Kowa 883 + 25-60 (and maybe also Kowa XD 8,5x44)...? (1 Viewer)

Henry,
In the post 13 reference you mention using a TMB 4mm Supermonocentric eyepiece.
I have an old uncoated monocentric but didn't use it much.

What interested me was finding a reference to the Zeiss 1.25 inch and Pentax 0.965 inch orthoscopics being considered the best planetary eyepieces made.

With the Pentax 100mm f/12 was a set of these 0.965mm orthos, and I hadn't realised they were something special.
Optically this telescope was probably the best scope I owned and I could use up to 300x on planets and with a 3mm Clave Plossl, 400x for testing.
I gave the telescope to a friend.

Also I didn't know that the 20.5 inch f/3.9 Newtonian mirror was 1/20th wave, until the professional mirror maker told me it turned out to be that good. I suppose the Seeing was never good enough for me to realise how good it was.
Jim Hysom who made the telescope did say he was transfixed by the view of the Orion nebula and spent an hour unable to look away from the view from his dark site, some way from Cambridge.
Unfortunately he recently passed away, but leaves many fine telescopes still being used.

I have now tried a second specimen of the Kowa 883. At first I thought it was a little bit softer than the first one, but after some more testing it seems to be a little bit sharper actually. Better up is that it snaps into focus faster and more accurate than the first specimen I tried. So..the Kowa 883 is a great scope..it's very likable! What I don't like is the color cast..a little bit on the yellow side for my taste. But I hope my eyes will get used to that with time (if I'll keep the scope)! Only time will tell...

The Kingfisher said:

I have now tried a second specimen of the Kowa 883. At first I thought it was a little bit softer than the first one, but after some more testing it seems to be a little bit sharper actually. Better up is that it snaps into focus faster and more accurate than the first specimen I tried. So..the Kowa 883 is a great scope..it's very likable! What I don't like is the color cast..a little bit on the yellow side for my taste. But I hope my eyes will get used to that with time (if I'll keep the scope)! Only time will tell...

Click to expand...

A bit strange that Kowa haven't fixed that over the 12 years it has been on the market?
It seems that the blue transmission lags a bit compared to Swaro, 10% or so.
KR-coating on outer lens surfaces would be nice as well (some cheaper Kowa models have it now).

But still a very good scope, fluorite chrystal does the job very well with CA-correction.

Vespobuteo said:

A bit strange that Kowa haven't fixed that over the 12 years it has been on the market?
It seems that it's blue transmission that lags a bit compared to Swaro, 10% or so.
KR-coating on outer lens surfaces would be nice as well (some cheaper Kowa models have it now).

But still a very good scope, fluorite chrystal does the job very well with CA-correction.

Click to expand...

But I wonder..is the yellow "colour cast" in the Kowa 883 really a colour cast or is the scope just showing the real colours of the nature? Maybe it's our own eyes which compensates for the yellow in the mother natures light?! I have yet only tried the Kowa 883 on sunny days.

I will answer my (maybe little stupid) question on my own...;-) If our "naked" eyes compensates for the yellow colour in the natural light they should also compensate for the yellow colour we see in the scope. Right?! So I suppose my question above was a little bit stupid... )

Hi,

you are right - after you have looked through optics with a slight colour cast for a few seconds, the eye adapts and you don't notice it any more. Obviously some very strongly tinted optics like old east bloc glass will still be noticeable.

But please make a star test and check if the rings are concentric...

Joachim

The Kingfisher said:

But I wonder..is the yellow "colour cast" in the Kowa 883 really a colour cast or is the scope just showing the real colours of the nature? Maybe it's our own eyes which compensates for the yellow in the mother natures light?! I have yet only tried the Kowa 883 on sunny days.

Click to expand...

The slightly slanted transmission curve might actually be a technical design decision by Kowa for increased contrast in some viewing conditions (long distance/haze etc.).

Do you think it affects the color fidelity?

I wouldn't mind the 883 optics at all, but I prefer to have a helical focus wheel.

jring said:

But please make a star test and check if the rings are concentric...

Joachim

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Mostly I agree with Joachim. Lemons are certainly to be avoided and star-testing is the best way to do that, but star-testing will also reveal that even among expensive spotting scopes cherries can be very hard to find. A cherry is what I want if I'm going to spend a large sum for a small telescope. I've seen a few that belonged to other lucky people, but so far I haven't found one that was available for me to buy. Definitely a First World problem.

Henry

Out of the box I star tested mine in controlled conditions. I saw perfect concentric circles throughout the full range. I followed with a resolution test and that, too, convinced me it was a worthy sample. I then move outside to study known objects at 100-300 yards. I saw exactly what I hoped to see and, unless there's a magic scope somewhere I haven't seen, the one I purchased is a keeper. MY ED82 is also exceedingly sharp so maybe I'm just lucky.

I do not see any color cast in my 883. Atmospherics, of course, change the view from day-to-day but the "best" views, when conditions are ideal, are stunning.

One last point. I once saw an alpha scope that I thought was pretty mediocre. Had I written a review it would not have been flattering. A short time later I saw a different sample of the same make/model that really impressed me. Atmospherics had no bearing on the view so I was left to conclude the obvious: sample variation.