fixing a raw image VS fixing a JPEG image in PShop

[AussieCat]

this is gonnamake me so sooo silly and simple

but

i just used raw for the first time.

i purposely took an underexposed picture then fixed it up in raw and it looks great.

i then, saved that same pic as a JPEG without actually altering the raw exposure.

so, in effect, i sved the raw image with NO alterations.

I then, fixed up the JPEG in photoshop

and comapred it to the RAW image i fixed up using raw software.


i could not actually see any real difference between which one was the origibal raw pic and which one was the cheaper JPEG image.


my question is - is this normal - to thenake eye to not take much notice of the difference

or was i just lkucky and must not have had a bad sahot to start with


i mean - i could not notice any loss in quality between the 2 images.

yet, raw is meant to look immaculate almost where as, when u alter a JPEG, it is usually more noticeable.


does anyone here relate to what im asking but has an answer / thoughts?

also - am i right to say that, in many cases its not always noticeable on a p.c. screen

but when u go to print images or watch back on massice screen / blown up images then u can appreciate that raw has little loss in quailty

[ofdphoto]

GREAT question - not silly at all!!

There are plenty of photographers who while knowing the benefits of RAW, choose to shoot JPEG. Just so you know.

The reason they do this is because:

1.) They know they will nail the exposure every time, so using RAW for highlight/shadow recovery isn't going to help them.
2.) They know they will select the correct white balance every time, so clipping colour channels (e.g. blowing out the reds in an image) due to incorrect white balance isn't going to happen (RAW is a defence against this).
3.) They're comfortable trusting their camera to apply sharpening, contrast, saturation etc. to their taste, or comfortable that whatever sharpening etc. they apply in-camera will not impact adversely on their final post processing.
4.) They don't want to waste time and storage space managing RAW's.

I personally prefer RAW because it gives me more freedom to shoot without worrying too much about white balance, processing settings, etc. Exposure I DO worry about because nothing can properly fix an underexposed (or overexposed) image... even though you can pull more out of a poorly exposed RAW than a poorly exposed JPEG.

I hope that helps.

[AussieCat]

lin

i hear what your saying

thanks

but i still dont really get how raw has a physical difference to JPEG


when actually editing the image.



is it right to say they can look the same when u edit both to your desired effect but

with raw, there will be more details / less loss in quality of final image??

./


yeah - i knwo what u mean, i do social events where i have to be on my toes and take poics instantly...and sometimes i just dont have the time to play with settings and trying to ensure that ecery single shot has excellent exposure

so, i will use raw in some cases now for sure!

Originally Posted by linarms

GREAT question - not silly at all!!

There are plenty of photographers who while knowing the benefits of RAW, choose to shoot JPEG. Just so you know.

The reason they do this is because:

1.) They know they will nail the exposure every time, so using RAW for highlight/shadow recovery isn't going to help them.
2.) They know they will select the correct white balance every time, so clipping colour channels (e.g. blowing out the reds in an image) due to incorrect white balance isn't going to happen (RAW is a defence against this).
3.) They're comfortable trusting their camera to apply sharpening, contrast, saturation etc. to their taste, or comfortable that whatever sharpening etc. they apply in-camera will not impact adversely on their final post processing.
4.) They don't want to waste time and storage space managing RAW's.

I personally prefer RAW because it gives me more freedom to shoot without worrying too much about white balance, processing settings, etc. Exposure I DO worry about because nothing can properly fix an underexposed (or overexposed) image... even though you can pull more out of a poorly exposed RAW than a poorly exposed JPEG.

I hope that helps.

[ofdphoto]

If you manage all of your camera's settings perfectly for every shot (exposure, white balance, sharpness, contrast, saturation, etc.) you will get the same end result out of a JPEG as you get out of a RAW.

If you make any mistakes when shooting JPEG, your options are pretty limited (the camera only gives you the file it produces after processing the RAW according to your settings), whereas with RAW you can fix slight exposure mistakes and set all the other bits to your liking afterwards.

In other words, yes, a RAW file contains more information than a JPEG ever will, but if you know how you would process that RAW and can get your camera to do it for you on the fly (which is effectively what you're doing whenever you shoot JPEG), you're ahead.

Personally I think 100% RAW shooting is the go because you have better workflow options (especially in Bridge / Adobe Camera Raw) and don't have to think so hard while shooting.

[tzalman]

You are right that the lower quality of the jpg will be more visible in big prints. But you also have to know what to look for. Open the 2 files in PS and compare their histograms. The one edited in the RAW converter will have a solid mass of black and the one edited in PS will have a histogram that looks like a comb, especially on the left side where the dark tones are represented. That is called banding and it means that the transitions from tone to tone are not smooth and done with small steps but rather with big jumps and gaps between the tones. It happens more in the dark tones because they are portrayed in the original image with very few tonal levels. (In a jpg image having a 5stop range from darkest to lightest parts, this range is divided into 256 steps. But the brightest stop is portrayed with half of all the steps, 128. and the next stop down gets 64 steps and so on. The darkest parts get only 8 levels.) When you make the image lighter you are taking that small amount of information and stretching it to cover a bigger interval, so gaps appear. This sort of banding can happen at higher levels also but is usually not very visible unless there are blocks of solid color like a blue sky. Those gaps in the comb between the teeth mean levels lost. A little bit of editing of a jpg isn't bad because the human eye can only see about 200 levels so you can lose 50 and still be ok. But lose more and it can be seen.

So how is RAW different? The jpg has 256 levels because it is written in 8 bits. The 40D RAW is 14 bit. That means 16,380 levels. Lots of levels for the dark tones too. And when they are made lighter the gaps are tiny. So tiny that they disappear when the data is reduced to 8 bit by the conversion to jpg. You can push a RAW a lot further without getting visible banding. In a similar fashion the same is true of noise.

Here's another advantage of RAW: Lets say your shot is not too dark but rather the opposite - slightly overexposed. A lot of RAW converters can reconstruct the data lost by slight overexposure. No way to do that in jpg.

One more point. Do your experiment again but this time use a photo where you have set the wrong WB, say Tungsten for an outdoor shot. Try to correct that in jpg. It can be done if you have skill and time, but it still won't look as good.

[guzzibob]

That's one of the best explanations of the advantage of shooting RAW that I've seen. Thank you Tzalman.

[Tixeon]

RAW images can be tweaked & adjusted.
JPG images need to be repaired.

The above is assuming less than correct exposure & color balance.

[cdifoto]

Underexposure isn't really the big argument for RAW.

[PhotosGuy]

When to begin shooting in RAW?

[AussieCat]

TZ


Cool, thanks for all that.

Its a bit technical but i can understand what you are saying overall.


sweet.



i cant wait to start using raw more often for social events i cover.

Originally Posted by tzalman

You are right that the lower quality of the jpg will be more visible in big prints. But you also have to know what to look for. Open the 2 files in PS and compare their histograms. The one edited in the RAW converter will have a solid mass of black and the one edited in PS will have a histogram that looks like a comb, especially on the left side where the dark tones are represented. That is called banding and it means that the transitions from tone to tone are not smooth and done with small steps but rather with big jumps and gaps between the tones. It happens more in the dark tones because they are portrayed in the original image with very few tonal levels. (In a jpg image having a 5stop range from darkest to lightest parts, this range is divided into 256 steps. But the brightest stop is portrayed with half of all the steps, 128. and the next stop down gets 64 steps and so on. The darkest parts get only 8 levels.) When you make the image lighter you are taking that small amount of information and stretching it to cover a bigger interval, so gaps appear. This sort of banding can happen at higher levels also but is usually not very visible unless there are blocks of solid color like a blue sky. Those gaps in the comb between the teeth mean levels lost. A little bit of editing of a jpg isn't bad because the human eye can only see about 200 levels so you can lose 50 and still be ok. But lose more and it can be seen.

So how is RAW different? The jpg has 256 levels because it is written in 8 bits. The 40D RAW is 14 bit. That means 16,380 levels. Lots of levels for the dark tones too. And when they are made lighter the gaps are tiny. So tiny that they disappear when the data is reduced to 8 bit by the conversion to jpg. You can push a RAW a lot further without getting visible banding. In a similar fashion the same is true of noise.

Here's another advantage of RAW: Lets say your shot is not too dark but rather the opposite - slightly overexposed. A lot of RAW converters can reconstruct the data lost by slight overexposure. No way to do that in jpg.

One more point. Do your experiment again but this time use a photo where you have set the wrong WB, say Tungsten for an outdoor shot. Try to correct that in jpg. It can be done if you have skill and time, but it still won't look as good.

[AussieCat]

oh

so what u are saying is raw is more uselfull when u overewxpose

Originally Posted by cdifoto

Underexposure isn't really the big argument for RAW.

[tzalman]

Originally Posted by AussieCat

oh

so what u are saying is raw is more uselfull when u overewxpose

Yes indeed. In fact, many RAW photographers intentionally overexpose - but not to the point of actually blowing out the brightest parts - and then pull the exposure back down with the RAW converter, which improves the quality of the image.

[AussieCat]

interesting, never realkly knew that it improves the quality.

i personally like the slightly overexposed look / high contrast images


maybe i should get into glamour photography.
ha

Originally Posted by tzalman

Yes indeed. In fact, many RAW photographers intentionally overexpose - but not to the point of actually blowing out the brightest parts - and then pull the exposure back down with the RAW converter, which improves the quality of the image.

[PhotosGuy]

so what u are saying is raw is more uselfull when u overewxpose

RAW is more useful anytime.
A max jpg from my 20D is about 2,754 KB. The exact same shot with the jpg extracted from the 12-bit RAW "negative" is 4,315 KB which is 1.57X larger.
Whatever info is in my from-RAW-jpg is a lot more detailed than what comes right out of the camera. Why throw those extra bits away?

[cdifoto]

Originally Posted by AussieCat

oh

so what u are saying is raw is more uselfull when u overewxpose

I didn't say that either.