Finally got skywatcher ED50 finderscope to work with diagonal. Now have nice little travel scope!!!!!!!!!!!!!!!

[Mark Daniels]

So after a couple of months faffing about, trying stuff out and trawlling the net for ideas, i think i have a solution that works. I wont take credit for basic idea but have refined it to make solution less hassle. 

So i read on post here and on some american sites that the use of a barlow would sort out the focusing issue and it did 

however it requires using a barlow between the diagonal and the extension tube. This inceases the length and makes for a wobbly affair. In a moment of enlightenment i wondered if i could combine the barlow and the diagonal to make one unit. I have other skywatcher scopes and so spare barlows and diagonals. I took the lens from a barlow screwed it to the diagonal and had ago

hey presto it worked. Whats more using the supplied spacer provided with the ED50 the scope now focuses in the center of travel of the focuser so no issues with lens length etc.

was up last night looking at jupiter which was small but clear, split a double or two again small but clear and took a look at andromeda which was not bad considering the moon was out.

because of the barlow the magnifications were doubled obviously but being 242 FL the FOV was the same as my 102 travel but wiegt wise probably 1/4 of it

42mm= 10x

32mm= 16x

25mm= 20x

15mm= 32x

12.5mm= 40x

9.5mm= 50x

give or take a few units

 

for a holiday affair i am extremely happy and i will be using this scope lots between now and my visit to La Palma in the new year in preparation

picture attached for those interested and i will up date as i work out some king of red dot finder fir it

cheers Mark

 

[Rick_It]

Good idea!! Any CA introduced by the Barlow?

[Mark Daniels]

Not that i noticed certainly not looking at stars and jupiter. That said they were small targets. Jupiter was a undifined but very sharp circle no CA and fairly big and the moons pin sharp dots.  i will look at the moon if out tonight. Probably there will be some but i can live with that as size of scope and wieght is the main thing. The alternative for same compact scope would mean at least 700 quid. 

Will let you know👍

[Mark Daniels]

Took the scope to the top of hill near where i live this afternoon

looked at tower approximately 1 mile away

no CA at all. Very happy 

[timwetherell]

What a cool project, that's made a nice little portable scope. Enjoy

[Peter Drew]

That's the way to do it!. The Barlow might give a tad more than 2x if the distance between it and the eyepiece is greater when screwed to the diagonal than used as a standard Barlow arrangement. I would be interested in your impression of the higher magnification potential.   😀

[Mark Daniels]

The furthest i could go with my eye pieces was around 50-60x but more than enough for star hopping. Sure you could go to 100x with the right lens   

I think this little scope is very well made indeed  and very clear to my eyes  with no vignetting or CA will try with a camera when i get goto set up  

👍

 

 

[Rusted]

What an interesting idea!
You could use a suitable target to confirm the true amplification factor of the forward positioning of your Barlow.
A tiled roof, with and without the Barlow, would be the easiest method. Assuming, of course, that you can reach focus without the Barlow.
Failing that, count roof tiles with the Barlow in the conventional position and then in your forward "advanced" position.
Suitably distant, equally spaced, fence posts would work too. 

Use the same eyepiece each time and see how many of your chosen "units" can just fit across the full field of view.
Try it with the Barlow in each position. Normal [close to the eyepiece] position and "advanced."
Then you will know the extra amplification factor and can make up a list of your real powers. 

[Mark Daniels]

At some point ill give it a go. At the moment happy gazing away.  

Can focus thats the main thing

good ifea though👍

[tico]

Hello,
I think that his instrument under the exceptional skies of La Palma will show him objects as he has never seen them before ...
tico

[Mark Daniels]

39 minutes ago, tico said:

Hello,
I think that his instrument under the exceptional skies of La Palma will show him objects as he has never seen them before ...
tico

I hope so 😀

[happy-kat]

Very interesting. I've got a 1.6x shorty barlow and hadn't tried placing the barlow before the diagonal plus I've got the 12mm ring. The ED50 may get a stay of eviction if this works for infinity for me. Thanks for sharing. 

[Mark Daniels]

On 13/08/2019 at 09:47, happy-kat said:

Very interesting. I've got a 1.6x shorty barlow and hadn't tried placing the barlow before the diagonal plus I've got the 12mm ring. The ED50 may get a stay of eviction if this works for infinity for me. Thanks for sharing. 

Just had a couple of hours looking up with it

so at 40x which was the 2x barlow conversion plus a 12mm wide field i was able to split the double in the plough which was clear and bright

all stars looked pin sharp no CA 

i got the great cluster in hercules even though skies here not very dark and quite light poluted it wasfaint but there

jupiter was small but banded and the four moons were out to play

and i added a second barlow before lens and after diagonal for saturn which showed bit of colour and defined rings but it was pushing it to be fair. Reckon got me up to around 80x

lots of stars around cygnus but had to give up on andromeda as behind neighbours house and i have work tomorrow

give it a second chance. I will take it to a darker site over next week or so and post agsin

👍

[happy-kat]

Great update. As an ongoing challenge could you try for Jupiter's great red spot with your setup please? There's a thread with success and so far I think it's a 70mm and possibly 60mm Ranger that's managed it.

[Mark Daniels]

4 hours ago, happy-kat said:

Great update. As an ongoing challenge could you try for Jupiter's great red spot with your setup please? There's a thread with success and so far I think it's a 70mm and possibly 60mm Ranger that's managed it.

I will have a go. I think though possibly not powerful enough. However with an astro camera and software using it that way should be good. It is designed to be used as astro lens. Have a go tomorrow as skies should be clearer will try with extra barlow like i did with saturn👍

[Mark Daniels]

Ok so today brought from hong kong a replacement bracket made by

Sybony £25 ish

well made aluminium and a shorter mount so i can reduce size in case. Trying to get it all as small as possible so i can take as hand lugage on plane. Tripod can go in suitcase in hold.

works well. Used thescrews from the supplied mount as locking ones.

last night it was quite bright from light polition and i was having trouble finding square inHercules so i could locate great cluster used my vixen binos to help and found if i placed behing red dot finder i could magnify enough to see stars well but also the red dot appeared in FOV and helped me align scope to around the right area 

next is to figure some kind of mount/ rest to hokd binos square to scope as it was a bit fiddly to do

pictures attached

👍

[Rusted]

If size really matters: A dewshield is not strictly necessary except to protect against dew on the front of the lens.
If the dewshield is sliding and retractable then you can ignore the following:
The problem is protecting the lens if the dewshield is absent.
Lens caps of all sorts might be available in particular size which avoids having the original dewshield. Binoculars?
Failing that, find a length of tube the same size as the dewshield and make a much shorter one.
I'd be looking at plumbing plastic pipe, aluminium tube or even a tough plastic bottle which once contained household products or foods.
My entire life seems to have been spent trying to find alternatives to foolishly expensive, commercial products.
Charity shops have aluminium ornaments and lamps, stainless steel tubular things. The weirdest stuff imaginable if it works for your project.
Just be careful not to force anything into place. Cloth or electrical tape can offer protection and ensure a snug, sliding fit.
Fix the tape inside the donor material. Not on the telescope.

[happy-kat]

The dew shield is miss leading as the lens goes up the black bit about 30,% roughly (mines in it's box currently)

[Mark Daniels]

2 hours ago, happy-kat said:

The dew shield is miss leading as the lens goes up the black bit about 30,% roughly (mines in it's box currently)

Yep not really a dew sheild. I am looking at possibilty of fitting a solar screen as it seems threaded if i can find a lens ring to fit say from a camera lens company then i can machine a cover to fit it snuggly and use a sun filter sandwiched between preventing sun penetrating and the obvious dangers. May even be able to find a manufacture one but something for the future. That said i may buy a dew shield to add as lens only about 30mm from opening. 

 

[Mark Daniels]

8 hours ago, Rusted said:

If size really matters: A dewshield is not strictly necessary except to protect against dew on the front of the lens.
If the dewshield is sliding and retractable then you can ignore the following:
The problem is protecting the lens if the dewshield is absent.
Lens caps of all sorts might be available in particular size which avoids having the original dewshield. Binoculars?
Failing that, find a length of tube the same size as the dewshield and make a much shorter one.
I'd be looking at plumbing plastic pipe, aluminium tube or even a tough plastic bottle which once contained household products or foods.
My entire life seems to have been spent trying to find alternatives to foolishly expensive, commercial products.
Charity shops have aluminium ornaments and lamps, stainless steel tubular things. The weirdest stuff imaginable if it works for your project.
Just be careful not to force anything into place. Cloth or electrical tape can offer protection and ensure a snug, sliding fit.
Fix the tape inside the donor material. Not on the telescope.

Thanks good idea. The black emd is more a protection for the lens i will need to extemd to help reduce dew so the pvc pipe will work well. 

[Mark Daniels]

On 16/08/2019 at 13:24, Mark Daniels said:

I will have a go. I think though possibly not powerful enough. However with an astro camera and software using it that way should be good. It is designed to be used as astro lens. Have a go tomorrow as skies should be clearer will try with extra barlow like i did with saturn👍

Had a look last night. Couldnt see the red spot but not great viewing as lots of light polution but i think if the sky was dark it would be possible. 

[Mark Daniels]

Update managed to just make out ring nebula with 9.5 lens. Sky was quite clear but still light poluted. Think it would be quite noticable if dark sky. Magnification was around 45x i think

love this little fella 

[happy-kat]

That's impressive you managed that spot.

 

[Mark Daniels]

Got some bits from China today. Couple of brackets. Bit of modding and now can fix camera to travel set up. Quite pleased

 😊

[happy-kat]

Looks like they potentially counter balance each other.