|
|
|
|
 |
|
|
|
|
|
|
|
|
OpticsBlog – Thoughts and reviews of binoculars, telescopes, scopes, sights, and much more - birdwatching, astronomy, target shooting - pretty much anything related to optics, nature, and life!Wednesday, July 29, 2009Film camera issues
They say you can't go home and with film cameras, that is almost, but not quite, true, I'm afraid. I went on an expedition to find a battery for my old Sears TL SLR film camera and discovered that the old 1.35 volt mercury batteries are no more, due to the problem with mercury. I can appreciate the need for that, so next best thing are the 1.35 volt hearing aid batteries, though they don't last very long. Still, I can live with that. Film, though, is more of a problem. It is getting harder and harder to even find a convenient source of film, especially if you are shopping for a specific brand and model. Then, too, you still have to have the film developed and a lot of places don't do that, anymore. Okay, I plan to develop my own film. Not so fast, there, gal. The state of Illinois is making it expensive to go down that road with more and more regulations on the chemicals and some nasty taxes and fines for improper disposal. In other words, what was supposed to be a move to a simpler type of photography with film has been anything but simple, so far. Guess the world wants to drag me, kicking and screaming all the way, into buying a digital camera. Of course, I'm just stubborn enough and contrary enough to push even harder to stay with film and a an old film camera.
Tuesday, July 28, 2009Birding or bird photography?
It is tough to mix both serious birding and serious bird photography like digiscoping on the same outing. You can be casual about one and serious about the other on a given outing, but not serious about both on the same outing. Serious birding and serious bird photography are both full time jobs and will require everything you have in terms of concentration and attention. Decide, before you leave, which you will be your primary activity for any given outing. That's from someone who does both and its also why most birding group leaders, myself included, and nearly all birding tour businesses offer separate trips for bird photographers and birders. The needs of these two groups are actually quite different and often conflicting. Think of it this way. Taking a good pic of a common bird can be just as hard as taking a pic of a rare bird, but, believe me, birders in a group are not going to wait an hour for you to set up your camera and/or camera and spotting scope to get a good pic of a Killdeer or other common species. You will get left behind.
Monday, July 27, 2009Is there a spotting scope in your future?
Every birder needs a field guide and a birding binocular and for many birders and bird watchers that is all that will ever be needed. Watching birds in the backyard or at the feeder is one thing, though; trying to identify a tiny shorebird across a distant marsh is another. A binocular is a wonderful a tool, for sure, but there are times when a birding binocular does not supply enough magnification to do the job. This most often happens with birds that are either too small or too distant or both, such as shore birds, marsh birds or birds far out on the lake. In this type of birding, a close approach is either not possible or not advisable. For these times and for these birds, we need a spotting scope. A spotting scope is simply a small telescope designed to be used by day. A spotting scope has some fundamental and important differences compared to a telescope used at night for astronomy, so be sure to read my article How to Buy a Birding Spotting Scope to see what these high powered birding tools are all about.
Wednesday, July 22, 2009Sorebirds and Starbucks
It's been dry, here, just north of Chicago, these last two weeks - relative to the very wet and cold month we had in June, at any rate. A long dry spell after a long wet spell creates exposed mudflats and that is the magnet that draws shorebirds during migration. My goal for the rest of the week, then, is to get serious about adding some shorebirds to my '09 list. To that end, I plan to take my spotting scope or, at the very least, my birding binocular with me no matter where I go. Of course, very few people will know why I am wearing a Leica binocular around my neck while I shop for groceries or sit outside a coffee shop, sipping a latte, but I am used to the odd looks, now and then. There is a method to my madness, however. I have actually seem migrating shorebirds, not to mention hawks and other birds from the vantage point of a grocery parking lot or a patio outside a coffee shop.
Tuesday, July 21, 2009Telescopes test
Finally got a break in the weather, this week, so managed to do some work with my astronomy binocular, even though I am still a bit under the weather, trying to recover from some facial surgery to reapir damage to my ear and nose. Ah, the life of a mountain biker is not without its perils. If the weather holds, I will give the Nikon 10x70 another workout, tonight and I may even work up enough energy to mount it on a tripod and do some double star work. Or, maybe, I will test a telescope or a spotting scope, instead. Stars and planets make some excellent test targets when reviewing optics on binoculars, spotting scopes and telescopes. Point sources of lights, such as stars, are great ways to test for colorcorrection, flare, coma and so on. Okay, it's also fun and one of the parts of my job I like the most.
Monday, July 20, 2009What is an aspheric lens?
What the heck are aspheric lenses? That was my question back in the 90s when I first saw the term used in reference to binoculars, but now you'll see the word aspheric used in lenses of all types, including lenses used in telescopes, microscopes, camera lenses , magnifiers and so on. So what is aspheric all about. It's simple. An aspheric lens is simply a lens with a surface which is not perfectly spherical or not perfectly convex or concave or, to put it another way, you can find different areas on the lens with different degrees of curvature. By using different degrees of curvature, a single aspheric lens can often do the job of two or more spherical lenses, resulting in a lighter instrument and/or a cheaper one. On the other hand, there is nothing automatic about the performance and quality of a lens just because it has the aspheric label. For instance, many low end optics use aspheric lenses that are poured into a mold, making them cheaper to produce than a conventional ground lens. At the other end of the quality spectrum are aspheric lenses which are ground just like a spherical lens but only in much more sophisticated shapes. These are very difficult and expensive to produce, but the results can be amazing. You'll see these aspheric lenses in some very expensive camera lenses.
Wednesday, July 15, 2009Monocular or binocular?
In terms of certain features, the monocular market needs to catch up to the binocular market. Eye relief is one example. If you wear glasses while you observe, it is not too hard to find a $100 binocular with enough eye relief to be used with glasses. Not so with monoculars. Very few monoculars under $100 have enough eye relief to be used with monoculars. Inexpensive monoculars, in particular have barely enough eye relief to be used even without glasses. Another example is waterproofing. Not too hard to find a binocular under $100 that is waterproof, but it can be a challenge to find a waterproof monocular at any price. If you need these features, my recommendation is to stay with a binocular. The only thing you gain with a monocular over a compact binocular is a little more portability.
Tuesday, July 14, 2009Astronomy telescopes for day work
I get a lot of customers that want to use an astromomy telescope for day work. That's okay with any telescope design, except for a reflector, which always produces upside down images.
The mount is the part that causes the most headaches when you try to use an astronomy telescope by day. The worst telescope mount for day use is an equatorial mount. Getting the scope moved and pointed from one target to the next with an equatorial mount is a time consuming and awkward chore, since this type of telescope mount involves two axis of rotation and the mount moves the telescope in an arc (gentle curve), to mimic the motion of stars in the night sky. This is great for astronomy, but not for day use, where objects are moving in straight lines. The best mount for day use is a manual, alt-az mounts without a computer, such as the Celestron Astromaster 90 AZ, though a computerized mount with a single arm or fork can sometimes be used. All of these telescope mounts are quick and easy to point and they move the telescope in straight lines, rather than curves. When using a computerized telescope on a fork or single arm mount, simply turn off the computer and motors and move the telescope manually. Be sure to loosen the telescope in its mount or you risk damage to the gears. Also, telescopes on arm and fork mounts that do not have a lock may not stay in position when pointed horizontally. Only option, then, is to use the motor or add some type of counterweight to the telescope tube. Monday, July 13, 2009Telescope making
You notice things in the telescope world come and go over the years if you've been around as long as I have. One of these is telescope making. Back in the 60s, 70s and even well into the 80s, a lot of amateurs ground their own telescope mirrors and built their own reflectors as a way to save money and, well, just for fun. Nowadays, though, with all the inexpensive telescopes coming out of China, it is really hard to justify grinding our own mirror as a way to save money. Then, too, just not too many places, anymore, that actually sell telescope making supplies. I suspect, though, that the biggest reason you don't see folks building telescopes the way they did a few decades, ago, is for the simple reason that it simply takes a lot of time, patience and effort and that approach is an anachronism in our contemporary, "hurry-up, I want it right now" kind of society. That's a shame, in my book.
Wednesday, July 08, 2009Nebraska Star Party
Funny how one bad month, namely June, can throw my binocular astronomy out of synch. June was always one of my best months for hunting globular clusters in Ophiuchus with an astronomy binocular and it is still hard for me to believe that I have not done any serious globular hunting, yet, this summer. Ouch. I have yet to turn my Nikon Astroluxe 10x70 on the great open star clusters, M6 and M7 in Scorpious and mid-July is closing in on me. Double ouch! The great star fields of Sagittarius? Triple ouch! Okay, I shouldn't expect too much living in the Chicago area, but my heart is breaking for one clear night with a dark sky. If home is where your heart is, I am a long way from home. Maybe I should hitch a ride and head west. Anyone going to the Nebraska Star Party? That's one of the best star parties going in terms of dark sky sites, way out there in the remote Nebraska Sandhills with lots of eager astronomers who stay up all night sharing the views in just about every telescope type you can imagine.
Tuesday, July 07, 2009The moon in a binocular or telescope
One of the things that makes our moon such a wonderful target for amateur astronomy is that the moon can support the widest range of magnifications of any astronomical object. For planets, you won't see surface detail at typical binocular magnifications, but you will see plenty of surface detail on the moon with those same binocular magnifications, even with the low magnification of a 7x50 astronomy binocular. At the other end of things, if you use too much on many faint galaxies and nebulae, they often go invisible, since you lose image brightness as magnification increases. The moon is so bright, though, that you can crank your telescope up for all its worth, up to the point where image quality starts to suffer and keep seeing more detail on the moon. All in all, the moon has something for everyone. It's a great object for a binocular, a small telescope or a large telescope. No other astronomical object can claim that.
Monday, July 06, 2009DEET and telescopes
It's official. We had the cloudiest June in four decades. No wonder my astronomy took such a big hit. Ouch. July shows some sign of improvement, but after all those heavy rains in June, mosquitoes are becoming a problem. That should not deter anyone from observing with a binocular or telescope, but here's a tip for beginners. Repellents that use DEET are the most effective at keeping those pesky mosquitoes at bay, but be warned that DEET is also an excellent paint and finish remover. It will gum up the covering on many astronomy binoculars and can also do damage to cameras and other delicate tools, not to mention gum up the finish on some telescope parts. That's why I like some other plant based repellents or Skin So Soft, which makes you smell great, too. That's a nice thing for an astronomer, after all.
Wednesday, July 01, 2009First telescope
I get emails every day from customers asking me if a 50mm or 60mm telescope is a good choice for a first telescope and my standard answer is no, not really. Telescopes this small just don't have enough potential to do more than whet your appetite for a larger telescope or, worse yet, may discourage you from staying with astronomy. I know the economy is down, but buying a 50mm or 60mm telescope is almost a guarantee that you will be buying another, though larger, telescope down the road should you manage to stay with astronomy. Telescope size, in terms of the lens or mirror diameter determines how much you can see, not advertised magnification. If you are shopping for a first telescope and you want to see more than just the moon and a glimpse of the planets, try to start with at least an 80mm telescope. There's a reason those small 50mm and 60mm telescopes end up in garage sales.
|
|
|
|
|
© 1999- OpticsPlanet, Inc
- telescopes,
binoculars,
microscopes,
riflescopes,
rangefinders,
& more.