Kowa Prominar TSN-88 vs 66 vs 773? (4 Viewers)

[D Lloyd]

Hi there!

Long-time lurker, first-time poster

I’m in the market for my first scope. I’m currently deliberating between the Kowa TSN 66A and 88A. I’ve also found a 773 on ebay at a good price. There isn’t a Kowa dealer nearby so I can’t try them out in person to compare. I would love to hear people’s thoughts on this dilemma.

I’m not an early riser and bird mostly during daylight hours, with the occasional dawn and dusk outings. It’s often cloudy and rainy where I live; I’m not sure if this counts as low-light conditions. I go on a lot of bird walks and hope to eventually do some guiding. As I’ve never had a scope before, I’m not sure how noticeable the weight difference will be over the course of a day in the field. I’m told by backpackers that an extra 0.4 kg (the difference between the 66 and 88) may not sound like a lot of weight but it makes itself felt the longer you have to carry it. The 88 is longer, too, so perhaps this makes it more awkward or cumbersome to carry?

The 88A will be better during lowlight conditions, but I’ve read the 66A still performs well, and that the 88A will at most get you a few more minutes of good viewing as the sun goes down.

I was thinking that the 773 may be the sweet spot between the two, but I’ve also read that the fluorite crystal in the 66A makes it just as bright and crisp as the 773. The fluorite is apparently also better with chromatic aberration.

I’m interested in digiscoping but it’s not a big factor in my decision.

I’m leaning towards the 66 because of its portability. I’m small and not very strong. My hesitation is whether there will be occasions in low light in which I’ll wish I’d got a bigger objective lens.

The last thing I’ll note is that I wear glasses and have often struggled to get a good view through scopes others have brought on trips, mainly Vortex, Swarovski, and Vanguard. I didn’t spend any time fiddling with the eyecup, though, because others were also using it. Perhaps some adjustment would have improved my view. I did have an amazing view once through a Nikon Fieldscope ED III; it was a revelation. But they are hard to find where I live (Canada). I would love to hear how other glasses-wearers have found the eye relief on their Kowas.

 

[Tringa45]

Hi, and welcome to Birdforum. I think it's a very sensible decision to go with a premium scope straight away.
Even the smaller Kowa 66A would be superior to all medium level scopes under most conditions.
For this series of Kowa scopes there are only two eyepieces avaiable, the 25-60x TE-11WZ zoom and a 35x ultra wide angle.
I have the 25-60x zoom on my 883 and find it comfortable with glasses. The 35x however, allegedly has shorter eye relief and with glasses you would probably not be able to take full advantage of the increased FoV.
The fluorite lens in the 66A will not compensate for the additional aperture of the 773, but whether you need this is a personal decision. Below a 2 mm exit pupil (33x on the 66A or 44x on the 88A) you are going to lose brightness even in sunny weather and the performance of your viewing eye will be diminished somewhat by diffraction effects. The capabilities of these scopes at normal magnifications will exceed that of your eyes.
Personally in terrestrial situations I perceive no significant gains with exit pupils smaller than 1,5 mm. This would correspond to magnifications of around 45x and 60x in the 66 and 88 scopes. However, depending on the terrain you may find that you are using lower magnifications most of the time, in which case the 2,6 mm exit pupil of the 66A would be sufficiently comfortable.
A weight difference of 0,5 kg may not seem much but I find that my 883 is rather top-heavy on my lightweight carbon fibre tripod and, being old and no longer fit, I always take my Swarovski ATM65 HD with me if I have to carry the scope any distance.
Even with a fixed 30x wide angle eyepiece it does the job at least 90% as well as the 883. Others on this forum have gained similar experience, so I'm inclined to think a 66A would be all you ever need.

John

 

[D Lloyd]

Hi, and welcome to Birdforum. I think it's a very sensible decision to go with a premium scope straight away.
Even the smaller Kowa 66A would be superior to all medium level scopes under most conditions.
For this series of Kowa scopes there are only two eyepieces avaiable, the 25-60x TE-11WZ zoom and a 35x ultra wide angle.
I have the 25-60x zoom on my 883 and find it comfortable with glasses. The 35x however, allegedly has shorter eye relief and with glasses you would probably not be able to take full advantage of the increased FoV.
The fluorite lens in the 66A will not compensate for the additional aperture of the 773, but whether you need this is a personal decision. Below a 2 mm exit pupil (33x on the 66A or 44x on the 88A) you are going to lose brightness even in sunny weather and the performance of your viewing eye will be diminished somewhat by diffraction effects. The capabilities of these scopes at normal magnifications will exceed that of your eyes.
Personally in terrestrial situations I perceive no significant gains with exit pupils smaller than 1,5 mm. This would correspond to magnifications of around 45x and 60x in the 66 and 88 scopes. However, depending on the terrain you may find that you are using lower magnifications most of the time, in which case the 2,6 mm exit pupil of the 66A would be sufficiently comfortable.
A weight difference of 0,5 kg may not seem much but I find that my 883 is rather top-heavy on my lightweight carbon fibre tripod and, being old and no longer fit, I always take my Swarovski ATM65 HD with me if I have to carry the scope any distance.
Even with a fixed 30x wide angle eyepiece it does the job at least 90% as well as the 883. Others on this forum have gained similar experience, so I'm inclined to think a 66A would be all you ever need.

John

Thank you for such a thoughtful and detailed reply.

I read somewhere (possibly on this forum!) the expression “Buy once, cry once.” It struck me as eminently sensible.

I appreciate you noting that your 883 is somewhat top-heavy with your tripod. I’ve heard it said “The best scope is the one you bring with you.” In that sense, the one that is easier and least cumbersome to pack around seems like a winner. I think I’ll order the 66A.

Thank you again.

 

[AlphaFan]

I have both an 88A and 66A.

The 88A is certainly a smidge better optically. They use the same eyepiece but where I see the biggest difference is at maximum magnification (60X). Although one might only notice the difference if viewing them side-by-side, the 88A is a smidge crisper on those long-range subjects. It is a joy to use on those longer sessions with waterfowl and waders, especially on the coastline. Another issue is eye fatigue - I can view for quite a while with the 88A before feeling any effects. As far as size, weight and balance = I find the 88A carries a hair smaller than its objective diameter would suggest. Anyway, it certainly feels lighter than my Meopta S2. But it is a full-sized spotter that takes up quite a bit of volume in a backpack and isn't the scope I'd be carrying if walking all day.

I bought the 66A specifically for those situations where I wanted something that was a bit easier to pack and carry but still provide a view in the same league with the 88A. It does this fairly well. During full daylight it performs quite well - the limitations being extreme distance subjects at highest magnification and I do experience eye-fatigue on those longer sessions more quickly than with the 88A. However, when packing it up for a trip or in a backpack the volume difference is obvious and the weight difference makes it much easier to deal with.

If I'm doing more dedicated glassing I'll generally be packing the 88A, if doing more walking than glassing the 66A comes along. If traveling and am not entirely sure the spotter will be necessary then it will be my 554.

Don't require corrective lenses so cannot opine there.

 

[Yukonjohnny]

Hi there!

Long-time lurker, first-time poster

I’m in the market for my first scope. I’m currently deliberating between the Kowa TSN 66A and 88A. I’ve also found a 773 on ebay at a good price. There isn’t a Kowa dealer nearby so I can’t try them out in person to compare. I would love to hear people’s thoughts on this dilemma.

I’m not an early riser and bird mostly during daylight hours, with the occasional dawn and dusk outings. It’s often cloudy and rainy where I live; I’m not sure if this counts as low-light conditions. I go on a lot of bird walks and hope to eventually do some guiding. As I’ve never had a scope before, I’m not sure how noticeable the weight difference will be over the course of a day in the field. I’m told by backpackers that an extra 0.4 kg (the difference between the 66 and 88) may not sound like a lot of weight but it makes itself felt the longer you have to carry it. The 88 is longer, too, so perhaps this makes it more awkward or cumbersome to carry?

The 88A will be better during lowlight conditions, but I’ve read the 66A still performs well, and that the 88A will at most get you a few more minutes of good viewing as the sun goes down.

I was thinking that the 773 may be the sweet spot between the two, but I’ve also read that the fluorite crystal in the 66A makes it just as bright and crisp as the 773. The fluorite is apparently also better with chromatic aberration.

I’m interested in digiscoping but it’s not a big factor in my decision.

I’m leaning towards the 66 because of its portability. I’m small and not very strong. My hesitation is whether there will be occasions in low light in which I’ll wish I’d got a bigger objective lens.

The last thing I’ll note is that I wear glasses and have often struggled to get a good view through scopes others have brought on trips, mainly Vortex, Swarovski, and Vanguard. I didn’t spend any time fiddling with the eyecup, though, because others were also using it. Perhaps some adjustment would have improved my view. I did have an amazing view once through a Nikon Fieldscope ED III; it was a revelation. But they are hard to find where I live (Canada). I would love to hear how other glasses-wearers have found the eye relief on their Kowas.

You mentioned you are not a bigger person so you need to ask yourself if you’re prepared to carry a larger tripod in the field . Any scope in the 80mm range is going to require that . With that size objective your tripod becomes paramount. I was going back and forth between the Kowa and an older Nikon. I was very lucky and found a ed82 field scope in British Columbia . I have the 30x and 75 fixed eyepieces that came with it. With the 30x eyepiece it is a spectacular set up. Chromatic aberration is all but non existent truly a beautiful scope . I would lean towards the 773 after reading your post or a smaller objective older Nikon . Either way you can’t go wrong .

 

[almond68]

Personally, I'd go with the 88, but you can't go wrong with any of those options. I just picked up an 884 couple of months ago, spent some time comparing to a 773 I was looking at trading for; both had the 25-60x eyepiece. The 77 hung in there surprisingly well even in low light. The biggest difference was the much larger apparent field of view in the 88.

 

[Tringa45]

The 77 hung in there surprisingly well even in low light. The biggest difference was the much larger apparent field of view in the 88.

Same eyepiece and same magnification, same AFoV. 66, 77 and 88 all have the same 500 mm focal length.

John

PS:- I have measured the AFoV on my TE-11WZ as follows. 57°@25x, 60°@30x, 66°@40x and 69°@50x & 60x.

PPS:- The resolution of my 883 was measured at 1,41 arcseconds, just short of being diffraction limited at 1,32". Bolden Eagle achieved the same result with his 883, so achieving the Dawes' limit with such a "fast" (f/5,7) is a strong challenge. AFAIK no-one has yet found a really excellent 99, which also has a "fast" focal ratio.
However, I would expect a good example of a 66 with its "slow" focal ratio of f/7,5 to be diffraction limited and achieve 1,76" - not as good as an 88, but better for its size.

 

[D Lloyd]

You mentioned you are not a bigger person so you need to ask yourself if you’re prepared to carry a larger tripod in the field . Any scope in the 80mm range is going to require that . With that size objective your tripod becomes paramount. I was going back and forth between the Kowa and an older Nikon. I was very lucky and found a ed82 field scope in British Columbia . I have the 30x and 75 fixed eyepieces that came with it. With the 30x eyepiece it is a spectacular set up. Chromatic aberration is all but non existent truly a beautiful scope . I would lean towards the 773 after reading your post or a smaller objective older Nikon . Either way you can’t go wrong .

Thank you! And congrats on finding an old fieldscope! I keep looking but the angled variety seems hard to come by.

I have both an 88A and 66A.

The 88A is certainly a smidge better optically. They use the same eyepiece but where I see the biggest difference is at maximum magnification (60X). Although one might only notice the difference if viewing them side-by-side, the 88A is a smidge crisper on those long-range subjects. It is a joy to use on those longer sessions with waterfowl and waders, especially on the coastline. Another issue is eye fatigue - I can view for quite a while with the 88A before feeling any effects. As far as size, weight and balance = I find the 88A carries a hair smaller than its objective diameter would suggest. Anyway, it certainly feels lighter than my Meopta S2. But it is a full-sized spotter that takes up quite a bit of volume in a backpack and isn't the scope I'd be carrying if walking all day.

I bought the 66A specifically for those situations where I wanted something that was a bit easier to pack and carry but still provide a view in the same league with the 88A. It does this fairly well. During full daylight it performs quite well - the limitations being extreme distance subjects at highest magnification and I do experience eye-fatigue on those longer sessions more quickly than with the 88A. However, when packing it up for a trip or in a backpack the volume difference is obvious and the weight difference makes it much easier to deal with.

If I'm doing more dedicated glassing I'll generally be packing the 88A, if doing more walking than glassing the 66A comes along. If traveling and am not entirely sure the spotter will be necessary then it will be my 554.

Don't require corrective lenses so cannot opine there.

Thank you! It’s good to hear from someone who has both. The impression I’m forming from what I’ve read is that while the 88 is a better scope, it’s not by too much, and the 66 is more versatile. I’m leaning to getting the 66 as my catch-all scope. Or ordering both to try them out, and sending one back.

Can you tell me what you mean by eye fatigue?

 

[D Lloyd]

Personally, I'd go with the 88, but you can't go wrong with any of those options. I just picked up an 884 couple of months ago, spent some time comparing to a 773 I was looking at trading for; both had the 25-60x eyepiece. The 77 hung in there surprisingly well even in low light. The biggest difference was the much larger apparent field of view in the 88.

Thanks! Are you enjoying the 884?

 

[AlphaFan]

Can you tell me what you mean by eye fatigue?

Sure. To me, the view from the 88A is simply a bit easier and slightly more detailed/saturated overall. That being the case I’m straining just a bit less to pull every last bit of detail from the image than from the 66A. Like mentioned earlier it doesn’t really emerge unless attempting to pull detail from extremely distant targets at the highest magnification or during more prolonged glassing sessions. Isn’t a huge issue and I very much enjoy using my 66A, but it can be a minor annoyance.

 

[benjsham]

I recently purchased a 774 with the TE-17w 30x eyepiece after going through this same conundrum. Price was the deciding factor in the end. I was able to pick up a like new scope and eyepiece on eBay for under $900 USD. Easily $1,000 less than a used 66A or 883. The 773/774 can easily be had on eBay with the TE-11wz for about $1,700. While I had heard that the 77 series has more chromatic aberration than the pure fluorite crystal models, I am only able to detect the faintest amount of CA in very poor lighting conditions at the edges of the field. In general, I am bothered by CA in optics but in the 774 I almost never notice it. That said, I haven’t personally had a chance to try one of the pure fluorite crystal models. I have had my 774 next to a Kowa 663 with TE-14w 30x eyepiece (which I believe has the same high fluorite content XD glass as the 774) and the difference in light gathering and resolution provided by the larger objective lens is clear. All that’s to say, if price is a factor I’d recommend a lightly used 773/774 in an instant.

 

[D Lloyd]

I recently purchased a 774 with the TE-17w 30x eyepiece after going through this same conundrum. Price was the deciding factor in the end. I was able to pick up a like new scope and eyepiece on eBay for under $900 USD. Easily $1,000 less than a used 66A or 883. The 773/774 can easily be had on eBay with the TE-11wz for about $1,700. While I had heard that the 77 series has more chromatic aberration than the pure fluorite crystal models, I am only able to detect the faintest amount of CA in very poor lighting conditions at the edges of the field. In general, I am bothered by CA in optics but in the 774 I almost never notice it. That said, I haven’t personally had a chance to try one of the pure fluorite crystal models. I have had my 774 next to a Kowa 663 with TE-14w 30x eyepiece (which I believe has the same high fluorite content XD glass as the 774) and the difference in light gathering and resolution provided by the larger objective lens is clear. All that’s to say, if price is a factor I’d recommend a lightly used 773/774 in an instant.

Price is not not a factor - I am prepared to pay for the 88 if that's the one I truly like best, but if the difference between the 88 and a smaller scope is (to my eyes) negligible, then I would gladly save the $. I've seen lots of Kowa on eBay. However, I'm a little leery of making a purchase of this magnitude from a vendor that won't accept returns in the event I'm unhappy with the scope. I've yet to actually look through a Kowa! And I'm not confident in my ability to judge whether second-hand optics are in good enough condition (aside from obvious flaws).

Glad to hear you're enjoying the 774! I feel validated in my choice of Kowa.

 

[D Lloyd]

You mentioned you are not a bigger person so you need to ask yourself if you’re prepared to carry a larger tripod in the field . Any scope in the 80mm range is going to require that . With that size objective your tripod becomes paramount. I was going back and forth between the Kowa and an older Nikon. I was very lucky and found a ed82 field scope in British Columbia . I have the 30x and 75 fixed eyepieces that came with it. With the 30x eyepiece it is a spectacular set up. Chromatic aberration is all but non existent truly a beautiful scope . I would lean towards the 773 after reading your post or a smaller objective older Nikon . Either way you can’t go wrong .

The best view I ever had through a scope was through an old Nikon Fieldscope ED III. I check eBay and Marketplace periodically in hope of finding an angled model in excellent condition. But I just moved to a new home seaside and there are so many birds on the water I want to see better. And I want to up my shorebird / gull game. My patience for the Fieldscope search has run out, hence the Kowa deliberation.

As for tripods, the fellow I spoke with at Pelee Wings suggested the Sirui ST-124 Kit with VA-5 Head kit, and noted it would work for either the 66 or the 88. Do you think a sturdier one would be necessary with the 88? Or I could get away with a lighter one for the 66? It weighs 2.6 lbs and can support up to 26.6 lbs

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

store.sirui.com

 

[almond68]

Same eyepiece and same magnification, same AFoV. 66, 77 and 88 all have the same 500 mm focal length.

John

PS:- I have measured the AFoV on my TE-11WZ as follows. 57°@25x, 60°@30x, 66°@40x and 69°@50x & 60x.

PPS:- The resolution of my 883 was measured at 1,41 arcseconds, just short of being diffraction limited at 1,32". Bolden Eagle achieved the same result with his 883, so achieving the Dawes' limit with such a "fast" (f/5,7) is a strong challenge. AFAIK no-one has yet found a really excellent 99, which also has a "fast" focal ratio.
However, I would expect a good example of a 66 with its "slow" focal ratio of f/7,5 to be diffraction limited and achieve 1,76" - not as good as an 88, but better for its size.

Thanks for sharing the info. However, we both know the 88 is the best of the lot.

 

[almond68]

Thanks! Are you enjoying the 884?

I love it and having fun with it.

 

[Tringa45]

As for tripods, the fellow I spoke with at Pelee Wings suggested the Sirui ST-124 Kit with VA-5 Head kit, and noted it would work for either the 66 or the 88. Do you think a sturdier one would be necessary with the 88? Or I could get away with a lighter one for the 66? It weighs 2.6 lbs and can support up to 26.6 lbs

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

store.sirui.com

Not this for goodness sake!!
Have you read A Tripod Primer It's a bit old but I'd go along with most of what I wrote then.
If the cost is not a major issue, you can't go wrong with Gitzo. For the smaller scope a GT2532 would be a good choice and for the larger, a GT3532 (both 3 section). You might also consider similar models from Feisol, FLM or Leofoto.
My "lightweight" tripod is a Novoflex TrioPod with 3-section carbon fibre legs. It alone weighs 1400 g and the Berlebach 510 head and QR plate add another 800 g. It's a good compromise with a 65 mm scope but a bit top-heavy with my 883 and might not be easily found in Canada.
My favourite head would be the Berlebach 553 (I have its predecessor the 552 on a Berlebach wooden tripod) but the Manfrotto MVH500AH is well regarded, is only a little heavier and a lot cheaper. Other possibilities are the Gitzo GHF2W or even the Sirui VA-5(X).

John

 

[Bill Atwood]

For dawn/dusk and cloudy/rainy conditions, above 40-45x you will likely find the 66A to be too dim.

Yeah the ST-124/125 is a bit short, and too light even for the 66. Tripod manufacturer load specs are utterly worthless when it comes to evaluating birding scope performance.

As a travel kit I purchased the 66A, GT2545T and Sirui VA-5 in December and I'm pretty happy with it. For local birding I'd probably prefer the GT1532 tripod.

For the 88A I'd use a GT2532 and GHF2W.

 

[Gzoladz74]

The best view I ever had through a scope was through an old Nikon Fieldscope ED III. I check eBay and Marketplace periodically in hope of finding an angled model in excellent condition. But I just moved to a new home seaside and there are so many birds on the water I want to see better. And I want to up my shorebird / gull game. My patience for the Fieldscope search has run out, hence the Kowa deliberation.

As for tripods, the fellow I spoke with at Pelee Wings suggested the Sirui ST-124 Kit with VA-5 Head kit, and noted it would work for either the 66 or the 88. Do you think a sturdier one would be necessary with the 88? Or I could get away with a lighter one for the 66? It weighs 2.6 lbs and can support up to 26.6 lbs

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

SIRUI Waterproof Carbon Fiber Tripod Kit ST-124 125+VA-5X Tripod head

store.sirui.com

I use the st125 with the va5 for my 88a and like the setup a lot. I do hook my backpack from it if it is windy.