Aperture vs. ISO at DVinfo.net

Michael Clark · March 12th, 2011, 07:52 AM

I've just made the switch from Canon HV40s to T2i DSLRs. I will primarily be shooting with a 1.4L 50mm lens, and wanted to see if I understood the relationship between aperture and ISO. In low lighting situations (receptions, etc.), is it preferable to keep the aperture open and the ISO as low as possible? It seems like if you kept a smaller aperture and higher ISO than things would be grainier.

Stephen J. Williams · March 12th, 2011, 11:56 AM

Hey Mike...

To answer your question quickly... yes more ISO equals more noise. But don't let that be the reason that you never bump it up. When you need to you need to. Keeping your aperture wide open has its draw backs.
for one, the line between in focus and out of focus will be very thin. I rather have a subject in focus with a little noise vs out of focus without.
I use the T2i and usually shoot around 800, but I'll go to 1600 when I need too. I can always use neat video in post to remove the noise (but this has some drawbacks as well).
Best of luck and hope that this helped answer your question.

Steve

Bill Grant · March 14th, 2011, 07:23 AM

Michael,
This is one of the "gotchas" with DSLRs that you have to get through; starting to understand ISO vs Aperture vs Shutter Speed. I would feel trapped and panicked with just a 50 1.4 Your DOF at 1.4 is potentially going to be VERY thin, so you will need to bump the ISO. I use the 5D which allows me to use the mechanical ISOs and I can shoot a very clean 2500 which allows for use of f/4 and above in very dim situations. I suggest you shoot everything that moves indoors and out(which can sometimes be more challenging) until you need the camera for paid work. Good luck. Also, I will drop the shutter speed to 1/30 as the lights go down...

Bill

March 12th, 2011, 07:52 AM	#1
Michael Clark Major Player Join Date: Aug 2009 Location: Chattanooga, TN Posts: 244	Aperture vs. ISO I've just made the switch from Canon HV40s to T2i DSLRs. I will primarily be shooting with a 1.4L 50mm lens, and wanted to see if I understood the relationship between aperture and ISO. In low lighting situations (receptions, etc.), is it preferable to keep the aperture open and the ISO as low as possible? It seems like if you kept a smaller aperture and higher ISO than things would be grainier. __________________ www.clarkvideoproductions.com

March 12th, 2011, 11:56 AM	#2
Stephen J. Williams Major Player Join Date: Jan 2008 Location: Mays Landing, NJ Posts: 768	Re: Aperture vs. ISO Hey Mike... To answer your question quickly... yes more ISO equals more noise. But don't let that be the reason that you never bump it up. When you need to you need to. Keeping your aperture wide open has its draw backs. for one, the line between in focus and out of focus will be very thin. I rather have a subject in focus with a little noise vs out of focus without. I use the T2i and usually shoot around 800, but I'll go to 1600 when I need too. I can always use neat video in post to remove the noise (but this has some drawbacks as well). Best of luck and hope that this helped answer your question. Steve

March 14th, 2011, 07:23 AM	#3
Bill Grant Major Player Join Date: May 2005 Location: Columbia,SC Posts: 806	Re: Aperture vs. ISO Michael, This is one of the "gotchas" with DSLRs that you have to get through; starting to understand ISO vs Aperture vs Shutter Speed. I would feel trapped and panicked with just a 50 1.4 Your DOF at 1.4 is potentially going to be VERY thin, so you will need to bump the ISO. I use the 5D which allows me to use the mechanical ISOs and I can shoot a very clean 2500 which allows for use of f/4 and above in very dim situations. I suggest you shoot everything that moves indoors and out(which can sometimes be more challenging) until you need the camera for paid work. Good luck. Also, I will drop the shutter speed to 1/30 as the lights go down... Bill __________________ Cinema Couture www.cinemacouture.com