I brought this classic refractor from my retiring optics dealer. It is a Yamamoto SYW 108mm /1600mm / F.14.8 refractor. Approx. 30 years old and in mint condition. The 108mm. version are rare esp. with the pedestals mount so was lucky to get on so mint. The 80mm. version was more common and they used to come under the 'Sportmaster' name. It is well over 6 ft. long and weights in at 170lbs. Images are almost APO like with minimal CA. The craftsmanship is of the highest quality. It looks like a piece of optical art.
The cost was approx. $A2000 which really was somewhat of a bargain, as these scopes really are rare. I have brought a few thousand dollars worth of optics from the dealer over the years so he took this into account.
It's build and optical qualities are to say the are least excellent. The chrome looks amazing up close. It has a clear aperture of 108 mm [ 4.1/4 in.] with a F/L of 14.8.
The lens wear made by Horiguchi optics who supplied early Takahashi scopes.
The controls are solid and smooth. It is perfectly balanced. The 50mm / 500 mm finder with .96in. interchangable eyepieces in it self gives great images up to 80x.
CA is not an issue with normal magnifications. Above 280x - 300x some very minor purple color fringing can be glimpsed on the edge of the moon but you do have to look for it. It would exceed my old Orion ED100 with CA correction and image quality. The 1.25in. focuser is smooth and the image snaps into view.
Star tests are text book. Stars are pin point sharp. It takes magnifications in the 200x -300x range well. Last week the seeing was not the best and my Meade 6.7 4000 UWA, which gives 240x, gave the best images of Saturn with surface hues and ring detail easily seen. It does give that 'wow' feeling. have been desiring a scope like this for 40 odd years. I Spend half my time just looking at it - even my wife thinks it looks impressive !
I weighed it on some bathroom scales and all up it was in the 160-170lb. range. Being fairly fit still, I can take it outside in 2x pieces, but it is easier in 3x pieces. It takes about 5 min to set up. Cool down is minimal. I have some very nice Japanese made Celestron Ultima Possel's plus the Meade 6.7mm UWA. These scopes like the 4 in. plus Unitron / Polerax's were designed for planetary and double star splitting. The very rare Tasco 20 -TE has the same optics and they were around $US5000 in the 70-80's, they were sold as 'semi professional' scopes. Actually, my dealer also has a 102 mm / F.15 Unitron / Polerex with the 2x finders and on a wooden EQ mount . I believe it is the 160 Photo-equatorial. I had the option of getting that one but he wanted twice the price and it's condition is only 'average'. It need's a fair amount of refurbishment. I believe he will place it on E. bay as they sell for big money in the USA. I am happy with mine.
By all up - I understand you mean the telescope tube, the pier, the mount, the counter-weights and the guide tube. This makes a bit more sense now - having a 4" telescope alone weight 170 lbs seemed kinda crazy on first read!
Do you have any pictures of it looking down the lens - how well is it baffled?
Being such long focal length, does it lessen the need for a fine focuser (one of the 10: 1 geared reduction jobs)?
Yes, it is a solid instrument - this does however make it rock steady even in windy conditions.
There are 3x main baffles and the internal tube is well blackened. There are some vague pencil marks and some Japanese hand writing in the barrel, presumably from the hand made craftsman.
There is no ghosting or secondary reflections.
The focused is very firm and has no play. The focus is fairly fine and it is easy to focus to pin point. I would not upgrade the focuser as really it is not necessary and it would make the scope 'non original'.
I only have a photo of the lens. The spacers remind me on my Orion ED 100 but as I do not do A.P. it is not a concern. The lens itself is mint. It has the adjustable cell. Collimation is spot on.
Some of these scopes may be in Australia – I do know of one and the owner has mentioned it with a photo of his on ‘Cloudy Nights’.
Last edited by chris lewis; 15-08-2012 at 08:54 AM.
Woaw! Now thats a refractor .., a solid investement for sure .
Are you willing to give the name of the retired optics dealer ? I am interested as I have got a lot of gear from Auckland over the years and I wonder if its the same person , most will be interested also .
Sure - it is 'Jacobs Photo and Digital' at 9 Mokoia Rd. Birkenkhead, North Shore, Auckland [09) 480 5903. Jacob is retiring in about a month and you can probably get up to 50% off on his optical gear. The 4in. Untron /Polerax is still there along with 30 odd years of collected optical equipment. There are about a dozen scopes and 40 odd binoculars still there.
Jacob is selling most of his equipment and taking the rest with him. It will not be an optics shop anymore. This is a shame as Auckland, which is similar in size to Brisbane, does not have many optical shops to start with - in fact there are no real optical shops as such, just the usual departmental stuff and even the One Tree Hill Observatory has mainly departmental type telescopes on display, but you can order GSO equipment in. Sad really