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What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Wed Feb 13, 2019 4:39 pm
by lperepol
Looking for ways to match up what I am seeing through the eyepiece with what is being displayed through the camera.

Re: What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Thu Feb 14, 2019 5:06 am
by gastrotrichman
On older scopes from film camera days I've seen ocular reticles that bore a rectangle that I inferred approximated what an attached 35mm film camera would "see." My Microphot has a similar rectangular image that is superimposed on the object image when the photo tube is engaged … it works reasonably well with a tethered, dedicated microscope camera, even though the scope is from the film camera era. I don't know if similar reticles are still available.

Re: What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Thu Feb 14, 2019 8:42 am
by abednego1995
If you want to have a sense of the field that is imaged, getting an ocular with photo reticles as gastrotrichman says is the simplest way.
However, those oculars and reticles are pretty rare and depending on your imaging setup the total system magnification might not match the reticle design.

Making reticles is hard...(If you also do astronomy, making one out of very thin fibers is one thing...) but cutting a mask out of a opaque material is much more easy.
If you have a stage micrometer or anything that has a definite size, image it on your scope. The sensor size is something you already know so determining
your system magnification is a breeze. Cut out a circle of black paper (most oculars allow 20-22mm reticles), trace a rectangle or square divided by the total magnification, and cut it out.
Unscrew the bottom part of your ocular. The reticle pocket is probably on the bottom side. Place your mask within and reassemble the ocular. If the ocular has a focusing ring, adjust it to
get a sharp image of the mask. Maybe difficult to get it perfect at first try, but eventually you will get a nice fitting mask.

Pros: dirt cheap.
Cons: you don't get maximum field out of your ocular

Cheers,
John

Re: What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Thu Feb 14, 2019 9:42 am
by 75RR
Looking for ways to match up what I am seeing through the eyepiece with what is being displayed through the camera.
I have found Charles Krebs pdfs very useful:

http://www.krebsmicro.com/pdf/trinoc_a3.pdf

and a link to the site where there are more articles on connecting a camera to a microscope + some pretty amazing images.

http://www.krebsmicro.com/

Re: What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Thu Feb 14, 2019 6:50 pm
by iconoclastica
What do you mean by 'match'? If I take that litterally, you are after a circular image, such as the top-left one of the bottom six in Charlie's document. The image projection on the sensor should then be small to see a full round black vignette. If on the other hand you mean 'about the same extent' then find a matching projection-eyepiece. It all depends on the ratio between the diameter of the image circle and the sie of your sensor or film.
With APS-C and 23mm tubes, focusing the primary image on the sensor can be an excellent means, especially if the head adds a little magnification to forgo the vignetting.

Re: What alternatives are there to match the eye piece field of view with a camera's field of view.

Posted: Thu Feb 14, 2019 7:19 pm
by lperepol
>>> What do you mean by 'match'?
I am stitching images and am having difficulty calculating the overlap from one image to the other. If the field of views matched then calculating the overlap would be much easier or when one segment ends and the other begins. I don't need much overlap when I visually stitch the images. Very touchy at 600x. I have used Microsoft ICE and Gimp Hugin for stitching -- they work well when they work, but fail miserably when they don't -- even with 50% overlap.