OT: Anyone Know How to Dissolve Norton UV Optical Cement

[Paul Alciatore]

I see an interesting assembly of prisms for sale by Surplus Shed.

https://www.surplusshed.com/pages/item/PL1295.html

The assembly has both the types and sizes of prisms that could make an optical device to turn the main camera in a smart phone around so that the person being photographed can also view what is happening. The problem is they are not assembled in the correct manner. And YES my phone does have a "selfie" camera, but it's resolution is not as good as the main camera so I would prefer to use the main camera. And this is true of virtually all smart phones. And, YES, YES, I do know about adding a separate viewfinder, but that also has it's own problems, including, but not limited to the cost. So a purely optical method would be a great way to go, IMHO anyway.

So if I could dissolve the optical cement and rearrange the prisms, it looks like this may just do the job and for a reasonable cost. I could then reassemble them and 3D print a frame to attach them to the cell phone. The problem would be in taking the present assembly apart. I am probably asking a lot, but does anyone here know of a solvent or other way to do that without harming the other properties of the prisms?

[rdfeil]

It appears the adhesive is actually made by Norland. They make several UV cured optical adhesive products. One of the common ones is NOA 61. In the tech data is says that it can be released by soaking the assembly in a solvent, methylene chloride, overnight and it will usually release. Check out www.norlandprod.com for more information.

[Richard P Wilson]

Methylene chloride is pretty unpleasant stuff, that used to be a major component of paint stripper, but I think its banned now.

[Paul Alciatore]

I got Norton via a direct copy from their web page. So much for Surplus Shed's descriptions.

It appears the adhesive is actually made by Norland. They make several UV cured optical adhesive products. One of the common ones is NOA 61. In the tech data is says that it can be released by soaking the assembly in a solvent, methylene chloride, overnight and it will usually release. Check out www.norlandprod.com for more information.

[psomero]

Methylene chloride is pretty unpleasant stuff, that used to be a major component of paint stripper, but I think its banned now.

depends on locality and application. the EPA has banned it for use in consumer paint stripper products, but I believe you can still get it as a plastic welding product. it has legitimate industrial uses, however it is nasty stuff.

[rdfeil]

Paul Alciatore , If the solvent is used for plastic welding you may be able to find it at a plastics supplier in your area. Many years ago (40+) I was making a large aquarium out of 1 inch plexiglass. I am actually not sure what the actual plastic was, I just used what the plastic shop recommended. Due to the quantity and cut and polish the cost was quite high for early 80's so the owner of the shop gave me some "welding solvent" that was a derivative of MEK only much more nasty. He showed me how to use a glass syringe to flow a small amount into a joint and plastic weld all the pieces together. It worked great and I had that 400 gallon fish tank for years until it just got to big to move as life moved on.....

[CalM]

A readily available small quantity source for Meth Chloride. is "Craftics Plastick Acrylic Solvent Cement."
I have a 2 oz bottle here on my desk, bought at the local hardware store.

https://www.craftics.net/msds.aspx

[genea]

Since this Surplus Shed assembly is made up of 3 right angle prisms why not bypass the disassembly step and just purchase right angle prisms?

[Paul Alciatore]

One word: size. To bend the image path of my cell phone's main camera around the edge of the phone, I need rather large prisms. Sure, I could just buy some NEW, large size prisms, but $$$$$$$$$$. And most of the surplus prisms are from things like binoculars where small prisms (<25mm) are the rule. I have been keeping an eye out for prisms that would do the job without breaking the bank and this is the first that I have found. The small dimension on the smaller prisms in this assembly is 34mm so the center to center offset is about that amount. With a bit of luck, I can get an even larger center to center offset by cheating the image path a bit to one side.

Oh, and that assembly is not made of three right angle prisms. Two of them are right angle style while the third, larger one reflects light on two faces and is effectively a 180 degree prism. The three together are intended to rotate the image in a scope by 180 degrees to turn an inverted image back to right side up while keeping left and right in the correct relationship: in short, it flips the image both vertically and horizontally. If I can separate the three prisms then I can reassemble them to do the same thing, while at the same time turning that image around so it is coming from the opposite direction. I can then take videos of myself while seeing the normal viewing screen of the cell phone. That image will probably be upside down, but I could still see the composition and focus and that will save a lot of time while making videos. And perhaps I can find a camera "app" that would turn that image about or I can just mount the whole cell phone/prism mess upside down and get a viewfinder image that is right side up.

I am working outside of the box here. Or, at least, trying to.

Since this Surplus Shed assembly is made up of 3 right angle prisms why not bypass the disassembly step and just purchase right angle prisms?

[Cenedd]

If you're talking about a cell phone camera, I'm assuming that the front-facing camera is either not present or not suitable but could you do anything in software with a remote viewfinder? On the Android platform, there are definitely apps available that you can use one phone to take the shots/video and another as a viewfinder. Often used for things like stop-motion to remotely take the pic when you don't want to risk moving the camera. You could pick up a cheap phone/tablet from eBay - the camera in it doesn't need to be much good as long as it has a screen.

[Paul Alciatore]

Yes, you would think that there was an easy AND INEXPENSIVE way to add a viewfinder to a cell phone. I would be willing to purchase one of the many viewfinders that are available and that can be attached to almost any digital camera. But after searching extensively I have come to the conclusion that it is all but impossible to add a viewfinder/monitor to a cell phone. Or at least, not to my cell phone. There are "apps" for recording video and "apps" for mirroring the screen to an external monitor, but, as far as I can tell, there are no "apps" that combine the two.

There are multiple software "apps" that allow you to use your cell phone AS a viewfinder. But that is the opposite of what I want to do. I want to use the cell phone's camera and also have a viewfinder so I can be sure of the focus and the composition (framing) of the image. And I am not in a position where I can spend the better part of $1000 to do so. As for those, numerous "apps" for using a cell phone AS a viewfinder, they just get in the way when I search for an "app" that does what I want.

As for using the front facing or main camera in the cell phone as opposed to the rear facing or "selfie" camera, the main camera in almost every cell phone, even the ones in that $1000 range, really is a lot better than the rear facing one. If I shoot some footage with one camera and some with another, then there may be a noticeable difference when I edit them together.

I also have two digital cameras that are capable of making videos. Unfortunately neither of them offers a viewfinder output. I am looking for an inexpensive way to do this, but in the end I may just have to break down and buy both a camera and viewfinder.

If you're talking about a cell phone camera, I'm assuming that the front-facing camera is either not present or not suitable but could you do anything in software with a remote viewfinder? On the Android platform, there are definitely apps available that you can use one phone to take the shots/video and another as a viewfinder. Often used for things like stop-motion to remotely take the pic when you don't want to risk moving the camera. You could pick up a cheap phone/tablet from eBay - the camera in it doesn't need to be much good as long as it has a screen.

[Cenedd]

Definitely better camera on the back....although that's changing with newer phones because the youth of today are more obsessed with taking pictures of themselves than anything/one else.
Might help if you can say what phone you have. That would let people know whether you're in the Android store, Apple store or something else. It would also give an idea how high a quality we're talking as if the same could be had (2nd hand) from eBay for $10 it would be worth looking at. If we're talking something that would be $1000 to get something comparable, it's clearly a non-starter.

[JRouche]

The problem would be in taking the present assembly apart. I am probably asking a lot, but does anyone here know of a solvent or other way to do that without harming the other properties of the prisms?

Sounds like a neat project. They say it is optical glass. Can that take a significant amount of heat or does heat affect the optical characteristics? What glue will you use to make the prism? JR

P.S. Jasco makes paint stripper with the meth-chloro.. Makes my skin itch just being around it in an open container. JR

[Bob Engelhardt]

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.

[nickel-city-fab]

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.

I also have two digital cameras that are capable of making videos. Unfortunately neither of them offers a viewfinder output. I am looking for an inexpensive way to do this, but in the end I may just have to break down and buy both a camera and viewfinder.