Barlow vs GPC

[Ricochet]

Has anyone here done a comparison between using a barlow element and a gpc with binoviewers? If so was there a noticeable improvement with the gpc? Finally, does anyone know if this applies only to the Baader gpcs or if cheaper variants such as the TS GPC and Barlow also produce such results (or is it a barlow simply marketed as a gpc?).

[Louis D]

Or for that matter, compared OCSs vs GPCs.

[mikeDnight]

I've never knowingly used a binoviewer with a GPC, I've only ever used a barlow lens. I've used several barlows over the years but all seem to be equally good. My usual method is to screw a SkyWatcher Delux barlow directly into the nosepiece of my binoviewer. Despite its low price, this is an optically superb barlow, so if anyone has one in their possession give it a try. You may not need to spend on a GPC that will likely show zero optical improvement.

[Stu]

I haven’t done a proper test but have everything I need to do it. Funnily enough I swapped a Barlow for a GPC the other day and thoaught I saw a significant improvement. However, when I swapped back I realised it was more an effect of the seeing, so more comparison needed.

[mikeDnight]

Don't be finding something else for me to spend my money on Stu! I'm already getting that look from my owner!!

 

[Ricochet]

 

1 hour ago, Stu said:

I haven’t done a proper test but have everything I need to do it. Funnily enough I swapped a Barlow for a GPC the other day and thoaught I saw a significant improvement. However, when I swapped back I realised it was more an effect of the seeing, so more comparison needed.

I've had a similar experience comparing eyepieces. I look forward to any conclusions you can draw from extended comparisons.

 

1 hour ago, mikeDnight said:

've never knowingly used a binoviewer with a GPC, I've only ever used a barlow lens. I've used several barlows over the years but all seem to be equally good. My usual method is to screw a SkyWatcher Delux barlow directly into the nosepiece of my binoviewer. Despite its low price, this is an optically superb barlow, so if anyone has one in their possession give it a try. You may not need to spend on a GPC that will likely show zero optical improvement.

Thanks, I'll have to give that barlow a go and see how it compares to the AE nosepiece I'm currently using.

[Louis D]

I've been using the Meade 140 2x barlow nosepiece myself to reach focus.  It's an incredibly sharp barlow that doesn't seem to degrade the view at all.  Unlike the TV 2x barlow nosepiece, the Meade is standard 1.25" filter threaded, so it can be threaded right onto the front of the binoviewer.

The OCSs that came with my Arcturus binoviewer were both horrible.  They introduced some sort of coma as if from tipped optics across the view.

[paulastro]

Like Mike I've long used a x2 SW barlow element instead of an OPC.  It works well enough to produce a notably better image in a basic (and cheap) binoviewer with two orthos than an expensive and excellent mono eyepiece on Jupiter.  .  In fact this combination has always performed better than any single eyepiece I have ever tested it against when used on any planet or the Moon using a good refractor.  The SW barlow element certainly does the business for me .

[Ricochet]

3 hours ago, Louis D said:

I've been using the Meade 140 2x barlow nosepiece myself to reach focus.  It's an incredibly sharp barlow that doesn't seem to degrade the view at all.  Unlike the TV 2x barlow nosepiece, the Meade is standard 1.25" filter threaded, so it can be threaded right onto the front of the binoviewer.

The OCSs that came with my Arcturus binoviewer were both horrible.  They introduced some sort of coma as if from tipped optics across the view.

I know what you mean about those OSCs! Everything tinged blue and noticeably blurry compared to the barlow I'm using instead. 

2 hours ago, paulastro said:

Like Mike I've long used a x2 SW barlow element instead of an OPC.  It works well enough to produce a notably better image in a basic (and cheap) binoviewer with two orthos than an expensive and excellent mono eyepiece on Jupiter.  .  In fact this combination has always performed better than any single eyepiece I have ever tested it against when used on any planet or the Moon using a good refractor.  The SW barlow element certainly does the business for me .

Two votes for the SW, definitely need to test it. 

[Moonshane]

As always my reasons for using GPCs over barlow is one of the convenience and utility of the T2 Baader system rather than any optical gain.