-
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.
Not a scope but a Fluorite camera lens! (6 Viewers)
- Thread starter RJM
- Start date
Rick,
As my Japanese is rather wanting, could you tell me whether the color-codes for the lenses in the cut-away diagram are as I'm guessing: no-color - standard (meaning no marketing hubris) glass; yellow - XDL glass; purple - fluorite?
As far as sharpness, I just last week saw another 883 which, in quick daytime glitter point tests, exhibited no aberrations I could see and which, boosted to 180x mag with a tripler, gave really clean and excellent views. Significantly less CA in defocused glitter points than in a Zeiss 85 FL (a very good scope in this regard) next to it.
Kimmo
As my Japanese is rather wanting, could you tell me whether the color-codes for the lenses in the cut-away diagram are as I'm guessing: no-color - standard (meaning no marketing hubris) glass; yellow - XDL glass; purple - fluorite?
As far as sharpness, I just last week saw another 883 which, in quick daytime glitter point tests, exhibited no aberrations I could see and which, boosted to 180x mag with a tripler, gave really clean and excellent views. Significantly less CA in defocused glitter points than in a Zeiss 85 FL (a very good scope in this regard) next to it.
Kimmo
Paul Hackett
Well-known member
I have been informed that the body is a new design, at the time of writing i did not have the information available to me and i am told it is not the same specification/ number of Lenses as the 883/4, i have requested a cutaway of the body to post on here if there is one available, and is in the public domain
Regards
Paul
Chris Galvin
Well-known member
That is the same image and zoomed by cropping of it to appear as if different lenses used. All exif data has been stripped from the images so probably prepared for web use by the 'Save for web' option in Photoshop
Last edited:
henry link
Well-known member
Paul,
The link that Rick supplied has some simple cutaway diagrams here:
http://www.kowa-prominar.ne.jp/pro/lens/feature.htm
They look a lot like the scope optics until you get to the extra doublet behind the focusing group. Maybe that doublet changes the position of the focal plane to make the lens more compact or possibly massages the field curvature to match a flat sensor for photographic use. The visual back then has another lens or group in front of the prism. Maybe that lens returns the field curvature to its original shape to match the eyepiece field curvature.
Henry
CharleyBird
Well-known member
I was lucky enough to be in the Bittern hide in the Lee Valley this morning with a friend and think I met Paul Hackett.
It was something of an equipment fest, as Paul had this fluorite lens/scope, together with the latest Kowa 88 scope and a pair of Kowa 8x33 binoculars.
Also notable, there was also one chap with a canon +500mm f4 with 1.4 converter, and another with a pair of 7x42 dialyt.
I had my Steiner 10x44 Discovery, but not my Swaro drawscope (would have been good to try it out in comparison set up as a 1200mm lens).
The kowa scope is probably the best I've looked through, it had a 30x eyepiece.
The bins, well, pick the one that meets your needs, but 20 year dialyts hold their own and are just so easy on the eyes. The Kowa 8x33 were light and very nice, at 900 quid they ought to be.
The kowa fluorite lens/scope is fascinatingly small and light for what you get, while the 500mm lens on the canon looked huge by comparison, bigger in some ways than my drawscope when used with the TLS800+ Nikon.
A bittern was showing well, posing for minutes near the hide, the guy with the 500mm + converter had to take his 1.4 converter off it was so close (so my swaro would have been useless); then it vanished for a while, and suddenly reappeared down the channel with a foot long pike hanging from its bill. There was a rush to get a shot of this relatively massive fish being carried on the ice. I have to say that the kowa seemed easier to get into position though both got shots.
Wish I could have seen the results clearly, but did see the feathers zoomed in on the bittern as taken on the kowa, sharp.
Very interesting to see the kit being used. Thanks to Paul, my friend & I talked about buying equipment all the way back.
That bittern is probably still suffering idigestion.
It was something of an equipment fest, as Paul had this fluorite lens/scope, together with the latest Kowa 88 scope and a pair of Kowa 8x33 binoculars.
Also notable, there was also one chap with a canon +500mm f4 with 1.4 converter, and another with a pair of 7x42 dialyt.
I had my Steiner 10x44 Discovery, but not my Swaro drawscope (would have been good to try it out in comparison set up as a 1200mm lens).
The kowa scope is probably the best I've looked through, it had a 30x eyepiece.
The bins, well, pick the one that meets your needs, but 20 year dialyts hold their own and are just so easy on the eyes. The Kowa 8x33 were light and very nice, at 900 quid they ought to be.
The kowa fluorite lens/scope is fascinatingly small and light for what you get, while the 500mm lens on the canon looked huge by comparison, bigger in some ways than my drawscope when used with the TLS800+ Nikon.
A bittern was showing well, posing for minutes near the hide, the guy with the 500mm + converter had to take his 1.4 converter off it was so close (so my swaro would have been useless); then it vanished for a while, and suddenly reappeared down the channel with a foot long pike hanging from its bill. There was a rush to get a shot of this relatively massive fish being carried on the ice. I have to say that the kowa seemed easier to get into position though both got shots.
Wish I could have seen the results clearly, but did see the feathers zoomed in on the bittern as taken on the kowa, sharp.
Very interesting to see the kit being used. Thanks to Paul, my friend & I talked about buying equipment all the way back.
That bittern is probably still suffering idigestion.
Paul Hackett
Well-known member
Good to meet you today, glad you enjoyed the kit, i do enjoy taking pics as you saw !
I have had the good fortune over the last 2 weeks to have the only model of the new "Photo Lens Scope" here in the UK, and only have the 500m extender to try out, but the weather has not been kind, and the few times i have been out, i have enjoyed using it and it has been a talking point with some people, attached are a few pics from today
ATB
Paul
Attachments
Well they look pretty good I have to say.
Is it possible to use this lens with a teleconverter? A 1.4X would give a 700mm F8.
Is it possible to use this lens with a teleconverter? A 1.4X would give a 700mm F8.
henry link
Well-known member
Thanks for the photos, Paul.
For me the most interesting bits for evaluating the optics are the defocused glitter points on the water in the center left photo. They tell us a few things we can't tell from the nice sharply focused bittern. For instance, they're close to perfect circles so no significant astigmatism or pinching is present The central point is well centered and the outer ring is evenly illuminated so collimation is good. They remain round to the edge which indicates no vignetting. No visible color fringes, even on out of focus glitter points, indicates excellent correction for longitudinal CA.
The outer ring of the diffraction pattern is very bright which gives the out of focus disk a hollowed out look. That pattern on glitter points more distant than the focal plane indicates undercorrection for spherical aberration. I can't guess how much from the photo, but some undercorrection is typical in a lens or scope like this. It would be interesting to see if using the prism changes this. Prisms add spherical correction so I wouldn't be surprised to see better correction in the visual configuration. I use a prism diagonal instead of a mirror with my Tak SKY90 because by sheer good luck the prism adds about the right amount of overcorrection to compensate for the objective lens' undercorrection.
For me the most interesting bits for evaluating the optics are the defocused glitter points on the water in the center left photo. They tell us a few things we can't tell from the nice sharply focused bittern. For instance, they're close to perfect circles so no significant astigmatism or pinching is present The central point is well centered and the outer ring is evenly illuminated so collimation is good. They remain round to the edge which indicates no vignetting. No visible color fringes, even on out of focus glitter points, indicates excellent correction for longitudinal CA.
The outer ring of the diffraction pattern is very bright which gives the out of focus disk a hollowed out look. That pattern on glitter points more distant than the focal plane indicates undercorrection for spherical aberration. I can't guess how much from the photo, but some undercorrection is typical in a lens or scope like this. It would be interesting to see if using the prism changes this. Prisms add spherical correction so I wouldn't be surprised to see better correction in the visual configuration. I use a prism diagonal instead of a mirror with my Tak SKY90 because by sheer good luck the prism adds about the right amount of overcorrection to compensate for the objective lens' undercorrection.
Last edited:
RJM
Don't Worry, Be Happy!
I'm in the USA now for the holidays, but the Digisco-ya shop in Japan has a "demo" scope with Nikon mount available for 200,000 yen. It has been available for ~2 weeks now. An owner of this shop (forgot his alias) has posted to BF a few times recently, so might be willing to sell it overseas.
CharleyBird
Well-known member
Well those photos speak for themselves; how much is it likely to cost in the UK?
The only drawback we could find with the fluorite was it's not autofocus, and despite how easy it is to just turn the focus ring a little while snapping to get some if not all shots pin sharp, my friend would still prefer an autofocus lens. Of course the price of a 500 or 600mm autofocus prime lens is prohibitive, so we'll see.
Talking about buying stuff on the way home in the car, we both fancy a dialyt, he the 7x42, me the 8x56, but my next bins if it ever happens will likely be the swaro 15x56; his first puchase is likely to be a scope and I wouldn't be surprised if it turns out to be that Kowa 88.
We were also laughing that your two gitzo tripods together cost more than most bins on the market. Guessing 800 and 500?
It was a pleasure to meet you, and that bittern with the pike was a moment to treasure! Will we see the it in a pro publicity shot
The only drawback we could find with the fluorite was it's not autofocus, and despite how easy it is to just turn the focus ring a little while snapping to get some if not all shots pin sharp, my friend would still prefer an autofocus lens. Of course the price of a 500 or 600mm autofocus prime lens is prohibitive, so we'll see.
Talking about buying stuff on the way home in the car, we both fancy a dialyt, he the 7x42, me the 8x56, but my next bins if it ever happens will likely be the swaro 15x56; his first puchase is likely to be a scope and I wouldn't be surprised if it turns out to be that Kowa 88.
We were also laughing that your two gitzo tripods together cost more than most bins on the market. Guessing 800 and 500?
It was a pleasure to meet you, and that bittern with the pike was a moment to treasure! Will we see the it in a pro publicity shot
Paul Hackett
Well-known member
Paul Hackett
Well-known member
Jaff
Registered Member
In case people have missed my earlier post you have to use attachments on the back making it either a 350mmf4, 500mmf5.6, or 850mm f.9.6. Also you can use turn it into a scope with an attachment. I suspect though most people who buy it will just have the 500mmf5.6 attachment with it.
Paul Hackett
Well-known member
Having spent a reasonable time with this lens now, it is proving not to be a toy, as some earlier remarks made to me, the quality of the glass has to be up there with the Canon & Nikon lenses for me with my eye at least.
I have tried to find CA with this lens but just cannot find it in the pictures I have taken so far (around 16 gig) the large focus ring is solid, no slip, and the fine focusing is very precise.
Need to go and do some flight shots with this lens to see how really good it is.
Having spoken with the Kowa Japan managers at Birdfair, the philosophy behind this product has an interesting background. They approached the old master photographers in japan to seek opinions, it seems that most bar none prefer manual focus and manual settings for their camera and lens.
They like to be in control of their equipment rather than the other way, this led me to think that this product will only be of real use to people who have their eye to hand confirmation and not for the beginner enthusiast.
Is the quality of the lens upto the big lens manufacturers ? IMHO yes, but i have yet to test the 350 mm and 850 mm extenders/reducer, so I will still reserve judgement on the whole package.
Jaff hit the nail on the head when he said people who do buy will buy the version they want, but if the quality matches, then the portability and compact design of the product will allow all sorts of photography to be covered bar the fast flying/ action shots, with a price tag greatly reduced over the ever rising cost of the big and small lenses, its really down to how much do you rely on autofocus when manual could have got you the same results?
As i have said from the start, an interesting concept and definitely thinking outside the box.
Paul
I have tried to find CA with this lens but just cannot find it in the pictures I have taken so far (around 16 gig) the large focus ring is solid, no slip, and the fine focusing is very precise.
Need to go and do some flight shots with this lens to see how really good it is.
Having spoken with the Kowa Japan managers at Birdfair, the philosophy behind this product has an interesting background. They approached the old master photographers in japan to seek opinions, it seems that most bar none prefer manual focus and manual settings for their camera and lens.
They like to be in control of their equipment rather than the other way, this led me to think that this product will only be of real use to people who have their eye to hand confirmation and not for the beginner enthusiast.
Is the quality of the lens upto the big lens manufacturers ? IMHO yes, but i have yet to test the 350 mm and 850 mm extenders/reducer, so I will still reserve judgement on the whole package.
Jaff hit the nail on the head when he said people who do buy will buy the version they want, but if the quality matches, then the portability and compact design of the product will allow all sorts of photography to be covered bar the fast flying/ action shots, with a price tag greatly reduced over the ever rising cost of the big and small lenses, its really down to how much do you rely on autofocus when manual could have got you the same results?
As i have said from the start, an interesting concept and definitely thinking outside the box.
Paul
Sandpiper
Mike Powell
Paul,
Many thanks for the update. I will be watching this thread with great interest as I like the idea of carrying just one lens/scope and quickly adapting it to use for either viewing or photography. Is there any chance of an angled eyepiece being introduced in the future?
Mike
Many thanks for the update. I will be watching this thread with great interest as I like the idea of carrying just one lens/scope and quickly adapting it to use for either viewing or photography. Is there any chance of an angled eyepiece being introduced in the future?
Mike
