New Barlow lens advice for a Mak telescope

[Hartmann]

Hello

I have a new  127 1500 mak telescope and i don´t know what barlow eyepiece  or  would be good for my telescope. My eyepieces are the two  stock eyepieces with 20 mm and 10 mm with two aditional super plosl of 32mm and 12,5 mmn purchased separately,

I know that there are some very good and expensive barlows , but  i don´t want a very expensive optics, only a good balance between cost and quality, My budget it´s a bit limited because i have to buy the Eq mount .

There are some that are very cheap but i´m afraid that this would  degrade the quality of the view too much.

which barlow would be good enough ?

thanks , and clear skyes

[brantuk]

"My budget it´s a bit limited because i have to buy the Eq mount"

It's hard to recommend a barlow if you don't state what your budget is for it. Of the ones below £100 there's the 1.25" Celestron Ultima 2x which is no longer in production - you can find them between £45 to £60 second hand depending on age/condition. Also the 1.25" Orion Shorty Plus 2x at a similar price s/h. Circa £65 s/h the Antares 1.6x 2" model is also good. And under £45 s/h you should be able to find a used 1.25" Tal 2x. I have all of them except the Tal which I sold on and they are all very good performers for the price.

I'm not aware of any of the newer crop of barlows or how good they are except the 2" TV Powermate 2x which is a superb magnifier and sells second hand around £180 to £220 'ish. Hope that helps.

[Stu]

Hi

Are you sure you want a Barlow, and what would you want to achieve with it?

I ask, because I think you would be better off buying another eyepiece which I think would get more use in your scope.

Assuming a x2 Barlow.....

....You have a 20mm and a 10mm, barlowing the 20 gives you the 10, so no need. Barlowing the 10 gives you 5mm which is x300, not much use in most conditions.

With the 32mm, it would give you a 16mm, which would be around x93 which may be useful, and with the 12.5mm it would give x240, which is still pretty high for most conditions.

Your scope has a long focal length, and a relatively narrow field of view. It will give great views of planets and most of the smaller dso's.

Again, it depends what you want to view, but if your interests are planetary, I think if I were you, I would consider a dedicated ep at around the x170 or x180 Mark (eg a 9mm or 8mm) which should give you great views, or perhaps an optimum dso ep, a wide angle around 24mm would give you a 1 degree field of view with 2mm exit pupil which would be good.

I'm sure there will be other opinions, but do consider what a Barlow would gain you before getting one, I think another ep would serve you better.

Cheers,

Stu

[ronin]

Not sure what use a barlow will actually be, unless your smallest eyepiece was going to be about 15mm.

A 2x barlow with a 15mm would give 200x and in realistic terms that is all you will likely use, and 150x would be used more often.

150x will give Saturn and Jupiter well it would struggle on Mars but Mars is trouble. 200x (or more) on Mars would be better.

After that not a lot to use magnifications on above that. DSO's will be too dim in a 127 to take high magnification.

My view is get an 8mm BST Starguider, or vixen plossl or the other BST, and do not bother with a shorter eyepiece focal length by whatever means.

The use for a barlow would be if you had a 15mm, 20mm and 25mm and barlowed each to supply a 7.5mm, 10mm and 12.5mm. That however means a barlow and 3 eyepieces. The drawback is you could be changing eyepieces and barlows all the time to achieve the magnification wanted.

[knobby]

Unless you are planning on webcam imaging, then a revelation 2.5 x Barlow is pretty reasonable

[Hartmann]

Hi

Are you sure you want a Barlow, and what would you want to achieve with it?

I ask, because I think you would be better off buying another eyepiece which I think would get more use in your scope.

Assuming a x2 Barlow.....

....You have a 20mm and a 10mm, barlowing the 20 gives you the 10, so no need. Barlowing the 10 gives you 5mm which is x300, not much use in most conditions.

With the 32mm, it would give you a 16mm, which would be around x93 which may be useful, and with the 12.5mm it would give x240, which is still pretty high for most conditions.

Your scope has a long focal length, and a relatively narrow field of view. It will give great views of planets and most of the smaller dso's.

Again, it depends what you want to view, but if your interests are planetary, I think if I were you, I would consider a dedicated ep at around the x170 or x180 Mark (eg a 9mm or 8mm) which should give you great views, or perhaps an optimum dso ep, a wide angle around 24mm would give you a 1 degree field of view with 2mm exit pupil which would be good.

I'm sure there will be other opinions, but do consider what a Barlow would gain you before getting one, I think another ep would serve you better.

Cheers,

Stu

it´s true ,

Good advice

Perhaps i will purchase another dedicated eyepiece and not a barlow, maybe two eyepieces  , and after a 8x24 zoom .

I´m interested in planets but i like   DSO too, so it´s a good idea as you say a 9 mm and a wide angle eyepiece for DSO. but  I have very good results with the 32 mm 52º Ep.

The stock 10 mm eyepiecet need to be replaced  because it´s very poor compared with a  super plosl. i will use it in a finder scope. Also I have a 4 mm and a 9 mm but are 0,965"  ortoscopic vixen eyepieces from an old telescope.