K10D dynamic range (DR) in JPEG's


Link Posted 12/12/2007 - 12:32
I saw this post on dpreview


And I found it interesting as I have been having problems with blown highlights. My problem was most probably because I was using +1 ev most of the time when i should have probably been dialing down to -.03 or simply keeping it at 0.

The author of the post states that keeping contrast to a minimum, ev at -0.7 and using the Bright curve will result in better dynamic range.

Bright Curve have not better DR ! But with combination :contrast to minimum, exposure to -0.7 , the results are different!

Contrast to minimum is "open" shadows without changing the lights.

With exposure to -0.7 you can save the lights , and after that to "open" shadows with contast to "minimum"

Does this make sense to some of you? Any other tips for maximising DR in general.

Pentax K10D, 50, 18-55, 28-70, 100, Sigma 10-20, Tamron 18-250, 28-75


Link Posted 12/12/2007 - 12:41
Have you tried using RAW? This sometimes allows you to pull back some detail in shadows and highlights.
Please call me aj,

I use a Pentax K10D, on a MacBook with LightRoom (vers 1.3 + beta 2)



Link Posted 12/12/2007 - 14:18
Following on from ericp's post, which I found extremely interesting, is there a general concensus of opinion on which settings (image tone, saturation, contrast and sharpness) are the most beneficial for the K10D?

Whilst researching, before I bought mine, I read that images benefitted from +1 contrast and +2 sharpness, which is what I've been using.

I normally shoot jpegs and although I am very happy with the results from these settings, ericp's post has opened a whole new can of worms!

Am I being paranoid or is it purely a personal preference thing?


Link Posted 12/12/2007 - 14:54
browngo1 wrote:
is it purely a personal preference thing?

I think it's entirely a personal preference thing.

But which way you go will have consequences.

An example of this is that it isn't generally considered to be a good idea to apply sharpening to a picture more than once, at the end of the editing process.

Now, for unsharp mask, for instance, the bigger the display size, the higher the USM settings need to be, and even then it's quite subjective. So how you sharpen will depend a lot on the target size, and the look you want to achieve.

If you let the camera do it, you are relying on whatever its assumptions are about about the target display size and this may not be the best for what you want.

So if you're likely to want to do much post processing on the computer, it makes sense to have the camera do as little as possible.

If, on the other hand, you want to use the results straight out of the camera, with very little computer work if any at all, there's no reason not to set the camera to whatever you like the look of.

When I use RAW+, I quite often have the JPEG sharpness up one notch, or sometimes even two. Then I get the best of both worlds - a crisper JPEG and a RAW file that I can attend to properly should the shot be any good.


Link Posted 12/12/2007 - 16:14
I have tried using RAW but I am afraid I am a novice. I don't even use the MANUAL mode on the k10d yet! When people talk about RAW conversion and getting the sharpest pictures if goes right over my head. How does one judge sharpness?? I have the 50m 1.4 and people keep saying it is not sharp below 2.8 . I can't tell the difference. Any links that are helpful for this and RAW conversions? I am using Lightroom as it is easy to use and my poor old computer (mac powerbook) slows down like crazy when I use Photoshop CS2 for a while.

I went to Costa Rica with 3 2gb cards and managed to take 1600 photos. I did take about 50 RAW but the rest where JPEG. I take JPEG because of space and because I don't really know much about post processing. And ideally, i really don't want to spend too much time on a computer post processing. If it was my job, i would but my passion for taking pictures does not easily extend to hours on Photoshop. So I would like to focus on composing better and managing the settings at capture time.

I compare my experience to playing football. Possibly a poor analogy but here it is anyway: I have been playing football for years at an intermediate level and I really enjoy it. I show up, run around the pitch for 90 minutes and maybe score a goal or two. I don't have to worry about anything else and when the game is over, I shower and have a few beers in the pub. I recently took over management of a team and now along with playing, I have to organise the team, find more players if we don't get at least 11, find a referee and two linesmen and motivate the players as captain on the pitch. Then at the end of the game I have to collect money from all the players and pay that to the officials and the owners of the pitch. I manage the team by email so I spend a lot of time emailing. This has taken a lot of the fun out playing football. That management to me is what post processing is picture taking

It is all personal at the end of the day. I just don't want blown highlights like I did with 90% of the pictures I took in Costa Rica. I know better now but there must be a wealth of knowledge out there but it is not very easy to get hold of. Everyone in this forum is VERY helpful and I thank you but at the same time everyone has a different preference so coming in as a novice it can be quite daunting and with so much information it can be hard to decide how to best capture those moment. I appreciate if i was taking a lot more pictures then I would probably get much better but unfortunately it is hard to find time along with my many other commitments.

Sorry to bore you all but I hope you will find some logic in my madness

Pentax K10D, 50, 18-55, 28-70, 100, Sigma 10-20, Tamron 18-250, 28-75


Link Posted 12/12/2007 - 16:34
ericp wrote:
I have tried using RAW but I am afraid I am a novice. I don't even use the MANUAL mode on the k10d yet! When people talk about RAW conversion and getting the sharpest pictures if goes right over my head. How does one judge sharpness??

I really wouldn't worry about all this.

A lot of people (not here so much) talk a lot of rubbish about "sharp". They show you an 800 pixel photo that's been reduced down from the original for a web page and would have you believe you can look at it and judge how sharply the lens can reproduce detail.

Well you can't. If the lack of sharpness is less than a screen pixel, you can't see it on a computer screen.

Most lack of sharpness on the sort of pictures you and I see every day (on the web, or on smallish prints) is to do with camera shake, motion blur, lack of depth of field, or simply not focusing properly. To guarantee to not get any of these can be quite difficult.

People also tend to confuse lack of contrast with lack of sharpness. It's not surprising, because black against white will look sharper than grey against a similar grey. But this confusion also leads to more rubbish being talked.

If you're relatively new to all this, concentrate on taking good pictures, not on whether at some fraction of a micro-pixel there's a lack of sharpness.

If you're making large prints and examining them from a distance of three inches, then sure, the lens makes a difference to the achievable sharpness. But then eliminating the factors I listed above becomes even more important.

I suggest you take some pictures, and experiment with them in Photoshop Elements - or even Picasa, which is free. You'll soon find what you like, and what you don't.


Link Posted 12/12/2007 - 21:53
Re RAW. You can take post processing to any level of detail, but the minimum extra processing is really quite tiny. In Adobe camera RAW, look at the RAW image, alter the white balance if you believe the alteration represents the light/colour better, look at the histogram, change the exposure if necessary, usually towards the right (original
under exposed), but making sure the curve doesn't run off the right hand side. Move the histogram to the left if the curve is already off the right hand edge (over exposed). Save as TIFF (the PS default). The RAW file remains intact. That's the RAW bit. In PS/PS Elements you can then play around in whatever way you choose with levels, colour saturation, etc, just as you would the jpeg from the K10D. Saving as TIFF means you can save again and again (as LZW to save space if you prefer) without loss of quality. Only apply USM just before final saving/printing.
White balance check and exposure adjustment are the only 2 really essential RAW processes and can only be done on a RAW file. You may be amazed what a difference adjusting the exposure in RAW followed by a levels tweak in PS (bring the left and right sliders up/down to around the ends of the histogram) does to the appearance of the image.
More expert togs may have better/more effective ways, but the RAW part of processing is very quick. Whilst I accept that Silkypix RAW processing produces marginally better results than Adobe RAW, Adobe RAW will provide far greater improvements over shots taken as jpegs. Shoot PEF RAW with the K10D, it's lossless compression means far more shots per card.



Link Posted 14/12/2007 - 12:19
Just to add my thoughts...

1) If you are a novice, then leave the exposure compensation at 0.0Ev. Trust the camera until you know otherwise

2) You can never get away from blown highlights completely. Some scenes have so much dynamic range that it's impossible to get a good shot with a single image (RAW or JPG). The human eye is orders of magnitude better than anything you can buy (currently at least).

3) It is better to slightly underexpose than overexpose. For tricky situations when using JPG, consider using the Shadows/Highlights tool in Photoshop Elements - it will bring out detail in the shadows and "even-out" difficult lighting.

Personally, I find it very rare that I need to use exposure compensation... but then you have to just learn what the camera is "seeing". Occasionally I will use the exposure lock feature when using Auto (actually Av mode).

Hope that helps!
(For gallery, tips and links)
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