Making a 35mm lens for my camera?

King Goldfish

King Goldfish

Is it possible to make a 35mm lens for a basic video cam corder that will give it the wide angle effect and even allow you do have depth of field where you can blur out the background or forground to focus on the person talking.


Is there a decent lens that is used on a regular camera that you could find at a local used camera store cheap that you could make an adapter and have it work?

sorry if this seems like a basic question, but i was wondering if you could make something that normally cost 6 thousands just for an adapter and another 10 for a decent lens.
 
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KG - Please read this thread fpr a good primer I made on the theory behind making an adapter: http://www.indietalk.com/showthread.php?t=5762&highlight=mini35

Also, oddly enough I was emailed through my personal site by a gentleman named Tim looking for info on these adapters a couple of days ago, would that happen to be you?

If not, you might check out http://www.redrockmicro.com/ for a $1k adapter, or simply do this: get a 35mm lens, a white piece of paper or if you happen to have it, ground glass or a focusing screen (I used Nikon Type D), and play with it for a sec. You'll see how it works for sure. Use standard PVC pipe and coupler for a tube, and a filter ring to hook the focusing screen or ground glass to. Finally, you will need at least a little seperation between the gg and the vid camera so give it about an inch or whatever it takes (vid cams are different with their macro ability) so that it can focus on the gg. You'll notice the image is vignetted a bit if you are not using a focusing screen, so youll have to get a plano convex lens (which already comes on a nikon d fs) to spread the light evenly. A bit of experimentation and you're set. Remember two things - 1) The image will be upside down, 2) cleanliness is paramount. any spec on the focusing screen will be clearly seen.

Oh I should probably add, however you decide to get it all together - epoxy, super glue, tape - make sure of two things - 1) you can remove and clean the focusing screen and the lens. 2) You can attach the whole adapter to the filter ring by adding a step-up ring to the end of the adapter.

Dont even try to understand any of this untill you can play with a 35mm lens and a piece of paper or something that will stop the image. From there you can go.

Someday I may finish that tutorial but my plate is so full I dont know when that will be.
 
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Nope, wasnt me. Im guessing alot of people with a fix income want a more film camera quality for their video cameras without having to spend more then they did for the camera itself.

thanks for the information. I didnt really understand much of it, but i got a semi understanding of it. As far as the picture being upside down, I can just turn it 180 degrees in post production in vegas.

Are you saying that if I get some kind of paper screen to place over the lens, It will filter the light evenly so I get a crisper image? If I do that, wont I get paper fibers on the lens that will distort the image?

confused!
 
No, I'm saying the image is projected from the 35mm lens out the back and comes to a focus about 2 inches back. If you put ANYTHING there from paper to frosted glass you will then see how this works. Of course with paper you cant see the image from the back (which is where the vid cam is shooting it). So you need a focusing screen, a piece of proper ground glass, plastic or soemthing that is opaque enough to stop the image, but transparent enough to allow the image to pass through and be seen from the other side (which you will then shoot it with the video camera. The Plano Convex lens simply spreads the light evenly so you dont have as much image falloff. You cant possibly understand all of this until you have a 35mm lens in your hands and play with it. Then you will understand the theory and you will be able to build an adapter which will accomodate it. As I said, if you dont want to build it, redrock micro is about your cheapest alternative to the P+S Tecnik mini-35 adapter. If you build it you should be able to build the adapter minus the lens and the ground glass/focusing screen for under $50. Of course 35mm lenses range in fields of view and price from $5 at a garage sale to $3k. The most expensive focusing screen Ive seen someone use was a Beattie Intenscreen that retails above $100. I used a Nikon Type D focusing screen which is around $30 but I have also had some luck with injection molded plastic which is really cheap once you have it injection molded.
 
I have to do more research. I kind of understand what you're saying. You're saying i use the paper to see how far away in front the adapter lens has to be in order for the camera lens to be able to view it properly? sort of like using the paper to make a proper judgment of how far forward the new lens has to be in order to refract the image properly?

perhaps its best if you drew a diagram and showed me what you're saying if possible.
 
I'm only saying to use a piece of paper so you can see how the the system works. Take a 35mm lens. take a piece of paper. Hold the piece of paper 2 inches from the lens and check it out, its the image thats coming through the lens, ie eventually what you will end up videoing with a video camera. But no in the end the adapter will not have a piece of paper to stop the image (you cant see the image from the other side of paper), it will have a ground glass instead.

My best and only suggestion is to get a 35mm lens, and hold a piece of paper 2 inches away from the back of it and hopefully youll get it.
 
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Here's a good diagram I found for you:

dofc.gif


And a good tutorial on how to make an adapter except this one is for a moving ground glass version, not static like I use.

http://www.mediachance.com/dvdlab/dof/index.htm
 
WideShot said:
Here's a good diagram I found for you:

And a good tutorial on how to make an adapter except this one is for a moving ground glass version, not static like I use.

http://www.mediachance.com/dvdlab/dof/index.htm
Click to expand...

I finally decided to join Indietalk, and this thread had to have my first post!

The mediachance link that WideShot posted excellent site- I used it as a basis for my 35mm adaptor. There are plenty of threads on other forums where it has been a bit of an obsession for many filmmakers, such as myself. :yes: -removed- forum (scroll down to Alternative imaging methods) and -removed- (film-look video) literally have hundreds of posts of people developing to get that elusive depth of field.

I used the moving ground glass method. I decided on this because it seemed like the best alternative to get rid of the grain that your camera will pick up in a static adaptor. The only problem with this is that it requires power and the housing can be bulky. I used a round cookie tin instead of the radioshack project box that mediachance suggested. It worked. All materials involved ended up only costing me < $50 and that's including the pentax lenses that I found at a goodwill second hand store. My day job is at a local TV station and everybody on the production side are film/video geeks, so when I brought this in to show my friend to "train" him on it for our shoot, word spread I had about 10 people come to my desk to check it out.


My friends and I just shot a short a couple of weeks ago, and plan on doing pickups tomorrow. I'll post some pics as we edit the thing. I hope all this helps!

Moderator's note - we do not allow posting of competitors forums/websites. If you want to PM that info that is fine.
 
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Thank you for that info and welcome griffinheart! As I said above we dont allow posting of competitors forums here so please PM the info if you can, thank you :)
 
WideShot said:
Thank you for that info and welcome griffinheart! As I said above we dont allow posting of competitors forums here so please PM the info if you can, thank you :)
Click to expand...

Oops! :blush: Sorry 'bout that- honest mistake on my part.

Thanks for the welcome, WideShot!
 
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