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DBK
July 22nd, 2006, 05:32 PM
Custom function questions:

CFn-02 Long Exposure Noise reduction Wouldn't setting this to on all the time give the lowest noise possible with all shooting conditions, not just long exposures and low light. It is a bit confusing but what is the disadvantage of keeping this function turned on rather than off or auto mode??


CFn= 08 ISO expansion why not keep this on all the time to give widest range of ISO speed, any downside?

CFn-13 AF point selection It seems to me that selection 2 "quick control dial direct" is the best for rapid selection of focus point and also additional use of dial to use exposure compensation (nice). The joy stick button is awkward to use when looking in the view finder.

CFn-17 AF pt activation why not use expanded mode all the time? Increase accuracy of auto focus with a moving target?? Any disadvantages?

Silence camera beep: If you use the focus confirmation green dot in viewfinder as your focus confirmation, when is the beep sound useful rather than annoying especially at music concerts or other quiet places?

I don't understand the utility of the Camera settings function "C" When and how would one want to set and use this function?

I don't understand when One Shot AF should be selected over AI Focus AF since if a still subject moves in the AI Focus AF mode AF switches automatically to AI Servo AF. In other words, when is One Shot AF preferred over AI Focus AF??

Under what lighting circumstances by example should the AWB feature be reset to a custom white balance or change in color temperature?? Can't these issues be handled with Photoshop editing of a RAW file??

Stan Jirman
July 22nd, 2006, 06:12 PM
1) NR: Because this function needs to take a dark frame to subtract from your actual picture, this may not be always desirable. Imagine you take a 5 minute exposure - you may not want to wait another 5 minutes before you can see it.

2) You may not want to accidentally get into H or L.

It's all about control. Sometimes, automatic this or that is desired; other times, there's a good reason not to have a "sensible" feature turned on.

Doug Kerr
July 22nd, 2006, 06:31 PM
Yo,

Custom function questions:

CFn= 08 ISO expansion why not keep this on all the time to give widest range of ISO speed, any downside?
No real downside that I know of.

CFn-13 AF point selection It seems to me that selection 2 "quick control dial direct" is the best for rapid selection of focus point and also additional use of dial to use exposure compensation (nice). The joy stick button is awkward to use when looking in the view finder.
The joy stick works fine for me, but to each his own. I can get to the desired point quicker that way.

Silence camera beep: If you use the focus confirmation green dot in viewfinder as your focus confirmation, when is the beep sound useful rather than annoying especially at music concerts or other quiet places?
When you are in other than a concert or other quiet place.

Of course, the beeper does things other than for focus confirmation.

I don't understand the utility of the Camera settings function "C" When and how would one want to set and use this function?
This allows you to preset an almost entire set of camera settings you find useful for some particular situation and call them all up quickly just by turning the mode dial to C.

I don't understand when One Shot AF should be selected over AI Focus AF since if a still subject moves in the AI Focus AF mode AF switches automatically to AI Servo AF. In other words, when is One Shot AF preferred over AI Focus AF??
Often when in AI Focus AF the system may not recognize as quickly as you would like when the use of the AI Servo mode is advantageous. By selecting AI Servo you assure that the AI Servo mode will be in force from the outset.

Under what lighting circumstances by example should the AWB feature be reset to a custom white balance or change in color temperature?? Can't these issues be handled with Photoshop editing of a RAW file??
Not when working with the JPG output.

Additionally, this allows the camera to determine the chromaticity of the ambient illumination and then report it in the raw file so when working with the raw output you can use that to guide the color correction if there is no "neutral" thing in the scene.

Tom Wilk
July 22nd, 2006, 07:34 PM
Custom function questions:

CFn-02 Long Exposure Noise reduction Wouldn't setting this to on all the time give the lowest noise possible with all shooting conditions, not just long exposures and low light. It is a bit confusing but what is the disadvantage of keeping this function turned on rather than off or auto mode??

Canon uses "dark frame subtraction" on shots 1 second or longer when the NR is on. It uses no NR when the NR is turned off. Presumably, there is logic that determines if noise reduction is needed when in "auto" mode. I just leave mine on.

Noise reduction of this type isn't effective on shots with a short shutter duration, which is why it isn't used on shutter speeds faster than about 1 second.


CFn= 08 ISO expansion why not keep this on all the time to give widest range of ISO speed, any downside?

I do leave mine on all the time. The only reason I can think of to have this function disabled is to avoid setting an ISO that is beyond the range that is normally used. For example, ISO 50 does reduce dynamic range a bit, and ISO 3200 is obviously noisier than ISO 1600. I don't feel that I need the limitation of making these settings unavailable but some might. Maybe...

CFn-13 AF point selection It seems to me that selection 2 "quick control dial direct" is the best for rapid selection of focus point and also additional use of dial to use exposure compensation (nice). The joy stick button is awkward to use when looking in the view finder.

I have mine set for the multi-controller direct. I associate the quick-control dial with setting either aperture or shutter speed depending on shooting mode. I'd have to stop and contemplate changing the focus point rather than quickly hitting the multi-controller. YMMV.

CFn-17 AF pt activation why not use expanded mode all the time? Increase accuracy of auto focus with a moving target?? Any disadvantages?

I generally leave mine on the expanded mode, but there are times when the expansion function can hinder the precision of AF (note that expansion only works in the AI-Servo mode). If the subject or point of intended best focus is very small and tracking is relatively easy (slow-moving object), then it might be better to just use one focus point rather than expansion.

Silence camera beep: If you use the focus confirmation green dot in viewfinder as your focus confirmation, when is the beep sound useful rather than annoying especially at music concerts or other quiet places?

I like the beep, and only silence it when the situation requires silence. I've become accustomed to audio focus verification.

I don't understand the utility of the Camera settings function "C" When and how would one want to set and use this function?

If you're like me (and few are), you generally shoot in typical conditions - sunlight, artificial light, flash, etc. But, there may be one condition in which you shoot that is quite different from the rest. In my case, it's taking images of the moon. The "C" setting is perfect for this because I can switch to "C" and have my pre-set exposure, ISO, and custom functions (like mirror-lockup) already in place rather than fiddle around setting each. So when I want to shoot the moon, I switch to "C" and have ISO 400, mirror lockup, aperture, shutter speed, manual mode, and the rest already set. All I need is a minor adjustment to take the shot.

I don't understand when One Shot AF should be selected over AI Focus AF since if a still subject moves in the AI Focus AF mode AF switches automatically to AI Servo AF. In other words, when is One Shot AF preferred over AI Focus AF??

One-shot is preferred when the subject and camera aren't in motion, or are moving very slowly. Focus is achieved precisely for a given distance and is locked. In Servo mode, the camera is constantly adjusting and attempting to predict movement - great for auto-racing, but bad for portraits. AI Focus attempts to make the switch automatically from one-shot to AI Servo mode, sometimes successfully and sometimes not. It will occasionally switch when you don't want it to do so, and will sometimes not switch when you need it to do so. If you know that your shots will be stationary, select One-shot. If you know that they're moving, select AI-Servo. Only if your shooting will see a variety of movement and still situations should you use AI-Focus.

Under what lighting circumstances by example should the AWB feature be reset to a custom white balance or change in color temperature?? Can't these issues be handled with Photoshop editing of a RAW file??

If you know what kind of lighting you're going to experience, pre-selecting white balance is desireable. Auto does well, but the pre-set options are better. Manual, using a gray or white card, is even better still if all your shots will be under the same light. I generally use Digital Photo Pro when working with RAW images, though I am certain that Photoshop can deal with WB issues as well.

Rob Peterson
July 22nd, 2006, 07:39 PM
Custom function questions:

CFn-02 Long Exposure Noise reduction Wouldn't setting this to on all the time give the lowest noise possible with all shooting conditions, not just long exposures and low light. It is a bit confusing but what is the disadvantage of keeping this function turned on rather than off or auto mode??
I see no disadvantage to leaving this setting on all the time. The function doesn't actually turn on until an exposure exceeds 1 second, so for the vast majority of shooting this setting has no impact. I suppose situations exist when one wants consecutive exposures, without the delay introduced by turning on this function, e.g., when shooting through a telescope with the intent to "stack" the exposures.

CFn= 08 ISO expansion why not keep this on all the time to give widest range of ISO speed, any downside?
Again, I agree that there's not much downside, unless one gets careless and unintentionally selects one of the expanded speeds.
CFn-17 AF pt activation why not use expanded mode all the time? Increase accuracy of auto focus with a moving target?? Any disadvantages?
I can envision scenes containing lots of movement that might confuse the focus tracking if more than the center point is active, e.g., if an object shorter than the intended subject and moving away from the camera passes in front of the actual subject that's moving toward the camera. Other than such rather special circumstances, leaving it on seems harmless.

Silence camera beep: If you use the focus confirmation green dot in viewfinder as your focus confirmation, when is the beep sound useful rather than annoying especially at music concerts or other quiet places?
When the camera is on a tripod and I'm using a remote release to avoid touching the camera? When the camera is mounted such that I can't look through the viewfinder, e.g., on the ground or on a pole?

I don't understand the utility of the Camera settings function "C" When and how would one want to set and use this function?
Michael Reichmann points out in his "A Hands-On Field Report" that "C" enables one to turn on mirror lockup without wading through menus. So there's one setting "C" simplifies.

I don't understand when One Shot AF should be selected over AI Focus AF since if a still subject moves in the AI Focus AF mode AF switches automatically to AI Servo AF. In other words, when is One Shot AF preferred over AI Focus AF??
There's a risk the camera will refocus if set to AI Focus and I focus and reframe. When shooting jumping horses I frequently focus on the jump before the horse arrives, then, while still holding the original focus, I pan with the horse as it approaches the jump. I suspect trying this technique with AI Focus on will result in the camera refocusing on the moving horse, which isn't what I want.
Under what lighting circumstances by example should the AWB feature be reset to a custom white balance or change in color temperature?? Can't these issues be handled with Photoshop editing of a RAW file??
Many event photographers do not shoot raw. They need the photos available as soon as possible, and processing raw files slows down their process. They might well set a custom white balance to avoid having to color correct the JPEG files. Note that many venues, including the lighted equesterian venues I shoot in, contain a nasty mix of mercury and natural light, which can lead to a rather odd color balance that shifts during the day.

Bob

Alan T. Price
August 30th, 2006, 08:49 PM
Custom function questions:

CFn-02 Long Exposure Noise reduction Wouldn't setting this to on all the time give the lowest noise possible with all shooting conditions, not just long exposures and low light. It is a bit confusing but what is the disadvantage of keeping this function turned on rather than off or auto mode??

If you are shooting events such as fireworks where you require long exposures but don't want to be locked out of taking another exposure straight away then you would not use the NR mode. Otherwise it probably doesn't hurt. Probably - we know it does dark-frame subtraction but there may also be some other noise reduction techniques applied too, in which case there could be some softening of long exposure shots.


CFn= 08 ISO expansion why not keep this on all the time to give widest range of ISO speed, any downside?

If you are using exposure safety shift you may want it to activate while you still have the full dynamic range rather than use the extended ISO settings, so then you would not want to use the ISO expansion. Otherwise, use it but keep an eye on the ISO in use.


CFn-13 AF point selection It seems to me that selection 2 "quick control dial direct" is the best for rapid selection of focus point and also additional use of dial to use exposure compensation (nice). The joy stick button is awkward to use when looking in the view finder.

I find the joystick (on my 20D) easier to use because it takes a just single movement to select the AF point, and it lets me use the quick control dial for exposure adjustment.


CFn-17 AF pt activation why not use expanded mode all the time? Increase accuracy of auto focus with a moving target?? Any disadvantages?

AF point expansion may result in you being able to better track a moving subject such as a bird against a clear sky, which is good, but it may also allow the camera to grab an unintended subject with greater contrast than the one you are trying to follow. Mixed blessings.


I don't understand when One Shot AF should be selected over AI Focus AF since if a still subject moves in the AI Focus AF mode AF switches automatically to AI Servo AF. In other words, when is One Shot AF preferred over AI Focus AF??

If the subject is moving or sure to move then use AI Servo for the fastest and best response to that movement. Otherwise use One Shot AF for the most stable AF. Note that AI Focus AF can switch mode when you don't want it to, and time will be wasted before it changes back again.


Under what lighting circumstances by example should the AWB feature be reset to a custom white balance or change in color temperature?? Can't these issues be handled with Photoshop editing of a RAW file??

If you are shooting raw then the WB can be fixed in most cases in post processing, one way or another, but there are exceptions. e.g. I use DPP. However, DPP cannot let you set a colour temperature below 2800K even though most high pressure sodium street lighting (the orange-ish lights) has a colour temperature of about 2100K. Therefore you would want to use a custom WB or at least have a selectable white or grey patch in your photo if you are using HPS lighting.

If the scene does not include a white or grey subject then you cannot use the colour picker to specify the white balance.

Also, in mixed lighting or indeed any lighting for that matter, you might prefer to use a custom WB rather than try to guess the best colour temperature later on. e.g. Just in case that white shirt was really off-white. However, custom WB generally requires that you shoot and register a test shot before you shoot the rest and it is a bit cumbersome, especially if you are shooting in variable lighting conditions.