trying to change magnification on an old American Optical Forty

[wex65]

I am starting out in watch making and due to my less than eagle-like eyesight I decided to get a microscope to assist me. It seems that the ideal magnification is 5x-10x where the bulk of the work is done at 5x and 10x only for very detailed work.

I picked up a VERY cheap American Optical Forty (AO040) stereo microscope for only $2 at an estate auction. It is in perfect working condition BUT, upon doing a little research, it has a little too much magnification.

There is a objective selector which switches between a 1x and 2x objectives. The eye pieces are 10x, meaning I have 10x and 20x. Like I say, the 10x is perfect for detail work but I would ideally like to replace the 2x objectives with 0.5x to give me the 5x total magnification.

Does anyone know if there are compatible lenses to replace either the objectives (i.e. to the 0.5x) or the eye pieces (say to a 5x).

I posted a similar question into a fb group and got a little feedback which, unless I misread it, seems to indicate that changing the objectives for 0.5x is preferred as it may produce a wider field of view whereas the eye pieces will not. Is that correct?

The objectives are small and about 13-14mm. the eye pieces are 24mm.

Hopefully I have managed to attach a photo which is one of the objectives.

Any input much appreciated
Paul

236232242_2296996093768336_1106918691947300615_n.jpg (64.24 KiB) Viewed 2408 times

[Scarodactyl]

Thr AO forty is a student scope, badically a vety simpligied version of their main stereo line. I am not sure if there's much customization possible on them.

[wex65]

Thanks, I had hoped the objectives or eyepieces could be replaced with others of the same size. So it doesn't sound too promising.

[Scarodactyl]

The eyepieces maybe, sometimes these didn't use conventional eyepirces but you might find 15x eyepieces for an AO stereostar fit and work fine (the size would be 23.2mm though, not 24). That will only enlarge the existing image but not resolve more detail.
The objectives will not be to any particular standard so it would likely be a huge pain to try and modify them.
Take this with a grain of salt since I've never owned a Forty in specific.

[wex65]

The eyepieces maybe, sometimes these didn't use conventional eyepirces but you might find 15x eyepieces for an AO stereostar fit and work fine (the size would be 23.2mm though, not 24). That will only enlarge the existing image but not resolve more detail.
The objectives will not be to any particular standard so it would likely be a huge pain to try and modify them.
Take this with a grain of salt since I've never owned a Forty in specific.

Thanks, I appreciate the input. I m really trying to reduce the magnification so ideally am looking for 5x eye pieces but I will look to see if other AO scopes used those.

Paul

[Scarodactyl]

Ohh yeah, reducing mag isn't going to work that way.
I hate to say it but you prpbably need a stereo that's a little more advanced and can accept auxiliary lenses. These student scopes can be a great deal but aren't exactly versatile.