Canon 20D

[fotograf]

A friend of mine had a question- I shoot in film, so I'm posting this question

for him. He's got the Canon 20D body, 580EX II flash, and the EF 85mm f/1.8

lens. He said he was testing the body(which he has owned for several

years),indoors with the ISO setting on 100 and all of the images are too dark.

He also said some of the images have a "bluish" tint. He's used the body

outdoors before with no problem but isn't sure why his images are so dark

(underexposed).I know very little about digital bodies, but am assuming he

should possibly set the ISO at 400 for indoor shooting. I think he said his

body has P mode and some other dials on top of the body for auto exposure mode,

etc., but he isn't sure what to do to allow better exposure indoors. Any help

would be appreciated.

[m3rdpwr]

The bluish tint is most likely a white balance problem.

He can either set it properly on the camera, or shoot raw and fix it in post later.

 

While being indoors shooting ISO 100 with a 580EX may work in some situations, it may not in others.

 

Is he shooting at F1.8?

 

I personally don't shoot in P mode.

I usually go full manual or Av priority and let the flash do its work.

 

 

-Mario

[jason_hall4]

The only reason to increase ISO is to allow for higher shutter speeds to stop motion and camera shake. It should not prevent one from getting good exposure. The 30D used to get a lot of complaints for the same reason.

 

There are several things to think about here.

 

1.You need to understand how a camera figures correct exposure. It is trying to achieve middle grey. So light colored object will often under expose if it fills the frame. A dark colored object will often cause over exposure. One must understand this when decideing on metering mode and technique.

 

2.Test have been done with these camera and have been found the meter to off by about 1/3 of a stop. This seems to be in general for the early DSLR models. Some even think it is on purpose to help prevent blown out highlights that DSLRs a prone to do. This "miscalibration" needs to be considered. This is not to be confused with Hight light tone priority in the newer models.

 

3.learn to read the histogram. Digital does not have the latitude that film has and so correct exposure is more important. WIth the histogram on the camera you can see how well the images are being exposed and adjust accordingly. Its called "Exposure Compensation" and that is what that wheel on the back of the camera is for.

 

4.Think about useing Av(Apature Value, Apature priority) mode. It will give much greater control over the camera. Tv (Time value, Shutter Priority) would also be an option. M (manual) mode is a great place to learn about exposure and to have complete control. Stay away for from all the other "auto" modes. P(Program) mode ain't so bad.

 

5.Post some examples would be a good idea.

 

6.Inside in low light with the flash being bounced off a wall or some other surface. I sometimes find that the flash needs a +1/3 stop increase. I to use the 580EXII (and the 580EX for that matter).

 

Jason

[mark u]

Start by checking he hasn't inadvertently set negative exposure compensation.

[tom_schutz]

Mario's suggestion to avoid P mode is likely to work. I have a Metz flash unit, not a Canon,

but on my 20D, flash shots are consistently underexposed when the camera is set in P mode.

In my case, it wasn't because I had something else incorrectly set (see Mark's post above) - P

mode just doesn't work in my case. I was assuming it was some Canon/Metz incompatibility

issue, but maybe it's more universal.

 

I never had any flash problems with the 20D in M mode.

[colinsouthern]

"The only reason to increase ISO is to allow for higher shutter speeds to stop motion and camera shake."

 

And for cutting down waiting time when bracketing looooooooong exposures.

[jason_hall4]

Yep, guess you got me there Colin.

 

Jason

[colinsouthern]

Hi Jason,

 

Sorry if that seemed like a dig at you - I was serious about it though (I do a lot of work with high contrast / strong direct light scenes). Nothing's more depressing when shooting a 7 shot bracket - and the low-side starts at 15 sec - and then you start doing the mental maths (30, 1 min, 2 min, 4 min, 8 min , 16 min) - if you can up the ISO to even something like 400 (which doesn't make a lot of difference to the quality on a 1Dx3 series) then you can cut the whole sequence down to 8 minutes instead of 32.

 

Cheers,

 

Colin

[fotograf]

Thanks for all the input. I forgot to ask my friend which exposure mode he was using(Partial, Spot, etc.), besides using the "P" mode. He said he was calling a large camera store, locally in this area so he may have gotten some tips from them as well.

[jason_hall4]

Never thought it Colin. :o)

 

Thanks for the insite!

 

Jason

[fotograf]

"insite?"

[jason_hall4]

Excuse me..."Insight". Colin's point of raising ISO to reduce the amount of time needed to obtain long, bracketed exposures for layering in post process. It allows very high dynamic range and pretty well makes it possible to eliminate the noise that long exposures are prone to.

 

Jason

[colinsouthern]

"Excuse me..."Insight". Colin's point of raising ISO to reduce the amount of time needed to obtain long, bracketed exposures for layering in post process. It allows very high dynamic range and pretty well makes it possible to eliminate the noise that long exposures are prone to."

 

Quick side note ...

 

I was just referring to normal bracketing to have more dynamic range to play with - but - I have done some work with multiple image layers to reduce noise as well, and I have to say it was quite impressive. On a 20D I shot 32 RAW shots at 3200 ISO - stacked them with opacities of 100%, 50%, 33.3%, 25%, 20% etc. Final result was equivalent to something areound ISO 200 (perhaps slightly better).

 

Cheers,

 

Colin

[jason_hall4]

What were you photographing? 32 shots at 3200ISO...

 

If I can find a worthy subject I just may have to give this a try. It would have to be a something worth the time and trouble. :o) Do you have any samples to post?

 

sorry, really not meaning to highjack the thread.

 

Did we answer your questions Brian? Hope so. If not just smack us around a bit or git your friend to post him self so we can communicate directly.

 

Jason