Stacking Barlows

[jjjnettie (Jeanette)]

Can you stack barlows?

Cheers
Jeanette

[ving (David)]

sure can! give it a try.

[rumples riot]

Yes, but bear mind that the image will get dimmer with the increase of glass.

[mickoking]

Don't go there

[Robert_T]

not sure if this is worthwhile visually, but I've certainly piggybacked 2 2x barlows for planetary imaging with reasonable results.

if you've got the money a 4 or 5xpowermate will be better of course, but failing that give it a try

[ving (David)]

Originally Posted by mickoking

Don't go there

[ausastronomer (John Bambury)]

Yes you can definately stack barlows for visual work or imaging. However be aware that as you introduce more and more elements into the optical path the image will become slighlty dimmer and also the likelood of introducing aberrations increases.

Consequently if you wish to stack 2 barlows and get reasonable results it helps if you use 2 high quality barlows. If you stack 2 average quality barlows, the results will be somewhat less than average.

I have stacked 2 barlows mainly as a "suck it and see experiment" on the planets and the images were good, not as good as a native eyepiece but very acceptable and I used 2 high quality barlows.

CS-John B

[jjjnettie (Jeanette)]

I've got a 2" and 1 1/4" GSO barlows. So I won't get my hopes up too high as far as quality goes. But it would be the only way, using what I have, to push my scope past 385x.

[ving (David)]

just dont insert the 2" inside the 1.25"

[matt]

385x

You must have some fairly good seeing to push your scope to that for visual?

[jjjnettie (Jeanette)]

Yeah, it's pretty good here. I'd love to have better quality optics to take advantage of it.

[ausastronomer (John Bambury)]

Originally Posted by jjjnettie

Yeah, it's pretty good here. I'd love to have better quality optics to take advantage of it.

Jeanette,

Scope should do it easily. I often push my own GSO dob over 400X on various targets when seeing permits. The scope optics are certainly up to it, or at least mine are and all other GSO dobs I have used have been as well. Good eyepieces and a good barlow does help a lot here, when you get to high power.

If you want to do some high power observing I suggest you try to buy a 7mm UO HD ortho which native will give you about 180X and a 2X Orion Shorty Plus barlow which will barlow it to 360X. At these powers the difference between a cheap eyepiece and barlow compared to good quality ones is very apparent. You could later add a 5mm UO HD ortho which native will give you 250X. Those GSO eyepieces and barlows wont be worth a cracker at those powers IMO.

Good luck !!

CS-John B

Most of my planetary imaging is done by stacking barlows. But I usually get
the best results when I screw the optical elements of one directly onto the
nose of the camera. You can even screw them onto your ep's.

Here are a couple of examples... So yes by all mean go there, experiment!


regards,CS

[iceman (Mike)]

I used to stack barlows for increased image scale when doing imaging, there's no reason you can't, but like others have said, the more glass in the way (and higher the magnification), the dimmer the image will be (especially photographically).

For visual stuff though, it would be a rare night you'd go above 385x. If you have a high power EP like in the 5-7mm, when you use a barlow on it it will be about all you'd need on 98% of the nights.