Image of the day

Captured by
Byron Davies

NGC 2264 Cone Nebula

My Account

New to Astromart?

Register an account...

Need Help?

Posts Made By: Mike Swaim

April 17, 2002 07:37 PM Forum: Astro Binoculars

Favorite Binocular Astronomy Link

Posted By Mike Swaim

One site with lots of links I like is:

Folks interested in what size astro binos to try might want to click on the links at that site titled Binocular Performance and Holding Index. Here's the direct link to the magnification chart:

I've found it to be a pretty good guide, but it's based on a very dark sky ideal site. But even from light polluted suburbia, the rough comparisons hold up.

Mike Swaim

April 19, 2002 12:28 PM Forum: Birding Optics and Photos

Birding with higher power

Posted By Mike Swaim

Like most folks, I started into birding using 7x35, 8x30 and 8x40 binoculars. But when I switched from 7x50's to 10x50's for astronomy I started using them for birding as well. I noticed that the extra few ounces of a 30-32oz. 10x50 wasn't really all that noticeable, but the increased light gathering and increased power really helped me notice subtle markings.

In his classic "Desperately Seeking Binos" article, Ken Rosenberg mentions using Zeiss 15x50s for birding. He also notes that given a choice between similar 8x and 10x binoculars his team of "Sapsucker" bird experts tended to favor the 10x.

Recently, I've been using the excellent Nikon Superior E 12x50's for birding and I'm very happy with them despite only a 5*FOV. There's nothing quite like effectively cutting the distance to the bird in half for better detail resolution. They don't work well at close range, and it's sometimes difficult to initially get the bird into the FOV. But the flip side is that by simply scanning with them, the increased mag. helps me identify birds that I otherwise wouldn't even know were there. On a recent trip with a local bird club there was a husband & wife team with his and hers Canon IS 18x50's. While I was surprised to see those on a birding trip, their reasons for picking them were apparently similar to mine.

Does anybody else on this forum bird with higher power binoculars?

Mike Swaim

April 21, 2002 10:21 PM Forum: Birding Optics and Photos

Revisiting Nikon Naturalist 7x35's

Posted By Mike Swaim

Back in 1987 I received a set of Nikon Naturalist 7x35 binoculars as a Christmas present from somebody that knew how frustrated I was with low end Bushnells and Wards. Back then the first or 2nd generation Naturalists came with rubber armoring in camoflage and were quite a good step up from regular dept. store binos in terms of image quality. I hadn't yet learned much about optics, but the views through the Nikons seemed to be much clearer than what I was used to at the time. Almost as a mistake, I learned that the orig. Naturalists cost a friend $109 to give me 15 years ago.

In the intervening years, I've had many, many binoculars and my taste in optics has been considerably refined. However, I've continued to recommend the budget Nikon Action series as a good starting place for those that want quality binos but don't want to spend very much. Generally, I tend to recommend the 8x40 Egret II's and have given a couple sets of them as gifts myself. But when a recent sale of Nikons put the 7x35 Naturalists into the category of interesting accessories I went ahead and ordered another set just to see how I like the newer versions. There've been some interesting changes.

The current version of the Naturalist IV features a much smaller polycarbonate body and is made in China rather than Japan. This seems to be the way of optics generally. More importantly, the current version shows very noticeable edge distortion even in the daytime. This was present to some degree on the older set, but no where near as much as on the current ones. It's so noticeable that people that don't know anything about binoculars comment on the "Coke-Bottle" effect of images around the sides. They are virtually useless as an astronomical instrument, and show so much edge distortion in the daytime that it's really distracting. I feel that they are a marked step down from the Naturalists of the past and may even be a major step down from the Egrets of the present. While they are reasonably sharp on center, and certainly comparitively inexpensive, I find it hard to recommend them on anything other than price.

None-the-less, the Naturalists and the Egrets do fill a sort of niche in inexpensive porro prism binoculars that may well still be a reasonable starting point for those on a tight budget. Even despite these shortcomings it's tough to dislike a binocular that features Nikon's no fault warranty and costs less than $80. For twice that much one can get into some serious instruments that don't show as much distortion as these little Nikons, but it's also possible to spend LOTs more on glass that isn't anywhere near this level of bargain.

Mike Swaim

April 22, 2002 04:20 PM Forum: Birding Optics and Photos

Interesting new binoculars

Posted By Mike Swaim

Pentax has announced waterproof versions of their popular PCF series of porro prism binoculars. The new PCF WPs come in all the standard PCF configurations, 8x40, 7x50, 10x50, 12x50, 16x60 & 20x60. The MSRPs are low enough that the street prices will likely be in the $150-$200 range. This puts high quality, long eye relief waterproof porro prisms within just about everybody's budget. I've owned both the non-waterproof versions of the 12x50 and 16x60. The image quality is very high but the FOV is quite small. Still, I'd think that the new waterproof Pentax porros may well be one of the better bargains on the market if their image quality is as good as previous PCFs. I'd imagine that the 8x40's and 10x50's will give Swift some real competition in the birding/sport market.

Also Konus has come up with a cheap 8x22 roof binocular mated to an inexpensive digital camera, so that you can take digital images of what you see in the binoculars. I wouldn't expect the images through this to be great, but it's an interesting idea and it looks like it'll be priced practically in the disposable range. Perhaps one of the other mfrs. will pick up on this idea and we'll get to see a really high quality merger between digi-cam and binos. Who knows?

I didn't see these products on the Anacortes site yet, but I'm sure that will change.
Mike Swaim

April 23, 2002 12:38 PM Forum: Astro Binoculars

Quest for the perfect binocular

Posted By Mike Swaim

I agree with what Zaharja alluded to in the Best 7x50 thread. In this day and age, there's really no reason why binoculars haven't taken the quantum leaps forward that other optics such as telescopes have. On the one hand, we have a market that is simply flooded with cheap binoculars, but trying to find those that are a near to perfection is very difficult. There really hasn't been much by way of improvement in the mid and top end binoculars over the past 5 years. The favorites today are pretty much the same as they were 5 or more years ago. Here is what I would propose as the MINIMUM standard for premium binoculars:

1. Absolute total optical clarity with stars appearing as pinpoints right out to the very edges and NO distortion or false color even on bright objects such as Jupiter and the Moon. Paraphrasing something Barry S. once said, "The glass should get out of the way of the viewing experience." Believe it or not, this criteria alone almost rules out the vast majority of current premium binoculars. The optics and the geometry of design should be so good that there is no eyestrain at all even after extended viewing sessions both at night and in bright sunlight with no glares, flares, ghosts, etc.

2. Center focus- (sorry Fujis)

3. Complete waterproofing (sorry Nikon SEs)

4. Rugged construction capable of surviving an accidental drop or two without loss of collimation

5. Light enough weight and good enough balance to be easily used handheld or carried around the neck for extended periods (ie. not more than 32oz. and with good ergonomics)

6.Of course a tripod socket adapter is required and assumed

7. And the line should include all the popular favorite sizes like 7x50, 8x40, 10x50, 12x50

8. Finally 20mm eye relief and screw down soft eyecups

That's just the bare MINIMUM standards and yet it virtually eliminates most of the competition. That's before we even get into things like interchangeable eyepieces, integrated digicam technology, or a zoom mechanism that actually works without dimming the views beyond acceptability: all of which should be within the capability of current manufacturing technology.

Mike Swaim

April 24, 2002 04:09 PM Forum: Astro Binoculars

Monster 7" objective binos

Posted By Mike Swaim

Check out the Russian Optics forum. Markus just gave a mini-overview of some 30x180mm Russian behemoth binos that Americansupply sells for $5K. Weighing in at 63lbs, they put a whole new meaning what heavy duty binos might be. There's also the smaller 20x140mm version for $3K.

The 30x180's would have a magnification index of 5400, whereas a 20x80 would have a "mere" 1600. That's some pretty serious light grasp.

April 30, 2002 04:16 PM Forum: Birding Optics and Photos

Request digiscoping primer

Posted By Mike Swaim

I've been really impressed by some of the pics posted on this forum, and was surprised that some are taken with a digital camera and a spotting scope. It encouraged me to do some web browsing on digiscoping. The idea of getting 60-80x magnification for my wildlife shots really intrigues me. I've done a little bit of 35mm photography with my Maks, but am very intrigued by the image quality of some of the digipics and I'm just about fed up with the hassle of 35mm for long range work. (I really like derry's closeup of the female cardinal. The feather detail is amazing!) I just got back from a trip to the coast, where I really could've used lenses with over the 500mm focal length that I had for better resolution of migrating shorebirds. So, my initial questions are these:

1. What digiscoping camera and scope would folks recommend and more importantly, WHY?

2. What are some of the non-obvious pitfalls of digiscoping?

3. Is getting the image from camera to computer difficult?

4. What's the concensus on best printer for reasonably priced photo-quality prints?

5. Is anybody using a Mak for eyepiece projection digiscoping? Or are there adapters to attach a digicam to a Mak/SCT?

Mike Swaim

April 30, 2002 11:55 PM Forum: Astro Binoculars

Exit pupils and age

Posted By Mike Swaim

I sure am glad to see Zaharja posting about the fallacy of the "If you're over 40 you won't be able to use exit pupils larger than 5mm" Myth. I've been preaching against the blanket acceptance of that myth for over 2 years on the YG bino-net, and yet have run across folks that believe that so adamantly that they won't even bother to measure their own eyes. I don't know where that all got started, but Zaharja is completely right in that humans vary a great deal, and pupil size is but one area. I've never understood how otherwise bright folks can accept that there are midgets and giants, skinny people and obese, and yet cling to the erroneous notion that at age 40 one's eyes have deteriorated to an exact even amount. The reality is that everybody is different and pupil size is no exception. I'll get to see the proof of this at the end of the month. Somehow I doubt my max pupil opening size will shrink a full 1.5mm in the next thirty days.

The other myth I'd like to see tossed completely out is that matching one's max. exit pupil to one's binos is somehow relevant or necessary. Again, the reality is that around the perimeters of our pupils, our eyes aren't optimized for resolution and on the outer edges of the pupils are some naturally occurring aberations. Thus if one's eyes are capable of opening to 6.5mm, there really may not be any great advantage in trying to take advantage of the whole of the opening.

That plus the increased contrast of slightly higher mag. binos with slightly smaller exit pupils may be where the whole mythos of the "over 40 needs 5mm exit pupil" got started. To me, the contrast issue is the overwhelming value to be considered. To others, it's a matter of what can be held steady without noticeable shake. But the reality experienced by most everyone is that bino choice is highly subjective, and no magic formula will give one the right answer to blindly follow to get the right binos.

Mike Swaim

May 9, 2002 04:09 PM Forum: Birding Optics and Photos

House Finch or Purple Finch?

Posted By Mike Swaim

They're so closely related that it's often hard to tell them apart. Basically, the House finch is slimmer and more towards red,red than dark red and the coloring is more confined to the head, neck and chest areas. The Purple Finch is plumper and has a deeper tail notch and is more likely a deeper raspberry red. The other thing I look for, is the Purple finch often has more of it's body colored than the House finch and usually has a couple of faded redish/purplish wing bars. Obviously, I'm only describing the males in full color. The only way I can really tell the females apart is to see what kind of male they're hanging around.

If anybody has any better descriptions or pointers I'd appreciate them.

Mike Swaim

May 10, 2002 12:56 AM Forum: Birding Optics and Photos

Resolving power of different powers

Posted By Mike Swaim

I've often heard that "Z" power equates to the maximum detail resolution in handheld binos. Likewise, I've often believed that doubling the power halves the apparent distance. So I wanted to see how these two conflicting theories related to my actual experience. To do that I taped selected brightly colored supermarket fliers with varying print sizes and fonts to cardboard boxes and set them at measured distances and then attempted to read the finest level of print possible with various handheld binos.

I did this 3 times in varying light levels from full sunlight, to twilight. What follows are the results from the most neutral lighting test conducted between 6:30-7:30 pm 5/9/02 with neither direct light nor shadow. Before I begin with the results, let me make it plain that the numbers themselves are meaningless. They change with each user, and with each lighting condition and with each different level of contrast. What's relevant is their relationship. What follows is the best possible situation for each bino in even lighting. Both bright light and shadow make things worse.

7x35 Nikon Naturalist-- 4mm, almost 3mm resolution
7x50 Steiner Night Hunters-- can't focus this close
8x24 Minox BD P-- barely 4mm, poor color separation
10x50 Leupold Wind River-- easily 3mm, not 2mm
12x50 Pentax PCF V-- easy 3mm, barely 2mm
12x50 Nikon SE-- 2mm if high contrast, easy 3mm phenomenal color separation

7x35 Naturalist- barely 4mm only w/extreme contrast and concentration
7x50 Steiner-barely 4mm, but good color separation
8x24 Minox-4-5mm but only with high contrast colors
10x50 Leupold--4mm, good even performance
12x50 Pentax PCF- very solid 4mm, shake evident
12x50 Nikon SE- 3mm across colors & contrasts, fantastic color separation

7x35-10mm at best, 17mm at worst
7x50- easily 10mm even w/poor contrasting letters
8x24- 12mm at best, 17mm on average, 28mm w/poor contrast
10x50- 10mm w/high contrast, 12mm w/poor contrasting letters
12x50 Pentax- easily 10mm, but not 8mm at all
12x50 Nikon SE- 9mm easy, 7mm w/high contrast letters

Comments to follow,
Mike Swaim