Canon 50D

Pete Gl

Pete Gl

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Errr Pete?
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I've had my new 50D for about a month now, and whilst really pleased with it overall, I have a couple of things I don't fully understand and the manual is not too clear on, if anybody would be kind enough to explain.

1. Specification - Viewfinder coverage 95% - 95% of what? (I know this question applies to any camera, but it has only just come to my attention when getting my new 50D)

2. Power switch, from the manual, 3 settings, Camera Off at the bottom, Camera On midway, Quick Control dial operates at the top setting. BUT, the quick control dial also operates at the midway setting ??

3. With my previous camera (400D) I always shot in Raw. Now I have 3 choices: - Raw, SRaw1 and SRaw2. Whilst I understand the second two options result in a lower file size, there's got be a pay back! What are the advantages/disadvantages of SRaw1 and SRaw2?

Thanks very much in anticipation

Pete
 
1. It means that the viewfinder shows the "middle" 95% of the image captured on the sensor (i.e. the image captured will be slightly wider)
2. Don't have 50D so don't know
3. sRAW has lower resolution (less pixels) so you are throwing away information at the capture stage. Proably doesn't matter for posting on the web, but why would you need a 15Mpx camera just to do that?

Paul
 
Thanks for your help Paul

grumpybadger said:
3. sRAW has lower resolution (less pixels) so you are throwing away information at the capture stage.
Click to expand...

Like a Jpeg?!? This is where I'm getting confused

Pete
 
S1RAW and S2RAW apart from being slightly different file sizes- one works by discarding pixels as Paul said, the idea being that at very high ISOs the lower pixel density should show less noise.

The other one works by combining pixels into larger pixels, with the effect of a lower pixel count and larger pixels, and should give less noise and smoother images. I can't remember which is which without checking, but they're both intended to get you the shot when you'd otherwise probably not bother due to low light and having to really bump up the ISO. Both produce substantially smaller files than normal.

I haven't really done enough with either format to decide if there's any real benefit the jury's still out. ;)
 
No, a JPEG actually can maintain the number of pixels but encodes the data in a way that means that some of the detail and colour information can be lost. A RAW file of the same resolution contains more data than a JPEG as it stores more information per pixel. This can help if you are adjusting brightness, exposure, white balance, etc in post processing as more information is available to work with.

According to the specs, a 50D offers resolutions of:

• 4752 x 3168 (15 Mpx)
• 3456 x 2304 (7 Mpx)
• 2353 x 1568 (~4 Mpx)

So, the smaller sRAW mode offers a resolution of less than an old 10D and the middle size less than a 20D. So, unless memory is short, I can't see why people would use these modes.

Paul
 
CT said:
S1RAW and S2RAW apart from being slightly different file sizes- one works by discarding pixels as Paul said, the idea being that at very high ISOs the lower pixel density should show less noise.

The other one works by combining pixels into larger pixels, with the effect of a lower pixel count and larger pixels, and should give less noise and smoother images. I can't remember which is which without checking, but they're both intended to get you the shot when you'd otherwise probably not bother due to low light and having to really bump up the ISO. Both produce substantially smaller files than normal.
Click to expand...

I would guess that the smaller one combines four pixels into an effective 1 (i.e. doubling up in each dimension) but still don't really see why effectively averaging in camera (which is what is happening) will give any better results on noise than averaging in post processing on the full size RAW file.

Paul
 
Well one obvious advantage is that you can still output the S1 or S2 RAW image as an uncompressed TIFF whereas there'll always be some quality loss when you shoot jpeg due to compression.
 
grumpybadger said:
I would guess that the smaller one combines four pixels into an effective 1 (i.e. doubling up in each dimension) but still don't really see why effectively averaging in camera (which is what is happening) will give any better results on noise than averaging in post processing on the full size RAW file.

Paul
Click to expand...

I think you're quite possibly right Paul. I suppose from Canon's viewpoint they're targeting these formats at people who aren't necessarily adept at processing and don't appreciate these finer points. Trying to give an 'in camera' solution in other words?

We tend to forget that simple things like resizing etc are a mystery to a lot of newcomers.
 
That's a very valid point Cedric. I'm just a big believer in bringing as much information back from the scene as possible but understand not everyone wants to be stuck in front of Photoshop.

Paul
 
Pete Gl said:
I've had my new 50D for about a month now, and whilst really pleased with it overall, I have a couple of things I don't fully understand and the manual is not too clear on, if anybody would be kind enough to explain.

1. Specification - Viewfinder coverage 95% - 95% of what? (I know this question applies to any camera, but it has only just come to my attention when getting my new 50D)

2. Power switch, from the manual, 3 settings, Camera Off at the bottom, Camera On midway, Quick Control dial operates at the top setting. BUT, the quick control dial also operates at the midway setting ??

3. With my previous camera (400D) I always shot in Raw. Now I have 3 choices: - Raw, SRaw1 and SRaw2. Whilst I understand the second two options result in a lower file size, there's got be a pay back! What are the advantages/disadvantages of SRaw1 and SRaw2?

Thanks very much in anticipation

Pete
Click to expand...

If you look at the bottom of page 37 Pete you'll see it gives a vague explanation of what you won't be able to adjust if the switch is not at the second 'ON' position. Essentially you'll find you won't be able to adjust anything that normally doesn't need another button pressed in combination with the 'speed wheel' to effect an adjustment ie. exposure compensation, exposure settings when in Manual mode, aperture when in Av mode, etc.
 
Steve, thanks for your input, it's no big deal this, but it can be frustrating when the manual contradicts it's self.

Paul and Cedric, I really appreciate your input to this thread, and thanks for trying to help, but, am I any clearer on advantages/disadvantages of SRaw1 and SRaw2? Errrrmmmm.......

Pete
 
LOL Camera manuals are all done by a Japanese sardine fisherman who's still doing night school English.

My advce quite honestly is don't worry about it, there's probably not a great advantage, if any, in using either. ;)

Shoot in full size RAW if you can and if you want optimum image quality.
 
CT said:
LOL Camera manuals are all done by a Japanese sardine fisherman who's still doing night school English.
Click to expand...

Nice one!! they certainly read that way sometimes.:lol:

CT said:
My advice quite honestly is don't worry about it, there's probably not a great advantage, if any, in using either. ;)

Shoot in full size RAW if you can and if you want optimum image quality.
Click to expand...

True enough, flash cards and computer external storage are cheap as chips these days.

Thanks again

Pete
 
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