what Ian_T said.... would be a shame to close down this project
kickstarter vote too
OK guys, i will give one more try to the project. I will take a look at kickstarter website, i did not know it until you point me there. (i am afraid if i fail i need to give the money back). I will ask the optical lab to build some cilindrical diopters and try some combinations with power and distance to see what i can get.
@apefos You surprise me, having access to all the means to get the job done, you omit to make a basic research :LOL
Start here: http://www.google.com/patents/US3002427 & download pdf from top right of page.
It shows how to make apo front & rear group, combine like afocal telescope, get the squeeze ratio and an idea for focussing.
@JohnBarlow I feel proud and happy because I did this without copy anything.
Had another meeting in the optical lab early morning today and they will grind more glass. I will try 5 cilindrical positive focus diopter power and 6 negative cilindrical squeeze power to combine.
I do not have knowledge to work with optical design softwares, all i am doing is experiment with a range of lenses power and lenses shapes, of course this increases the amount of money to reach the result.
If one of these combinations let me shoot something i can upload to vimeo. But it seems It will not become a product due to no available optical large glass pieces to buy and large glass grinding to hire. If I have luck maybe some design will not vignette with the available glass.
It seems the resultant power of the anamorphic adapter must be zero. Probably this will reduce or even cancel the chromatic aberration, so there are chances the two element design work without achromat correction, or maybe using achromat correction just in the squeeze lens will do the chromatic aberration correction, because maybe the squeeze needs more power than the diopter and the squeeze lens will be far from camera lens and these things increase the chromatic aberration from it. So maybe a three lens design in two groups using a flint glass just in the squeeze can do the job...
you go apefos! look at kickstarter, it is an awesome way for projects just like this! :) And if I am not mistaken you either reach your desired amount of money, then you get it and then you can start the project off for real- or if the target is not reached nobody has to pay anything. very nice model and perfect for you! :)
I would love to see anamorphic dslr lenses done right! you could go a long way if you can do this- look, no one else does it! :) And it is no shame to read into the basics of this stuff. it is just some more optics knowledge. not copyrighted ideas. :)
@fatpig thanks for encouraging me. yes i need to understand the way kickstarter works too see if is good to me. but first i will test the positive cilindrical focus diopter in combination with the negative cilindrical squeeze to see if it will work. I just can open a project if i am sure it will work. the project would be the tweaking to find the final design, i need to make it work first, i cannot open a project to do unreliable experimentation.
In my researches i found a possible way to make the big squeeze front element. the acrilic plastic have good optical quality, the refraction index is close to glass, and it can be cut with laser, and it is available in large sizes, it is less heavy. I need to find informations about the abbe number to realise the chromatic aberration will not be an issue. also i need to quote prices to do laser cut on it and be sure the laser cut will be perfect, without waves in surface.
acrilic Abbe Number is 57: GREAT
I am studying Kickstarter website.
As I said before, i will NOT start a project without the squeeze and focus works good. To be sure these two goals will work i need to experiment with the new positive and negative cilindrical lenses. I am waiting them to get ready from optical lab to try. Also I just can open a project if I can found a way to build the large squeeze lens, PMMA Acrylic is an option.
Considerations about Kickstarter:
Before Start a Project:
1-Need to test the new design to see if it works, waiting for lenses to become ready.
2-Need to find an Acrylic partner, ask for prices, try it to see if the laser cut can do it without waves in surface.
If the design do not work shutdown, if it works show results on vimeo and go on:
3-Calculate the amount of money and the project deadline.
4-find a partner to start the project in kickstart because i do not live in US so I cant do that. I invite @Ian_T to be my partner because he knows my adapter job since 2006, if he does not want I open to volunteers.
5-Share the project in all forums to find backers.
6-if get the money, do it
What do you all think about?
Sound very good! How about getting somebody who studies optical design into the boat as well? I guess if you are at the point to kickstart, this could be a good investment. Maybe somebody even knows a student of this matter that might be willing to get involved?
+1 for kickstarter :)
There are also similar sites to kickstarter in other countries! Where do you live? You might also need someone to partner up with you to create good looking kickstarter/alternative site.
Advertisement is important, so the more professional this page looks, the more likely this will work. I, for one have done some work in designing my own website and several posters, etc - but it is not my main profession. I can show examples.
If in need, I will offer to do some work there- but maybe you will get an offer from someone who studies design.
I live in Brazil, South America. As I said before I just will open a kickstart project if I am sure the adapter will work. So I need to test the new positive cylindrical lenses in combination with the negative cylindrical lenses to see the results, and if it works I need to build the first acrylic piece to try it. I need to do this with my own money because at this moment nothing is 100% sure. The kickstart projetc cannot be an unreliable experimentation, it must be the final tweaking, so we need to wait.
I prefer to go on myself alone on the optical design for a while. Let me try the new batch of lenses next week to see what I will get.
A good website would be great. What I myself can do is: If I find good results, I can do a vimeo video showing the experimentation, the lenses, the optical design, the prototype adapter assembled and the results in image. also I can do a text explaining the project to put on vimeo description and some draw of optical design and photos to put on flickr. And some threads/topics in video / photo / cinema forums.
If I find I cannot go on due to not find good results so it will be the moment to share all the experimentation, all optical designs and to find optical help. Lets wait. Time to wait the tests next week.
Okay, It is understandable, then I can only wish you the best of luck, and I am looking forward to - sometime in the future - buying your anamorphic adapter :)
From Wikipedia:
"In optics an afocal system (a system without focus) is an optical system that produces no net convergence or divergence of the beam, i.e. has an infinite effective focal length. This type of system can be created with a pair of optical elements where the distance between the elements is equal to the sum of each element's focal length (d = f1+f2). A simple example of an afocal optical system is an optical telescope imaging a star, the light entering the system is at infinity and the image it forms is at infinity (the light is collimated). Although the system does not alter the divergence of a collimated beam, it does alter the width of the beam, increasing magnification. The magnification of such a telescope is given by: M = -f2 / f1 "
So it seems this principle can be applied to the anamorphic adapter, proven my theory using two cylindrical lenses was correct. Oh God, I invented the Galilean telescope again. LOL
Now it is so easy to calculate the lenses power and distance between them to get the 1.33x squeeze. And i can apply these formulas to the adapter using the lenses i will get from the optical lab next week. Will the magic happens? Will the image quality be good? Lets wait to see.
great news :)
also, check your PM :)
First results using new cilindrical lenses i got today. Using two cilindrical lenses, one positive as diopter, one negative as squeeze. Results are far from good yet, but it works. In this first test I got just something about1.25x (the first uploaded image was stretched wrong, the second is stretched correct). Also a photo showing the first prototype
second test increazed squeeze to 1.5x but corners got very bad quality due to strong power and curve in negative cylindrical lens.
1.33x squeeze, but corners are soft and IQ is not so good.
I think the corner sharpness is also due to coating and glass quality.
@sicovdplas no, this is not coating or glass quality issue, the glass is crystal optic glass. it is the glass curves issues. when lens power is big, the curves on glass are big, big curves causes soft corners. The first images was using smaller curves and results are better.
more 1.33x and some flares
I could use the nikon 35mm 1.4 lens without vignetting and without try the big acrylic lens, just using the glass I have.
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