Buying eyepieces

[Alan64]

"The AH ortho’ has a 43° FOV which is slightly less than a Plossl but it isn’t a problem on an unmotorised scope to use them. "

Is that the 12.5mm orthoscopic?  It appears to be; very nice.

When using 4mm, 5mm, 6mm, 7mm orthoscopics, and for the planets, motorising the mount helps out a lot, and in waiting for the seeing to improve for that once-in-a-blue-moon, tack-sharp image.

[REG78]

Cheers mak for th info much app

[Mak the Night]

1 minute ago, REG78 said:

Was actually thinkn about getn GSO Barlow cus th Barlow I got free isn't too good not really tht clear a view

I'm pretty sure GSO make the Celestron Barlows: http://www.gs-telescope.com/

The Barlow giveaway with the Explorer is rubbish. I used to use a TeleVue 3x Barlow in my Explorer, although it nearly cost the same as scope and mount lol! The Powermate I bought actually did cost more. It was worth it though.

[Alan64]

6 minutes ago, REG78 said:

Was actually thinkn about getn GSO Barlow cus th Barlow I got free isn't too good not really tht clear a view

The included barlow would need replacing, too.  However, if you were barlowing the included 10mm eyepiece, and for a simulated 5mm(180x), then the telescope's aperture-limit and the atmospheric conditions may have been conspiring against you.

 

[Mak the Night]

5 minutes ago, Alan64 said:

"The AH ortho’ has a 43° FOV which is slightly less than a Plossl but it isn’t a problem on an unmotorised scope to use them. "

Is that the 12.5mm orthoscopic?  It appears to be; very nice.

When using 4mm, 5mm, 6mm, 7mm orthoscopics, and for the planets, motorising the mount helps out a lot, and in waiting for the seeing to improve for that once-in-a-blue-moon, tack-sharp image.

That's the 18mm AH. I use the 25mm and 12.5mm as bino pairs. I've never thought much of the clockdrive with the 130M. A GOTO would make a difference! I'm getting one soon. I'll make sure to test the ortho's with it lol. My Baader ortho's (18mm bino pair) are 50° in FOV. I honestly don't find the AH ortho's any harder to use with the slo mo controls.

[Mak the Night]

11 minutes ago, REG78 said:

Cheers mak for th info much app

You're welcome. The Celestron Barlows are quite decent. I recommend this particularly: http://www.firstlightoptics.com/celestron-eyepieces/celestron-2x-universal-125-barlow.html

The detachable Barlow element from one of these can be seen threaded into the WO SWAN in my jpeg.

[Alan64]

20 minutes ago, Mak the Night said:

That's the 18mm AH. I use the 25mm and 12.5mm as bino pairs. I've never thought much of the clockdrive with the 130M. A GOTO would make a difference! I'm getting one soon. I'll make sure to test the ortho's with it lol. My Baader ortho's (18mm bino pair) are 50° in FOV. I honestly don't find the AH ortho's any harder to use with the slo mo controls.

Do you have focal-lengths shorter than 18mm of the Astro-Hutech line?  I have the BGOs from 5mm to 12.5mm.  I've never felt the need for the 18mm and 25mm orthoscopics, of any brand, as I prefer the wider-field oculars at 12mm and above, although I always went ahead and got the 12.5mm orthoscopic in the past as it's not that far removed from a 9mm.  I can see the use of the 18mm and 25mm orthoscopics in binoviewers however.

[REG78]

Yea seen tht on your 1st EP nice collection you have ther aswell

[REG78]

Think I'm gona go for th omni plossl was thinkn 9&15mm just to get me started off for th price range aswell

[Mak the Night]

6 minutes ago, REG78 said:

Think I'm gona go for th omni plossl was thinkn 9&15mm just to get me started off for th price range aswell

The 15mm plus the Omni or Universal Barlow would be better as it effectively can turn your 15mm into a 7.5mm.

[REG78]

Yea seen tht on your 1st EP nice collection you have ther aswell would you not bother getn 9mm aswell thn

[Alan64]

For the higher and highest magnifications, I use orthoscopics, along with a 6mm Plossl...

Click on the image for a larger view.

For the low-to-high magnifications, I have the odd assortment...

...along with the barlows...

[Mak the Night]

33 minutes ago, Alan64 said:

Do you have focal-lengths shorter than 18mm of the Astro-Hutech line?  I have the BGOs from 5mm to 12.5mm.  I've never felt the need for the 18mm and 25mm orthoscopics, of any brand, as I prefer the wider-field oculars at 12mm and above, although I always went ahead and got the 12.5mm orthoscopic in the past as it's not that far removed from a 9mm.  I can see the use of the 18mm and 25mm orthoscopics in binoviewers however.

I have one 18mm AH ortho and pairs of 12.5mm and 25mm. I have a pair of 18mm BCO's. The pairs are mainly for the bino, I regularly use the 1.6x & 2x nosepiece Barlows combined with the 12.5mm to 18mm. The 25mm ortho pair aren't generally used with a Barlow. They give me 52x on my Mak which is perfect for M42. They will give me 94x on the SCT I'm getting.

[REG78]

Does th end of th Barlow screw onto th omni plossl 

[Mak the Night]

4 minutes ago, REG78 said:

Does th end of th Barlow screw onto th omni plossl 

Normally you would place the Omni in the Barlow itself.

Most expensive Barlows and the cheaper Celestron Universal Barlow and some others have detachable elements. When that is threaded into the eyepiece it magnifies by a factor of about 1.6x instead of 2x giving you more options. I make the WO SWAN 9mm a 5.625mm in this way.

I can do a similar thing with this 10mm Celestron Luminos eyepiece, effectively turning it into a 6.25mm.

[REG78]

When doin this is th view still as clear than when you put th EP into th Barlow itself

[Mak the Night]

49 minutes ago, REG78 said:

When doin this is th view still as clear than when you put th EP into th Barlow itself

A lot depends on the quality of the Barlow. I usually use exclusively TeleVue eyepieces and Barlows together, predominantly, as the Barlows have brass compression rings and they will easily connect to themselves and my better quality diagonals which also have compression rings. The smooth barrelled or flared safety undercut types are fine. Unfortunately, the Celestron eyepieces mainly all have old safety undercuts and can't be easily extracted from anything with a compression ring. However, on my 90mm grab'n'go scope I use a lightweight diagonal with no compression ring enabling me to utilise my older lighter eyepieces. I honestly don't think the Celestron Barlows dim the viewing particularly noticeably. They may not be TeleVue standard but they are pretty decent and I find the Omni 'shorty' useful in a little scope.

These Celestron Barlows have old fashioned draw tube undercuts, there is no problem unless they are pushed into an adaptor or diagonal with a compression ring, then they can often get hung up on extraction.

A TV 15mm Plossl with flared undercut, 15mm Omni with an old undercut and a 15mm Kellner with no undercut.

Compression ring on my Powermate.

This is the Barlow that came with my 130M. The best thing to do with it is throw it away. I think the lenses are plastic. There is absolutely no comparison with the Celestron Barlows and the plastic cheap Sky-Watcher giveaway. TeleVue Barlows are even better than the Celestron Barlows. But you'll pay over a hundred quid for one. The Celestron Barlows are good quality though. As I said, I still use mine in a small portable scope as they are light and short. My TeleVue 2x Barlow is rather heavy and long.

Plus it has a compression ring, so extracting the Celestron Plossls from it is often tricky. I find no difference in placing the eyepiece into the Barlow or threading the element on the end, apart from the magnification difference.

[Mak the Night]

After doing some sums I realised I can achieve 181x with a 5.5mm EP for a 0.5mm exit pupil. So I eschewed the SW 25mm MA for a TeleVue 11mm.

Well ... I had to lose one as they don't all fit into my grab'n'go box lol.

[REG78]

What's th hole for at th front of reflectors cap 

[Mak the Night]

3 hours ago, REG78 said:

What's th hole for at th front of reflectors cap 

Nobody knows. It's one of the great mysteries in astronomy. One theory I heard was that it was a standard for Asiatic telescope manufacturers (like Synta) to put these 1.25" caps in the main lens caps as to be able to use them for solar observing during eclipses. Which would be highly dangerous without a sun filter of some description. You should never look directly at the sun with a telescope, or anything for that matter. It may be for ventilation if the scope is in storage.

[Mak the Night]

I forgot this 25mm Kellner.