F-Stop

Chai · 22nd Apr 2004, 06:39 PM

Sorry for going off topic, how do you calculate one F-stop? Both Aperture and Shutter? Thanks!

atwl77 · 22nd Apr 2004, 07:10 PM

1 F-stop =

f/1.0 -> 1.4 -> 2.0 -> 2.8 -> 4.0 -> 5.6 -> 8.0 -> 11 -> 16 -> 22 -> 32 etc

or

1/15s -> 1/30s -> 1/60s -> 1/120s -> 1/240s etc but most cameras usually don't have these numbers so practically, this is more or less the same:
1/2 -> 1/4 -> 1/8 -> 1/15 -> 1/30 -> 1/60 -> 1/125 -> 1/250 -> 1/500 -> 1/1000 etc

atwl

Chai · 22nd Apr 2004, 07:32 PM

Is there any formula, or do I have to memorise all that?

atwl77 · 22nd Apr 2004, 09:19 PM

The apertures are based on a sequence of square root of 2... i.e.

if x = 2^(1/2) (or 1.4142135623730950488016887242097) then the sequence is

0x, 1x, 2x, 3x, 4x, 5x, ... (n-1)x, nx

And the shutter speed... it's basically doubling/halving... except that the camera doesn't have certain values so I took the next closest speed.

atwl

Chai · 22nd Apr 2004, 09:33 PM

But from 5.6 -> 8.0 -> 11 -> 16 -> 22 -> 32 isn't following the formula anymore...

or is it?

Thanks for the explanation!

Falcone · 23rd Apr 2004, 01:50 AM

0^(1/2) -> 1^(1/2) -> 2^(1/2) -> 4^(1/2) -> 8^(1/2) -> 16^(1/2) -> 32^(1/2) -> 64^(1/2) -> 128^(1/2) etc

Adrian Wong · 23rd Apr 2004, 01:44 PM

OMG, can someone speak English here? My brain is about to blow!

22nd Apr 2004, 06:39 PM	#1 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 26,272 Reputation: 3862 Rep Power: 71	Sorry for going off topic, how do you calculate one F-stop? Both Aperture and Shutter? Thanks! __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

22nd Apr 2004, 07:10 PM	#2 (permalink)
atwl77 Active Join Date: 13 Dec 2002 Location: Kuala Lumpur, Malaysia Posts: 916 Reputation: 82 Rep Power: 6	1 F-stop = f/1.0 -> 1.4 -> 2.0 -> 2.8 -> 4.0 -> 5.6 -> 8.0 -> 11 -> 16 -> 22 -> 32 etc or 1/15s -> 1/30s -> 1/60s -> 1/120s -> 1/240s etc but most cameras usually don't have these numbers so practically, this is more or less the same: 1/2 -> 1/4 -> 1/8 -> 1/15 -> 1/30 -> 1/60 -> 1/125 -> 1/250 -> 1/500 -> 1/1000 etc atwl __________________ "It is too late for me, son. Joss Whedon is my master now." "Then my father is truly dead." www.AdrianTung.com

22nd Apr 2004, 07:32 PM	#3 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 26,272 Reputation: 3862 Rep Power: 71	Is there any formula, or do I have to memorise all that? __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

22nd Apr 2004, 09:19 PM	#4 (permalink)
atwl77 Active Join Date: 13 Dec 2002 Location: Kuala Lumpur, Malaysia Posts: 916 Reputation: 82 Rep Power: 6	The apertures are based on a sequence of square root of 2... i.e. if x = 2^(1/2) (or 1.4142135623730950488016887242097) then the sequence is 0x, 1x, 2x, 3x, 4x, 5x, ... (n-1)x, nx And the shutter speed... it's basically doubling/halving... except that the camera doesn't have certain values so I took the next closest speed. atwl __________________ "It is too late for me, son. Joss Whedon is my master now." "Then my father is truly dead." www.AdrianTung.com

22nd Apr 2004, 09:33 PM	#5 (permalink)
Chai Administrator Join Date: 6 Oct 2002 Location: Maranello Posts: 26,272 Reputation: 3862 Rep Power: 71	But from 5.6 -> 8.0 -> 11 -> 16 -> 22 -> 32 isn't following the formula anymore... or is it? Thanks for the explanation! __________________ Chai (Contributor & Forum Admin) http://www.techarp.com/

23rd Apr 2004, 01:50 AM	#6 (permalink)
Falcone Official Mascot Creator Join Date: 18 Dec 2002 Location: Kay El, Em Wai Posts: 3,177 Reputation: 1672 Rep Power: 25	0^(1/2) -> 1^(1/2) -> 2^(1/2) -> 4^(1/2) -> 8^(1/2) -> 16^(1/2) -> 32^(1/2) -> 64^(1/2) -> 128^(1/2) etc

23rd Apr 2004, 01:44 PM	#7 (permalink)
Adrian Wong Da Boss Join Date: 10 Oct 2002 Location: In front of my BenQ Joybook 7000 notebook! Posts: 29,679 Reputation: 2878 Rep Power: 64	OMG, can someone speak English here? My brain is about to blow! __________________ Dr. Adrian Wong Tech ARP \| Blog @ Tech ARP \| The Free Trade Zone DYKT : The only offshore account I have is at the sand bank? Keep Tech ARP free! Visit our sponsors! We need PROGRAMMERS and TECHNICAL WRITERS! Contact us if you are a hot shot programmer or technical writer! My items for sale : 50x SD Card \| Memory Stick PRO \| Cyclone Energy Saver \| Seiko SS watch \| Tiger/Carlsberg beer jugs \| Travel Speakers \| Motorola V600 \| Nokia N90 SOLD! \| New Lowepro Mini Trekker AW Other items for sale @ the FTZ : Zalman CNPS9500 LED @ $20 \| Zalman CNPS7700 Cu @ $20 \| Zalman CNPS7000 Cu @ $20 \| Swarovski bracelet watches \| Dell 17" LCD \| Hi-Fi speakers \| English DIVX movies \| HP LaserJet toners! \| Office chairs