Why Raw?

I'm getting to grips with my DS after (originally) grudgingly giving up my MZs. Overall very impressed with digital DS (but knobs were better than menus), great with 16-45, 24-90 and the excellent Sigma EX 100-300, but still using my MX and Ricoh GR1v for slides.

I have been experimenting with Raw and generally disapointed at unweildlyness of Pentax photlab, (not helped by my slowish 1Gz PC).

Is there any benefit with Raw over jpeg if you get the white balance and sensitivity right when you take the shot?

DO they both translate to similar quality Tiff files (via photoshop)?

I have heard some of the issues re sharpness; does applying USM to the Ds' jpegs give as good a result when starting with Raw?

Is the photshop Raw plug in better then Photlab, and is it available (free?) for photoshop 7.0?

Thanlks for any help

Kevin

There are others who can go into more detail regarding RAW capture than I can, but for myself I have only used the best quality of JPEG. The results up to A3 are, I think, superb and I can't find any reasons for using RAW and suffering the inconvenience that causes. But then I am, arguably, a very lazy photographer constantly looking for simple solutions!

Exposure I do not find a problem with the *istDS, so there is nothing to rescue (one of the arguments for using RAW).

I find I am using less USM as time goes by, and in general I now use no more than 50%. It is possible to sharpen more for specific effects, especially when just sharpening the Lightness channel in Lab Colour.

A TIFF saves all the information in the file with no loss, so whatever you produce either via RAW or JPEG will be preserved. In theory, the RAW file will provide a superior result, but the downside is more processing of the images and far fewer pictures to each SD card. Also JPEGs can be handled by any computer, anywhere.

Kevin,
The RAW vs JPG is perhaps a complex subject. It depends on your needs. John has raised some valid points, and if you find that JPG is good for you - stick with that. RAW files are much larger, and do require processing at the PC.

There are many RAW convertors out there, and I'll deal with those at the end.

Personally, I find only use RAW. Here are some reasons why:

* Greater dynamic range. For shots into sunlight, or where there are great variations in light and shadow, RAW gives much more headroom. You can shoot first, and decide later.

* Push/Pull processing. Since the RAW file has a finer degree of sensitivity, you can push and pull at between 1 to 2 f-stops with RAW. I have found this invaluable when doing low light shots - gigs etc.

* Colour control. When using RAW you have a much finer control over colour balance. Not just a case of picking the WB setting, but you can colour match each shot, handle mixed lighting, make the image slightly warmer or cooler. Depending on the convertor you use, you can have control over individual hue ranges and adjust them! For tricky lighting you only need a small patch of grey, or one frame of grey for the session and you can colour match all the frames to that one sample.

* Better resolution. Again, depending on the convertor, you can get much higher quality (in terms of fine details) than JPG. The PC software can apply more complex algorithms in converting from the RAW Bayer matrix image. Some RAW convertors can upsample up to 4x (Photoshop CS RAW and Capture One Pro). Has to be seen to be believed!

* Hot pixels. Some RAW convertors (notable Capture One) can automatically remove pixel hot spots in RAW. This has saved me hours of processing when using ISO800 to ISO3200 when doing concerts and plays.

* Better noise control. Again, depending on the convertor, you can get much, much cleaner images than you can ever get with JPG, especially for low light.

* Wider colour gamut. JPG when set to sRGB is a very limiting colour gamut. You will find that the red channel can often "blow out" (examine it in Photoshop, say on a portrait to see what I mean). You can use AdobeRGB which gives you a wider gamut and solves a lot of those problems. However, in RAW you can choose your colour gamut on output. For images that need a fair bit of Photoshopping, converting from RAW to 16-bit TIFF in the ProPhoto colour space gives ample headroom for editing and saves you from a lot of posterization problems (like when you tweak curves, levels etc).

* Double processing. For tricky shots - like very wide dynamic range images, or images with multiple light sources - you can process RAW several times. For example, you can create one JPG or TIFF that's exposed for the highlights, one for the shadows and blend them in PS using layers and layermasks. Alternatively for difficult lighting, you can create a JPG/TIFF with colour balance for the tungsten, then one for daylight and blend the two (this technique is useful for creating natural looking room shots where there's a window).

* More consistent results between frames. The RAW convertor usually allows you to copy the settings for one image frame to others. This yields very close results between frames.

Phew! Sounds like I need to write an article!!

In addition, the RAW convertors vary greatly. Here's my thoughts on the convertors:

* Camera supplied convertor. Usually not much good. Just provides basic processing. Doesn't really show the benefits of RAW.

* Photoshop CS, CS2, PSE3. The RAW convertors are pretty good, and I used these before discovering other products.

* Pixmantec RAWshooter Essentials. Great product, mainly because it's free! Takes a bit of learning. Handles low ISO images very well, but personally I find the image noise unwieldy at ISO1600 and ISO3200 particularly. Definitely worth trying though!

* Phase One Capture One. Available in two version. The Pro version is $500 (I think), and the LE is $99 (plus VAT etc). I use the LE version exclusively. The hot spot removal, noise control, excellent film-type response curves all make this a complete breeze. It actually saves me time! You can also purchase it in the UK from www.ephotozineshop.com

Hope that helps!
Matt

RAW is intended to be, basically, a digital version of unprocessed film. You can render a file once for highlights and once for shadows, then layer them and use the best part of each. Beats copy stands, glue and Exacto knives by a hot mile!!

If you can get Adobe Raw converter (free from Adobe site) and/or you use Photoshop or Photoshop Elements, you can insert RAW into your workflow and get much better results. You can apply the ammount of sharpening you want, do subtile color adjustments, make up for forgetting to set white balance, and so on.

I'd say try the Adobe DNG converter if you don't have Photoshop. It's free, and it works really well.

Just for clarification:

Adobe DNG is just another RAW format, and not completely compatible (yet) with all convertors. It will squish a PEF file down to around 5.5Mb, while still retaining the same information (it uses lossless Huffman encoding).

Even if you use Adobe DNG you still need a RAW convertor

Photoshop Elements 3 is a good place to start if you don't have Photoshop, and as I said, Capture One is IMHO the best all round (if you can get to grips with it).

Other points - the RAW quality difference can be seen at 6x4 It's not just about printing big - it's about squeezing the most information out of the CCD. In camera JPG will apply sharpening to some degree or other. RAW gives you the ability to process first before sharpening, thereby avoid unnecessary artifacts, posterisation and the like.

Matt

Thanks Matt

I think I will be getting P1C1 then save Tiffs for Photoshop 7

Having said that more or less same price as Elements 3 with free Raw plug in

Kevin,
As you have PS7, I'd go for P1C1
Download a trial version and give it a go! If you need any pointers, drop a new forum thread here and I'll do my best to answer!
Matt

hmmm

Just found my PC is not up to either option, more expense

I ran Photoshop CS for several months on a PII 450MHz and 512RAM; well below the minimum spec. Resampling could be slow but in the main it was perfectly usable.

The downside is that when I upgraded to a 3.2GHz machine (yes it was noticeably quicker) I used up the second activation. I suppose that next time something like that happens Adobe are going to lose another customer.

You have not used up your second actvation, if you TRANSFERRED that activation. Contact Adobe and find out if you transferred it, and how to fix it if you did not. An email will get you the necessary informationl

They're not THAT stupid. lmost, but not quite.

I may put off the new pc for a while

I guess shooting and saving in RAW, then using Pentax Photbrowser to save copies as TIFF for editing in PS7 is the best route for the time being.
Is there any reason why TIFFs created in this way are likely to be of lesser quality than TIFFs created from RAW via P1C1 or the Adobe plug in? (so long as no changes to white balance etc are required for the RAW conversion)

Thanks again

Kevin

Huge difference Kevin. Huge. But if all your PC can cope with is the Pentax convertor - then that's all you can do. If you can run RAWshooter Essentials (www.pixmantec.com) then that's better. Different again is the Adobe one (Photoshop Elements 3, or Photoshop CS2 or CS). Best, IMO is Capture One. For the reasons I gave above (Film-like response, quality, detail, noise reduction, hotspot etc etc etc)
Matt

In answer to your question, there's no good reason why Pentax's own RAW convertor, like, totally sucks. It just does. The Mac version is even worse (in terms of results, not just usability). As Matt says, the difference in results from Pentax's own offering and P1C1 have to been seen to be believed, particularly if you're trying to recover a bit of underexposure.

Why this should be is a bit of a mystery, particularly as Pentax presumably know much more about the internal workings of the camera and their RAW format than PhaseOne or Adobe. But I guess if you spend all your time making great cameras you can't be expected to write decent software for them.

Steve

http://www.siblingmedia.com/
http://www.siblog.co.uk/

I wasn't going to put it quite as strongly as that, but now that you mention it!!

The reason is quite simple and is to do with what RAW actually is. RAW isn't "complete", as it were. In the resulting TIFF image, there are three values per pixel - red, green, and blue. However, in the CCD although there are 6 million pixels, but they are divided up into 2x2 squares. Each square has two greens, one red, and one blue pixel. (i.e. GR/BG) That's the Bayer filter. Each physical pixel can only measure the brightness - not the colour, so the Bayer filter is the trick to get colour. So you have 3 million green pixels, 1.5 million red, and 1.5 million blue pixels.

When building up the final image, you have to guess the level of the other two greens, three reds, and three blues for each 2x2 square. You have to "guess" them so you end up with 6 million pixels each of red, blue, and green. It's the maths behind that "guessing" that accounts for most of the differences between RAW convertors.

You can just average them out - but that produces a softened image, a bit like a gaussian blue. Or you can use more complex maths (FFT and other such stuff) to guess the levels. (In a way it's the image equivalent to oversampling on the old CD players, if you know what that is.)

In the process of converting the RAW image into full pixels, you often get moire patterns. Good RAW convertors tackle that too.

Additionally, there's the way you process the intensity levels from the CCD and convert them to the final image - ie whether you try and replicate film, do it linearly etc. This area was the biggest revelation when it came to P1C1. I had some very high dynamic range images that I just couldn't wrestle with in the RAW convertor (PS-CS at the time). They were looking into the sun, and I just shelved the images. P1C1 got the result I wanted in 5 minutes.

Phew! Hope that explains some of the reasons why you can't really expect the camera manufacturer to write really good software. Though that said, there is a large room for improvement!!
Matt

I have found this thread very interesting and it has help me put a few more pieces of the digital jigsaw into place but regarding the above quote surely the camera has to have good software built into it so that it can produce JPEG images. If this is the case, then surely the same software algorithms can be used in their RAW converters.

Or, alternatively is the software good enough for the quality you can get with JPEG, or is Pentax JPEG inferior?

Dave.