• Welcome to BirdForum, the internet's largest birding community with thousands of members from all over the world. The forums are dedicated to wild birds, birding, binoculars and equipment and all that goes with it.

    Please register for an account to take part in the discussions in the forum, post your pictures in the gallery and more.
ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

kowa glass Quality (1 Viewer)

I asked a similar question a few days ago (look a few threads down). I have been told yes, there is a noticeable difference. If you search, you will find a few other members who have posted similar sentiment/discussed upgrading from 662 to 664 etc. I have not personally tried either version, just reiterating what others have posted.
 
Hi,

first of all, welcome to birdforum!

As for your question, yes for fast refractors like your usual spotting scopes, ED glass (Kowa calls it XD) or fluorite crystal (Kowa calls scopes using it Prominar) helps a lot to avoid longitudinal chromatic aberration which will make it difficult to find a good focus at magnifications above ca. 40x in instruments using normal crown and flint optical glass.

The effect was quite visible when I had the opportunity to compare my fluorite TSN-3 vs a plain glass TSN-1 (otherwise identical) of a fellow birder.

PS: the ED/fluorite models (model # ending in 3 or 4) are often sold alongside their plain glass brethren (model # ending in 1 or 2).

Joachim
 
jring said:
Hi,

first of all, welcome to birdforum!

As for your question, yes for fast refractors like your usual spotting scopes, ED glass (Kowa calls it XD) or fluorite crystal (Kowa calls scopes using it Prominar) helps a lot to avoid longitudinal chromatic aberration which will make it difficult to find a good focus at magnifications above ca. 40x in instruments using normal crown and flint optical glass.

The effect was quite visible when I had the opportunity to compare my fluorite TSN-3 vs a plain glass TSN-1 (otherwise identical) of a fellow birder.

PS: the ED/fluorite models (model # ending in 3 or 4) are often sold alongside their plain glass brethren (model # ending in 1 or 2).

Joachim
Click to expand...
https://sportingoptics.kowa-usa.com/scopes/

It looks like only the 883/884 use fluorite. The 770 series uses XD.
 
Last edited:
All the ED models are Prominar...The 613 and 663 are included in the nomenclature.Is not a marketing plot and they dont advertise them as Fluorite.Some binoculars and photo lenses are also made under the Prominar name.Prominar doesnt mean Fluorite, I think It designs a high end instrument using special glass
 
Last edited:
mayoayo said:
All the ED models are Prominar...The 613 and 663 are included in the nomenclature.Is not a marketing plot and they dont advertise them as Fluorite.Some binoculars and photo lenses are also made under the Prominar name.Prominar doesnt mean Fluorite, I think It designs a high end instrument using special glass
Click to expand...

Erm no, I beg to disagree... show me the word Prominar on the 663 page linked below or on any 603/613/663 bodies...

https://www.kowaproducts.com/KowaTSN-660SeriesSpottingScopes/KowaTSN-663MAngledSpottingScope/

Joachim
 
Hi,

interesting - so they seem to slap on the Prominar to their current top model as needed... because clearly today the 663/4 models are neither marketed as nor labeled as Prominar - unlike the 770 and 880 series.

But still a 663 will give a nice view.

Joachim
 
Prominar is just a marketing label. The fluorite glass in the 883/884 series is absolutely amazing and must be seen to be appreciated.
 
Pileatus,

I'm sure you already know Kowa likes to remind us that the Fluorite lens in the 883/884 isn't glass at all, but the mineral crystal Calcium Fluoride (CaFL) with an Abbe value of 95. It was unequaled as a low dispersion optical material until Ohara FPL53 glass, with essentially equivalent but not better characteristics came along about 25 years ago. Now the are a few other equivalent glass types, but it's still the case that most of the "ED" glass types used in spotting scopes have Abbe values between 80 and 85 and therefore have less potential for color correction.
 
henry link said:
Pileatus,

I'm sure you already know Kowa likes to remind us that the Fluorite lens in the 883/884 isn't glass at all, but the mineral crystal Calcium Fluoride (CaFL) with an Abbe value of 95. It was unequaled as a low dispersion optical material until Ohara FPL53 glass, with essentially equivalent but not better characteristics came along about 25 years ago. Now the are a few other equivalent glass types, but it's still the case that most of the "ED" glass types used in spotting scopes have Abbe values between 80 and 85 and therefore have less potential for color correction.
Click to expand...

Thanks for the insights. I knew about FPL53 but none of the details. After an hour or so of reading I know enough about it to know I don't much about it.

In any case, from a purely layman's viewpoint, the image in the Kowa 883 is so clean it begs to be used.
 
Warning! This thread is more than 5 years ago old.
It's likely that no further discussion is required, in which case we recommend starting a new thread. If however you feel your response is required you can still do so.

Similar threads

Z
Bought new KOWA PROMINAR 500mm F5.6FL
Replies
1
Views
877
zhanghl1698
Z
binomania
New spotting scope from KOWA
2
Replies
26
Views
4K
jring
J
G
Using KOWA TSN-EX16S (1.6x) Extender with a TSN-823?
Replies
5
Views
861
Grando
G
Y
883 or 66a?
Replies
10
Views
2K
Yippeekiay
Y
binomania
REVIEW KOWA TSN-66 A PROMINAR - a little fluorite gem with incredible performance!
Replies
10
Views
5K
kwikstaart
K

Users who are viewing this thread

Total: 2 (members: 0, guests: 2)
Back
Top