# Is the PanLeica 25 f/1.4 equal to a 50 mm f/1.4 on Canon FF?

Started Aug 28, 2012 | Discussions thread
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 Re: Same FOV, same light gathering, different DOF In reply to ZoranC, Aug 31, 2012

ZoranC wrote:

jim stirling wrote:

ZoranC wrote:

jim stirling wrote:

ZoranC wrote:

It's hard to believe it but you continue to be entertaining. Just don't give up your day job yet, competition in stand up comedian market is ruthless.

The points Anders has made are perfectly correct, with clear and simple explanations provided. Considering this exact topic has been explained a 1000 times before and follows simple laws of physics I canâ€™t for the life of me see what you are disagreeing with.

I see you are not paying attention. Sorry, I don't have time to re-explain it all over again to every single visitor that is not paying attention.

"When it comes to light gathering his F1.4 will gather same amount as his friend's F1.4. Sensor behind it is different story and is not a topic of a bet and question here, is it? "

Makes no sense a lens aperture is a ratio not a fixed size of hole. To make it very simple regardless of the size of a room behind it what would let in more light a one metre square window or a 3.84 square metre window

Like I said, you are wasting my time by not paying attention. I would recommend you go through same brain exercises I have recommended to others. Starting first with looking up and answering what is unit of measure of light gathering ability. If you don't know that's OK, you shouldn't be making it up instead, just look it up.

You are not paying attention Zoran. I already answered the question you are asking Jim specifically for you so no need to ask a second time. The unit you are wondering about is known as a photon. Here is a page where you can find out what that is:

http://en.wikipedia.org/wiki/Photon

Lenses gather photons so as to form an image. An FF lens at f/1.4 will gather four times more photons per time unit than an MFT lens at f/1.4. So when an FF lens and an MFT lens are both used with the same exposure (same f-stop and shutter speed), the FF lens will gather four times more photons.

Let me know if anything is still unclear.

Anders W's gear list:Anders W's gear list
Panasonic Lumix DMC-G1 Olympus OM-D E-M5 Panasonic Lumix G Vario 14-45mm F3.5-5.6 ASPH OIS Panasonic Lumix G Vario 7-14mm F4 ASPH Panasonic Lumix G 20mm F1.7 ASPH +18 more
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