8mm Forum: Why do I see an inverted image from a 9.5mm Pathescope projector?

This is topic Why do I see an inverted image from a 9.5mm Pathescope projector? in forum 9.5mm Forum at 8mm Forum.

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Posted by Guy Burns (Member # 5887) on May 31, 2017, 08:44 AM:

I'm using a Pathescope 9.5mm GEM projector as an editor. So as not to cause any damage to the films, I run the films very slowly at about 25% speed, and use a low power light source – without any modification my Zebralight torch fits in place of the original 100 Watt bulb. I run the Zebralight at its lowest setting.

See these two images:

http://www.mediafire.com/view/fu47qa9tjqa1afu/Projector_01.jpg
http://www.mediafire.com/view/aq6apypayq0a0cd/Projector_02.jpg

To view a film I simply look straight into the lens – and I see an inverted image.

What I can't explain is why the projected image appears the right way up. So, sitting in front of the projector:

• I can see the film entering the gate is upside down
• Looking through the lens the image is upside down
• But replace my eye with paper, and the image is right-way up.

Why is that? Maybe I've been peering through the wrong end of the lens for too long.

Posted by Guy Burns (Member # 5887) on May 31, 2017, 10:18 PM:

This question is about Physics, so I've taken it to the Physics forum (https://www.physicsforums.com/threads/image-is-inverted-when-i-look-into-a-projector-lens-why.916257/).

Moderator: delete if you want.

Posted by Maurice Leakey (Member # 916) on May 31, 2017, 11:25 PM:

Guy
The simple answer is that the lens is acting just like a magnifying glass when you look into it.

Posted by Ken Finch (Member # 2768) on June 04, 2017, 02:50 PM:

Guy, The answer is in the word "Projector". The lens inverts the picture as it projects the image onto the screen. A projector is not a viewer. The images are always inverted as they pass through the projector gate no matter what gauge of film it is. Ken Finch. [Smile]

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