Need advice on mechanical quality of zoom binos
Posted 22 January 2013 - 04:56 AM
I found your forum very interesting and got answers to lot of questions while reading. However, there are still some aspects on which I need your advice.
I want some large binoculars with power zoom. I will mainly use it for wildlife observation during daylight, and ocasionally for sky viewing. I perfectly understand what is exit pupil, front lens diameter, focal distance, multicoating, field of view and so on. In military, I was serving at borderline security, so there we had all kind of serious optics, with up to $100K price tags.
So, considering my practical observations and past experience, I came to conclusion, that I need something like 40x80 or even 60x80 binoculars. Unfortunately, such binoculars appear to be made only in zoom binocular department, so my choice is quite limited. Since this is just hobby, I'd prefer not to spend more than $200 for that. I understand perfectly that in this price range I should not expect anything serious, so, for start-up, I've purchased celestron Upclose G2 binoculars 10-30x50. Besides heavy chromatic abberations, it has another serious flaw. The piece, on which eyepieces are mounted, is made of very thin plastic, so even if you touch it slightly with your eye, it changes position and looses focus. Since I'm using it for terrestrial observation, even slight movement of eyepiece makes focus loose, so I need to constantly re-adjust the focus, which is very troublesome.
Unfortunately, these zoom ones aren't sold in local stores, so I depend on amazon/ebay/etc for such purchases.
So, I'd like to hear, whenever these giant large zoom, inexpensive binoculars from barska, celestron, bushnell and so on, suffer from the same issue? As I mentioned above, personally, I'd prefer fixed 40x80 binoculars, but was not able to find such one for my price range.
Thanks in advance,
Posted 22 January 2013 - 05:10 AM
To be honest a $200 80mm zoom binocular is going to be a waste of money. Your best bet at getting close to your target, IMHO, is looking for a fixed 30x80 binocular. But my recommendation would be to save up for something better (a 70 or 80mm binocular telescope with interchangeable eyepieces) or think outside the box (a spotting scope with zoom eyepiece).
Posted 22 January 2013 - 05:18 AM
I currently also own the following setup:
Camlink 15-45x50 spotting scope, to which I attached 1.7x tele zoom attachment from old Sony DSC-717 camera. It works quite nicely. Also, I have 1000mm/F10 reflex lens, for which I DIYed eyepiece holder, and using 12mm C mount CCTV camera lens as eyepiece. It also works fine, especially for observing the moon, when it is low on horison and located above distant mountains, in this case, mountains also do appear in view, and huuuge moon above them, very spacey and extra-terrestrial look it gives.
Posted 22 January 2013 - 05:45 AM
Posted 22 January 2013 - 05:49 AM
you could also get one of the Binocular-Telescopes with inter changeable EPs and use zoom EPs (but need click stops)
Posted 22 January 2013 - 06:28 AM
Posted 22 January 2013 - 06:51 AM
Posted 22 January 2013 - 07:03 AM
Posted 22 January 2013 - 07:17 AM
There are no good reasons to buy a zoom binocular.
Posted 22 January 2013 - 07:39 AM
Posted 22 January 2013 - 07:46 AM
Posted 22 January 2013 - 08:13 AM
Binoviewer with richfield scope (YES)
BT-70 Definatly YES
Posted 22 January 2013 - 08:19 AM
Posted 22 January 2013 - 09:04 AM
Binoviewer excluded, if I wanted one eyed, I would stick with telescope. I'm doing mostly terrestrial observations, so binoculars are must.
I saw you had a small spotting scope as well as a reflex lens, what other telescopes do you have? Good views at higher powers require decent optics. The view though and inexpensive spotting scope or reflex lens is not going to be anywhere near as Sharp as a decent quality telescope.
The real issue here is the $200 budget. Good optics cost money and binoculars have many optical components, many opportunities to degrade the image. They also must be properly aligned, so robust mechanical construction is a necessity. Telescopes can be much simpler so a decent astronomical telescope can be more affordable.
Posted 22 January 2013 - 09:26 AM
C'mon Jawaid; say what you really mean!
You have asked about the "mechanical quality of ZOOM binoculars."
THERE IS NONE!!! Yes, there are some who will give the old “What about the . . .” However, I’m not one to give Jack the Ripper a pass because he once helped a cripple across the street.
You have also received some very informative posts from some very informed observers. SO, to help you further if I can, I would like to SEE their years of practical observing experience and RAISE decades in the optical industry and repairing and collimating more binoculars than most bino executives have ever seen in a warehouse—including thousands of military units.
The following is from a monograph on binocular realities:
12. ZOOM BINOCULARS AND OTHER CONCEPTS FROM ****
There are many reasons to be even more aware of “ZOOM” binoculars! To the uninitiated the ability to “ZOOM” is a feature; to the serious observer they are anything but! For the most part, the zoom is made possible by the movement of an auxiliary system in the ocular (eyepiece) assembly of each telescope. The tubes move fore and aft along the optical axis by means of a small brass screw which passes through helical slots in the walls of the auxiliary tubes. When the zoom is operated, a series of spur gears move the screws to send the auxiliary lens systems back and forth.
As you may have guessed, there’s going to be a lot of lost motion. And, even if the lenses were flawlessly matched in curvatures, spacings, thicknesses and glass types, the lost motion in the zoom mechanism is usually bad enough (especially as the instrument begins to age) to degrade the image. Also, while the brain can compensate for small errors in collimation, it can’t compensate for differences in magnification. That means your binocular could be collimated exceptionally well and you still wouldn’t have a good image!
Another negative attribute of almost all zoom binoculars is that they produce smaller fields of view than their fixed-power counterparts at any given magnification. Some are so bad, one might get the impression he or she is looking through a pipe instead of an optical instrument!
Finally, the auxiliary systems that make zooming possible are seldom sufficiently blackened. This causes a scattering of light and a loss of contrast across the entire field of view. So, can I recommend a really good zoom binocular? All the really good ZOOM binoculars I know of are listed in the box below:
(small rectangular box)
And, if you still feel it would be great to have a zoom mechanism on your binocular, please stop to consider why three of the most respected manufacturers of binoculars (Zeiss, Leica and Swarovski) don’t have a zoom binocular in their line-up. NOTE: The Leica Duovid only appears to zoom between its two fixed powers. If a high-quality zoom ever comes to the market, Leica is likely to be the company responsible.
Yes, the above has been posted several times. But then, the problem has been raised several times, too.
If you still want a zoom instrument, please go ahead; sadly, experience is a far better teacher than I will ever be.
That monograph addresses several other bino misconceptions and I would be happy to send it to you should you send me your personal email address—my computer is full of them.
Again, welcome to our little family of misfits who might—just after taking the dog out at 3 a.m. in 18 degree weather—have to check the Cloudy Nights account before returning to bed . . . GUILTY!
Posted 22 January 2013 - 11:31 AM
The cheap binoculars have very poorly made focusing system. So I asked, whenever such problem exists in larger ones?
Regarding the zoom binoculars, as I said, I can "convert" them into fixed zoom ones, by mechanically fixing the zoom components in place, so no miszoom will occur.
As I'm aiming mainly for daylight observation, say 15x80 will be less usable for me, than say 25x60.
Posted 22 January 2013 - 11:45 AM
I should have bought a $4000.00 fixed zoom instead the sub-$100 binocular but did not have that kind of money.
Posted 22 January 2013 - 12:17 PM
You are going to be limited to looking at low quality Chinese made binoculars for the most part. Just try searching Amazon and other websites for the requirements you desire.
The best advice for you is simply to use a source that will allow you unlimited returns, since you should expect any binocular meeting your requirements to have quality issues. Just keep trying until you get one that is acceptable to you.
And most of all...
Posted 22 January 2013 - 12:30 PM
Are you capable of professionally "convert" it? or you are just planning on gluing the mechanism with gorilla glue when you feel the magnification is what you want? Having looked trough 100K optics is different than having the skills for doing that job, and for sure, someone that have the skills to do that job probably think is a waste of money and time.
And, I'm really not sure of having seen a $200 good high magnification 80mm binocular... maybe a bit more saving would help..
Posted 22 January 2013 - 12:37 PM
You have already been given most of the advice you need, whch amounts to STAY CLEAR OF ZOOM BINOCULARS, and ESPECIALLY ones that provide maximum magnifications above 15x.
I've tried many, and they are ALL A COMPLETE WASTE OF MONEY!!
Even your idea to fix the magnification at a high setting is fraught with danger and probably doomed to disappointment.
For one thing, to do so would do nothing to change the fact that the resulting exit-pupil would be around 0.5mm.
Another thing is it would only provide an acceptable image if the two sides were PERFECTLY aligned ( which they almost certainly WON'T be)
A third proviso is that BOTH sides are set to EXACTLY THE SAME MAGNIFICATION ( see Bill C's wise words about mechanical construction )
Your only hope I can think of within your stated budget would be a fixed focus 30x80, but every one I've tried has been pretty terrible too.
Posted 22 January 2013 - 01:00 PM
I always heard that the one zoom exception is the 8-16x40 XL Nikon zoom. So when I checked one out, I personally found that it was certainly usable and sometimes convenient.
But it's costly and nowhere to be found....
Posted 22 January 2013 - 01:01 PM
Regarding the "conversion" I have acces to precise lathe and milling machine, also own light duty 3 axis CNC milling machine which can work with aluminum, brass and other soft metals, so, doing custom parts is not that hard for me.
Posted 22 January 2013 - 01:03 PM
I don't need zoom function at all.
even simpler: "gimme cheap 40x60, 50x70, 60x80" and so on
Posted 22 January 2013 - 01:08 PM
"If you still want a zoom instrument, please go ahead; sadly, experience is a far better teacher than I will ever be"
So go ahead, buy, convert and share with us your experience...