• 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.

Reviews by cspratt

Recommended
Yes
Price
2800$
Pros
  • Excellent optic, balances well on tripod
Cons
  • Poor documentation, peep sight on the side is unuseable with case on.
The top-of-the-line Kowa fluorite scopes are the 820M series consisting of the 824M straight scope and the 823M angled or offset scope. This review covers the 823M spotting scope, we can hope that most of the assumptions can apply to either flourite model. The scope has a focal length of 450mm giving it an F ratio of 5.5.

The 823Ms (angled or offset) multi-coated fluorite 82mm objective end optics are unchanged from the earlier 823 model, but the carbon-fibre body has been reinforced to make it more impact-resistant. With these changes, the new model weighs in at about 100g more than the old. (The length is 383mm and total weight is 1480 grams). The scope is also, dust-proof, nitrogen-filled and waterproof, but I still would not want to use it in the rain!

The 823M\'s image is excellent especially in side and front light, which was very good; and its brightness and clarity in daylight at all magnifications was also very good. Viewing against the sun, the Kowa did not fare quite as well, exhibiting a little flare and slightly reduced color contrast. The field of view of the Kowa bayonet mount zoom (2.0-1.0 degrees) is a typical narrow, tube-like zooms field. The extreme edge quality varied from somewhat poor at 20x to very good at 40-50x, but deteriorates a little again when increasing magnification to the maximum 60x. Between 25-40x there is also a shiny surface visible inside the eyepiece barrel beyond the field edge. When zooming from 20x to 60x an adjustment must be made to the focus. Going from 60x down the focus hardly changes at all. For eyeglass wearers the zoom\'s small eye-relief will be disconcerting even with the fold down or removeable eyecup removed or folded in place. Thus, the Kowas image is not one of the most even and restful to view over extended periods. The eyepiece zoom adjustment was very light but does have a somewhat rough feel. However, with practice, finding the optimum eye position is easy, and the best image isn\'t that hard to find even for this reviewer who wears glasses.

Under the bayonet eyepiece mount is a \"dust protection glass\". This is to keep out humidity or dust, and is easily kept clean with a small lens blower or air canister.

One can focus as close as 6 metres, but with the edition of a \"close-up\" optional adapter the close focus range can be narrowed to 3.5 metres but at the sacrifice of infinity focusing (the range is now 3.5 to 7 metres). This optional item wasn\'t tested.

Another option (not tested) is an eyepiece converter which allows other Kowa eyepieces to be used with the 823/4 (non-flourite) and 823/4M series.

The rubberised focus knob at the top side of the prism housing is very smooth and the precise focus adjustment point was found easily. The front objective lens end has a slide-out rain/glare guard. The main body can be rotated through 360 degrees when tripod mounted to allow the user to get to a comfortable viewing position.

Other eyepieces available are 32x and 50x wide-angles and a long 31mm eye relief eyepiece especially made for target shooting and yielding 27x. Only the LER (31mm) was tested. It gives a nice bright image but the field of view is somewhat narrow. It is very easy to use with eyeglasses as the rubber eyecup slips off. It works well with the digital adapter for digiscoping.

The zoom eyepiece is supplied with a large screw cover which will fit over the entire eyepiece and screw into the telescope body. This will not work if the optional \"digital adapter\" (reviewed below) is in place. In this case there is a supplied eye-end cover, which can be used when the eyepiece is removed. There is also a small end cap for the bayonet end of the eyepiece. The objective lens has a screw-in cover which can be awkward to get threaded on a cold day. A slip-on cover would have been better here. A 86mm filter (perhaps a solar filter) can also be threaded on the objective end.

The optional waterproof case can stay in place, but is a handicap when trying to use the \"peep-sight\" on the right side of the scope. The peep-sight isn\'t that useful for birding anyway. The case lacks the shoulder strap of earlier models which makes carrying the scope, using the built-in \"hand-strap\", awkward especially if the tripod and head is still attached. No slinging this combination over the shoulder!

The optional digital camera adapter can be used with various digital cameras, but you must purchase the required step ring for your particular digital camera model. In this review the 28mm ring fitted nicely to a Nikon Coolpix 4500 digital camera. Once installed, part of the adapter stays on the scope at all times and doesn\'t interfer with visual use. There is an extension tube (also an extra cost) that is hollowed out, allowing the zoom to be turned when the camera is in place for digiscoping. The whole unit with camera attached slips over the eyepiece and there is a single large lock screw which is tightened against the previously installed housing. This digital adapter takes getting used to but is very efficient and can be quickly removed to allow the next target to be found. The digital camera adapter can also be used with other Kowa scopes and eyepiece combinations as a step ring is included for this purpose.

The scope plus camera can be very \"back-heavy\" so the tripod head tension must be adjusted so that the scope doesn\'t fall forward when the camera unit is removed. Without the camera and digital adapter, the 823M balances very well on the Manfrotto 128RC (Bogen 3130) \"micro video head\", and also the Manfrotto 390RC \"Junior pan and tilt head\" used during this review. I might add that the Manfrotto \"Junior\" 390RC is a better head for the Kowa (or any spotting scope) when \"digiscoping\" (using a digital camera coupled to a spotting scope).

For film buffs there is a photo-adapter (not tested) which with the 823/4M\'s can increase the focal length to 840mm and the F stop to about F/10.4. A \"T-ring\" (also extra) is required to attach a specific 35mm SLR camera model to the adapter.

There is a limited lifetime warranty on the scope. A warranty card is provided.

The scope\'s serial number is on the side of the small \"tripod block\" affixed to the bottom of the scope. The number is also on the cardboard shipping box.

The instructions, such as they are, consists of a small pamphlet in poorly written (translated) English with a Japanese translation. In my view, a waste of good paper. The instructions for the digital adapter aren\'t much better.If Kowa were to improve anything, the instruction pamphlets for both products could be improved greatly. As it is now, one can soon figure how everything works without resorting to the limited and mediocre documentation now provided. This is one case where two great products are spoiled by the documentation. Funny thing though, the Kowa advertising is very slick and colorful but the \"manual\"(?) is just and black and white slimmer version of the advertising brochure with no additional useful information. Is the manual provided with the other high end scopes on the market any better? Or are theirs, like Kowa\'s, just an after thought?
  • Like
Reactions: David Kirman
Recommended
Yes
Price
475$
Pros
  • Good eye-relief for eye glass wearers
Cons
  • Barely fits into supplied case with large neck strap
As someone who wears eyeglasses I often had problems with eye-relief. Thus, finding a pair of binoculars I could use without removing my glasses every time an interesting bird came along became a challenge. Then I purchased a pair of Swift Audubon 8.5 x 44 HCF Roof Prism binoculars and found my eye-relief problem went away! It\'s a pleasure using these when birdwatching. The wide field of view and contrast, along with waterproofing makes these binoculars exceptional value for the money! Birdwatching is now fun!
Back
Top