More on RAW files.

Hi Matt, (and everyone else of course)

I started to post this in Mannesty's thread, but I thought it would be unfair to take the conversation off on a different tangent..

Whilst we're on the subject of RAW files, how much of the work do you do in Rawshooter, Capture 1 etc., and how much do you do in PS. For instance, do you just alter the WB and exposure before converting to TIFF, and then sharpen/saturate etc. in PS, or do you do more than that with the RAW file?

Also, as I'm now accumulating enough memory for a good day out shooting RAW (220+ images), I'll be concentrating more and more on that format now. I understand that RAW takes all the data direct from the sensor, and that there must be certain limitations on what gets recorded; ie. that an image taken at 1/4000 @ F32, when it should be 1/4 @ F4 is going to be a long way outside the limits, but if you take an image in RAW, what sort of latitude for over/under exposure would be easily corrected as a rule?

I ask this because I took lots and lots of photos (***jpg) in Bruges at the weekend, while using aperture priority rather than Auto. It was a very bright sunny day, and although I was using my hand as a 'grey card' for many, I ended up with a lot of under exposed photos, that although not so far off that I couldn't rescue them, did make for a little extra work in GIMP. If I'd shot in RAW, the RAW plugin for GIMP (UFRaw) would have let me do a far quicker job of adjusting them just by sliding the er.. slider. and obviously so would RawShooter Ess.

That's it really,

Cheers

Liam

Hi Liam,

For me I do most of the work in C1LE: WB adjustment, exposure, and contrast (I often tweak the curve in C1 to add contrast or deepen the perceived saturation). Generally it's saved me a lot of time doing boring stuff in PS.

I never sharpen in C1. I always do that in PS (with my action of course ).

Additionally, if a shot is particularly demanding, then I'll do localised adjustments in PS. Dodge & burn (usually with a soft-light layer), localised saturation changes, and localised contrast changes.

If it's a really, really, tough image then I'll expose twice in C1 (once for shadows, once for highlights) and manually blend the images with layers in PS. This technique is very helpful for landscapes where there is no "one" exposure that fits the whole image.

As far as lattitude goes in RAW: I reckon you can overexpose a touch (around 1.5 stops) - but watch out for being completely blown out. As far as shadows: 2 stops is the practical limit. The deeper you go into the shadows, the more noise there is, and although you may be able to eek out 3 stops the noise just gets horrible.

(FYI, this is a result of having a linear response in the CCD, while light is logarithmic. A full half of the data range is in the top stop of exposure, the next stop has a quarter of the data range, the next has an eight and so on.)

For correcting badly () exposed JPGs, I found the "dSLR Tools" plugin a real help in PS. ( http://actions.home.att.net/dSLR_Tools.html )

Hope that sheds some light on the matter
Matt

Liam,

I mostly use RawShooterPro (RSP) to adjust exposure and colour temperature (when I get it wrong). RSP gives you + & - 3 stops exposure latitude.

I think I'm right in saying that the human hand (which most of us carry about is not quite a neutral (18% grey) colour and that some compensation is necessary. Trouble is, I can't remember which way . . . I'm sure somebody else does.

What perhaps you ought to do is to compare a reading from your hand to tone from fresh green grass, say, or better still, a proper 18% grey card to be spot on.

Lastly, why haven't you got a hand held light meter yet?

Finally & lastly why didn't you trust your cameras reading?

Just quick note about exposure compensation: I was referring to what compensation is preferable, not to what's available

Hi Matt,

thanks for that. I reckon my shots were in the 1-1.5 stop under exposed, as I did bracket some manually within that range with good results. I also had a play with setting the exposure to the autofocus (spot) with a midtone in view, and that sort of worked.

As far as sharpening goes, I've got GIMP, and halving the default value for the radius (from 5.0 to 2.5) with the inbuilt unsharp mask, I find gives excellent results. Of course, these are for displaying on the intermerweb thingy, rather than print at the moment, so I'll start playing with your action, or transfer the principle to GIMP anyway, when I do get more into print.

Hi Peter,

I've got a hand held meter.. somewhere. It's an old Hanimex Sekonic (about half way down the R/H column) , born before I was.

I do trust the camera.. I assume you mean by leaving it on AutoWB? Normally I have had great success with it, but as I only got the camera back at the end of last year, it's the first time, it's been made to perform on a bright sunny day in a built up area, with lots of contrasting areas. As I've concentrated on a single focal element to the majority of my images, such as a single bird or person, I've not had the practice at a severe multi-tonal images, needing only the main object to be perfect.. by that, I mean that if the background is a stop under it generally adds to the definition of the bit I actually want.. umm.. if you know what I mean.

As for using my hand, it could be that I'm doing it wrong anyway, as it's not a fraction of a stop out, but a stop or more. I just started to type how I used my hand.. and worked out why it wasn't working.

I was trying to take a picture of a building, for instance that was in shade.. I was in direct sunlight and took a reading off my hand, whilst it was being lit up by the sun.

I guess taking a reading off the paving, but in the shadow I cast, would be a lot more accurate. Oh well.. live and learn. That's probably the only (perceived) disadvantage of digital for me.. I'll take a couple of hundred shots with little technical thought, rather than set up each short carefully with film, knowing that each shot was going to cost around 50p a go.

Anyway, enough typing practice for now..

Cheers

Liam