Ed Kessler
professor emeritus
Reged: 05/17/06
Posts: 749
Loc: Millersburg, PA
|
|
Hello,
I just came home from the Black Forest Star Party where I noticed that Howie Glatter sells deep sky filters for binoculars. They are mounted in round disks (that look like washers) and are placed between the eyecups and the lenses on binoculars. Has anyone used these who could report on their performance?
Does any other vendor provide deep sky filters for binocs?
Thanks,
Ed Kessler
--------------------
Ed Kessler
sic itur ad astra (Just to look profound!)
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
Sounds interesting. Are they on the Howie Glatter website? I don't recall seeing them there. I've always been fascinated with trying to use filters on a big binoculars. I tried using a UHC filter in conjunction with my 100mm binocular and had mixed results.
But, I'd be interested in hearing about others' experiences with binoculars and filters.
Clear dark skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
Ed Kessler
professor emeritus
Reged: 05/17/06
Posts: 749
Loc: Millersburg, PA
|
|
I haven't been able to find any reference to them on the web. I know he makes them; I've seen the things!
Ed
--------------------
Ed Kessler
sic itur ad astra (Just to look profound!)
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
Do you recall how much they were selling for? And are they standard 1.25" filters fitted into a bushing/washer of some sort like this :
Clear dark skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
Ed Kessler
professor emeritus
Reged: 05/17/06
Posts: 749
Loc: Millersburg, PA
|
|
I think he was selling them for $100. They were mounted in washers that fit beneath the eyecup which holds them in place. He had a variety of sizes to fit different binocs. They were quite flat. It looked like he glued the filters to the round washers. They didn't appear quite as thick as in your photo.
--------------------
Ed Kessler
sic itur ad astra (Just to look profound!)
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
I assume that is $100 each right? Any idea what kind of filters are being used? Broadband, narrowband, OIII...? And does he use a specific brand like Lumicon, Thousand Oaks, etc?
I'd be interested in adding a pair to my growing Xmas list !They will make a good match for my Obie/Garrett 22x85IF Series-8 Kunming bino. (*nudge nudge wink wink*)
Clear dark skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
Ed Kessler
professor emeritus
Reged: 05/17/06
Posts: 749
Loc: Millersburg, PA
|
|
Sorry, Mike, I don't have any more details. I think they were $100 for the pair!! But I may be wrong on that.
--------------------
Ed Kessler
sic itur ad astra (Just to look profound!)
|
Phillip Creed
Idiot Seeking Village
Reged: 07/25/06
Posts: 1033
Loc: NE Ohio
|
|
Ed,
$100 per PAIR? I am SOOOOOO buying these things for my 25x100s. I can't wait to let that combo loose on IC 1396.
Clear Narrowband-Enhanced Skies,
Phil
--------------------
"Why suffer from insanity when you can revel in it?"
Wilderness Center Astronomy Club member since 1995
ICQ Comet Observer Code: CRE01
*****
16" f/4.5 Truss Dobsonian (FOR SALE!!)
Orion 120mm ST Refractor
23mm Axiom LX
13mm Nagler Type 6
9mm Nagler Type 6
1.75X Siebert Barlow
*****
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
For $100 a pair, that is $50 per filter plus the labor to prepare it for bino use - even if that is just a little adhesive and a washer. Quality filters usually retail for almost double that, assuming a standard 1.25" filter. I just wonder what kind of filters are being used when the pair is being sold for $100. Now, if they are $100 each, that makes a little more sense. But heck, why should I complain if they work? I'm a cheapskate and would much rather pay $50 each than $100 each.
I did a little research on this subject a while back, and I read accounts of people using OIII filters with some success and others using broadband LPR filters with some success. I tried placing a Celestron UHC narrowband filter over one eyepiece of my 25x100 Skymaster - the results were mixed. On M42, I did notice increased nebulosity, but the surrounding view was drastically darkened - a trade off that resulted in zero net gain, aesthetically speaking, IMO.
Clear dark skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
Rick
Carpal Tunnel
Reged: 04/12/05
Posts: 2574
Loc: Tokyo, Japan
|
|
Quote:
On M42, I did notice increased nebulosity, but the surrounding view was drastically darkened
Not to be glib Mike, but that is what a narrowband filter is supposed to do. I dims or blacks out the surrounding star field, only letting the nebula's spectrum to pass.
clear skies,
Rick
--------------------
www.japanastro.com
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
Rick -
No problem, it seems obvious now. It took an "I told you so" or two (or five) before I learned to keep my expectations realistic. That was my problem with the UHC-binocular experiment - I had completely unrealistic expectations, fed in part by the misleading advertisments for deep sky and nebula filters that have the "no filter" and "with filter" photos. I was expectating a more dramatically positive effect, and I underestimated the amount of darkening the entire field would suffer. In a large aperture scope, say 8" or more, brighter field stars will shine through the filter? Correct? So the nebulosity is not the ONLY thing visible, depending on the object and field, correct? For example, if viewing the Cone Nebula with a filter, would the associated Christmas Tree cluster totally vanish from sight, leaving only the nebulosity to be seen? I expected the filter to enhance the nebulosity, darken the entire view, but leave some stars visible.
In my 100mm binocular, when I closed one eye and viewed through the filtered side only, the view dramatically darkened, leaving only nebulosity to be seen. All other stars and field stars were completely snuffed out. When viewing M42, the nebulosity was of greater extent, and some hints of texture could be detected while using the filter, but the entire field was utterly-black and devoid of field stars. Even the Trapezium appeared to mostly vanish.
When viewing through both eyes, the brain "averaged" the views and a combined effect produced a mildly-enhanced image. Nebulosity appeared to increase, but only to a marginal extent, not really noticeable unless trying really hard to notice. The view appeared darkened somewhat, but nowhere near as drastically as viewed through filter alone. This actually improved contrast somewhat and contributed to the marginal gain in apparent nebulosity, I suspect - more so than the passband's effect, IMO. I could be wrong and probably am. At any rate, the net gain was hardly worth the expense and trouble of using the filter - again, in my opinion. But, there are some caveats to my experiment :
I simply placed the filter inside the rubber eyecup which I partially rolled back. It fit snugly with no modifications. I may not have had the filter positioned 100% correct - it may have been tilted off-axis, or it might have been improperly distanced between the eye and eyepiece lens. Perhaps the Glatter filters, which has a slimmer profile (presumably they do not have the standard threading ring of 1.25" scope filter, which increases the profile of the filter), and mounts behind the eyecup, function to more positive effect. I would be interested to try them on a pair of 22x85 Ultra/Grizzly to find out. 
In the end I concluded that the idea had some merit, and possibly some usefulness under better conditions than my simple, awkward trials. But several members of this forum warned me not to expect much, if anything, and they turned out to be right. That's happened more than once. 
Eventually I'll learn.....
Clear dark skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
rushintuit
sage
Reged: 04/01/06
Posts: 264
Loc: Farpoint Observatory
|
|
Howie Glatter imports the filters from the Kasai Trading Co, Ltd. from Tokyo, Japan. The filters are wafer thin.
--------------------
/// Stellarvue SV102ED /// Nikon 12x50 /// Fujinon 16x70 /// SkyTools 2 /// The Desktop Universe All Sky CCD Mosaic In Monochrome Mode ///
Edited by rushintuit (08/31/06 11:57 AM)
|
Howie Glatter
Vendor
Reged: 07/04/06
Posts: 87
|
|
Hi Ed,
The binocular nebula filters are a narrow-band type similar to UHC, and are very effective for viewing emission nebulae. They have about 90% transmission in the passband, which is from about 480 to 505nm. They are serialized, and come with transmission printouts for the actual filters you get. The multilayer interference coating is cemented between two pieces of glass and is therefore protected, so the filter can be cleaned without damage, an advantage for over-the-eyelens filters. The glass is mounted in a 30mm diameter metal disc, which I can supply cut smaller if necessary. More usually, I increase the outside diameter of the filter by attaching it to a thin adapter ring that can be sized from 32.5mm to 41.5mm O.D. The size is chosen to be 0.5mm larger than the cavity in the rubber eyecup. The eyecup is rolled down, the filter with adapter ring is placed on the eyelens mount(it doesn't contact the eyelens), and the eycup rolled up. The elasticity of the rubber eyecup retains the filter.
To me they seem to give a 4 - 5 times increase in contrast in moderately light-polluted skies. It's amazing when you do an A-B test, installing the filters in only one side and blink-switching to compare the views.
The filters cost $140/ pair with one set of adapter rings + $5 priority shipping. Extra adapter ring sets are $10, so one pair of filters can be used with many binoculars.
Clear skies, perfect collimation,
Howie
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
|
|
Howie,
Some filters, in order to give proper performance, may need to be used with minimum aperture. For instance, you mention 90% transmission in the passband range of 480 to 505nm. Am I correct to assume that light outside that passband range is blocked? Would that mean that total transmission, as compared to unfiltered, is significantly less than 90%, maybe more on the order of 50%? Any recommnedations for minimum aperture to use these filters?
Also, wouldn't it be correct to assume that users with binoculars already having tight eye relief may need to accept a small loss of field of view. Seems that these filter assemblies, because they mount on top of the eyepieces, at least take up a few mm of the usable eye relief. No different than how Fujinon does it, and they lead to field restriction also. Just something to keep in mind. If you have short eye relief to start, you are going to have really short eye relief with these filters in place. On the other hand, in a very long eye relief binocular like the Fujinon FMT-SX 10x70, Oberwerk Mariner 10x60 or the Nikon SE 12x50, these would actually help take up some of the slack.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
Edited by EdZ (08/31/06 01:39 PM)
|
Howie Glatter
Vendor
Reged: 07/04/06
Posts: 87
|
|
"Some filters, in order to give proper performance, may need to be used with minimum aperture. For instance, you mention 90% transmission in the passband range of 480 to 505nm."
I'm not sure I understand. Aperture and passband are not directly connected.
"Am I correct to assume that light outside that passband range is blocked?"
Yes.
"Would that mean that total transmission, as compared to unfiltered, is significantly less than 90%, maybe more on the order of 50%?"
It might be, but if by "total transmission" you mean all the light that was transmitted in the field without the filters, it depends on what other objects (maybe stars) are in the field, and what their spectral characteristics are. Also, the level of sky glow from light pollution would be a factor. If the only thing in the field is an emission nebula, I think you would get quite a bit more than 50% throughput.
"Any recommnedations for minimum aperture to use these filters?"
No. I've had good reports with 35mm binos.
"Also, wouldn't it be correct to assume that users with binoculars already having tight eye relief may need to accept a small loss of field of view."
They take up 1.5mm + the distance between fiter and eyelens, from the eye relief. The clear aperture of the filter is 19mm. It may or may not restrict the field of view, depending on the binocular.
Howie
|
EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
|
|
Thanks Howie.
Re: this question
Quote:
"Some filters, in order to give proper performance, may need to be used with minimum aperture. For instance, you mention 90% transmission in the passband range of 480 to 505nm."
I'm not sure I understand. Aperture and passband are not directly connected.
I assumed since the filter passband, being narrower than full spectrum, reduces the light transmitted, then it seems that most, if not all, of the light to which we are most sensitive is blocked. Therefore I assume total transmission is greatly reduced. If that's the case, isn't is generally a good idea to use greater aperture to increase light gathering to help compensate for all the light that is blocked? Hence, my question about whether or not you had a recommend minimum aperture.
edz
--------------------
Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
|
Ed Kessler
professor emeritus
Reged: 05/17/06
Posts: 749
Loc: Millersburg, PA
|
|
Thanks for the response, Howie. You'll probably be hearing from me. I'd like to try a pair of these on my 25 x 100s.
Clear skies,
Ed
--------------------
Ed Kessler
sic itur ad astra (Just to look profound!)
|
Rick
Carpal Tunnel
Reged: 04/12/05
Posts: 2574
Loc: Tokyo, Japan
|
|
Quote:
Howie Glatter imports the filters from the Kasai Trading Co, Ltd. from Tokyo, Japan. The filters are wafer thin.
Makes sense since they sell his collimators (I have one, good stuff!). These filters are actually pretty good and are made in partnership with some Russian Science Academy according to Kasai's sales blurb. I've been thinking of trying a pair in my Canon's.
clear skies,
Rick
--------------------
www.japanastro.com
|
Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14686
Loc: Hurricane Alley
|
|
I think I have something else on my Xmas list!
Clear dark filtered skies...
MikeG
--------------------
Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
|
refractory
Pooh-Bah
Reged: 02/05/05
Posts: 1016
|
|
OK guys, now comes the ridiculously useless caca post from me- what would happen if one had a motorized rotating gradient filter? That is, think of something like a disk rotating at high speed, whose coatings vary in thickness so that at one side of the disk filtering is at maximum and on the opposite radius minimum (the first color TV systems come to mind with their rotating color filters).
Done right one could even have several different coating gradients one after another (for different filterings).
If rotated very fast would the mind unify the effect- so that you could have your cake and eat it too with regard to seeing the background stars and nebulosities?
In addition, if sized and positioned correctly the system should be able to pass over both eyelenses, and thus alternate there as well.
Does any part of this sound like a reasonable thing to experiment with?
Jess Tauber
|
rushintuit
sage
Reged: 04/01/06
Posts: 264
Loc: Farpoint Observatory
|
|
"made in partnership with some Russian Science Academy"
Interesting - Thanks, Rick!
I've dedicated a pair of Oberwerk 11x70's to these bino filters.
--------------------
/// Stellarvue SV102ED /// Nikon 12x50 /// Fujinon 16x70 /// SkyTools 2 /// The Desktop Universe All Sky CCD Mosaic In Monochrome Mode ///
Edited by rushintuit (09/01/06 01:07 AM)
|
Blind-Cyclops
sage
Reged: 11/28/05
Posts: 449
Loc: Kitchener, ON, Canada
|
|
Hello Howie,
I was wondering what types of filters you sell for binoculars?
Could you give us a web site with that information on it?
Also, I was wondering if you have filter reports from your customers? and on what binoculars have your filters been use?
Thanks
--------------------
Clear skies...
Duncan 
"Watch the skies, everywhere! Keep looking. Keep watching the skies!"
-- Closing line in movie spoken by newspaper report Ned "Scotty" Scott (Douglas Spencer) in the Sci-Fi movie
"The Thing From Another World", RKO Radio Pictures, 1951.
Antares (refractor) 127mm f/6.45. w/2-spd Crayford
Orion (Maksutov) 150mm f/12 w/2" EP adapter
Giro 3 (twin), 18" pier, EQ5 tripod.
Garrett 20x80mm, 410 head, 055 tripod.
|
HfxObserver
professor emeritus
Reged: 11/12/04
Posts: 624
Loc: Waterloo ON, Canada
|
|
After much experimenting last year I decided not to persue these sort of filters. Don't overlook the fact that neb. filters are designed to be placed at the recieveing end of the light cone before it enters the eyepiece and not the exiting lens end. Eyepieces act to spread out the image and nebula filters are designed to be in front of the lens systems. Although they do work to a certain extent on binocular lenses their usefullness is limited and I find that useing my 2" in between the lens and my eye is useful enough that I wouldn't buy a dedicated filter, it's just not worth it.
Just because someone builds a housing to allow us to place them on top of the eyepieces doesn't mean the the filters are tuned to have light pass through them in such a way. I consutled a physics professor who is also an astronomer and he assured me this would be difficult, costly and have only a slightly better result. One of the main limiting factors is that the highly reflective surface tends to bounce light off so a cloak or towel must be placed over the head/bino while using them even if they are sandwiched into a recessed sleeve.
-Chris
--------------------
Chris
7X50 Vixen,22X100 Antares
80mm William Optics Megrez II ED
Santel MK6
Borg 125SD f6 (Pentax/Oasis version)
Tak-Lapides
Pentax XW's 40,20,14,10,3.5 3.8XP, Speers 5-8, 30mm Widescan III
|
rushintuit
sage
Reged: 04/01/06
Posts: 264
Loc: Farpoint Observatory
|
|
While the filters do a dramatic job of reducing the background skyglow, they do little else. They will not turn a light polluted sky into a dark one.
--------------------
/// Stellarvue SV102ED /// Nikon 12x50 /// Fujinon 16x70 /// SkyTools 2 /// The Desktop Universe All Sky CCD Mosaic In Monochrome Mode ///
|
Littlegreenman
Pooh-Bah
Reged: 05/09/05
Posts: 1021
Loc: Southern California
|
|
Quote:
OK guys, now comes the ridiculously useless caca post from me- what would happen if one had a motorized rotating gradient filter? That is, think of something like a disk rotating at high speed, whose coatings vary in thickness so that at one side of the disk filtering is at maximum and on the opposite radius minimum (the first color TV systems come to mind with their rotating color filters).
Done right one could even have several different coating gradients one after another (for different filterings).
If rotated very fast would the mind unify the effect- so that you could have your cake and eat it too with regard to seeing the background stars and nebulosities?
In addition, if sized and positioned correctly the system should be able to pass over both eyelenses, and thus alternate there as well.
Does any part of this sound like a reasonable thing to experiment with?
Jess Tauber
Well Jess (Hiya!), I thought I saw this in a Sci-Fi movie where they had a rotating disc. The disc was about 2 feet in diameter, and was sectioned into 4 wedges or pie slices if you will. The subject was placed in front of the disc. Behind the disc was a light source. Two opposing wedges blacked out the light, and the two wedges allowed the light to pass through.
Then, the mad scientist at the control center would pull the lever to cause the disc to spin...okay. This is not from a Sci-fi movie. The actual contraption was a piece of art work I saw at the art Gallery in college, 1969. When you look at it while still your logical mind says that when you spin the disc it will appear brighter near the edge where there is more square inches of light, and evenly fade to a less less bright as you move in the center.
So you start spinning and what you see instead are concentric rings of bright light separated with thinner rings of black! It turns out the signal processing in the retina has an edge sharpening effect to fix the blurring caused by the fluid in the eye! This is a known effect, there may be a name to it. If someone wants to look up the physology of optical illusions and give us a source that would be appreciated.
If you really want to get weird, Science magazine mid 1980's, some scientist did this: Special contact lens with fiber optic feeds. They would send blue light to the left side of each eye, and red light to the right side of each eye. The signal from the left half of both eyes goes to the right brain, and vice versa. Give yourself a gold star if you already knew this. Subjects variously saw one color with the other color bubbling in around and shifting and, or switching field/ground. Or, and I like this, they would see a brand new color they had never seen before: blue- red or red - blue !  !
Just call me Mr. Wizard.
Steve the Littlegeenman
-end of transmission
Edited by EdZ (09/03/06 07:10 AM)
|
Littlegreenman
Pooh-Bah
Reged: 05/09/05
Posts: 1021
Loc: Southern California
|
|
Quote:
SNIP!...I did a little research on this subject a while back, and I read accounts of people using OIII filters with some success and others using broadband LPR filters with some success. I tried placing a Celestron UHC narrowband filter over one eyepiece of my 25x100 Skymaster - the results were mixed. On M42, I did notice increased nebulosity, but the surrounding view was drastically darkened - a trade off that resulted in zero net gain, aesthetically speaking, IMO.
Clear dark skies...
MikeG
Hi Mike,
This is referring to regular eyepiece filters, not binocular filters, I have an Astronomik UHC filter. I decided to try it precisely because they claimed their design allowed more light from stars to pass through. From their website:
"Compared to the UHC filters sold by other manufacturers the Astronomik UHC shows you more stars and more details in the nebulas." I can vouch that this filter shows more stars than other UHC filters I've used. (Lumicon, Parks, Orion, Celestron, maybe a few others).
http://www.astronomik.com/english/eng_uhc.html
Steven
Littlegreenman
Edited by Littlegreenman (09/03/06 01:14 AM)
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
[Re: