Should I shoot in "M" now?

[ghaleon109]

Ok, so I've had my XT for about 2 and a half months now and I'm pretty comfortable with most of it's settings but...

I haven't tried a custom WB yet, but I just have to shoot a small white card and then go to custom WB and select the card I believe (if I'm wrong I can just read the manual lol...)

The other thing that I don't quite 100% understand is the 18% grey thing associated with the partial metering mode? (I think that's right) But I have a book that might explain some of that.

What I'm really wondering about is shooting in Manual mode. Everyone always talks about how letting the camera decide the exposure is bad, but in M mode don't you just set it to the appature you want and adjust the shutter speed untill that exposure bar goes to the middle? (or vice versa for picking shutter speed first) but isn't that just letting the camera pick the exposure as well? I mean it is telling you where the exposure would be correct. So how is this different from Av or Tv?

Finaly, Flash and M mode? I've heard that you can just set it to whatever appature and shutter speed you want regardless of the exposure reading and the flash will fill in for the correct exposure... this sounds very false... does anyone have anything to say about this?

Thanks for your help eveyone :) I'd really like to learn more about my camera and start shooting in Manual mode :D

[DavidW]

If you're going to use the camera's metering anyway, and you don't need to hold exposures between shots (as you would if you were shooting a panorama), there's no advantage in using M mode over Av. Av automates the setting of the shutter speed according to the metering - there's no point you manually dialling in shutter speeds to centralise the 'needle'.

18% grey represents the middle tone. If you meter off a dark scene, the camera will try to move that to 18% grey, and will overexpose. If you meter off a light scene, the camera will try to move that to 18% grey and will underexpose. Exposure correction is your friend in these circumstances.


If you want your exposure based purely on the flash, choose M mode, set the aperture as you wish and the shutter speed to the sync speed (I don't know what it is for the 350D - it's 1/250s on the 20D). Assuming you don't have high speed flash set on your flash, the camera won't allow you to select a shutter speed faster than the sync speed.

Remember that a flash picture is really two exposures in one - an ambient light exposure and a flash exposure. Setting to the sync speed is saying that you're not interested in the ambient light exposure and you intend to take the picture purely with the flash. The converse would be using Av mode (without the custom function that sets the shutter speed to a defined value), where you are using an ambient light exposure.


Typically, M mode, shutter at the sync speed and maybe some positive FEC (maybe +1 to +1 2/3) is typically used for "main flash", where you're not interested in an ambient light exposure.

Av mode, probably with some negative FEC (maybe -1 to -1 2/3) is typically used for "fill flash".



David

[ghaleon109]

Thanks David :)

I didn't really know if there was going to be a difference between M and Av because it is still the camera's metering system. Thanks for the responce.

And thank you for the information about the flash and 18% grey as well, It helped out a lot!

[Bob_A]

Finaly, Flash and M mode? I've heard that you can just set it to whatever appature and shutter speed you want regardless of the exposure reading and the flash will fill in for the correct exposure... this sounds very false... does anyone have anything to say about this?

Thanks for your help eveyone :) I'd really like to learn more about my camera and start shooting in Manual mode :D

I only use flash in Manual mode (unless I'm using it for outdoors fill flash). ETTL II sets the subject exposure, while you use the shutterspeed and aperature to set the background exposure using the camera's light meter.

Typically, for indoors flash, I set aperature to get the depth of field I want and set shutterspeed to gain some control over how light or dark the background is. If the background is very well lit, I set the shutterspeed at the max sync speed of the camera (1/250s for the 20D) to ensure there is no background blur from camera shake or slight ghosting of my subject. If the light is very low, all or most of the illumination is from the flash, which is a very quick burst, so you should be able to get away with a pretty slow shutterspeed to get a sharp image.

I've only used High Speed Sync when using flash outdoors as fill flash since for indoors flash the lighting is usually quite low and it isn't necessary for most situations.

By the way, for doing quick snapshots at family birthday parties, etc. the following works pretty well:

- Man mode
- Shutterspeed at max sync speed (1/250s for 20D)
- f5.6

I also start with +2/3 stop FEC (flash exposure compensation) because I find that ETTL II underexposes by a tad.

[Bob_A]

Typically, M mode, shutter at the sync speed and maybe some positive FEC (maybe +1 to +1 2/3) is typically used for "main flash", where you're not interested in an ambient light exposure.

Av mode, probably with some negative FEC (maybe -1 to -1 2/3) is typically used for "fill flash".

David

Using ETTL II I've seen no difference in the amount of FEC required. If I need +2/3 for Av or Tv, I need +2/3 for Manual. Canon has confirmed via email to me that this is the way it should be.

For indoors flash, IMO, Manual is just easier to use and it gives you more control over the background exposure.

[ghaleon109]

I only use flash in Manual mode (unless I'm using it for outdoors fill flash). ETTL II sets the subject exposure, while you use the shutterspeed and aperature to set the background exposure using the camera's light meter.

Typically, for indoors flash, I set aperature to get the depth of field I want and set shutterspeed to gain some control over how light or dark the background is. If the background is very well lit, I set the shutterspeed at the max sync speed of the camera (1/250s for the 20D) to ensure there is no background blur from camera shake or slight ghosting of my subject. If the light is very low, all or most of the illumination is from the flash, which is a very quick burst, so you should be able to get away with a pretty slow shutterspeed to get a sharp image.

I've only used High Speed Sync when using flash outdoors as fill flash since for indoors flash the lighting is usually quite low and it isn't necessary for most situations.

By the way, for doing quick snapshots at family birthday parties, etc. the following works pretty well:

- Man mode
- Shutterspeed at max sync speed (1/250s for 20D)
- f5.6

I also start with +2/3 stop FEC (flash exposure compensation) because I find that ETTL II underexposes by a tad.

Thanks Bob :)

That really makes sense now. I'll have to play around with my camera tomorow and see how it goes. I've got to get some sleep right now though.

[tim]

If you have to ask if you should shoot in M mode, the answer is no. I shoot in M when i'm using studio flash or a small flash unit, other than that I rarely bother, Av works well for me.

[PhotosGuy]

If you're going to use the camera's metering anyway, and you don't need to hold exposures between shots (as you would if you were shooting a panorama), there's no advantage in using M mode over Av True. But if you want to use the histogram to get the right exposure, then "M" is one way to go. The chrome on cars will reflect the sun & sky & throw off the meter reading, so there's no way that I would use anything but M for them.

[MattyB]

would i be right in assuming only external flashes have the FEC? and it's on the LCD of the external camera?
or do other cameras have it?

my 300D doesn't have it, correct?

[nitsch]

would i be right in assuming only external flashes have the FEC? and it's on the LCD of the external camera?
or do other cameras have it?

my 300D doesn't have it, correct?

Not until you install the hack MattyB. Well worth doing for FEC alone but there's some other nice goodies in the hack too.

[JMAS]

If you're going to use the camera's metering anyway, and you don't need to hold exposures between shots (as you would if you were shooting a panorama), there's no advantage in using M mode over Av.

I don't agree. I would advise reading this post:
http://www.photography-on-the.net/forum/showthread.php?t=86497

[DavidW]

There's some great lessons in that thread. However, my point was a narrower one, answering what I took to be a question specifically asked. If you're merely going to follow what the camera's meter says in M mode, you may as well be in Av. The shot doesn't mysteriously get better just because you used M mode rather than the same settings in Av.

As with all tools, the best results come when you understand how they behave. That includes any form of exposure meter, be it built in to your camera or handheld.



David

[ghaleon109]

There's some great lessons in that thread. However, my point was a narrower one, answering what I took to be a question specifically asked. If you're merely going to follow what the camera's meter says in M mode, you may as well be in Av. The shot doesn't mysteriously get better just because you used M mode rather than the same settings in Av.

As with all tools, the best results come when you understand how they behave. That includes any form of exposure meter, be it built in to your camera or handheld.



David

Thanks :)

That's exactly why I started this thread. I thought M mode might be a little diferent than Av, but seeing as it is still the camera's metering system a difference is unlikely.

However, One thing that made me want to start shooting in M is so i could begin to start to understand the relation of exposure to the different ammounts of light. In Av I just set the appature and shoot... but I think that if I have to set the appature and the shuter speed together, I might begin to understand what I could expect to shoot at in different situations.

ie: "Wow, it's pretty bright outside right now, since my ISO's at 100 and I want to shoot at f8 I can expect a shutter speed somewhere around 1/320" (if that makes sense)

[Bob_A]

For indoor flash Man and AV give you the same thing IF you just zero the meter in Man anyway. However, sometimes you don't want the slow shutterspeed that Av would give since you can get some blurring (from camera shake) in the background where there may be sufficient ambient illumination. You can even get some ghosting around the subject if the subject moves.

In a well lit room, using Man with a higher shutterspeed (yes, resulting in an underexposed background) is sometimes the way to go.