Difference between Program mode and Full Auto mode?

Well I get full auto is full auto.  But Program mode changes everything but your ISO?  If you move your ISO, your camera adjust shutter speed and aperture right? 

So how does it prioritize which to move?  

If you want to grow in photography, whatever the type,
don't approach it through programs — as you will not
learn to control but surrender it to the camera's OS.

G'day Steve

Okay - you've asked a very good Q in the beginners' area - so let's answer along those lines ...

Full Auto Mode is where the camera [every camera] takes full control of things, most menu offerings are removed from view and the camera becomes a glorified 'point and click' job, like the old Kodak Instamatics. 95% of students arriving to my beginner workshops have their dSLRs set to 'full auto'

In Program mode, things change considerably and it is a most valuable mode for many people. a) beginners who want to see in the viewfinder what the camera does with settings so that they can learn a bit more about the camera's inner workings, and b) more experienced users who want some exposure setting options with full menu controls, but who for one reason or another do not wish to use any of the "A" or "S" or "M" modes on the P-A-S-M mode dial

If the camera's ISO settings are fixed on a specific ISO number, then the user can modify the camera's "P" settings via the rolly-wheel control - and the speed and aperture will go up or down just like a see-saw. The user can see all these alterations in the viewfinder

If the user alters the ISO number up or down, then the starting set of exposure numbers that the camera comes up with will be different from earlier, but the rolly wheel modifications still apply.

There is a lot more to it, but does this answer your Q? If you want more info I'm happy to oblige

Hope this helps
Phil from the great land Downunder
www.flickr.com/photos/ozzie_traveller/sets/

Thanks guys.  I wasn't suggesting I was going to use it.  Just trying to understand what it actually is.  When I was looking at it, it seemed kind of like Auto mode of some sort.  

Just to clarify, you can't control shutter and aperture with it?  It's just an ISO play right? 

There is nothing wrong with using Program mode. I use it a fair amount of the time, certainly not for everything.

Instead of Auto mode, another way to think of it is a blend of Aperture priority and Shutter priority. But instead of aperture or the shutter, the one exposure element you have direct control over is the ISO. You can also choose to bypass that with Auto ISO.

As Phil explained, you do have relative control over aperture and the shutter, just not the ability to set specific values. EV compensation will affect either aperture or the shutter, or both, depending on circumstances. Program-shift will affect both the aperture and shutter, in the see-saw manner that Phil described. So you are far from helpless regarding aperture and the shutter.

In my experience Program mode is especially useful with TTL flash.

Kelly

KCook wrote: In my experience Program mode is especially useful with TTL flash.

I use TTL flash on location along with M mode all the time.
TTL is usable with all modes but different possible results.

Since predictable results in constant productions is the key
word, using powerful a light source — to insure both output
supply and speed — is the only prerequisite.

In Program mode you can change the shutter and aperture but they are tied together. The camera goes into "Program Shift" mode if you adjust the setting from what the camera chooses. If you want more shutter speed, you can do that, If you want a different DOF you can adjust it by watching the aperture. It's like combining Shutter Priority and Aperture Priority into one setting. Auto mode, I don't recommend but Program mode isn't the big bad wolf most photographers think it is. Most use Aperture Priority and that is just a specific Program setting. You can achieve the same thing in either mode with the same results. I have to chuckle when some make Program mode out to be a horrible thing to do but they use Aperture or Shutter Priority. It's the same thing. The Manual only shooters make me chuckle also. They think they are doing something magical but they still match the meter when they shoot. It's they same thing except you have to fiddle with everything. There are times when you do need to shoot manual but not for general shooting. That's my 2 cents on the subject. 

As every beginner should know, aperture affects depth of field and shutter speed affects motion blur.  You can set either one to accomplish your exposure goal and the second one needs to follow along to achieve that exposure.  The advantage of program mode is that the meter determines an exposure recommendation.  You can step through the various combinations of shutter speed and aperture while maintaining the same overall exposure with every combination.

Let's say lighting is pretty flat and I can trust the meter recommendation.  My subject needs a certain depth of field to get two parts of the image in reasonable focus.  I flip through  combinations and find the aperture setting that will get the job done.  If the shutter speed shown is OK I can hit the shutter.  If it is not, I may need to get out a tripod or make a compromise with the aperture.  No matter where I go, I will get the same exposure if not the same image.

Program mode, then, is my auto.  The only other mode I use is manual.  I've never understood why some photographers decry the P mode.  It is fast and efficient.