17 replies to this topic

[paulsky]

Hello,
I'm thinking of a BT-70 as a tool for observing bright DSOs, not dark or complicated ones, I have and use a 20x80 with ep. straight but this does not convince me for astronomy, for terrestrial it is something else, it is magnificent.
What is your opinion on this?
I know that the bigger the better, but I want something light and quick to set up, half an hour or so or for specific events, such as conjunctions, eclipses, lunar rises, taciturn Venus,..., even if I sacrifice opening.
I would use this BT-70 with two magnifications, at most, one around 20x and another 40x or 50x...what do you think?
My neck is already asking for a truce!!
Thank you
Paul

[wrighty338]

Moving from a 25x100 Deluxe and 20x65 ED Deluxe to my BT70 was quite a revelation for me and i cannot imagine even attempting anything near zenith now on a mounted straight through binocular, the 45 degree viewing angle was a game changer.

 

i keep a baseplate attached to my BT 70 so setup simply involves taking the Oberwerk 5000 tripod out of its bag, popping the eyepieces in and attaching. This process takes less than 5 minutes. I can pick the entire setup off the ground no problem to relocate around the garden and even better If i see a run of clear nights forecast i simply place the setup in the garden summer house ready for the next night. I often setup prior to twilight so there is no fumbling around in the dark, just when im waiting for my cup of tea. 

 

My equipment goes back in its box and onto the garage shelving once im done, sometimes for months at a time but it never seems a chore to get ready. With the British weather iv realised i just have to be ready to setup and take what observing windows i can because at the mercy of the Atlantic jet stream opportunities can be few and far between. If you have space to keep the BT setup with the covers on and perhaps the legs collapsed you would be laughing. I own 3 baseplates for the tripod just incase i want to mount anything else, but currently dont own any other mountable binocular worth mounting

 

Beauty of a BT is you can pick & choose your binocular for whatever session you're planning. IMO 3 sets of eyepieces would leave you with all bases covered, something around 20x or just either side lets say 18x (Oberwerk 22mm) or 22x (Morpheus 17.5), you have standard oberwerk 14mm's giving 28x, then perhaps a nice high quality 10mm like Pentax XW for 39x? il probably pickup the oberwerk 22mm's myself, as they will be handy on another BT but for more zoom i think id go for a higher quality item.

[DeanD]

I agree, but my concern relates to 45 degrees vs 90 degrees for astro viewing. I have been using a borrowed 45 degree 125 BT, which is great: but I find it awkward for higher objects, and if I was considering purchasing one I would go for 90 degrees. I know there has been lots of discussion on this forum about this, and lots of arguments for and against, but I am firmly in the 90 degree camp.

 

Just a thought for consideration.

 

- Dean

[paulsky]

Moving from a 25x100 Deluxe and 20x65 ED Deluxe to my BT70 was quite a revelation for me and i cannot imagine even attempting anything near zenith now on a mounted straight through binocular, the 45 degree viewing angle was a game changer.

 

i keep a baseplate attached to my BT 70 so setup simply involves taking the Oberwerk 5000 tripod out of its bag, popping the eyepieces in and attaching. This process takes less than 5 minutes. I can pick the entire setup off the ground no problem to relocate around the garden and even better If i see a run of clear nights forecast i simply place the setup in the garden summer house ready for the next night. I often setup prior to twilight so there is no fumbling around in the dark, just when im waiting for my cup of tea. 

 

My equipment goes back in its box and onto the garage shelving once im done, sometimes for months at a time but it never seems a chore to get ready. With the British weather iv realised i just have to be ready to setup and take what observing windows i can because at the mercy of the Atlantic jet stream opportunities can be few and far between. If you have space to keep the BT setup with the covers on and perhaps the legs collapsed you would be laughing. I own 3 baseplates for the tripod just incase i want to mount anything else, but currently dont own any other mountable binocular worth mounting

 

Beauty of a BT is you can pick & choose your binocular for whatever session you're planning. IMO 3 sets of eyepieces would leave you with all bases covered, something around 20x or just either side lets say 18x (Oberwerk 22mm) or 22x (Morpheus 17.5), you have standard oberwerk 14mm's giving 28x, then perhaps a nice high quality 10mm like Pentax XW for 39x? il probably pickup the oberwerk 22mm's myself, as they will be handy on another BT but for more zoom i think id go for a higher quality item.

Have you noticed a lot of difference in how objects look on the 25x100 compared to the BT-70?
thank you

[wrighty338]

Have you noticed a lot of difference in how objects look on the 25x100 compared to the BT-70?
thank you

Aperture difference aside, Yes an instantly noticeable difference in quality was apparent as you would probably expect for an additional $1000 over both Deluxe series binoculars. Truer colours on stars, no halo effect on stars were stand out differences (there's probably a technical term for that). I sold my straight through binoculars right away and wish i started with a BT earlier. 

 

Last night i viewed the 39% waxing crescent moon which is not something i do often and was reminded just how good the optics were, super sharp high resolution images even with the oberwerk EP's

[wrighty338]

We have no clear sky forecast this week so i just packed the setup away and also timed it at 3 minutes 10 seconds so well under 5mins, a good estimate of setup time but in reverse. All lens caps replaced, tripod collapsed in its bag and all back on the shelf.

[gwlee]

Hello,
I'm thinking of a BT-70 as a tool for observing bright DSOs, not dark or complicated ones, I have and use a 20x80 with ep. straight but this does not convince me for astronomy, for terrestrial it is something else, it is magnificent.
What is your opinion on this?
I know that the bigger the better, but I want something light and quick to set up, half an hour or so or for specific events, such as conjunctions, eclipses, lunar rises, taciturn Venus,..., even if I sacrifice opening.
I would use this BT-70 with two magnifications, at most, one around 20x and another 40x or 50x...what do you think?
My neck is already asking for a truce!!
Thank you
Paul

If you have a small refractor, I suggest buying an inexpensive 45° diagonal for it to evaluate whether your neck will enjoy looking at high elevation astronomical objects through a binocular telescope with a 45° eyepiece orientation. Mine doesn’t, but yours might, or might not. It’s better to find out with a $52 diagonal before buying a $1,600 binocular telescope. 

https://www.celestro...-image-diagonal

Edited by gwlee, 14 April 2024 - 05:47 PM.

[Rich V.]

Since you're in Europe, and you're primarily looking for astro use, it's easy enough to shop for a 90° model made by KUO from one of the vendors over there.  Achromat and ED models available.

 

https://www.apm-tele...fernglaser-70mm

 

https://www.teleskop...ece-holder-9346

 

https://www.omegon.e...x70-90d/p,61489

[revans]

If you want it pretty much for astronomy then I'd get a 90 degree tilt BT.  Orion is as good as anything.  You could consider their BT-70 or BT-82. Personally, I'd get the BT-82 only because I know that from personal experience in my Bortle 6 sky at least, practically anything faint and fuzzy in the sky that is mag 10 or brighter is visible in a BT-82.  I'm not sure about a BT-70.  

 

Rick

[sevenofnine]

If I had $3k to spend on a BT for astro & good mount, it would be this one 

 

https://www.telescop...60/p/132191.uts.

[revans]

If I had $3k to spend on a BT for astro & good mount, it would be this one 

 

https://www.telescop...60/p/132191.uts.

I bought one of those a few days ago.  I'm hoping it will be decent.  I'm working on what I'm going to do for a finder.  The handle is different than the rails on the Oberwerks that hold the red dot finders.  I'm thinking of taking a small 8x30 finder and fixing it to the handle with a couple of zip ties.  I think that should work.  I didn't pay $3K... it was "only" $2.25K.  The glass turns out to be FK-61 so it is ED.  It is heavy though... about 16.5 lbs give or take.

 

Rick

[sevenofnine]

Rick...good for you!! I think that's the right choice especially if your targets are at zenith. The $3K included Orion's mount 

[BWAZ]

I have been using my Orion 100ED for a while I'm very satisfied. For the typical magnifications,  I don't feel like I'm missing the SD glass.

[aznuge]

I bought one of those a few days ago.  I'm hoping it will be decent.  I'm working on what I'm going to do for a finder.  The handle is different than the rails on the Oberwerks that hold the red dot finders.  I'm thinking of taking a small 8x30 finder and fixing it to the handle with a couple of zip ties.  I think that should work.  I didn't pay $3K... it was "only" $2.25K.  The glass turns out to be FK-61 so it is ED.  It is heavy though... about 16.5 lbs give or take.

 

Rick

More expensive than zip ties, but this one is bullet proof.  It is a two piece pedestal - you can leave the base plate attached for quick storage, then retrieval without change in zero.  Any finder that can be mounted on a picatinny will work with this.  I have one ea. on my 82mm and 100mm APM BTs.

[aznuge]

The Orion BT100 has an identical handle I'm pretty sure.  Just FYI as a finder option...

 

The one on my APM82/90:

 

[revans]

More expensive than zip ties, but this one is bullet proof.  It is a two piece pedestal - you can leave the base plate attached for quick storage, then retrieval without change in zero.  Any finder that can be mounted on a picatinny will work with this.  I have one ea. on my 82mm and 100mm APM BTs.

Nice solution.... but I suppose it has to be ordered direct from Germany... it would be nice to buy from a US dealer if possible.  

 

Rick

[sevenofnine]

Pretty sure that RDF is the same as the W/O version from Agena Astro that include an extra shoe...very nice BTW 

 

https://agenaastro.c...se-bracket.html.

[Jeff Morgan]

I agree, but my concern relates to 45 degrees vs 90 degrees for astro viewing. I have been using a borrowed 45 degree 125 BT, which is great: but I find it awkward for higher objects, and if I was considering purchasing one I would go for 90 degrees. I know there has been lots of discussion on this forum about this, and lots of arguments for and against, but I am firmly in the 90 degree camp.

 

Just a thought for consideration.

 

- Dean

 

Agree. I have arthritis from a neck injury, 45 degrees is only half a solution.