"auto mode" vs "manual mode"

[Mystwalker]

I'm playing with 17-40 f/4 and thought, "what if I duplicate setting for auto mode in manual mode"?

I take a shot (indoor) with auto mode - photo came out 1/60, f/4, not sure what default ISO was

I change to "M" mode, pop up the flash, same set up, I left ISO at 400 ... resulting photo was darker. I definitely missed something

"Av" does not like 1/60 and f/4 ... again, I'm missing "something".

What is auto mode doing that I'm not doing in "M" or "Av"?

Thanks.

 

[sabbath999]

You can check the ISO when it was on auto by reading the EXIF data... If you don't know how to do that, just ask.

 

[pregnantcowlady]

you have to play with the aperature settings and the shutter speed to get the exposure right. you can't just go into manual mode and have it work. i dont know what kind of camera you have, but i'm assuming it's a dslr.

when you turn to any mode, you should see a
-----------------------
-2 -1 0 +1 +2

see it? that means the exposure is - (underexposed) and + (over exposed) you want it in the middle.

which auto mode were you taking the pic in?
portrait, landscape, sport, green box, etc?

 

[Big Mike]

1/160, F4, ISO 100 will be the same in any mode...manual, automatic or whatever.

Flash changes everything, so leave that out for now.

 

[Mystwalker]

I was using the "Green Box" auto mode on 30D.

When in "M" mode, the exposure meter was all the way left (underexposed). Since I had same settings as green box mode (1/60, f/4), I thought the photo will have same result? I remember reading that "green box" mode defaults ISO to 100 or 200 - when in "M" mode, I left it at 400. Am thinking this should have given me more leeway.

I can drop shutter speed and get same result, but wanted to use faster shutter - my daughter is on the move.

In "M" mode, do I need to control the built-in flash? Do not remember anything in manual that allow me to do this.

 

[Stranger]

when you shot on auto, did the flash come on? or is that something you did on your own in manual...

As Mike said, regardless if the camera decides 1/60, f/4 or you decide 1/60, f/4 it is still 1/60, at f/4 and will yield exact same results.

 

[Big Mike]

When in "M" mode, the exposure meter was all the way left (underexposed). Since I had same settings as green box mode (1/60, f/4), I thought the photo will have same result?

Were you pointing the camera at exactly the same thing, same direction, same light?

In all the modes except M, the 'meter' should be centered on --0--. When you switch to Manual, it probably won't be...so you need to adjust the settings to get it back to zero (or close to it, depending on what you want to do.

Manual mode is good when your light and subject stay the same from one shot to the next. If your subject is running around and changing position relative to the light source...then your exposure may need to change.

If your light is changing and your subject is moving around...then why not use one of the Auto modes?

The flash will pop up on it's own, when in Green Box mode (or maybe the picture modes) but in the 'real' modes (P, Av, Tv, M) you need to press the button to pop it up yourself.

 

[Miaow]

I've found a few times when I've done pics in Manual i keep forgetting to change the white balance - maybe that could be a reason some pics are different as I found mine was going to Sunny at the start?

 

[Big Mike]

white balance - maybe that could be a reason some pics are different as I found mine was going to Sunny at the start?

Manual mode has to with exposure...not white balance. Completely different things.

 

[JIP]

I think with an issue such as this some examples would be in order. I imagine your problem could be solved very quickly if you attached the images in question.

 

[Mystwalker]

Will go home and duplicate test.

I think the key may be I was in same room, but daughter was moving around - reason I wanted to keep the 1/60 ... if I manually "centered exposure meter", I am not able to get a fast enough shutter speed. I assumed exposure would be same (same room). Will try again by shooting something static

Thanks.

 

[gendarmee]

I've been after this too initially.
Later i figured that it not just the aperture and shutter but also the ISO / white balance / focus type / metering mode / flash level that influence the picture.
We can look at the Exif and replicate most on camera scene modes.