal.

#18 Sorny

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Posted 23 July 2013 - 09:39 AM

Is the Baader diagonal body strong enough to not deflect with the not inconsiderable weight of the Binotron and a pair of eyepieces? My Binotron body and pair of D21s have some heft, and will act like a lever off the diagonal. I've never used Baader stuff, but given the praise they get, I'm assuming they are pretty stout in construction.

How did testing go with the C14 last night? I imagine mounting/unmounting the scope was a chore, but I'm curious if the T2/dovetail setup allows your scope to work at full aperture with the reducer arm in particular.

I'm hoping I can get by without taking the eyepiece adapter off my S2 power switch using the Binotron and D21 eyepieces and use the reducer arm without having to use the dovetail. Unlike my WO bino, the binotron goes right into the 2" holder, so I gain a few mm there by not using a 2" to 1-1/4" adapter, and the D21s have the field lens very close to the bottom of the barrel (internal field stop), instead of up past the barrel like my Agenas, so I gain a lot of mm there, but then I think I lose a lot of that in longer light path of the binotron. I'm not concerned about aperture reduction with my C11, but I am concerned about running out of focuser travel. I'll find out tonight (forecast is looking stellar, no pun intended). If I run out of focuser travel, then I'll be making a call to Russ to inquire about either a shorty nose or IVB nose for my diagonal.

#19 Eddgie

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Posted 23 July 2013 - 01:22 PM

First, the Baader Maxbright Prism is a very high quality diagonal (and this is not the much more expensive Zeiss unit either) in a very robust metal housing. This diagonal was designed for binoviewer use.

I use mine with my Mark V all the time and I feel 100% comfortable with it. Otherwise, I would not hang the $1400 binoviwer off of it.

I also routinely use long heavy Baader Hyperion eyepeices.

Just out of curiousity, I weighed the different configurations and here is what I came up with.

The Mark V with the Dovetail installed is a porky 786 grams.

The Binotron with the prototype T2 dovetail is actually much lighter coming in at a very svelte 616 grams (no Powerswitch).

Even with the Powerswitch and the T2 adapter, the Binotron is still lighter than the Mark V coming in at 773 grams (vs 786 for the stripped down Mark V.

Only with the 2" nose does the Binotron come in heavier (819 grams) but of course if you were using it with the T2, it would not need the nose.

Anyway, there is absolutely no issue at all with using the Binotron on the T2. It is a rugged diagonal and I trust it 100% even with the heavy Mark Vs and a pair of 13mm Hyperions.

#20 crow

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Posted 23 July 2013 - 01:53 PM

Binotron plus T2 and no power switch sounds tempting to me. Being bino'less at the mo this could be what I'm looking for.

#21 axle01

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Posted 26 July 2013 - 10:52 PM

Eddgie can you post a photo of the tube adapter that screws into the bino that then goes into the dovetail connector.

I want to see how long it is compared to the original one.

I have a order for a dovetail connector #44/46 and adapter #42 and was interested in how long the new one is.

#22 Eddgie

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Posted 27 July 2013 - 04:20 PM

I am not at all sure that I know exactly what you want a picture of, but if you just want to see the Dovetail that will allow the Binotron to work with the T2 diagonals, here it is.

This is the prototype and the unit will be 1.5mm longer than this on the dovetail in the picture. I determined that the prototype did not have sufficient engagment with the quick connector and recommend the change... The next revision is being cut soon and I will have it hopefully in a week or so, and it should be about the same lenght as the Baader dovetail then.

I get the impression that B27 sales are very strong and Russ is giving his attention to filling back orders now so this is (rightfully) a lower priority.

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#23 Eddgie

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Posted 27 July 2013 - 04:21 PM

Again, this is a prototype and not at all indicitave of the final product. It is like a first draft.

#24 axle01

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Posted 27 July 2013 - 08:02 PM

Thanks Eddgie, so that screws into the bottom of the bino, so how can you rotate the bino if the taper is locked into the diagonal.

I have a Williams Optics diagonal and the eyepiece adapter has the same taper but it is locked in place with 4 grub screws under the side plates, so I don't understand how the bino can rotate if the taper is locked in place.

Do you know what size thread it is, I can easily machine one up if I know what size thread it is.

I hope you understand what I mean.




#25 Eddgie

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Posted 28 July 2013 - 12:25 AM

This part is designed for use with the Baader Quick Connector, which threads on to the top of the Baader T2 Prism and Maxbright Mirror diagonals. It is not really intended for any other application.

The Baader T2 prism is only 38mm in light path, so that is an important factor for keeping the light path short in an SCT.

Look up "Baader Quick Connector" and you will see the parts involved, and again, the quick connnector goes on to the top of the baader Diagonal, which has T2 threads.

The Quick Connector has a screw on it that retains the flare of the part in the picture and the screw is inserted enough to lock the diagonal into the Quick connector, but not so tight taht it can't turn...






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