Category Archives: Email Questions/Answers Archive

I’m planning to purchase a binocular, thinking about the Bushnell Powerview 20×50.  I just want to know, in this binocular how long a distance can we see clearly? 

You’re asking Oberwerk if we would recommend the 20×50 Bushnell Powerview?  Let’s just say that Oberwerk doesn’t make a 20×50, and for good reasons.
20x magnification is far too much magnification to hand-hold and still have a steady view.  So a 20x magnification binocular needs to be mounted on a tripod to make it usable.  Secondly, 50mm objectives are generally too small to gather enough light to support 20x magnification with good clarity and brightness- especially so for the inexpensive Powerview series.   There is one exception to the above- the $3000 image-stabilized Farvision 20x50S.  If that’s not in the budget, let’s continue…
The Powerview uses “InstaFocus”, which while very fast, is hard to control precisely- and 20x magnification requires very precise focus.  20x magnification also requires perfect collimation (alignment), otherwise you won’t see a well-merged image, and you’ll experience eyestrain at best, and possibly even double images.  Oberwerk is the only USA seller that tests and aligns every binocular before shipping- which is especially necessary at 20x.
If you need 20x magnification, you’re going to also need a tripod.  And as long as you are using a tripod, you might as well get a binocular that is large enough to gather enough light to have a bright image with good clarity.  The Oberwerk 20×80 LW ($199.95) mounted to the Oberwerk 3000 tripod ($149.95), would be the least-expensive binocular that can offer 20x magnification with high-quality.  Let me know if you have any more questions.
Regards,
Kevin Busarow

I am new to viewing astronomical objects and I have not bought any astronomical binoculars before. I am wondering if those binoculars could be too LARGE for me, as I am a petite female at 5’3″ tall.  Also, am a (young) senior citizen nearing 67 years, so I was wondering if I will have any problem seeing things with my smaller exit pupils.  The web says this is a good price for a good pair of binoculars, but it never hurts to ask if you ever have any sales or discounts on them. Thanks for you help and advice.

You probably saw the SPACE.COM review for the 8×40 Mariner?  That article made it a best-seller for us, and it’s hard to keep it in stock.  But we have 30 other models, and SPACE.COM only looked at two of them.  So often times, other models are more appropriate for customers, depending on how they intend to use them.  The 8×40 Mariner does offer a very wide 8.4 degree FOV (field of view).  But in your case, you may find the 8×40 Mariner to be rather bulky and heavy for the  relatively-small 40mm objective size.  It also has a minimum IPD (inter-pupillary distance) of 60mm, which is not narrow enough for some customers, especially women.
For the same weight as the 8×40 Mariner, you could have the 8×56 LW, which gathers much more light.  While the 7mm exit pupils may be more than your dark-adapted eyes can take in, it’s likely that you could use more than the 8×40’s 5mm- resulting in an overall brighter image.  The larger exit pupils are also much more forgiving with eye placement.  It has a minimum IPD of 58mm, so works well for more customers than the Mariner.  It’s also just $99.
At the other end of the price scale, we have our finest bird-watching binocular, the 8×42 Sport ED ($299).  It also gathers more light than the 8×40 Mariner, yet is much smaller and lighter weight.  You’d find this model much easier to handle than the 8×40 Mariner.  It has an even wider IPD range, and goes down to 57mm.  The 8.1 degree FOV is very close to the Mariner.  Because it uses ED glass (which is what makes it considerably more expensive), chromatic aberration (also called “false color”) is greatly minimized, making it an excellent binocular for astronomy, as well as bird-watching.  When I’m traveling light, the 8×42 Sport ED is the only binocular I need to bring.
To answer your last question, our products never go on sale (except for discontinued items).  Whenever you’re ready to buy, you’ll know you’re getting our best price.  Let me know if you have any other questions.
Regards,
Kevin Busarow

Hello Kevin-  I’m a returning customer and very pleased with your products.  I need your help with my next purchase.  For terrestrial viewing and long distance bird watching, which will provide better image and better resolution in high magnification? I mean which has better power without getting blurry.  The 20×110 binoculars OR 82mm spotting scope that has smaller aperture than the binos?  Thank you.

Your question is interesting, as these are two very different instruments- like comparing apples and oranges.   So to be sure, I just tested this for myself.  The 20-60×82 Sport ED spotting scope set to 20x is  sharper than the 20×110 Ultra binocular.  While the 20×110 Ultra is one of our finest fixed-power binoculars, I can resolve very small lettering on a sign about 1/2 mile away with the scope that I can’t read with the binocular.  This is not very surprising as the scope, with its single 82mm objective, is a little more expensive than the binocular with two 110mm objectives.   The scope is apochromatic, so chromatic aberration, which is always present to some degree in an achromatic instrument, is almost non-existent in the scope.  On the other hand, the binocular view is brighter and more pleasing because each eye has its own 20x110mm refractor, giving a feeling of depth perception and perspective.  But if the primary goal is best resolution, the spotting scope is the clear choice.  It also has the advantage of zooming all the way to 60x, with good quality.  It’s also much lighter and smaller, therefore much more portable.  Let me know if you have any more questions.
Regards,
Kevin Busarow

I am interested in purchasing entry-level binoculars for astronomy.  I have read a little about this pursuit and am hoping to use a Slik universal U-112 tripod with my new purchase.  It is currently equipped for camera use.  I have looked at the binocular adapters and am unsure of how they work and if I should stick with the smaller binoculars to have a more successful result.  Do you have a recommendation for a simple setup?  My husband is an amateur but I think would love something easy to use.  Thank you.

The Slik tripod is limited in how much weight it can carry, I estimate the head can handle 4 lbs. maximum.  It also does not go high enough to get a binocular overhead so you can stand under it and look up.  Therefore you’ll probably need to use it with a stool or chair.  Any of our LW Series binoculars, or any of the Mariner Series, could be used on this tripod, but you will need an L adapter.  I recommend the Oberwerk Heavy-Duty L adapter ($14.95), it will work with any binocular.  If you’d like to consider a more capable tripod, we have the Oberwerk 3000 Series ($149.95).  It has plenty of height and can handle up to about 8 lbs.  Let me know if you still have questions.
Regards,
Kevin Busarow

Hi-
I like the 20 x 110 mm model.  How neck friendly is this for astronomy?  What reasonably priced tripods are available for “neck friendly” viewing?  I have kids and also 70+ year old parents to consider.
If I went with the 45 degree x 100 mm, how wide a view can I get with say 32 mm plossls?  Is there a wider eyepiece than these?  How much less is seen with the 100 vs 110 mm aperature.  I have had 50 and 70 mm binocs in the past.  Thanks.

The 20×110 is a great binocular, but heavy at 16 lbs.  The Oberwerk 5000 Series tripod/head ($279) can handle it, has plenty of height to get it high overhead, and would be the least-expensive mounting option.  A parallelogram would be the most comfortable for astronomical viewing, but you’d need the UA Millennium ($499) and our wood tripod to support it, so it ends up being a rather expensive setup.
The BT-100-45 is our finest instrument.  But Plossl eyepieces are actually rather narrow.  A 32mm Plossl would give you 19x, but would have a FOV of only 2.6 degrees.  The included 25x eyepieces are a wide-angle design, and have almost the same FOV (2.5 degrees), therefore no advantage to using the Plossls.  I think the difference between 110mm and 100mm is negligible, the comfort of the 45-degree viewing more than makes up for that.
Regards,
Kevin Busarow

Thanks Kevin
The 100 mm sounds more advantageous. How are the views of planets / moon at say 100-150x? Is there much color?  Thanks.

I recommend a maximum magnification of 75x (8mm eyepieces), chromatic aberration is minimal at 75x and below, but some of our customers are running as high as 100x (6mm).  At 75x, Jupiter and Saturn show nice detail, the moon is fantastic.
Regards,
Kevin

Hi,
I just bought a second-hand Oberwerk 10.5 X 70 Ultra and I’m a rookie when it comes to individual-focus binoculars.  When I try to focus the binos I feel like my eye is compensating for improper focus and when I look with both eyes the image takes some effort to focus on.  I think my eyes are compensating because the image can be in focus over quite a broad range of the eye piece’s movement and when I check after focusing each eye individually the right and left sides are often quite different.  It’s a bit hard to describe what’s happening but I thought this might be common trap for young players.  What’s the correct procedure for focusing IF binoculars?  Thanks.

With an individual-focus binocular, if you try to focus with both eyes open, you’ll have lots of trouble as your brain compensates for out-of-focus images.  I always close one eye, while I focus for the other eye.  Then I do the same for the other side.  When you close each eye, do so gently, otherwise you may temporarily change your eye focus from excess pressure.  After you do this a few times, it will become quite natural, and fast.  Let me know if that helps, or not.
Regards,
Kevin Busarow

Hi Kevin,
Thanks for your help, it just took some experimenting to get worked out. The binoculars are fantastic,  particularly at night.

Dear Sirs,
I’m looking for binoculars to install on a ship’s outdoor deck that operates in the Galapagos Islands.  Similar to coin operated but without coins, for use of the passengers aboard so they can look at animals on the islands.  They must withstand salty weather conditions.  Please suggest anything you might have.

There are very few binoculars that can withstand a marine environment.  One would be the Fujinon 25×150 MT-SX, however it is quite expensive ($6195 not including mount).   The outdoor binoculars that you typically see at tourist sites are not very good optically, but you can find those at seecoast.com.  You can read more about why I don’t recommend them at this link.   Our 25/40×100 Long-Range Observation binoculars are optically excellent, and affordable (under $2000), but can only be outdoors when the weather is good.  The cruise ship Crystal Serenity, which is just completing a 30-day Northwest Passage expedition, has 12 of these strategically placed onboard.  Let me know if you have any questions.
Regards,
Kevin Busarow

Hi Kevin,
We would be interested in the 25/40×100 at $2000.  What do you mean by good weather?  No rain?  Most of the time we have trouble in equipment with the salinity.  Everything gets rusty.  IF it rains we could tell the crew to cover them or to take it inside.  What do you think?  Thanks.

Yes, the 25/40×100 is water resistant, not waterproof or weatherproof.  So would be best to mount these in the pilothouse or somewhere out of weather.  If that’s not possible, we do have weatherproof covers available.
Regards,
Kevin

Hello,
I was some 30 years ago invited to visit a US Navy destroyer and had the opportunity to view one of its high power stationary binoculars from off shore and was very much impressed on its quality.  I can view through the bino some miles away like it was just like in front of you.  My question is do you carry something similar?  Thanks.

The Navy binocular you saw was a 20×120, probably manufactured by Litton.  I’ve had a few of those in our shop. The Oberwerk 25/40×100 Long-Range Observation binocular is the closest thing on the market to that 20×120.  The Oberwerk comes with both 25x and 40x magnification built-in, so this binocular has even more power.  Available in two styles, “Classic” and “Contemporary“.  Let me know if you have any questions.
Regards,
Kevin Busarow

Hi Kevin,
I actually bought a used Swarovski 30×75 binoculars with a Manfrotto Bogen Italian tripod but find it difficult to focus and therefore will be trying to sell it.  Instead I might buy the Oberwerk BT-100-45, yet I have following questions:
1) The 25/40×100 can easily turn the eye piece from 25x to 40x and vice verse. How about the BT-100-45
The 25/40×100 Long-Range has two pairs of eyepieces permanently attached to turrets, they simply rotate to switch in 25x or 40x.  The binocular telescopes hold just one pair of eyepieces.  To change magnification, you must remove the eyepieces and insert a different pair.

2) Is the BT-100-45 comes with the 45x?
No, the “45” means the eyepieces are mounted to the body at a 45-degree angle.  The binocular comes with 25x eyepieces.

3) The 75X eyepieces too powerful or should I go for lesser magnification?
75x is the maximum usable magnification, the image quality at 75x will not be as good as 25x.  If you are concerned about that, the 38x or 50x might be a better choice.

4) What is your honest recommendation for someone that knows very little about binoculars?
If you are not using this for astronomy, you might be better off with the 25/40×100 Long-Range (Classic or Contemporary).   For most customers, 25x and 40x is enough, and these are easier to use because everything is built-in, you are not dealing with loose eyepieces as you would on the BT’s.
Regards,
Kevin