Relay Lens

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

Moderators: MacroMike, nzmacro, Ken Ramos, twebster, S. Alden

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Kenv
Posts: 852
Joined: Mon May 24, 2004 6:51 pm
Location: New Zealand

Relay Lens

Post by Kenv »

I have a minor problem and I wondered if it might be fixed by a different relay lens. My problem is that the image I get on my camera is considerably magnified over that which I get through my eyepieces - so much so that I sometimes have to use a lower power objective in order to be sure to get the whole of the subject into the frame. The relay lens has, as far as I know, a 2.5X magnification factor. Is it possible to remove this lens and still use the camera on the tube? Would it be possible to get a relay lens with a lesser magnification factor?
When it comes to the technical knowledge of microscopes I am a real dunce - hopefully I will catch up one day.
Cheers Kenv
Ken

Charles Krebs
Posts: 1200
Joined: Tue Jul 13, 2004 10:50 am
Location: Issaquah, WA USA

Post by Charles Krebs »

Ken,

What power eyepieces are you using?

With a 2.5X and the sensor size on the 300D you will get less than the full amount you see, left to right, with 10X eyepieces. But not so much so that you should not be able to get a "feel" for the amount being recorded.

The 2.5X was the "standard" photo-eyepiece for 35mm cameras. The sensor in the 300D/10D/20D is smaller than a 35mm frame.

However, I use a 2.5X and a 3.3X with my 10D. I've developed a pretty good sense of the field size recorded by the camera. Also, just about any type of reticle in an eyepiece greatly helps, because it provides a reference.

A relay lens of lower power would help (1.6X would be good). But lower powers are not too common and you may not find one that is a good match for your objectives.

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Kenv
Posts: 852
Joined: Mon May 24, 2004 6:51 pm
Location: New Zealand

Post by Kenv »

Thanks Charlie, I guess that I will get used to the situation as it is.
Cheers kenv
Ken

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