Question Correction : aux lens adaption for video camcorders

[William Estes]

Greetings,
The following question was stated wrong. (My appologies)
Has anyone developed a method for using a 35mm lens or other large format lens directly in front of a video camera without a unit such as the SGpro?
The question is, has anyone developed a lens adaption system for using 35mm and other large format lenses in front of a consumer/prosumer camcorder (std 8mm, Hi8, or digital ) with a unmountable or stationary lens ?. The aux lenses can range from 35's smallest to largest mm values. Would anyone be interested in a system of this nature ?.
William

[Jeff Anderson]

Ummm you just described the sgpro, brevis, m2, letus35, and many many more 35mm adapters.

[William Estes]

Thank you for the reply,
My lens adapter does not have a ground glass or focus screen, or a motorized spinning disk. I use the lenses earlier mentioned without my images being upside down or reversed. All of the lenses produce a definable depth of field keeping the primary subject in focus.
Regards
William

[Jeff Anderson]

So you've actually made this or are thinking about making this?

[Huy Vu]

I'm not sure how you can get the camera to "see" all of the lense due to the smaller chip size. There have been interchangable lense systems that allow for alternate lense mount such as the Canon XL adapter, but the result is a eight-fold magnification of the focal length. You'll get a very short DOF for sure with those, but it's not very useful because the FOV is so narrow.

[William Estes]

So you've actually made this or are thinking about making this?
Greetings from William,
I have working prototypes and i will be posting still and video samples soon. I've been working on this idea for some years now, the formula and component research has been intense as everybody (experts alike) i've talked with tell me it cannot be done. The sgpro, brevis, m2, letus35, and many more 35mm adapters are very good, but i have to do things differently. My old video editor is down, but will have raw tape samples samples soon.

[Kholi]

That's some major claimage. Looking forward to seeing some stills and video.

[NOMADIC]

Do you have a degree in optical physics?

[William Estes]

Greetings
Thank you, I will be posting a few images shortly.
Bill

[William Estes]

Greetings NOMADIC,

No sorry to say I do not have a degree in optical physics, I just like to do things the hard way, asking lots of questions, reading subject books and some specific journals, Backward engineering or taking things apart and seeing just how they work and what each element does gets the job done for me. I work in a specialized electronics field, thats about the limit of any information about myself for now. I will deliver what i have described.
Bill

[j]

Perhaps impolite, but I don't think he meant any disrespect.

The claims of an aerial image that can have shallow DOF, and full coverage sound too good to be true - in other words, a holy grail of sorts for us 35mmDIY geeks.

That's not to say it can't be done. Looking forward to the pics!

[Luis Caffesse]

So no footage?



I don't think it can be done! In order for the camcorder Lens to "see" the Image it needs to be a "Real Image" The Image from the 35 mm lens is a Virtual Image. The only way to see a Vitual Image is to let it "shine" on a screen of some sort, and produce a REAL IMAGE that the Camcorder can SEE!!!


Well I guess no one told JVC (http://www.abelcine.com/articles/index.php?Itemid=34&id=170&option=com_content&task=view) or Angenieux that it couldn't be done...because they both have released lens adapters that work with only optical elements and no 'ground glass'

:thumbsup:

Now whether nor not you can go from 35mm down to 1/3 inch using an optical relay....that I don't know.

[NOMADIC]

oh sorry if it came off rude.. i really didn't mean it... I was asking honestly

[Car3o]

can't remember what lens was attached. i know was a zoom lens 28-70mm and this is purely optical. i just attached a lens to the front of my cam using 18x achromat. there is DOF and if i hadn't have told you, you may have thought it was an adapter.

http://www.fileden.com/files/2007/1/8/612706/Optical2.mov

[Luis Caffesse]

OK Luis you are much better read, than the rest of us. I notice you don't come up with any ideas. Looking back over your posts you only Criticise and make Sarcastic Comments. Perhaps you could give us the benefit of your knowledge?

By the way what is an optical relay?

WOW.
Are you being serious?
I'm just going to move on pretending I didn't read that...

An optical relay is exactly what is being talked about in this thread.
An adapter which uses lens elements (and not a ground glass or something like that) which allows you to mount a lens of one frame size onto a camera of a different frame size while keeping the attributes of the original format (ie. 35mm dof on the Angineux adapter made for 2/3" cameras or 16mm dof on the JVC adapter made for 1/3" cameras).

Check out the link to the article about the JVC adapter that I posted above - it has a much more detailed explanation than I can possibly give.

The thing with the optical relay adapters that are out on the market is that they are taking either 35mm lenses down to a 2/3" chip or 16mm lenses down to a 1/3" chip. I don't know if it's possibly to build an adapter in this way to go from a 35mm lens down to a 1/3" chip and keep the attributes (mainly DOF) of a 35mm lens. It seems that there is something inherent in the optics which may not allow for it - but I'm not sure as I don't understand the intricacies of it.


Edited to add:
If you have any personal issue with me, feel free to PM me.
I will gladly discuss anything with you that way.
I'm not about to clog up the boards with that kind of thing, though.
Thanks.

[Jeff Anderson]

Whoa Luis that JVC adapter is pretty tricky. Says its for 1/3" CCD's and uses a virtual focal plane instead of ground glass. Now thats beyond my level of even wanting to understand. Images look nice though, now I'll have to find some time to read the entire article later.

Syncman - chill out.

[Luis Caffesse]

Jeff - yeah, it's pretty wild - but like I was saying above, as far as I understand it it will only retain the DOF of 16mm, not 35mm. So while it's really nice - its not going to give people the 35mm dof they're looking for (and meanwhile it costs somewhere over $4K).

BUT - it's totally clean, no gg, no grain, no shutter speed limitations, etc etc.
Pretty amazing stuff.

[Jeff Anderson]

For me 16mm DOF would be plenty, but 4k is a bit high. Guess I glossed over that part :) I wonder who their market is going to really be though - seems like people in that price bracket are more apt to shoot with a red or similiar.

[Zephyrnoid]

I never doubted it was possible. I mean, it's 'just' light path modulation via optics, what every compound lens does anyway. This business of essentially 'copying' the image projected by a front lens system off of a screen is kinda yesteryear for me! It's how people converted films onto Video tape in the begining:grin: The information lost is large, even if the end effect is sorta acceptable. It's just a matter of time before a manual follow focusable HV20 formfactor camera comes out. Worth the wait IMHO:thumbup:


Jeff - yeah, it's pretty wild - but like I was saying above, as far as I understand it it will only retain the DOF of 16mm, not 35mm. So while it's really nice - its not going to give people the 35mm dof they're looking for (and meanwhile it costs somewhere over $4K).

BUT - it's totally clean, no gg, no grain, no shutter speed limitations, etc etc.
Pretty amazing stuff.

[Luis Caffesse]

For the record - all is cool.
Lets keep it that way and just drop this line of discussion right now.

Back on target.

[Jeff Anderson]

what Luis said.

still interested to hear more of what the OP has developed if he's still following this thread.

[William Estes]

Greetings I'm still following the thread items. Still working on the lens adapter mechanics and mounting hardware. Video capture system dead!! . I experiment too much some times.
Also lost contact with Paul Martin who had contacted me via email, any one else here or know of him?.
Regards

[Jeff Anderson]

hmm, dont know paul martin so I cant help you there. Glad to hear your still working on this. So does this operate in a similiar manner to what Luis linked to from JVC? Just curious, without the ground glass the physics seems to be way over my head. Or at least more involved than I care to even try and figure out. Good luck! Whats your location? Perhaps a fellow dvxuser can assist in video capping if you need it.

[William Estes]

Greetings Jeff,
The lens adapter and all of the components is simular in regards to using the image relay principle with optics. My system was originally designed so i could use 35mm and larger format camera lenses in front of a standard consumer camcorder without altering the camcorder. I wanted extreem telephoto capabilities with the sharpest image i could get with out spending a fortune.
The capability of my lens configuration allows me to use a standard 35mm 50mm or larger lens ((note here)) (using a lower mm lens through 55mm lens gives me a video image very close to what you get in 35mm still framing) in front of my sony camcorder and have to my estimation full focus imaging without loosing depth of field or. In other words i can keep my subject in focus with either the back and or forground out of focus while tracking. Using the lens adapter in the manner and for your and others purposes wasn't even thought of in my original design application.
I was and have been told by knowledgable people that the principle used by manufactures and designers was quite complex. The JVC and other engineered lens systems all give you a high quality image for the purpose it was designed for a hefty price, the only drawback being for my use would be the upside down and reversed image.This is too much for me. Again my system is for the consumer designed camcorders. If a person has the finances to purchase a high end camcorder with lens changabilities, that is the way to go. If you do a patent search you will find some complex systems for this purpose of video imaging and expensive. I live in Mesa AZ and would like contact, Better yet contact by email. Please be advised though my lens adaption system is confidential material, as you can see i will discuss it but i'm not ready to tell how it's all put to gether and what all of the components are comprised of. Thinking of a marketable item.
Regards
Bill
william_nell2@hotmail.com

[Car3o]

Why does it seem that 60% of DIY projects become some sort of marketing scheme?

[William Estes]

Greetings,
Please , use comonsense with a question of this nature here!. I have developed and designed various tools for the electronic industry of which I'm employed by. I also have given the same with out any monetary return and gladly will continue to contribute this way. The idea of maybe marketing this item stems from seeing the already manufactured adapter systems of which led me to this site.
Others have actually received my system free and used it successfully in their line of work. My only stipulation was a confidentiality agreement. If i do market this system, it will be due to the fact i would not like being a part of anything which would undermine anyone Else's product to the point of ruining a business venture. If you were marketing a lens adapter, would you rather have a competitor or have some one develop a product of equal capabilities and then just flood the market with freebie's. Who knows maybe some potential customers so inclined to be interested in my system in the near future, might be granted a permanent try one out for free. (you know: One to keep for ever. But there is never a free lunch!!!)
Regards
Bill

[Car3o]

Kind of negates the purpose of a DIY thread...I don't know. I've seen so many people market instead of share their DIY...just personal opinion. Good luck and much success with your adapter.

-rh

[j]

Feel free to use me as a Beta tester...

-J