> Hi Group,
>
> It has taken me ages to produce this MF viewer, but it is finally
> available. Please see it on my website. This is an adjustable focus
> viewer with huge precision achromats and a very bright LCD screen. The
> wrap-around hood makes viewing very immersive.
>
> www.freewebs.com/larryeda
>
> I am also producing a fixed lens version which will be showing next week
> on the website.
>
> Kind regards,
>
> Larry Heyda
>
>

> Hi Group,
>
> It has taken me ages to produce this MF viewer, but it is finally available. Please see it on my website. This is an adjustable focus viewer with huge precision achromats and a very bright LCD screen. The wrap-around hood makes viewing very immersive.

>On 12/31/2013 11:18 AM, larryeda@nc.rr.com wrote:
> > Hi Group,
> >
> > It has taken me ages to produce this MF viewer, but it is finally
> available. Please see it on my website. This is an adjustable
> focus viewer with huge precision achromats and a very bright LCD
> screen. The wrap-around hood makes viewing very immersive.
>
>Awesome!
>
>Now I need to choose a color. Can you give a side-by-side
>picture of the colors?
>--
>John Thurston
>Juneau Alaska
>http://stereo.thurstons.us
>
>
>------------------------------------
>
>Yahoo Groups Links
>
>
>

> On 12/31/2013 11:18 AM, larryeda@nc.rr.com wrote:
> > Hi Group,
> >
> > It has taken me ages to produce this MF viewer, but it is finally available. Please see it on my website. This is an adjustable focus viewer with huge precision achromats and a very bright LCD screen. The wrap-around hood makes viewing very immersive.
>
> Awesome!
>
> Now I need to choose a color. Can you give a side-by-side
> picture of the colors?
> --
> John Thurston
> Juneau Alaska
> http://stereo.thurstons.us

> looks good, the wrap around hood, will that accommodate eye glasses?
>
> At 12:45 PM 12/31/2013, you wrote:
> >On 12/31/2013 11:18 AM, larryeda@nc.rr.com wrote:
> > > Hi Group,
> > >
> > > It has taken me ages to produce this MF viewer, but it is finally
> > available. Please see it on my website. This is an adjustable
> > focus viewer with huge precision achromats and a very bright LCD
> > screen. The wrap-around hood makes viewing very immersive.
> >
> >Awesome!
> >
> >Now I need to choose a color. Can you give a side-by-side
> >picture of the colors?
> >--
> >John Thurston
> >Juneau Alaska
> >http://stereo.thurstons.us
> >
> >
> >------------------------------------
> >
> >Yahoo Groups Links
> >
> >
> >
> ---------------------------------------------------------------------------
> Danny Vint
>
> Panoramic Photography
> http://www.dvint.com
>
> voice: 619-647-5780
>
>

Larry, congratulations.  What a sweet looking viewer!  I can imagine one of these sitting on a small tripod on the cherry hutch in the living room :-).

Not sure how to ask this quantitatively, but maybe 'how does the focus range compare with the 3D World backlit viewer?'.  I am right at the end on the latter (i.e. have to rack it all the way out).  I'd like to buy one of yours, but don't want to have to put on any 'reading' glasses.  Don't know quite how to ask this either, but anyway, is the focus action silky and smooth (the 3D World could seem a little stiff and cheesy)?

Thanks,

John 

> If John Thurston likes this viewer, then I've done something worthwhile.

> But, I can pour almost any color resin, so if you have a color in mind, I will try to match it.

> > If John Thurston likes this viewer, then I've done something worthwhile.
>
> What if he doesn't ??? :-O
>
> > But, I can pour almost any color resin, so if you have a color in mind, I will try to match it.
>
> "My Little Pony" Rainbow ?
>
> Francois

> Yes, My Little Pony Rainbow is on the color list right between Florida Flamingo and Texas Armadillo. I aim to please...

> > Yes, My Little Pony Rainbow is on the color list right between Florida Flamingo and Texas Armadillo. I aim to please...
>
> If the viewer had been ready just a few weeks earlier, you could even have added a "candy cane" version ! ;-)
>
> Francois

Mr. Heyda,

What's the maximum image height your viewer can accommodate?  I'm asking not only for myself but the fellow who's making 4x5 stereo images.

Thanks,

Steve

> Mr. Heyda,
> What's the maximum image height your viewer can accommodate? I'm asking not only for myself but the fellow who's making 4x5 stereo images.
> Thanks,
> Steve

 

Hi Group,

It has taken me ages to produce this MF viewer, but it is finally available. Please see it on my website. This is an adjustable focus viewer with huge precision achromats and a very bright LCD screen. The wrap-around hood makes viewing very immersive.

www.freewebs.com/larryeda

I am also producing a fixed lens version which will be showing next week on the website.

Kind regards,

Larry Heyda

> That looks great. One suggestion (which you may have already implemented,
> but if you have, it should be mentioned). That is that inside, including
> the hood (perhaps I should say, especially the hood), should be coated or
> painted ultra flat black, or, preferably flock coated). I have
> black-flocked the inside (and hoods) of most of my viewers in all formats,
> and the difference to image contrast is remarkable. If someone does wear
> prescription eye glasses, black flocking the inside of the hood, in my
> opinion, is a must.
>
> The first time that I did this was about a half a century ago. Although
> they called it a "viewer", it really wasn't. It was a TDC Project-or-View,
> which had the rather unique attribute of being able to show Realist-size
> slides either on a built-in rear-projection screen, or by flipping a
> mirror, on a regular silver projection screen. Although the images were
> sharp, in either configuration, the image quality was abominable. The
> housing was a light grey molded plastic, shiny on the inside. As a result
> of all of the stray light bouncing around, the images (as compared to a
> regular TDC 116 projector that I also owned at the time) were dim and
> washed-out, with no true blacks; no shadow detail. I painted the inside
> with flat black paint, and the image quality immediately improved
> remarkably. I sold that unit, and bought another. This time, I coated
> the inside with black flock paper. Now the front projected images looked
> just as clear as those from the 116, and nearly as bright (even though the
> lamp was much smaller). On the small rear projection screen they were
> stunning, even with the room lights on. Not only the blacks, but shadow
> detail on near-black image areas really popped. I even thought of building
> my own MF version, but never got around to it.
>
> Although that was not what you would technically call a viewer, per se, the
> same concept applies to viewers of all formats as well. Lining the
> interiors, and the inside of the hoods with black flock really makes a
> qualitative difference, especially when used under strong ambient light,
> and especially when you cannot get your eyes close enough to the lenses,
> such as in the aforementioned prescription glasses situation. Yes, you
> could even have a clear champagne color if you black-flocked the inside.
>
> JR
>
>
>
> On Tue, Dec 31, 2013 at 12:18 PM, <larryeda@nc.rr.com> wrote:
>
> >
> >
> > Hi Group,
> >
> > It has taken me ages to produce this MF viewer, but it is finally
> > available. Please see it on my website. This is an adjustable focus viewer
> > with huge precision achromats and a very bright LCD screen. The wrap-around
> > hood makes viewing very immersive.
> >
> > www.freewebs.com/larryeda
> >
> > I am also producing a fixed lens version which will be showing next week
> > on the website.
> >
> > Kind regards,
> >
> > Larry Heyda
> >
> >
> >
>
>
>
> --
> stereoscope3d@gmail.com

> JR,
>
> Great suggestion. I will do it. I was already wondering if flat black paint would be good enough for the hood.

> On 1/1/2014 2:46 PM, larryeda@nc.rr.com wrote:
> > JR,
> >
> > Great suggestion. I will do it. I was already wondering if flat black paint would be good enough for the hood.
>
> Krylon Ultra-flat Black is the deepest, darkest, blackest
> light sink available in a retail can. I love the stuff. The
> early versions of the 3D World viewers were greatly improved
> with the liberal application to the insides. The later
> versions were much better, but all of the focusing 3D World
> viewers I've ever seen still had a few un-coated internal
> surfaces which could benefit from a little Ultra-flat.
>
> I read an amateur astronomy article a number of years ago
> rating different black paints on their reflectivity. As I
> recall, the only thing which came in better than Krylon
> Ultra-flat was Krylon Ultra-flat sprayed over a surface
> coated with powdered walnut shells.
>
> John Thurston
> Juneau, Alaska
>

> On 1/1/2014 2:46 PM, larryeda@nc.rr.com wrote:
> > JR,
> >
> > Great suggestion. I will do it. I was already wondering if flat black paint would be good enough for the hood.
>
> Krylon Ultra-flat Black is the deepest, darkest, blackest
> light sink available in a retail can. I love the stuff. The
> early versions of the 3D World viewers were greatly improved
> with the liberal application to the insides. The later
> versions were much better, but all of the focusing 3D World
> viewers I've ever seen still had a few un-coated internal
> surfaces which could benefit from a little Ultra-flat.
>
> I read an amateur astronomy article a number of years ago
> rating different black paints on their reflectivity. As I
> recall, the only thing which came in better than Krylon
> Ultra-flat was Krylon Ultra-flat sprayed over a surface
> coated with powdered walnut shells.
>
> John Thurston
> Juneau, Alaska
>

> Larry,
> Sounds great! I've a few questions:
> 1-how is the battery accessed? If it "goes bad" and has to be replaced?
> 2-Does it need to be removed to charge, or does the charger just plug into viewer?
> 3-if we have to clean bits out of the body or slide channel, or from behind the lenses, is it tricky to open?
> 4-how strong is the urethane casting resin (looking at the face shield for example).
>
> I quite like the nice brown with the gold/yellow channel under the focussing slide)!
>
> G
>
>
> Sent from my iPad
>
> --
> Gfpguy1@gmail.com
>
> **Consulting on Protein Solubility, Folding, Engineering, & Detection**
>
> Geoffrey S. Waldo, PhD
> Mail Stop M888
> Los Alamos National Laboratory
> Los Alamos, NM 87545
>
> Tel: 505-667-8161 email: waldo@LANL.gov
> Fax: 505-665-3024
> Cell: 505-204-6979
>
>
> Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/
> •Superfolder, Folding Reporter, Split Proteins
> •Tools for engineering protein folding, stability, and solubility
> •Protein interactions, tagging, and detection
>
> ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu
>
> > On Dec 31, 2013, at 1:18 PM, <larryeda@nc.rr.com> wrote:
> >
> > Hi Group,
> >
> > It has taken me ages to produce this MF viewer, but it is finally available. Please see it on my website. This is an adjustable focus viewer with huge precision achromats and a very bright LCD screen. The wrap-around hood makes viewing very immersive.
> >
> > www.freewebs.com/larryeda
> >
> > I am also producing a fixed lens version which will be showing next week on the website.
> >
> > Kind regards,
> >
> > Larry Heyda
> >
> >

Hi Geoffrey,

Thank you for your inquiry.

The back of the viewer is attached with small screws.  When it is opened, the rechargeable battery is spring-clamped to the back wall.  It can easily be replaced by popping it out and putting in a new one.  A standard 9V clip attaches to the two terminals on the battery.

On the back panel, there is an external socket for the charger and a small switch to commence the charging.  Viewer can be run with the charger plugged in without opening the back or  disconnecting the battery.

The high-impact urethane is very strong and does not break easily.  Unless someone severely abuses it, the body of this viewer should last a lifetime.

No, it is not tricky to open.  Just undo the screws on the back panel and you have access to the whole inside.

Glad to hear you like the cool brown with the gold slider channels.  I was searching for the best color, and that is one of
my favorites, too.

Kind regards,

Larry

Larry,

Sounds great! I've a few questions:

1-how is the battery accessed? If it "goes bad" and has to be replaced?

2-Does it need to be removed to charge, or does the charger just plug into viewer?

3-if we have to clean bits out of the body or slide channel, or from behind the lenses, is it tricky to open?

4-how strong is the urethane casting resin (looking at the face shield for example).

I quite like the nice brown with the gold/yellow channel under the focussing slide)!

G

Sent from my iPad

--

Gfpguy1@gmail.com

**Consulting on Protein Solubility, Folding, Engineering, & Detection**

Geoffrey S. Waldo, PhD

Mail Stop M888

Los Alamos National Laboratory

Los Alamos, NM 87545

Tel:  505-667-8161                 email: waldo@LANL.gov

Fax: 505-665-3024

Cell: 505-204-6979

Los Alamos Fluorescent Proteins Website: http://www.lanl.gov/projects/gfp/

•Superfolder, Folding Reporter, Split Proteins

•Tools for engineering protein folding, stability, and solubility

•Protein interactions, tagging, and detection

ISFI Integrated Center for Structure and Function Innovation web site:http://techcenter.mbi.ucla.edu

On Dec 31, 2013, at 1:18 PM, <larryeda@nc.rr.com> wrote:

Hi Group,

It has taken me ages to produce this MF viewer, but it is finally available. Please see it on my website. This is an adjustable focus viewer with huge precision achromats and a very bright LCD screen. The wrap-around hood makes viewing very immersive.

www.freewebs.com/larryeda

I am also producing a fixed lens version which will be showing next week on the website.

Kind regards,

Larry Heyda

> It has taken me ages to produce this MF viewer, but it is
> finally available.

Hello Larry,

The viewer looks great and I'm sure that it performs as well as it looks.  Question: Will you be able to produce the viewers on request in the future?  I'm asking because the viewer isn't in my budget right now but may be in the coming months.

Thanks,

Ted

>
> If you need something that can be brushed on, like to touch up a
> small specular surface, such as a metal piece of hardware, I have
> found that an ultra flat black paint with the brand name Floquil
> that is sold in model railroad stores, and called "Engine Black"
> works very well.

> For simplicity however, I have found adhesive-backed black flock
> paper works quite well. Not all flock paper is the same, and some,
> often called "velvet flock" actually has a sheen that is counter to
> flatness. One that I have found good, is sold by Edmund Optics for
> lining optical devices like telescope tubes.

> Hello Larry,
> The viewer looks great and I'm sure that it performs as well as it looks. Question: Will you be able to produce the viewers on request in the future? I'm asking because the viewer isn't in my budget right now but may be in the coming months.
> Thanks,
> Ted

> > It has taken me ages to produce this MF viewer, but it is
> > finally available.
>
> How wonderful; it looks great!
>
> Your website description (graphic) has "The light is
> turned on by an easily accessible push-button switch
> underneath..." I'd like to know if this is a momentary
> type or an on-off switch (i.e., press once to turn on,
> press again to turn off). I prefer the latter because it
> makes for more relaxed viewing, imo. I feel that
> having to keep a button depressed to keep the light
> on imposes a kind of constraint on the view.
>
> John G.

> It is a momentary switch, but the effort to push it down is so slight, you hardly know you are doing it.

> > It is a momentary switch, but the effort to push it down is so slight, you hardly know you are doing it.
>
> Does that mean that if one rests the viewer on a flat surface it might turn the light on ?
>
> Some years ago, there was a viewer that worked the other way around. It had a pin at the bottom which would turn the light off when pushed in. Therefore when the viewer was left on a table, the light would be off but if someone picked up the viewer to look through the lenses, that would turn the light on. I think this may have been the "Like Life" viewer.
>
> Francois
>
>
>
>
>
> ---In MF3D-group@yahoogroups.com, wrote:
>
> Hi John,
>
> Good point about the switch. It is a momentary switch, but the effort to push it down is so slight, you hardly know you are doing it. However, I have thought of adding a slide-over lever to close it without pushing it. But I'm not sure it's necessary. This is not a commercial push-button which usually requires a bit of effort. It's very subtle. (but when it's off, it's off, and when it's on, it's on.)
>
> Larry
>
>
> ---- John Goodman wrote:
> > > It has taken me ages to produce this MF viewer, but it is
> > > finally available.
> >
> > How wonderful; it looks great!
> >
> > Your website description (graphic) has "The light is
> > turned on by an easily accessible push-button switch
> > underneath..." I'd like to know if this is a momentary
> > type or an on-off switch (i.e., press once to turn on,
> > press again to turn off). I prefer the latter because it
> > makes for more relaxed viewing, imo. I feel that
> > having to keep a button depressed to keep the light
> > on imposes a kind of constraint on the view.
> >
> > John G.
>

 

> It is a momentary switch, but the effort to push it down is so slight, you hardly know you are doing it.

Does that mean that if one rests the viewer on a flat surface it might turn the light on ?

Some years ago, there was a viewer that worked the other way around.  It had a pin at the bottom which would turn the light off when pushed in.  Therefore when the viewer was left on a table, the light would be off but if someone picked up the viewer to look through the lenses, that would turn the light on.  I think this may have been the "Like Life" viewer.

Francois

> Not sure about the "Life-Like", but the Photax viewer certainly did that.
>
> I'm sure Larry will have looked carefully at the possibilities, and
> cannot house a second switch. Which is a pity, because the Photax style
> "put it down and the light goes off" system is really convenient. But it
> does need a separate master switch to turn the lamp off when putting the
> viewer away...
>
> Bob Aldridge
>
> On 02/01/2014 17:26, depthcam@yahoo.ca wrote:
> >
> > > It is a momentary switch, but the effort to push it down is so
> > slight, you hardly know you are doing it.
> >
> > Does that mean that if one rests the viewer on a flat surface it might
> > turn the light on ?
> >
> > Some years ago, there was a viewer that worked the other way around.
> > It had a pin at the bottom which would turn the light off when pushed
> > in. Therefore when the viewer was left on a table, the light would be
> > off but if someone picked up the viewer to look through the lenses,
> > that would turn the light on. I think this may have been the "Like
> > Life" viewer.
> >
> > Francois
> >

This whole discussion seems a bit 19th century. Why not fit an accelerometer - if there's a light unit fitted, when it moves switch the light on, after a minute without movement switch it off? 

You take your slides and your viewer on holiday then? A truly dedicated viewer!

> This whole discussion seems a bit 19th century.

> I have just built a viewer that has two switches. One is a toggle
> switch but I also have a microswitch on the bottom of the slide holder
> that switches the backlight on only when there is a slide in place.
>
> Timo
>
> On 2-Jan-14, at 1:58 PM, <larryeda@nc.rr.com> <larryeda@nc.rr.com>
> wrote:
>
> > I like the idea of the switch that turns off when you set the viewer
> > down, but this viewer could be set down either on its back (very
> > convenient) or on its bottom. Some folks might prefer one or the
> > other, and I'd hate to have to put in two switches like that. Best
> > if I keep it as it is.
> >
> > ---- Bob <Bob@Stereoscopy.net> wrote:
> > > Not sure about the "Life-Like", but the Photax viewer certainly
> > did that.
> > >
> > > I'm sure Larry will have looked carefully at the possibilities, and
> > > cannot house a second switch. Which is a pity, because the Photax
> > style
> > > "put it down and the light goes off" system is really convenient.
> > But it
> > > does need a separate master switch to turn the lamp off when
> > putting the
> > > viewer away...
> > >
> > > Bob Aldridge
> > >
> > > On 02/01/2014 17:26, depthcam@yahoo.ca wrote:
> > > >
> > > > > It is a momentary switch, but the effort to push it down is so
> > > > slight, you hardly know you are doing it.
> > > >
> > > > Does that mean that if one rests the viewer on a flat surface it
> > might
> > > > turn the light on ?
> > > >
> > > > Some years ago, there was a viewer that worked the other way
> > around.
> > > > It had a pin at the bottom which would turn the light off when
> > pushed
> > > > in. Therefore when the viewer was left on a table, the light
> > would be
> > > > off but if someone picked up the viewer to look through the
> > lenses,
> > > > that would turn the light on. I think this may have been the "Like
> > > > Life" viewer.
> > > >
> > > > Francois
> > > >
> >
> >
>

> On 1/2/2014 11:28 AM, billhibbert@designforlife.com wrote:
> > This whole discussion seems a bit 19th century.
>
> Nah. This is totally modern technology. It even uses those
> new-fangled electric lamps. I don't see what was wrong
> standard, widely available, whale oil lamps. But if Larry
> says this is better, I'm willing to give it a try.
>
> --
> John Thurston
> Juneau Alaska
> http://stereo.thurstons.us

> Oh well, it was slightly tongue in cheek of course ;¬) but that's how a lot
> of cameras eg my Sony Nex-5 control the lcd. I'm not aware of a circuit
> that does the whole job, but it could be built pretty straightforwardly
> using components like this:
>
>
>
> accelerometer:
>
> http://www.adafruit.com/products/1018
>
> http://www.analog.com/en/mems-sensors/mems-accelerometers/adxl362/products/p
> roduct.html
>
>
>
> tiny Arduino and interfacing:
>
> http://www.femtoduino.com/
>
> http://www.ele.uri.edu/courses/ele205/Arduino%20-%20Learning.pdf
>
>
>
> Do-it-all board? I haven't looked closely:
>
> http://vimeo.com/18565441
>
>
>
> If you can't find an off-the-shelf solution it would make a great
> crowdsource project - there must be a ton of applications that could benefit
> from a simple on/off activity switch.
>

> Hello, this is a question for Larry Heyda : what is the lens separation for this viewer ?
> Sorry if I missed it, but it seems that this crucial design parameter has not been documented.
>
> (About the fact that this is a crucial design parameter, I'll be glad to dicuss).

I agree with you, though : the larger the lens diameter, the wider the tolerance to eye separation.

These are all important issues with the optical design of a slide viewer, but they omit the most important factor when dealing with a very low production run. Cost.

                         I am not blinded by the costs, hence why I never went into production on any 3d viewers...

 but never with mismatched lenses. Have I been lucky to get matched lenses by accident? I don't know, but I just assumed that lenses made in batches tend to match well with each other for the same reasons all mass produced products match each other. Correct me if I am wrong.

                          No lenses have MATCHED fl's per say....   When I used to build 3d cameras (see pix below),  on average it took Schneider a run of 400 digitar lenses to provide me a single pair of matched fl's within a tolerance of  +/-  .25% fl...when I gave them a tighter tolerance, I would not get any matched pairs for 9-12 months.   To produce doublets with very tight fl tolerances would be very cost prohibitive, and in this case, it does not appear that Larry proivded a hard set of tolerance specifications on all aspects of the lens build parameters...if so, the design software would provide a fl tolerance (the actual fl range is a function of all the tolerances that make up the lens design...by joining them in a process called "tolerance stacking", you know the range of fl's that design will produce if all the build tolerances are maintained)  ... for most doublets, they are of relatively low tolerance, such as,  +/-  5% fl would be considered average from my experience.   For most all applications, this is a non-issue, EXCEPT 3d viewers, which they are used in a comparative scenario.  

So, when I did a small run of doublets, the best I could do was "pair them", as their exact fl was irrelevant vs. their variance in fl to each other.   Because I only ran 20, I paired them from their laser test ($75 each), .... could only achieve 6 usable pair under +/-  2%.   U either pay on the manufacturing end, (higher build tolerances), or on the pairing end, with waste.   Unless, as always, you have high enough volume, where the waste factor is greatly reduced.   That was the last run I ever did of doublets...never produced the viewers, instead, sent them to a customer who bought my 3d cameras in China.    I later developed a system with an optical bench and a DSLR where I photographed a chart with lines, brought the images into PS, did a comparative measurement through pixel count tool.. while this provides no reliable fl data, if your bench set-up is accurate enough, you can get very reliable fl matching %'s ....which is all that matters here.  

Can our visual system overcome mismatched fl's?  Sure, we can also see through heavily scratched eye glasses, and still walk around and function... all visual variances from our unaided vision causes visual stress, most can be overcome, the question is always, for how long?    Of course, everyone varies in this area, some are very visually sensitive, others, not as much.     There was many studies done in the Army about mismatched fl's in binocs and 3d viewers for aerial 3d... all back in the 1950's.... they measured how long it took large groups of people to feel sick from mismatched viewing fl's  (time vs. fl mismatch charts were produced)  ....and from that, they created a min. fl mismatch tolerance for 3d viewing products, it was very tight, IIRC, +/- .2%.   But, that's the Govt. 

I would rather see a good quality viewer that is affordable, rather than a near perfect viewer that nobody can afford.

                                 As I mentioned in my previous post, when you buy good quality "visual" optics, the maker provides most of this data for you, no testing required, except exact fl's vs. nominal fl.   Which as I mentioned above, can be accomplished with a home-brew method to keep cost down.    However, when you buy off-the-shelf "optics", they are rarely if ever designed for visual use...most optics are for machine vision, projection, imaging, etc.   At best, u try to adapt a pair of off the shelf optics for visual use.... I recall buying about 30 doublets from Edmunds and Newport, when I first my quest to design viewers, they all had sufficient too many shortcomings for 3d viewing.  3dWorld did a good job designing a very low cost lens for their viewer...however, they fell way short in eye relief, and the viewer had no IPD adjust (the lens has a tiny eyebox, at most +/- 1mm off axis viewing)....but creating an IPD adjust and much longer ER for eyewear users would create lenses that cost 3x what the entire viewer sold for....

the other issue with IPD adjust, unfortunately, it's NOT just about the acceptable eyebox size, ....its about reducing divergence for short IPD users, and potentially excessive convergence for those with wide IPD's.   To eliminate this variable, the film center to center separation should always equal the IPD adjustment, basically two monoculars.   Anyway, more cost for sure, and now mounts would have to change, etc.    BTW, I never read ANY studies on divergence and convergence vs. time.  However, military binocs all had strict collimation standards, which in essence addressed this issue.   The aerial 3d viewers were never confronted with this due to very long fl viewing lenses as the images were quite large...once again, long fl's inherently solve a lot of visual optical design obstacles. 

Hope this helps.



Bill G

Timo 

On 6-Jan-14, at 12:42 PM, Bill G wrote:

 

Wow, incredible product Larry, congrats on the long and winding road to a final product...
It's a wonderful story, very well written....

I recall writing lengthy emails and some phone calls to you during your R&D phase... Sounds like you had a very knowledgeable team of beta testers who reviewed the optics before you made your final decision.  
Reading through your web pages, I could not find the critical optical specifications though....

fl of lenses?
variance in lens fl's?   often expressed as focal length tolerance....+/- %
what method do you use to pair the fl's in the viewer?   what min. fl tolerance mismatch do you allow?
focus range in diopters? 
Eye Relief (in mm?)
Distortion graph?


Is this something that you will post soon?   You mentioned the optics used were "off the shelf" copies....  if not specifically designed for this viewing application, do you know what use they were designed for?   for most good visual optics, the maker will provide the FOV at the subject plane, back focal distance, ER, AFOV and distortion values.  

Also, you mentioned the 2" wide diameter eliminating the need for IPD adjustment.  How did you determine this?  Did you run a laser analyzer on-axis and compare the MTF values and distortion values graphs at each mm from on-axis?   This would demonstrate an "IPD range of acceptability" (to keep mismatched distortion within tolerable levels)..  with childrens IPD's at 45mm to wide-eye'd adults at 75mm, this represents a whopping +/- 7mm off axis.   Of the 9 prototype designs I built, the largest "eyebox" that was within an acceptable range of distortion mismatch was +/-2.5mm (from on-axis), and this was a 5 element design that weighed nearly 2lbs.    Hence why I was committed to IPD adjustment to increase the market "usability factor".      Anyway, I know we discussed this in detail while u were in your conceptual stage....so I am interested in how you addressed it.  

It would be great if there was a regular source of MF 3d viewers, glad to see your product finally surface....again, congrats, wishing u the best...

Bill G