Fujinon 25 x 150 Binos

[Buck]

Just wondering if any members own, or have used a pair of Fujinon 25 x 150 binos. I'm considering purchasing a pair - the "standard" MT-SX straight through version. (The ED and 45 degree versions cost an extra $3500 & $3000 USD resepectively!) Wanted to discuss with any owners their impressions and/or pros & cons.
Thanks, Paul

[Ian Robinson]

I used to crave a pair , but too expensive .

You'd be better off with the angle version , unless you like getting a stiff neck.

[Satchmo]

I've looked through the standard achromat version ( F5 ) objectives and thought them pretty unremarkeable for $12000 Australian. The eyepieces seemed quite narrow apparent field and were not interchangeable. There was chromatic aberration and the stars did not seem that sharp. You would have to pay another $2500 mount them. Whilst It would be nice to own them, I think the eyepieces let them down. For that size and bulk a pair of JMI 10" Reverse Reflecting binoculars would be a much better buy, and more comfortable to use.

On the other hand I was blown away by the sharpness of the 100mm 45 degree Fork mounted Binos from Kunming Optical ( they are available locally for about $1800) . You can use your own quality eyepieces and they are triplet objective . Panning through the Milky Way with 24 Pans, the contrast and field sharpness was incredible. Even with Nagler 13mm the sharpness and quality knocked my socks off. With Nagler 7mm the Cassini division on Saturn was also razor sharp. Sometimes smaller can be better. Cost aside I would really like apair of these.

[koputai (Jason)]

Originally Posted by Satchmo

Cost aside I would really like apair of these. (Kunming Optical 25x100 45degree)

I'd love a pair of these too, and a non-astro friend is a definite too. Maybe we could get a bulk order together and have them shipped direct from China. I'm sure they'd be in the $1000-$1200 range, rather than the $1700-$2500 they are advertised for around these parts.
Any other interest?

Cheers,
Jason.

[Dennis]

I have the (smaller) Vixen 30x125 and they have 45 degree eyepieces. Having used these on a (home made) tripod with the Vixen alt-az mount, I would definitely not recommend a straight through bino for astronomical purposes.

Even with a solid mount, I suspect straight through bino’s would only be comfortable up to around 70 degrees altitude? Even though you could wait for objects at the zenith to drop down to more comfortable angles of altitude, I suspect you would find this frustrating.

My Vixen’s weigh 11 Kgs (bino’s only) and I would shudder to think how heavy the Fujinon’s are. I would recommend doing some extensive research on how easy they are to set up, how often you would be likely to use them, what types of objects and viewing they are best suited to, etc. before making a decision, as they are a huge investment. Better still, can you get to use a similar sized giant bino to get a feel of whether this is a path you really want to go down?

Cheers

Dennis

[Buck]

Originally Posted by Dennis

I have the (smaller) Vixen 30x125 and they have 45 degree eyepieces. Having used these on a (home made) tripod with the Vixen alt-az mount, I would definitely not recommend a straight through bino for astronomical purposes... snipped ....

Cheers

Dennis

Thanks Dennis, (& Mark & Jason & Ian). I already own a pair of straight through Vixen 25 x 125 binos and am used to the limitations for viewing at or near the zenith. I would like the 45 degree eyepieces but the extra cost is prohibitive. The Vixens also exhibit some colour fringing on bright contrasty objects, plus some coma on point sources, more so near the edge of the FOV. I believe the Fujinons do this also, but to a lesser amount - after all they are achromats at about f5 (same as the Vixens). The ED versions would eliminate some of this, but at an extra cost (of USD$3500 !) Mark's report of a lack of sharpness is the first I have encountered, and is a concern. I know there is a drop off at approx 80% out from the centre of the FOV. The colour and coma can be eliminated fairly effectively by using field stops in front of the objectives that "mask" the outer edge 20% of the objectives. I have done this with my Vixens and the light loss is not an issue as it is only necessary with bright objects such as the moon, planets, starts brighter than mag 3.5 to 4. Colour and coma is not really an issue when observing extended deep sky targets such as nebulae, galaxies, faint clusters etc with the large binos.

Yes, the price really scares me, but I've lusted after these for many years, and as I approach retirement age, I figure if I don't get them now, I never will!

Any further comments/opinions from members will be appreciated.

P.S. the price in the USA is nearly half that of Aus - even allowing for exchange rates, postage & GST/duty.

Thanks,
Paul (Buck)

[Dennis]

Hi Paul

A couple of years ago I had a look through some Fujinon 25x150’s that York Optical set up at the Qld Astrofest and the views were simply stunning. I think the bino’s were the ED model (?) but certainly, the colour correction was noticeably superior to my Vixen 30x125 model.

Seems like you know what you’re doing, having had the experience with your straight through Vixen’s, so I guess that the only additional comment I have is that even though the ED’s are more expensive, for a lifetime’s viewing experience, just make sure you don’t regret some years down the road not finding the extra $’s to go for the ED’s.

Good luck with the decision!

Dennis

[Satchmo]

Buck

Yes , I was referring to off axis sharpness. I found the pinpoint edge stars in the BT100's +24 Panoptics, far more staisfying than the somewhat narrower apparent field and comatic edges of the Fujinon's. I don't think straight through binos are well suited for astronomy which is why I feel in larger apertures a reverse Newtonian bino makes more sense. A 10" JMI would leave a Fujinon 6" for dust deep sky viewing and be far more comfortable to use for extended periods IMHO . The sky overhead is the best transparency and seeing and above 60 degrees or so straight through binoculars are literally a pain iin the neck.