Classic Pentax Refractor..

[F15Rules]

Hi everyone,

I've just today picked up a nice Pentax J80 F12 refractor OTA.

It dates from c1990 and is really nicely built, with a nice 6x30mm finder and tube rings. The original altaz mount was sold some years ago, sadly, but I intend to adapt my dovetail to allow it to sit on my CG-5 and/or Meade Bresser Mounts.

Interestingly, the finder sits right smack in the middle of the focusser mount, not offset to one side or the other as is usual. This means that it is nigh on impossible to look down into your diagonal in the straight ahead position, you have to incline the diagonal a bit. I have heard that it is the Japanese tradition to observe straight through, without a diagonal (maybe it's easier if you are only about 5 foot 6!), so that might explain it.

I aligned the tube and finder this afternoon on a nearby chimney and the image was razor sharp, and colour free. The seller claimed that this scope is every bit as sharp and colour free as his Zeiss 63/840.. we will see, but first impressions are excellent. The whole tube feels nicely built, solid and the lens cell is collimatable.

The lens itself looks flawless and has its own plastic cover which fits down inside the long, aluminium screw on dewshield.

I attach a few pictures. Note in these pictures I mounted the tube on my Towa 339 mount, and the ring was slightly too big, so I had to pack it out with some foam filler to ensure a snug fit.

hope you like it, and I will post more details once I have had a proper first light.

cheers

Dave:hello2:

[AndyH]

Lovely stuff !!

Really looks the part.

Now that's a strange position for the finder. Never seen that before.

Cheers,

Andy.

ps: If you wish, you could join the newly formed classic scopes section.

Stargazers Lounge - Classic & Vintage Scopes

[matt c]

Wow! that's a great looking scope and quite a focal length

[russ]

wow what a classic looking scope. I notice there's a few people on here now with these older classic refractors. I must take a look through one at some point, would love to see what the views are like.

Russ

[F15Rules]

Hi Guys, thanks for the appreciative comments. A long focus scope is something different. Most eyepieces work better with them for a start, as the long focal length is very "forgiving" of eyepiece defects. The longer fl does mean a somewhat smaller field of view, so they are better for use on Lunar, Planetary and Double star targets than say Clusters or DSOs.

There is something about the "depth" of the field which I like as well...you seem to home in to the target. Also, the longer focal length (say F11 or higher) greatly reduces chromatic aberration, so you get pretty good colour free images.

Andy, I have joined the new group, at the time of posting this I had trouble finding it, so posted it here..but in future I will use the new forum!!

Can't wait to see all your pictures guys and gals..

cheers

Dave

[Towa]

Dave

That is a stunner, beautiful lines. In fact the lines remind me of a Carton refractor. The focus mount looks like it has been taken straight of a Carton. The finder scope looks identical to a Carton S-2504 finder, and those large knobs are typical of the Carton's from the era.

I know that on some Pentax products the parts were identical to those of Kenko. I often wonder if Pentax took the tubes and focus mount parts from other scope makers and then put their own lens in.

Can't wait for first light, I bet it's a cracker.

[philj]

Now thats a nice scope Dave. The mount threw me a bit till I read your post fully

I have never come across one of these before, you will have to give us a blow by blow account of 1st light, especially Mars

Philj

[F15Rules]

Still waiting for first light :-(...

got the tube rings sorted for my CG-5, just need something to look at!!

will come back when I have something to tell you...

[F15Rules]

Well, here she is, sitting proudly on my CG-5. Rock solid on the timber legs made for the Tal 125R.

All I need now is some SKY to look at!!

[JAO]

Dave

That's a fine instrument indeed. As several folk have commented it has the classic refractor lines, but most importantly that OG will almost certainly be of excellent quality. I look forward to your fisr light report.

Adrian

[ollypenrice]

I've heard it said that nothing beats a long focus refractor in light pollution. I've never had a look through one so I wonder what you think? If its true you could see them making a comeback which would be rather nice.

Olly