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15mm ortho or near ortho....


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Alas, there do not seem to be any 15mm orthos being manufactured at the moment - I want to find a near-equivalent  ie to match the resolution, contrast and lack of reflections that an ortho design delivers. The EP is for my 180 Mak - 2.7m focal length. The scope is fairly tolerant wrt EPs as it is f15, but obviously EP designs with a lot of elements will tend to produce bright reflections with targets such as planets or bright doubles compared with the four elements of an ortho.

Anyone like to make a suggestion?

Chris

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Hello. Orthos are getting less available unfortunately. Going out of fashion I think with all the other designs available. But I still love them for there basic design, Tak sharp image and sensible price.

What about a televues plossl. Their is a 15mm in the range. Great sharp optics, ,50d fov and eye relief is not to bad. Not an Ortho but still a top class eyepiece IMO and still available 

I hope the above helps☺

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I'm looking for this FL too and so far the only candidates I see are the TV 15mm Plossl and the Brandon 16mm. A friend compared an SLV to the extremely low scatter Zeiss zoom- the zoom came out on top for scatter and sharpness. I've heard the Brandons are excellent and espc in slow scopes (edges). To be honest that zoom is the lowest scatter EP I have, but is too big for my binos.

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The Vixen SLV 15mm ?.

I found that the 6mm SLV matched the 6mm Baader Genuine Ortho - in fact I could not distinguish between them when observing Jupiter and Saturn.

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The two that jump out at me in the 50deg range are the TVP aso previously mentioned or the SLV.. both little crackers.

I'm pleased the SLV'S are starting to get a bit more press/recommendations recently in a few threads, I've always thought they've been underrated for some reason.

Ta

Fozzie 

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56 minutes ago, chiltonstar said:

Alas, there do not seem to be any 15mm orthos being manufactured at the moment - I want to find a near-equivalent  ie to match the resolution, contrast and lack of reflections that an ortho design delivers. The EP is for my 180 Mak - 2.7m focal length. The scope is fairly tolerant wrt EPs as it is f15, but obviously EP designs with a lot of elements will tend to produce bright reflections with targets such as planets or bright doubles compared with the four elements of an ortho.

Anyone like to make a suggestion?

Chris

You could try a 15mm RKE (Rank Kellner Eyepiece ) that are currently available from Edmund Optical. They are very pure and are very well thought of among planetary observers. 

Mike 

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Of the readily available EPs, I'd think 16mm Brandon,  15mm SLV or 18mmBCO+QT barlow(1.3x) are among the best candidates for planetary in your Mak. 

Brandon for their authentic plossl, i.e. unsymmetric, which has better spotsize than any symmetric plossls(actually achromat pair as shown in the picture below).

spotsize.thumb.jpg.8b5aefebe58ca8bdf794705849fcfc42.jpg

http://www.telescope-optics.net/eyepiece_aberration_2.htm

15mm SLV are among the best SLV's according to this quite comprehensive review here. you may need to use English translation to read it.

http://www.astrotest.it/test-reports/eyepieces/vixen-slv-eyepieces/

 

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As promised, a mini review!

The Vixen 15mm SLV was ordered from FLO on Monday morning, and arrived 1 day later by Royal Mail (well done FLO)! (the clear nights I ordered arrived the next day). The Vixen packaging was "minimal", the FLO external packaging was very good.

Apparently well constructed, light (160g), no rattles and no dust or marks under white light and UV.

With the 180 Mak, gives a theoretical x180 (nearer to x190 as the scope FL is a bit longer than stated due to the 2" back and diagonal). This is my preferred mag with eg Jupiter as it gives enough detail, but doesn't wash out the contrast. The 50 degree FoV is fine for me, although perhaps too small for some people (my preferred is 50 to 60).

I tested it out on Night 1 (seeing 4/5) on a series of close and dissimilar mag doubles and the Moon; Night 2 (seeing 3.5/5) on Jupiter and Izar.

Polaris: very sharply defined, with Polaris B brighter than I was expecting, and compared with an older 15mm Plossl I tried at the same time.

Rigel: similar effect, very well defined and the companion bitingly sharp (clearest I've ever seen it I think).

Castor: beautifully defined, again with the faint third component very clear and sharp. Jewel of the Heavens indeed!

Sirius: B just visible several times, although Sirius was close to a neighbour's roof - not ideal.

52 Orionis: Very sharply split, although more mag really needed for this one.

Trapezium: all six stars clearly defined, with pointlike star definition of C so that F was seen clearly separated from it.

Izar: bitingly sharp, gold and blue, although more mag really needed to show the full colour of Izar A.

The Moon (Day 11): I used it to see how sharp the EP was across the field (apparently sharp from edge to edge) and to look at Tycho and Copernicus, both of which were very sharp and showed a lot of crater wall detail. No reflections or false colour visible.

Jupiter: Wow! Sharp from edge to edge of the field like the Moon, the tiniest bit of false colour when the disk was at the edge of the FoV, no reflections of the planetary disk (cf two other EPs I was using).

The belt detail was amazingly good - the best I've seen it so far with this scope and clearly demonstrates the contrast and resolution. Ganymede was a clear disk, with an obviously darker albedo than the other moons.

Overall, a very nice EP, very sharp, a  silvery-white rendition of stars, and clearly good light transmission judging by how bright faint secondaries seemed, even in moonlight.

Thank you for the recommendation folks!

Chris

 

 

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1 hour ago, chiltonstar said:

As promised, a mini review!

The Vixen 15mm SLV was ordered from FLO on Monday morning, and arrived 1 day later by Royal Mail (well done FLO)! (the clear nights I ordered arrived the next day). The Vixen packaging was "minimal", the FLO external packaging was very good.

Apparently well constructed, light (160g), no rattles and no dust or marks under white light and UV.

With the 180 Mak, gives a theoretical x180 (nearer to x190 as the scope FL is a bit longer than stated due to the 2" back and diagonal). This is my preferred mag with eg Jupiter as it gives enough detail, but doesn't wash out the contrast. The 50 degree FoV is fine for me, although perhaps too small for some people (my preferred is 50 to 60).

I tested it out on Night 1 (seeing 4/5) on a series of close and dissimilar mag doubles and the Moon; Night 2 (seeing 3.5/5) on Jupiter and Izar.

Polaris: very sharply defined, with Polaris B brighter than I was expecting, and compared with an older 15mm Plossl I tried at the same time.

Rigel: similar effect, very well defined and the companion bitingly sharp (clearest I've ever seen it I think).

Castor: beautifully defined, again with the faint third component very clear and sharp. Jewel of the Heavens indeed!

Sirius: B just visible several times, although Sirius was close to a neighbour's roof - not ideal.

52 Orionis: Very sharply split, although more mag really needed for this one.

Trapezium: all six stars clearly defined, with pointlike star definition of C so that F was seen clearly separated from it.

Izar: bitingly sharp, gold and blue, although more mag really needed to show the full colour of Izar A.

The Moon (Day 11): I used it to see how sharp the EP was across the field (apparently sharp from edge to edge) and to look at Tycho and Copernicus, both of which were very sharp and showed a lot of crater wall detail. No reflections or false colour visible.

Jupiter: Wow! Sharp from edge to edge of the field like the Moon, the tiniest bit of false colour when the disk was at the edge of the FoV, no reflections of the planetary disk (cf two other EPs I was using).

The belt detail was amazingly good - the best I've seen it so far with this scope and clearly demonstrates the contrast and resolution. Ganymede was a clear disk, with an obviously darker albedo than the other moons.

Overall, a very nice EP, very sharp, a  silvery-white rendition of stars, and clearly good light transmission judging by how bright faint secondaries seemed, even in moonlight.

Thank you for the recommendation folks!

Chris

 

 

 

 

Interesting feedback. I have a vixen NLV and which was seemingly the predecessor to the SLV. The quality of the eyepiece build when I first looked and felt it I was a bit underwhelmed to be honest. But then I realised the plastic feel was only the outer eyepiece  eye placement sleeve. Under this plastic sleeve is a very well built eyepiece.

Another point that does seems to be raised is was the  SLV a replacement for the NLV ? . I say this as I understand the NLV was Japan made and then the production of the SLV was produced in Taiwan . But are these the same eyepieces in essence?, but possibly just a different name and produced in different locations. I had originally believed in essence SLV and NLV they were the same eyepiece. But I am not sure if this is correct. The NLV has a 45d fov and I see the SLV has a different fov of which is at 50d fov. Therefore there must of been some sort of redesign of the eyepiece as well as a move of production to Taiwan . So are the NLV of Japan, really the same as the SLV of Taiwan ? I am beginning to think possibility of a different eyepiece, as there has been some obviously redesign features.

In regards to your findings of the quality optics of the SLV. This is certainly backed up by my use and finding with the NLV. The NLV has very sharp optics and very much what I class as top class optics but at sensible money. I have my NLV for use in my refractor and it lives in with the Baader Genuine Orthos. And the Vixen certainly is extremely good ,and is great company and performance in the same sort of optical league as the BGO.

Happy you have found a eyepiece that lives up to your expectations, this is always good to hear , as some eyepieces unfortunately do not live up to hype .

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