OT: Anyone Know How to Dissolve Norton UV Optical Cement

[Paul Alciatore]

Bob, come on, I am not that stupid. Turning the camera's optical path around it what I have been talking about. To turn the viewfinder around would need crazy large prisms or, more likely mirrors. The prisms in that assembly are just about large enough for the camera. And, at that, I am not completely sure I won't get some cutoff of one or more edges of the image. The path I envision would not be centered on the prism faces, but rather off to one side in a couple of them. I guess I could try to calculate if it would work, but it is also worth just taking a shot at it by rearranging the prisms. And there may even some other arrangement other than the one I am thinking about.

From the ideas here and others that I have been reading, I think I am going to get two or three of the prism assemblies and see what I can do.

Thanks to all.

It sounds like you want to be able to see the phone's screen as a viewfinder while the main camera is focused on you. So you want to create a 180*, full size, optical path for the screen. How about having the screen facing you and creating a 180* optical path for the camera? It would use much smaller and more available prisms.

[Paul Alciatore]

Yea, I have a couple of Olympus cameras too. Trouble is, I can't find a way to attach a viewfinder to them. The output needed for a viewfinder seems to only come with more expensive cameras. But I have thought about doing some experimenting on that too. Perhaps something would work. Perhaps there are some undocumented features in my Olympus cameras.

But the prism thing is less expensive so I am going to try that first.

Well Paul, I've been getting some of my best pics ever from the front (main) camera on my $99 Samsung Galaxy Tab A. All the pics in my build thread are done with it, and the resolution etc is amazing. When I click on the manufacturers built-in camera app, the entire screen becomes the viewfinder, with camera controls overlaid over the pic, allowing me to perfectly setup everything. I do all my post-editing in the GIMP for things like gamma correction, size, etc. The system works amazingly well for the price. I've basically quit using my actual Olympus cameras.

[Bob Engelhardt]

Bob, come on, I am not that stupid. ...

Of course you aren't, sorry. It just sounded like you wanted to bring the screen around, without your being explicit about it. It is surprising that you'd need a 55mm x 34mm prism for the camera path, but I suppose that it is its wide angle that is the problem.

[Optics Curmudgeon]

Getting back to the original question, I've done this a number of times. Get some good liquid stripper (yes, the methylene chloride stuff) from a paint store. The consumer stuff, as pointed out, rarely has what you need. Put a wash cloth that has been washed a lot in the bottom of a paint can (a new one, also from the paint store), lay the prism assembly on the wash cloth and pour in enough stripper to cover the parts. Lay the lid on (don't seal it) and put the can out of the way somewhere it won't get knocked over. Check on it occasionally, this process could take a week or more. The stripper will slowly work its way in, and the softened cement will extrude from the joint. Eventually it will reach the center and the parts can be separated by hand. Proper gloves are a must. Residue can be cleaned off with acetone. As for Surplus Shed, take their name literally, I've visited the place and it's pretty much what you expect. It's in an old school, filled on all floors with shelves full of "stuff". I have no sense of smell, but my wife described it as particularly musty smelling. The are somewhat well informed on their "products", but not experts.

[Paul Alciatore]

Of course the optical path of the camera can be turned around with prisms that are far smaller. The only problem then is it runs into the phone so I would be taking a photo of the front of the phone. My main camera lens is about 0.75" or 20mm from the closest edge of the phone so there goes 20mm before you even start. Assuming that you use an assembly of prisms that are cemented together you can easily see where the 34mm width of the individual prisms in this particular assembly would be close to the minimum dimension needed.

I could mount the prisms in two groups but even then, the angle covered by the width of the picture is about 44 degrees. So that gives the angle of the expanding angle of coverage that should not be cut off by the edges of the prisms. And if the prisms are separated by an air gap, that angle would only continue to produce a wider aperture across that air gap.

In any case, it is the last prism from the actual camera lens in the chain and it's optical distance from that camera lens that will probably determine amount of any such reduction of the field of view in the image.

I think I am going to do some CAD work.

Of course you aren't, sorry. It just sounded like you wanted to bring the screen around, without your being explicit about it. It is surprising that you'd need a 55mm x 34mm prism for the camera path, but I suppose that it is its wide angle that is the problem.

[JRouche]

Getting back to the original question, I've done this a number of times. Get some good liquid stripper (yes, the methylene chloride stuff) from a paint store. The consumer stuff, as pointed out, rarely has what you need. Put a wash cloth that has been washed a lot in the bottom of a paint can (a new one, also from the paint store), lay the prism assembly on the wash cloth and pour in enough stripper to cover the parts. Lay the lid on (don't seal it) and put the can out of the way somewhere it won't get knocked over. Check on it occasionally, this process could take a week or more. The stripper will slowly work its way in, and the softened cement will extrude from the joint. Eventually it will reach the center and the parts can be separated by hand. Proper gloves are a must. Residue can be cleaned off with acetone. As for Surplus Shed, take their name literally, I've visited the place and it's pretty much what you expect. It's in an old school, filled on all floors with shelves full of "stuff". I have no sense of smell, but my wife described it as particularly musty smelling. The are somewhat well informed on their "products", but not experts.

Bingo. Only thing I would change is wrap it with a saran wrap type covering to keep it from drying.

I still wanna hear the glue together process you have in mind Paul? That is difficult to say the least. Love the project. JR

P.S> This "As for Surplus Shed, take their name literally" is what my place is.

Yeah, when I see California phase stuff out, I stock pile it. Completely within the bounds of the law. As its Grandfathered in.

Miss use the chems I have protected? Never.. That in fact would be illegal.

The methylene chloride is not longer available at cost. I quart might run you 30 bucks.

Seemes like there should be a less expensive way? House hold lye, you have some? Make a solution and soak it. JR

[Paul Alciatore]

Well, so much for seat-of-the-pants engineering. I started a CAD drawing to show the light paths through the prisms to see if there would be any cutoff of the image at the edges. I did not get past the first right angle prism before the incoming light cone hit the 34mm width of that first prism.

I need to go over this again, perhaps after a time-out. But from the looks of it, I am going to have to abandon this approach completely.

And yes, the camera software will allow me to zoom in to use a smaller angle, but then that is a "digital" zoom, not an optical one so I would just be decreasing the resolution of the camera (using fewer pixels) which is just what I want to avoid.

Thanks for all the help and ideas here but it looks like I will have to take another approach.