ISO 3200 or ISO 1600/Raw?

[fredmitcham]

If you shoot in raw, am I correct that you are better off shooting at ISO 1600 and them increasing exposure by one stop in ACR or DPP than using ISO 3200? WellI have another question, I did a search on this and found every answer said:

"you get the same effect as ISO 3200 for RAW shots by shooting at ISO 1600 and underexposing by a stop"
"you're best shooting at ISO 1600, underexpose it by one stop and then bring it back up in the RAW convesion"
"ISO 3200 is just an in-camera software boost. You can do the same, often with slightly better results, by shooting at ISO 1600 with exposure compensation set to -1 and then use software on your computer to brighten it up"

I don't understand this. Why would you underexpose ISO 1600 by one stop or 1EV? ISO 1600 is one stop lower than ISO 3200, if you throw in -1 exposure compensation you're now two stops underexposed compared to ISO 3200 and have to give it a two stop boost in ACR or DPP? What is the purpose of this? Wouldn't it make more sense to shoot at ISO 1600 and then only have to give it a 1EV boost in raw? Im clearly missing something here.

[TeamSpeed]

If you want to simulate the camera 3200 ISO speed, you would have to reset your exposure settings in each and every mode (M, Av, Tv, etc). Why not just set the camera to 3200 (H), and not mess with your exposure settings? That is why it is a custom function, it saves you work in setting/resetting exposure settings in all the modes you might shoot in for one session.

Again, it comes down to what you need to do to get your shot, some folks might like to not use the 3200 internal software function of the 30D, and just control every single aspect of the shot manually, while others want to keep some settings the same, and let the camera compensate for the 3200 setting.

If you shoot in Raw, it shouldn't matter. If you underexpose 1600 at some set shutter speed, or use the 3200 at normal exposure at same shutter speed, you will be able to tweak both in the Raw converter to bump the exposure to your liking. Either way, you will have noise that has to be cleaned up with the noise tool of your choice.

Just my opinion on all of this.

[bildeb0rg]

Not all bodies run up to 3200, so sometimes you have to deliberately under expose by a stop or more to get useable shutter speed. Then it gets messy as you try and recover it in pp and have to give it a rinse with noise ware.

[fredmitcham]

Originally Posted by TeamSpeed

If you shoot in Raw, it shouldn't matter. If you underexpose 1600 at some set shutter speed, or use the 3200 at normal exposure at same shutter speed, you will be able to tweak both in the Raw converter to bump the exposure to your liking. Either way, you will have noise that has to be cleaned up with the noise tool of your choice.

Just my opinion on all of this.

Oh I see, you underexpose 1600 by one stop to get the same shutter speed you would have gotten at 3200? I get it now. I hadn't thought about that.

[fredmitcham]

Originally Posted by bildeb0rg

Not all bodies run up to 3200, so sometimes you have to deliberately under expose by a stop or more to get useable shutter speed. Then it gets messy as you try and recover it in pp and have to give it a rinse with noise ware.

Thanks I just figured it out The reason I ask is because recently I was shooting some action shots at F2.8, 1/500th in raw and even at 1600 the shots were coming out underexposed so I was trying to decide whether to shoot at 1600 and boost them by 1.5-2 EV in PP or shoot at 3200 and boost them 0.5-1 EV in PP. I went with 1600 but was wondering if that was a mistake or not.

[canoflan]

I think that you get less noise properly exposing at 3200 than increasing 1600 at -1 exposure to proper exposure.

I have tried it. Proper exposure is the best case always, with one caveat that you should always put getting the shot above settings, noise, etc..., when in doubt.

[prime80]

Originally Posted by canoflan

...you should always put getting the shot above settings, noise, etc..., when in doubt.

Well said! I don't know how many blurry, sorry shots it took me to figure out that a noisy "good" shot is much better than a clean blurry shot.

[E-K]

Originally Posted by canoflan

I think that you get less noise properly exposing at 3200 than increasing 1600 at -1 exposure to proper exposure.

Generally speaking for ISO 1600 and below that is true with todays cameras. However, there should be little difference between an ISO 3200 shot and an ISO 1600 pushed +1 in post processing. This is because unity gain is reached somewhere around 1200-1600 ISO for dSLRs (see http://www.clarkvision.com/imagedeta...mance.summary/ )

e-k

[basroil]

if you are constantly pushing 3200ISO (except for indoor sports, where that it a fact of life), you need faster lenses..

[René Damkot]

ISO 1600 at EC -1 (so a ISO 3200 exposure) is slightly better then ISOO 3200 with EC 0.
Have a look in this thread from post #14 on...

It also offers the advantage it's easier to keep highlights from blowing out, since you are shooting at ISO 1600 instead of ISO 3200

[TeamSpeed]

Originally Posted by René Damkot

ISO 1600 at EC -1 (so a ISO 3200 exposure) is slightly better then ISOO 3200 with EC 0.
Have a look in this thread from post #14 on...

It also offers the advantage it's easier to keep highlights from blowing out, since you are shooting at ISO 1600 instead of ISO 3200

I don't see that, really pretty close to each other. And as others stated after that post, like in #18, it appears other folks lean toward the 3200 and not the underexposed 1600. It is so close in performance, that I think each person has to try it in their own situations as a test to see what works best. Since they are all so close, and the camera in H mode presumably does the same thing, I think the ease of just setting the ISO is quicker or more user-friendly. In the end, when you run them through your favorite noise eliminator, the difference will be even less and most likely won't matter.

[E-K]

I don't lean towards it because I don't have the option on my 350D .

If I was shooting JPEG I would say using ISO 3200 (in situations which demand it) would be pretty much a must.

However, if you're shooting RAW you can simulate an ISO 3200 camera setting by pushing an ISO 1600 shot with near identical results (within a margin of error). Pushing an ISO 800 shot is close but there will be subtle differences. Below that I wouldn't bother.

So why would you push an ISO 1600 shot? As others have already mentioned,

1. You don't have an ISO 3200 setting on your camera .
2. It's a quick grab and you don't have time to change the ISO.
3. Like René pointed out, you can fiddle with the highlights.

e-k

[Curtis N]

Originally Posted by René Damkot

ISO 1600 at EC -1 (so a ISO 3200 exposure) is slightly better then ISOO 3200 with EC 0. Have a look in this thread from post #14 on...

Looking at the images from PacAce in that thread, it's really tough for me to see any difference betweein ISO 1600 (+1) and ISO 3200.

It also offers the advantage it's easier to keep highlights from blowing out,

This point I believe has some validity, and is one I hadn't considered before. Merely cranking up the exposure slider with a RAW converter will still blow out the highlights, but if you use other methods to bring up the shadows and midtones while maintaining the highlights (and there are several ways to do that) you could be better off.

My biggest hesitation with deliberately underexposing at ISO 1600 is being able to chimp and properly interpret the histogram to get the exposure 1 stop below optimum. I have a hard enough time getting it right to begin with!