This is topic The lower the inch, the shorter the throw? Help please :)... in forum 16mm Forum at 8mm Forum.

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Posted by Elyas Tesfaye (Member # 3356) on February 13, 2015, 11:22 AM:
Hello all,

thanks to you all, I now know the significance of 'f' on lenses (The lower the 'f', the brighter it is)... I am now interested in inches and mm as related to throw distance. I think I might have a clue but it's always a better bet to go by our veterans, anyone [Smile] ?
Thanks in advance and hope you all are having an awesome weekend [Big Grin] !!!

Posted by Martin Jones (Member # 1163) on February 13, 2015, 11:49 AM:
Yes, the lower the inch or mm figure the shorter the throw for the same size of picture.
Posted by Elyas Tesfaye (Member # 3356) on February 13, 2015, 12:07 PM:
Hi Martin,

thanks a lot for the prompt response and have yourself a great weekend, good sir [Big Grin] !!!

Posted by Paul Mason (Member # 4015) on February 13, 2015, 03:35 PM:
An easy way to relate the lens focal length to the throw distance and picture size is to remember the ratio of the throw to the picture width. For example a 2 inch (51mm) lens on a 16mm projector has a throw of 5.2 times the picture width. A throw of 15 ft gives a picture of 2.88 ft wide with this lens. The ratio for a 1 inch (25mm) lens is half of 5.2 ie 2.6, so a 15 ft throw gives a picture 5.77 ft wide.
Posted by Elyas Tesfaye (Member # 3356) on February 14, 2015, 07:57 PM:
Hello Paul,

thanks a lot for that detailed explanation, I'm learning so much from all you helpful forum members and can't thank you enough [Big Grin] !!!

Posted by Dino Everette (Member # 1378) on March 09, 2015, 01:03 AM:
Elyas, just remember when it comes to lenses "LESS IS MORE"

1 - The lower the inch or mm, the larger the picture
2 - the lower the "f" number the brighter the picture...
Posted by Elyas Tesfaye (Member # 3356) on March 09, 2015, 01:43 PM:
Hi Dino,

thanks for the tip and hope you're having an awesome start to the week [Smile] !!!


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