Why not more DIY “big eyes”?

[SikaSeeker]

 

[SikaSeeker]

Set of Kowa 822 I saw for sale in Deadwood South Dakota, of interest is the bracket design . These are more difficult to make and some say less capable of holding collimation than AA type design. kowa have repainted these I think, as they use the “820“ stencilled design on repainted scopes of this generation.

 

[BBob]

Over the years the adjustable inter pupillary designs seem to have come more from back east. Out west they’ve mostly been adjust and fixed in place designs.

 

[Antares]

I'm selling my Adam's Adapter Kowa 884 plate if anyone is interested.

https://rokslide.com/forums/threads/kowa-884-big-eyes-plate-adams-adapters.355336/

 

[SikaSeeker]

Managed to obtain a set of Highlanders, I’d also considered the 884 paired but that’s on the long finger for another day.

The highlander eyepiece eyecup is compatible with other kowa eyepieces , I had to replace the rubber pieces as they’d went a bit gummy. I’d hazard a guess UV exposure did this.

Thus far I’ve not gotten ideal conditions to test but already the Highlanders are impressive, they give a depth of field you don’t have with one eye.

The optics in the highlander differ to the Kowa 824 which is a straight forward porro arrangement. The highlander uses a Schmidt pecan arrangement, a 45 degree prism and a rhombus prism for the IPD adjustment mechanism. Also has a neutral density filter. The tubes have more girth Vs the 824 and subsequent filter thread of 95mm(same as 884). It seems the main reason for this is manufacturing process designed for robustness.

I was lucky the example I found for sale is mint condition throughout as it has sat indoors looking out across a port.

The major downside is of course the weight, they are brutes. 6.2kg

The little aiming spike is useful enough.

I am on the lookout for Docter 40x 80 Aspectum ED as well, had a swap deal (for the non ED version) fall through this week.

 

[Antares]

View attachment 718869
Managed to obtain a set of Highlanders, I’d also considered the 884 paired but that’s on the long finger for another day.

The highlander eyepiece eyecup is compatible with other kowa eyepieces , I had to replace the rubber pieces as they’d went a bit gummy. I’d hazard a guess UV exposure did this.

Thus far I’ve not gotten ideal conditions to test but already the Highlanders are impressive, they give a depth of field you don’t have with one eye.

The optics in the highlander differ to the Kowa 824 which is a straight forward porro arrangement. The highlander uses a Schmidt pecan arrangement, a 45 degree prism and a rhombus prism for the IPD adjustment mechanism. Also has a neutral density filter. The tubes have more girth Vs the 824 and subsequent filter thread of 95mm(same as 884). It seems the main reason for this is manufacturing process designed for robustness.

I was lucky the example I found for sale is mint condition throughout as it has sat indoors looking out across a port.

The major downside is of course the weight, they are brutes. 6.2kg

The little aiming spike is useful enough.

I am on the lookout for Docter 40x 80 Aspectum ED as well, had a swap deal (for the non ED version) fall through this week.

Jealous of the Highlanders! Nice score. Congratulations!

 

[hawgchaser]

Out west the only two I know of currently are Wells Sports in the Prescott Valley, AZ and AdamsAdapters in San Manuel, AZ. Montour Rifles used to make some. Swarovski sold a set for awhile but no idea who's bracket they used. There were quite a few back east but I don't know who they were or are.

Kevin at Montour County Rifles still makes them on occasion.

 

[SikaSeeker]

Finally got a good clear night, was blown away by a double star cluster(in Perseus aka Caldwell 14). I stumbled on this scanning the sky then confirmed via maps. Reading cloudy Nights forum (astronomy) I came across this review of the Highlander and have to agree. The black sky was properly black , I'd compare it to how OLED screens compare to previous generation of backlit screens.

"very high on-axis sharpness paired with rock-hard contrast. On-axis sharpness and contrast of the Highlander 82mm f/5.5 optics cannot be described other than shocking. The contrast is fully comparable with my Takahashi TOA-150B APO refractor. Be it at day or at night, the Highlander optics shows the finest variances in color hues and shades"

Note the Takahashi TOA 150B is a rolls Royce tier telescope that costs around $20-25k depending where you shop. Few brands in astronomy is as respected as Japanese maker Takahashi and they use Flourite lens systems. High praise indeed.

The Highlander does need proper mounting and has some CA at field edges , 70-80% sharp sweet spot and lacks the edge sharpness of more modern offerings. Those factors don't really detract because the sweetspot is VERY sweet.

 

[SikaSeeker]

Note I've just ordered the 50x eyepieces and later this year the 21x so will update accordingly.

 

[4090Sharps]

I took some measurements on my 13-39x56 Razor that I have on hand. Max diameter is on the focus ring at 2.800". Accounting for clearance to turn (unless I'm missing something), that would leave a pair mini Razors too wide for budget big eyes. Oh well! Maybe a pair of STCs will work for my eyes.

Well, Adams Adapters came out with a mini Razor adapter and got the minimum IPD down to 2.5” with some armor trimming. I just bought one and a second Razor from a member.

Has anyone else bought or looked through one of the mini Razor big eyes setups?

 

[SikaSeeker]

50 x eyepieces for the Highlander definitely make a difference, in fact was a bit amazed. Just last night there was mist on far away hill(5 miles). Below that is the house of a guy I know who has a van with his business name on it. I could clearly read the business name printed on the side of his van at a distance of 4 miles exactly as the crow flies.

On another day up on the hill at 4.5 miles I could easily make out age profile of guys out collecting hay bales, what they were wearing etc. the extra resolving power of two eyes is something else.

Downsides would be in windy conditions you get a little shake even with good tripod due to mass of the unit.

Another downside (sort of) is you need optimal conditions to truly appreciate how good these things actually are. True of all optics to an extent I suppose.

 

[4090Sharps]

Second Razor is on the USPS truck, and my adapter is expected to deliver today .

 

[4090Sharps]

I got my mini Razor setup together today. The machining on Adams Adapers is remarkably clean.

Collimated them late afternoon and had a little bit of time to test right around sunset. First impressions for optical performance are positive. Not what I would have got out of the STC setup, but my eyes were too narrow.

This compact pair of scopes should carry a bit nicer than the BTX I had before, as soon as I sew a case.

 

[UpTop]

That mini razor setup looks money!

 

[Block]

Why don’t I see more folks creating their own big eyes? Am I missing something? It seems like you could throw together a couple older razors and have a solid value “BTX like” set-up. Please school me on what I’m overlooking, other than weight.

Cuz it’s a monstrosity to carry. BTX-95 done.. carry it everywhere.

 

[4090Sharps]

Cuz it’s a monstrosity to carry. BTX-95 done.. carry it everywhere.

The big eye setups with small scopes are changing that.

I'd much rather carry a pair of Swaro STC, Kowa 55S, Maven S.2, or Vortex mini Razors since they're more compact. The comparable (or lighter) weight for less bulk, zoom, competitive price, and straight scope body give the BTX some serious competition.

 

[Block]

The big eye setups with small scopes are changing that.

I'd much rather carry a pair of Swaro STC, Kowa 55S, Maven S.2, or Vortex mini Razors since they're more compact. The comparable (or lighter) weight for less bulk, zoom, competitive price, and straight scope body give the BTX some serious competition.

Sounds like you could use some more protein in ur diet haha.. JK,, but I don’t care about a little extra weight I’m takin the BTX everywhere,, for me NL 12x and BTX-95 is perfect for just about any hunt..

 

[BBob]

I’m takin the BTX everywhere,, for me NL 12x and BTX-95 is perfect for just about any hunt..

I own BTX, a pair of Swaro Twin 65’s and NL 12’s. Nothing wrong with the BTX but at even greater weight and bulk I prefer the Twins and use them almost exclusively now. I’ve posted mby in this thread or another on why I prefer them. Friends have BTX and we glass side by side and we all do pretty well with both. I think I do better but that just might be my opinion

 

[4090Sharps]

Sounds like you could use some more protein in ur diet haha.. JK,, but I don’t care about a little extra weight I’m takin the BTX everywhere,, for me NL 12x and BTX-95 is perfect for just about any hunt..

Haha! While I loved the clarity and convenience, the angled bulk of the BTX combined with the fixed magnification increasingly bothered me. I couldn't scan an area as effectively as I would have liked and found I was likely missing deer in certain scenarios due to the (comparably) limited FOV.

NL's fix that issue handily with 4x the area covered in its FOV compared to my mini Razors, but you've still gotta switch between optics. There's always a compromise, just gotta find the preferred compromise.

 

[4090Sharps]

I made this little table to compare some optics with regard to area covered by the FOV (sq ft) when I was looking at big eye setups since I felt like it was a better comparison than straight FOV. Sharing in case anyone is interested.

There was some conflicting information on the max FOV for the 55S, so I went with the smaller of the two (192 vs 210 iirc).

I threw my CL 8x25 pocket binos on there since I pretty much always carry them.

Optic	Mag	Max FOV	Min FOV	Max Area	Min Area	Max Area % of Vortex
BTX 65/85	30​	112​	112​	9852​	9852​	44.4​
BTX 95/115	35​	96​	96​	7238.2​	7238.2​	32.7​
NL 8x42	8​	477​	477​	178700.9​	178700.9​	806.2​
NL 10x42	10​	399​	399​	125036.2​	125036.2​	564.1​
NL 12x42	12​	339​	339​	90258.7​	90258.7​	407.2​
NL 14X52	14.7​	279​	279​	61136.2​	61136.2​	275.8​
Vortex Mini Razor	13-39	168​	89​	22167.1​	6221.1​	100​
Maven S.2	12-27	173​	110​	23506.2​	9503.3​	106​
STC	17-40	186​	102​	27171.6​	8171.3​	122.6​
Kowa 55S	17-40	192​	105​	28952.9​	8659​	130.6​
CL 8x25	8​	357​	357​	100098.2​	100098.2​	451.6​