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Equipment Discussions >> ATM, Optics and DIY Forum

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Gary Fuchs
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Reged: 05/22/06

Loc: Easton, PA, USA
Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5561140 - 12/08/12 04:18 PM

I used to see a lot of newcomer's questions here and elsewhere replied to with "Search the archives, this has been answered before." Lately I think folks are starting to realize that while the answers might be in the archives there's so much there that a search can take a long time unless you know the subject well enough to structure a very specific search phrase--which of course being a newcomer you don't know how to do.

When something is posted here that piques my interest--like the current thread--I want to learn about it because maybe there's some improvement I can make in what I'm doing. Who knows, I might even be able to offer a suggestion.

Now I know of a couple of ways to make and test a convex surface...but one thing that got me interested in this thread was the idea that there might be other easier ways--ways that might not have been either known about or described before, either online or in various books--which might be known to a person with particular professional optical fabrication experience.

The answers to my questions were, with one minor exception, not forthcoming. This isn't the first time the OP has either not described a technique, or given a partial explanation, or just tantalizing glimpses.

This is an amateur forum. Not, at least for the participants as far as I know, a place to self-promote. If you're going to talk about a design or technique then you should be prepared to answer reasonable questions--questions like how do you make and test the glass you're describing as relatively easy to make and test.

If the techniques you're using aren't proprietary and are well known and you don't feel inclined or have the knack to explain what's been said well elsewhere then go ahead and cite references that any of us can lay our hands on.

Now, as far as the Wall Hypo is concerned, there were a lot of pictures posted but almost all were of fairly poor quality and not of astronomical targets and many had obviously been post-processed. So what they show is questionable. To my eye about what you might expect from a cheap pair of binoculars. There was nothing compelling to induce me to build one or even to place any faith in the claims.

Now if it were actually harder to make say a 12-16" mirror for a Newtonian then a refractor that size would be more appealing as an alternative.

It sounded to me like the OP's design had color issues with two of the extra lenses along two axes. If the alignment procedure is easy for that I'd like to have it described--and not just as being easy and simple for anyone who's made two good mirrors.

And hijacking threads...well, there are tangents and then hijacking. Not always easy to say when what occurs but certainly not hard to just say. Before we call any kettles black it might be good to consider history.

I'm all ears for those explanations of tools and techniques. I'm working on a convex surface right now and if there's an easier/simpler/cheaper way to do it than making a test plate and interference testing against that I'd love to hear it.

And if I can easily make a big loose tolerance objective and add some cheap loose tolerance OTS lenses and with a simple alignment technique end up with a 50X/inch color-free refractor with great contrast...wow, count me in as soon as I can lay my hands on that big glass...but, if it's going to end up for sale with crucial specs either secret or patented then go ahead and make it and pay for advertising like any other business...

(Incidentally, we've heard enthusiastic things before; and that attitude is fine...but attitude alone doesn't make something work.
If I were to get the idea that gasoline might make a new kind of very effective fire extinguisher material and head over to the Fire Extinguisher Forum and talk about what a great new idea I had--after all, there's nothing like this in the literature or patented and since water and gasoline are liquids and one ought to work as well as the other--should I expect all sorts of acclaim and support and lively discussion of the relative possible merits of one octane over another or the value of varying amounts of ethanol? Should my feelings be hurt because people point out the obvious? At the very least, if I have in mind to do something special and new with the gasoline to make it better at putting out fires than say water then shouldn't I describe it? Peer review?)

Gary


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Aljr
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Reged: 12/08/10

Loc: BRAZIL
Re: Hypo/Dialyte testing discovery new [Re: DAVIDG]
      #5561310 - 12/08/12 06:31 PM Attachment (28 downloads)

Quote:

What new theory are you trying to prove with a Hypo Dialyte ? The math discriping the interaction of light with refractive and reflective surfaces has been well established and tested many times. So unless there is a bug in the software of both OSLO, Zemax or any other raytracing program, they predict the results extremely well of any optical design that uses these materials. There are millions of designs to prove this. So why should one throw all that data away and experiment with a design that using these proven tools that shows it not to have very good performance ?

- Dave




Maybe John Wall can never agree with what I say:
The person who will find the bug / get the credit.
The programmer who wrote the program(Oslo, Zemax, DBoptic) might help. Maybe some student who wants to defend his doctoral thesis. John measured the results on your countertop and the program gives another result. In my simulations with DBOptic, I noticed that when we insert in the program DBoptic, a series of lenses to form an equivalent lens(this is similar to a combination of resistors) the program provides a result that agrees / is similar to experiment / practice. I would like to apologize to John Wall for doing your Hypo with a OG lens F/D 17, he recommends f/d 30 or f/d 40. HE NEVER ACCEPTED IT. I then decided to put a series of negative meniscus (common spectacle lens), in front of the OG lens, in order to extend the focal length of the lens at F / D 40. In my mind, every time I put a negative meniscus of -0.25 diopters in front OG lens, the focus of the OG lens would be far / long, so focus lens OG could also be infinite... Anyone can try this in the program. Take a OG lens 150/3000mm, place 8 meniscus of -0.25 diopters, 1700mm after OG lens front, and an achromatic doublet 70/500mm behind( +/- 50mm distance after meniscus). See soluction.jpg and bug.jpg


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Aljr
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Reged: 12/08/10

Loc: BRAZIL
Re: Hypo/Dialyte testing discovery new [Re: Aljr]
      #5561313 - 12/08/12 06:34 PM Attachment (31 downloads)

The Bug, this system is Better(only one negative CR39 meniscus lens -2 diopters = -0.25x8). Good Results in practical. See bug.jpg

Edited by Aljr (12/08/12 07:35 PM)


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MKV
Carpal Tunnel
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Reged: 01/20/11

Re: Hypo/Dialyte testing discovery new [Re: Aljr]
      #5561505 - 12/08/12 09:05 PM

Excsue me, Aljr, how can you have three air spaced elements and only 5 surfaces??? Thanks.

Mladen


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Aljr
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Reged: 12/08/10

Loc: BRAZIL
Re: Hypo/Dialyte testing discovery new [Re: MKV]
      #5561561 - 12/08/12 09:50 PM Attachment (19 downloads)

Surfaces are 7 in total. Is understood: there are three elements. Please, see this new drawing: I went down the "scroll bar" on DBoptics.

By other hand: is important I say: the sketches above are referring to dialyte Petzval. These drawings do not refer to Hypo.


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MKV
Carpal Tunnel
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Reged: 01/20/11

Re: Hypo/Dialyte testing discovery new [Re: Aljr]
      #5561599 - 12/08/12 10:20 PM

Quote:

Surfaces are 7 in total. Is understood: there are three elements. Please, see this new drawing: I went down the "scroll bar" on DBoptics.

By other hand: is important I say: the sketches above are referring to dialyte Petzval. These drawings do not refer to Hypo.



Thank you, sir, for clarifying this.

Mladen


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MKV
Carpal Tunnel
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Reged: 01/20/11

Re: Hypo/Dialyte testing discovery new [Re: Aljr]
      #5561615 - 12/08/12 10:36 PM

Aljr, are you saying this configuration is corrected?

Regards,
Mladen


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Crayfordjon
Vendor - Zerochromat
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Reged: 06/17/09

Loc: UK
Re: Hypo/Dialyte testing discovery new [Re: MKV]
      #5561849 - 12/09/12 03:45 AM

Yerse Mike, point taken. The snipe at " shewn" is of course how we spikka da lingo ere in good old Blighty. As to the bad images taken with a hypo, you are right, they are bad, but I have already admitted that, the quality is mainly due to the fact that I am not using an imaging camera, but an ordinary bog standard camera such as a Panasonic Lumix, great for the snap shot general public but not too good on critical focus, next the shots are also taken through double glazing, which dont help much, however the images are to illustrate the lack of " huge amounts of colour" that have been levelled at the system, which of course is untrue, if it were so, I would have abanded the Hypo at birth, and none of you would have heard about it. Now I come to the nub here, you have still not grasped the points I laid down in my original thesis, so I will go over them once more. The Hypo is a visual instrument. The hypo only works at low power as found in binoculars etc, so it belongs in that region of use. The Hypo is incredibly cheap to build. The Hypo can be made by those starting out in ATM or Astronomy. The Hypo when used visually gives bright and very clean images. The Hypo has colour in the system, but it is of a low order and is tolerable to ordinary folk. The Hypo is not the new scope that will sweep the board. Now Mike, it is a matter of choice, as you sniffilly aver that you will never bother to make one, so be it, I am not bovvered one bit, its your choice. Finally we come to my egotistic attitude, sorry about that and you have a right to say so, but in my defence my attitude is due to the obdurate refusal to entertain my point of view, not accept it mind you, and so far the whole idea of the Hypo has been met with derision and hostilty, by the majority of the ATM population here, which says something! believe you me. I will say no more on this topic.

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Mark Harry
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Reged: 09/05/05

Loc: Northeast USA
Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5561898 - 12/09/12 05:43 AM

This thread has totally fallen thru the floor; nowhere near on topic of an interesting facet of a test I made on longitudinal color. That was totally ignored.
Otherwise fine and good minds here have allowed themselves to be drawn into endless bickering, nitpicking, pontifying, and posturing.
******
It's sometimes a wonder (to myself) -WHY- I even bother to try posting about something interesting that I may have observed, come across, or might be working on....
M.


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kfrederick
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Reged: 02/01/08

Re: Hypo/Dialyte testing discovery new [Re: Mark Harry]
      #5562014 - 12/09/12 08:46 AM

Mark there are many who read and get informed from your posts. Think you could use two eyepieces with one lens if the large singlet was slow enough .

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ed_turco
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Reged: 08/29/09

Loc: Lincoln, RI
Re: Hypo/Dialyte testing discovery new [Re: kfrederick]
      #5562230 - 12/09/12 11:18 AM

Mark,

Please please, keep up the posts. Nitpicking sometimes help discover something better.

As to those pictures shown; they were taken through Double Glazing I can only imagine what these systems work outside! Open that window forget the seeing and the heat loss and look through air only. It may be lousy but a lot better than glazing and/or a window screen; (mine has both).

Maybe on a warmer day; but please, take new piccys.

Ed


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Mark Harry
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Reged: 09/05/05

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Re: Hypo/Dialyte testing discovery new [Re: ed_turco]
      #5562908 - 12/09/12 06:25 PM

They ain't my pictures!
Actually using this meniscus like a hypo can resolve small overspray specs down to .005-.010" in diameter at about 35 yards- window open, or closed.
It impresses me at the moment that without any baffling that the extraneous light is spoiling the MTF to a degree.
M.


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jgraham
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Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Hypo/Dialyte testing discovery new [Re: Mark Harry]
      #5563292 - 12/09/12 10:51 PM

Despite the lively banter, I've seen nothing in this discussion that would stop anyone from pursuing this design if they wanted.

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Crayfordjon
Vendor - Zerochromat
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Reged: 06/17/09

Loc: UK
Re: Hypo/Dialyte testing discovery new [Re: jgraham]
      #5563570 - 12/10/12 04:59 AM Attachment (23 downloads)

Ed. Here are a couple of test pics outside using a six inch standard Hypo. The greenish cast is Cyan, as the 50mm Plossl is coated with "Ruby" coating. Minus red from RBG gives Cyan. Yes it is about time this thread was put back on the rails so here is the kick off.

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Crayfordjon
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Reged: 06/17/09

Loc: UK
Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5563571 - 12/10/12 05:00 AM Attachment (18 downloads)

Same greyscale

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Crayfordjon
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Reged: 06/17/09

Loc: UK
Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5563572 - 12/10/12 05:03 AM

Any slight fuzz is due to the quality of the Camera, which is cheap and cheerful.

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ed_turco
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Reged: 08/29/09

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Re: Hypo/Dialyte testing discovery [Re: Crayfordjon]
      #5563748 - 12/10/12 08:50 AM

Your pics are most informative. Why not go for a full color shot? Pretty please?


Ed


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Crayfordjon
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Reged: 06/17/09

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Re: Hypo/Dialyte testing discovery new [Re: ed_turco]
      #5563924 - 12/10/12 10:48 AM

The green imageis a full colour shot, the other is greyscale.

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Crayfordjon
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Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5563934 - 12/10/12 10:55 AM Attachment (16 downloads)

To follow on I have been developing a Hypo style refractor which had no achromatic elements in it at all, the idea behind the concept is to get three monochromatic images: R G B, and then combine them into a colour image free of CA and LCA. Three interference filters were used. The last image is the green one greyscaled.

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Crayfordjon
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Reged: 06/17/09

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Re: Hypo/Dialyte testing discovery new [Re: Crayfordjon]
      #5563939 - 12/10/12 10:57 AM Attachment (12 downloads)

The three separate images. First

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