Weather - win some...

I mentioned in Pete's frosty morning post from Sat morning that my camera bag was packed - headed down to London again both that afternoon and again very early on Sunday morning... I had mixed fortunes shall we say. Sat afternoon was gorgeous and I'm still playing with the shots in a now fully paid up Silkypix (my God why won't they send you the product key at the weekend?!?!). Anyway here's a couple that I've had a little look at. Let me know what you think...

http://www.pbase.com/diffractionphotography/image/73911806
K10D, Sigma 12-24




http://www.pbase.com/diffractionphotography/image/74018615
K10D, Sigma 24-70 f2.8



http://www.pbase.com/diffractionphotography/image/73912115
K10D, Sigma 24-70 f2.8

That last one's superb Will.. not much more to add really..

Cheers

Liam

Will,
I love the light in the two latter ones. Great shots!
Did you use the awkwardly named "Sky bule emphasis" colour adjustment option in SPDS on the second one?

Cheers,
Prieni

I like all of them.

PS Good news for Sigma.

I like the last one a lot - good position of the sun

Cheers for the positive comments guys!

The bottom one was pure luck in the positioning of the sun - if you check out the full size image via the link I posted I got a lovely starburst effect of the sun between the towers of Westminster Abbey - doesn't show up so well in the small image!

As for the blue sky in the 2nd one, a quick tweak of the exposure minus about 2/3 stop and add Memory Colour1 in SPDS3 for Velvia like colours.

Loving Silkypix and the K10D but finding that I'm dialing the exposure of RAW's back to anywhere between minus 1/3 to 1 1/2 stops on a lot of the shots I'm playing with. Is anyone else finding the same thing?

I'll have a play with some more when I get home...

Will

I'm finding the other way - having to give +1/3 to +1 stop

And yes Silkypix is worth every penny Although if you try CS3 its catching up!

I think it depends on the kind of shot. Don't forget as well, that white balance and colour profile will have an effect on the histogram as well as exposure

I'm finding that I often have to increase exposure by up to 1 stop - but again that could be down to the combination of lens & scene.

The general way of working with RAW in SPDS3 is:
1. Adjust basic exposure
2. Adjust white balance
3. Tweak contrast
4. Select colour
5. go back to 1 if necessary and loop until happy
6. Adjust sharpness and noise reduction
7. Output

In any of the steps 2-4 you have to keep an eye on the histogram to see where the levels are and go back a step or two until you're happy.

For really rich colours, try pulling down the gamma slightly, and possibly up the contrast a touch (e.g. this image - no polariser, just SPDS3)

Matt

Very nice shots Will, #3 takes the honor's this round

With regards to Silkypix I find like Matt, it all depends on the variables, I've had to adjust upto +/- 2 on some images, but have always ended up with a very usable image.

BTW There is an early preview version of SP3.0.5.2 available for download.

Really finding some of the tips useful chaps - funny how things start to come together... I'm amazed at the additional detail that can be gained by dialing in unsharp once everything else has been tuned to my liking.

Just had another play with my only decent shot from the Sunday morning before the fog came down the Thames - wonder what I could have achieved if I'd not been thinking more about setting up the big MF gear and plonked the K10D on the tripod instead of a quick grab shot at ISO400.

http://www.pbase.com/diffractionphotography/image/74060247
K10D, Sigma 24-70 f2.8, 1/15 @ f4.5, ISO400, Handheld




What do you think? Tell you what I've been thinking - this is one film head well and truly converted...

Will

Will - you've got some serious CA on the left tower. Use the lens adjustment tool in SP-DS3, zoom in, and slowly adjust the CA controls until the red and green converge. (But be sure to check both sides of the image, because you can't always get it perfectly.)

If you can't align in SP-DS3, then try the following in Photoshop:
* Add a new layer
* Change the layer blend mode to "Color"
* Pick a small soft brush, set at 50% opacity
* Alt-click on an adjacent area to pick up the colour, and brush over the CA
* Repeat as necessary

That will keep the luminosity, but reduce the glaring red/green

HTH!
Matt

Hi Matt,

Thanks for that - I've just had a look at the large original on the website as don't have access here at work to the original files and I can see what you mean. To be fair I've read about CA but never really understood what it meant - nice to have an example...

In layman's terms please...

What causes it? Is it a digital only phenomenon? Is there a way of cutting down on it at the taking stage - i.e. what can I do to avoid it in future? Would it be less visible from a better quality file, either the original RAW or processed TIFF?

I'll probably have a shed load more questions when I get home this eve and have a go at the rectification techniques you've suggested...

Cheers!

Will

Hi Will,
Wikipedia has an article: Chromatic Aberration

It's not just digital - it's primarily down to the lens where different wavelengths (ie colours) of light bend at different rates within the lens.

It's often most visible when you have backlighting - but it's always there and if your lens suffers from CA, then correcting it will improve overall sharpness for other images as well

If you shoot RAW, and use Silkypix then that has CA adjustments which can pull the red/green or blue/yellow back into alignment. In SP-DS3 it's the button to the left of the rotation control - it looks like an hourglass figure.

Zoom in to 100 or 200%, and adjust the "R" rate - that's Red/Green.
If you have blue or yellow CA, then adjust the "B" rate.

(In your example, an R rate of +9 looks about right )

Just tweak it very slowly (use the arrows rather than grabbing the slider) and you should see the effect of the adjustment.

Matt

Thanks again for the tips Matt - perhaps you could gather together some of these odd threads together and put together a guide?

Joking aside, having been able to put all of this into practise I can really see how much of a difference that it's possible to make to a shot. I ended up using a value of +11 on that R channel but it's still not fixed it completely (see top of left tower with bright sky behind) but it has cleared up the worst of it. What I did notice was that it appeared a little worse again in this spot when I applied the final unsharp mask in PS.

I've certainly learnt a lot from this little exercise - the best part is being able to see a real example in one of my own shots. Even reading the article you linked too has widened my knowledge loads - always found this side of things facinating at school hence the website name!

Thanks again for all your help and very constructive comments!

I now need to revisit your tips on setting up screen and printer as the one I've just printed is much more orangey and not the subtle purples I see on screen

Further tweaked version below...
http://www.pbase.com/diffractionphotography/image/74094088



Cheers!

Will