Brandon 48mm EFL

[25585]

I was wondering if anyone on SGL owns, has owned or used a Brandon 48mm EFL eye piece.

https://www.widescreen-centre.co.uk/astronomy-eyepieces-and-barlows/vernonscope-eyepieces-and-barlows/brandon-48mm-2-ocular

It has big eye relief, but not FOV, unusual if EFL means its an Erfle.

As the Brandons seem niche, and have narrow FOV, are they more Plossl/Ortho than Erfle? How good is the 48mm & compare against a Masuyama 50mm?

[L8-Nite]

Oh boy, I see another Brandon controversy approaching.  

The 48 has about an inch and a half of eye relief, and what I would estimate as a 40 + degree field of view. Its great for deep sky viewing and under dark conditions provides very high contrast.  Its considered a research or professional grade eyepiece and is arguably, as with other Brandon orthoscopics, one of the finest eyepieces in the world. I would describe the views as a " breathtaking, magnified naked eye view."

I love our Brandon 48 and hold it in high regard.

Edit: Note. Our 5 scopes are all long focal length.

[25585]

22 hours ago, L8-Nite said:

Oh boy, I see another Brandon controversy approaching.  

The 48 has about an inch and a half of eye relief, and what I would estimate as a 40 + degree field of view. Its great for deep sky viewing and under dark conditions provides very high contrast.  Its considered a research or professional grade eyepiece and is arguably, as with other Brandon orthoscopics, one of the finest eyepieces in the world. I would describe the views as a " breathtaking, magnified naked eye view."

I love our Brandon 48 and hold it in high regard.

Edit: Note. Our 5 scopes are all long focal length.

I don't understand why there is controversy, really!

My interest in the Brandon 48mm is effective eye relief, eye placement ease & viewing comfort. 

AFOV comes after those considerations, as they are my criteria. 

Brandons are not the most expensive eps, though up there price-wise, with Ethos, Nagler, Masuyama, Zeiss & some ES. 

The 48 seems in the weight class of a Vixen LVW 42mm, which I own & am pleased with. So an objective appraisal discussion would be welcome. My scopes run from F5 to F10 currently. 

[L8-Nite]

I've been on astronomy forums for nearly a decade now, and over the years there have been many a controversial thread which has given rise to tit-for-tat heated debates, which to me are always good for a laugh; hence my opening sentence. Sorry, thought you would see the humour in it.

I don't follow a brand, but select eyepieces which are optimized for my scopes to enjoy them to their fullest potential. The 48 Brandon is used almost exclusively in our 7" Mak. which has a focal ratio of  f/13.5 , and occasionally in our 5" Mak. which is f/10 .   

[25585]

3 minutes ago, L8-Nite said:

I've been on astronomy forums for nearly a decade now, and over the years there have been many a controversial thread which has given rise to tit-for-tat heated debates, which to me are always good for a laugh; hence my opening sentence. Sorry, thought you would see the humour in it.

I don't follow a brand, but select eyepieces which are optimized for my scopes to enjoy them to their fullest potential. The 48 Brandon is used almost exclusively in our 7" Mak. which has a focal ratio of  f/13.5 , and occasionally in our 5" Mak. which is f/10 .   

Do you find the narrower FOV, though a 2 inch fit, avoids vignetting with your Maks? My C8 is F10, 2/4 fracs are F9. 

[L8-Nite]

I have not experienced vignetting in either of the Mak's. I only have 2" diagonals, and have not had experience with this eyepiece through a focuser or diagonal of 1.25" design. The field stop for the Brandon 48 is 38mm according to Vernonscope.

[jabeoo1]

Personally I would love this EP as my low-power dark-sky-scanner.

Plenty here from jrbarnett from cloudynights:

https://www.cloudynights.com/topic/489868-legendary-eyepiece-profiles-48mm-brandon/

[BillP]

Not sure how long the focal ratio is for the 5 scopes Mike E. mentions, but my experience with the 48 Brandon was not so pleasing.  I purchased it directly from Don Yier.  In my TSA-102, which is f/8, I found that a good portion of the off-axis was astigmatic.  In addition while the eye relief was long, maintaining the exit pupil was quite difficult and the eyepiece was prone to blackouts.  Finally, the AFOV was quite narrow, somewhere around 50 degrees which meant for such a low magnification eyepiece that would produce a relatively bright exit pupil in my scope, the TFOV was not making up for the brighter background from the larger exit pupil.  Overall the views through it were no where near as good as in my 40XW.  I sold it not long after.

Now I have used the other Brandon's and generally like them and put up with their poorer off-axis performance even in f/8 scopes because of their nice on-axis.  And in an f/15 scope they clean up really nice.  But most of my scopes are at or near f/8 and the Brandons just do not show a nice off-axis in their already small 50-ish degree AFOV.  If they altered the field stops to given them all a 42 degree AFOV like a standard Abbe they would be fairly killer next to all the other common Abbes out there.  But at 50 degrees they are hurting IMO.

[25585]

1 hour ago, jabeoo1 said:

Personally I would love this EP as my low-power dark-sky-scanner.

Plenty here from jrbarnett from cloudynights:

https://www.cloudynights.com/topic/489868-legendary-eyepiece-profiles-48mm-brandon/

Lots of reading, & more!

Brandons seem to be an enigma, if not an icon.

There seem to be few objective opinions or comparisons.

Shame performance in faster scopes is rated poor. However its not an ep for those anyway at 48mm FL anyway.

My 2 50-ish eps, a TV 55mm Plossl & Vixen NLV 50mm both have = or <50 deg AFOV. The Brandon 48mm 45 deg is not that far off, TV & Vixen being 50 deg & 45 deg respectively there. I expect the TV's extra 5mm FL allows the extra 5 deg AFOV.

So off-axis, that would matter for whole FOV as a finder & rich star field ep is what matters most I think. Big eye relief good. Light transmission will matter more, but real life viewing may render that aspect mostly academic as a viewer will switch to a shorter FL after initial use.

 

 

 

[25585]

38 minutes ago, BillP said:

Not sure how long the focal ratio is for the 5 scopes Mike E. mentions, but my experience with the 48 Brandon was not so pleasing.  I purchased it directly from Don Yier.  In my TSA-102, which is f/8, I found that a good portion of the off-axis was astigmatic.  In addition while the eye relief was long, maintaining the exit pupil was quite difficult and the eyepiece was prone to blackouts.  Finally, the AFOV was quite narrow, somewhere around 50 degrees which meant for such a low magnification eyepiece that would produce a relatively bright exit pupil in my scope, the TFOV was not making up for the brighter background from the larger exit pupil.  Overall the views through it were no where near as good as in my 40XW.  I sold it not long after.

Now I have used the other Brandon's and generally like them and put up with their poorer off-axis performance even in f/8 scopes because of their nice on-axis.  And in an f/15 scope they clean up really nice.  But most of my scopes are at or near f/8 and the Brandons just do not show a nice off-axis in their already small 50-ish degree AFOV.  If they altered the field stops to given them all a 42 degree AFOV like a standard Abbe they would be fairly killer next to all the other common Abbes out there.  But at 50 degrees they are hurting IMO.

My Tak FC100DL& 100mm SW Equinox are F9. SCT is F10. 120 SW is F7.5. So in-between.

As a finder ep, the TV scores highest for FOV. Vixen v Brandon are close.

Viewing big spreads such as the Pleiades or M31, 

They all seem ideal for framing the above, small AFOV but not TFOV, for limited FOV. Off-axis is the crunch for me & OIII filter use. Pop in the 2 big Panoptics,

 

 

and more magnification for equivalent FOV. Maybe the Brandon is a good travel ep for its FL. Its hard to justify with the TV Plossl 55mm, apart from to collectors, US patriots..and magpies. 

 

[Roy Challen]

On 4/7/2018 at 21:19, L8-Nite said:

Oh boy, I see another Brandon controversy approaching.  

The 48 has about an inch and a half of eye relief, and what I would estimate as a 40 + degree field of view. Its great for deep sky viewing and under dark conditions provides very high contrast.  Its considered a research or professional grade eyepiece and is arguably, as with other Brandon orthoscopics, one of the finest eyepieces in the world. I would describe the views as a " breathtaking, magnified naked eye view."

I love our Brandon 48 and hold it in high regard.

Edit: Note. Our 5 scopes are all long focal length.

Lovely EP, but why the cheap box?

[L8-Nite]

1 hour ago, Roy Challen said:

Lovely EP, but why the cheap box?

Because I couldn't find an upgrade.

 

[25585]

1 hour ago, L8-Nite said:

Because I couldn't find an upgrade.

 

Needs it's own individual wooden box, preferably walnut in keeping with the complete boxed set. Velvet lining over memory foam. And a Nagler-style personal "thank you" for buying one. 

It must be intriguing to own an eyepiece designed by the same person who designed the Norden bomb site. Clarity, light transmission & 3D in daylight must have been important for those too. 

[L8-Nite]

The 48mm actually resides with our other eyepieces in a waterproof case, and I did get a thank you when talking to Don Yier upon ordering it and others a few years ago. Don was also very helpful in providing the 1.7x barlow I asked for at the time.