Curves
 

I see Ron Bigelow has just posted Part 1 in a 5 part series on his web site.

Very interesting for learners like me. http://ronbigelow.com/articles/curves-1/curves-1.htm

Don

Don, it all seems rather a lengthy and wordy tutorial on the Curves tool. and its only number 1 of 5. I can't wait for the rest ;) :(

Frankly I would sooner get a decent book.

I knew you would ask which one ;)

The Photoshop CS2 Book for Digital Photographers by Scott Kelby. Without a doubt the best one around and by the leading exponent of the program. Its very readable and informative. Get over to Amazon and do yourself a favour :)

Thanks for the recommendation Stephen.

All a bit of a puzzler when you don't know the program and are trying to work out which is going to give the best info on features you are likely to use. Thats why I have been doing a bit of web trawling to get a bit of basic understanding of some of those regular features.

It will take me time to understand Tone Mapping for example, a feature from your critique post.

Don

Ah yes, I'm still experimenting with this, but its something I see great potential in. If you want to know more you could try here http://www.hdrsoft.com/resources/dri.html#tone_mapping

I personally feel that what I have done is more of a conceptual thing, I am not trying to play by the rules so to speak, rather I'm pushing the bounds of what the program can do, just to see what happens.

By the lack of comments it would appear that people here are not too keen, are not prepared to open their minds to it, or simply are being polite and not offering any input for fear of offending. Frankly I wonder if the critique forum is the best place, but thats another issue I'm struggling to come to terms with on this site :)

Just as a further offering though, this is another test with the tonemapping plugin from Photomatix, Ipersonally think there are great possibilities :)

Beautiful image, Stephen.
I'm still trying to work my way through the basics of my 20D + PS7 so I'm a long way from geting to Tone mapping or other exotic subjects. That doesn't mean that I can't appreciate the results though.
As an aside, I rather wish that some one would do a series on Sharpening.

I love this. Did you start off by generating a new .hdr with a few repeated and varied 'tweaked exposure' copies from the original - or did you do it purely by several repeats of just the one 16bit image (without the nedd/use of any further repeated copies and a new .hdr).

I haven't tried pushing the tone mapping on anything yet but I'm keen to give it a bash as soon as I feel i have a suitable image to work with. :)

Pol

Hi Pol, I simply used a single file converted to 16bit. I then applied the TM plugin 4 times, each time adjusting the strength and white/black point sliders to get a good histogram

Aha! Thanks for that! I haven't tried using the white/black sliders to any great extent so far - I've only been using them in tiny doses.

I feel some serious geekery sessions coming on in the very near future.

Wahey! :D

Pol

Stephen did you dowload the plug-in or is it with CS.

It's a download available from http://www.hdrsoft.com/download.html ...... scroll down and look for the "Tone Mapping plugin" - but I think it's only compatible with CS2. If you don't have CS2 you can still use the standalone "PhotomatixPro" programme which also has the same tone mapping functions. The trial software versions are fully functional though they leave a watermark on the final image.

Dunno about Stephen but I found the following link helpful and easy to follow as it's written in easier-to-follow terms. It explains more about high dynamic range (HDR) in photography.
http://www.cybergrain.com/tech/hdr/

Also see the homepage of the photomatix site at http://www.hdrsoft.com.

I'm just experimenting with it too - ain't done anything 'arty-clarty' with it yet, just testing it with regular photos, using the plugin to tweak highlights/shadows/colours and fiddling about with it using layers.

I don't think there are many 'expert' users about so almost everyone is just experimenting, having fun and seeing what they can achieve with it.


Pol

Thanks Pol I have downloaded it and having a play.

Have fun - it can be very addictive once you get going.

I'm attaching a couple of pictures showing what I've been doing with it so far.

They're not 'arty' like the ones from Stephen. What I did was to take a series of shots a different exposures then i merged them to create a .hdr image which I then tone-mapped aiming to bring out the details of both the sky AND the dark areas.

The exposures of the original shots ranged from under-exposed to over-exposed .. with reading taken a) from the sky and b) from the darkest areas -then shooting a short series with 1.5 stop intervals between shots.

What I did *wrong* in the shot of the yew tree was to take too long over the series of shots so the final image shows the movenment in the clouds 'cos I'd underestimated the breeze.

The one in the graveyard didn't have so much cloud movement - but it wouldn't have been possible to get so much sky detail AND church detail if I hadn't shot a series and created the HDR image and the tone mapped it.

Hope that all makes sense.. I'm not exactly techie, nor am I a very experienced photographer. :o

Two images attached - content is nothing special but they show something of how you can get extra detail in light/dark areas of the same image

Pol

Polly I notice you don't have the watermark all over the photo's have you removed them.

Did you mean to ask me about the watermarks? (you addressed the posting to Don)

I've bought the plugin so mine is registered therefore there are no longer any watermarks on my saved images. :)

Pol

Sorry Polly My mind is going I had better correct that. I looked at the price and thought I would just play for now.

S'ok. I have 'senior moments' myself but don't tell anyone. :D

Aye, I agree it's worth playing about with it for a while before you decide whether or not to buy it. It works out at about £48.18 with the VAT added so be sure you're likely to want to use it - or maybe share the use of it with other members of the family who use the same PC and/or laptop.

Pol

Hi Pol,

Thanks for posting those. The church pic really does show how much extra detail you can get. I am having a bit of a play with D-Lighting in Nikon Capture and am amazed at the amount of shadow detail that it is capable of bringing out.

Don

If you, Saphire or anyone else is interested - I'm attaching a screenshot showing the source images and the CS2 'merge to .hdr' interface for the church/graveyard image.

The merged image, seen on the right, was then opened in CS2 then tone-mapped with the photomatix plugin to produce the final image which I'd attached to my earlier posting.

As I said - the content isn't anything special but the opportunity had presented itself for me to set up in a quiet corner where I could try out a series of shots for experimenting with .hdr and tone-mapping.

I used spot metering - took a reading from the sky and a second reading from the darker wall - then took 5 shots with one stop intervals (as seen in the attached source image)

Dimensions are approx. 1000 x 735 pixels as that was necessary to show the full CS2 interface and source images.

Pol

Firstly, let me apologise to Don for hijacking his thread, these things are sometimes like chinese whispers and the subject seems to end up totally different to how it started out :)

Pol, I seem to be having a problem with the way in which CS2 is blending your images in the example you have shown. The sky in the blended preview still seems burnt out in places, whilst the the shot taken at 0.0EV seems to look pretty good in the sky area. In fact the preview looks much like the one in the +2.0EV. So whats going on here? Could it be modified by switching off one of the images at the extremes for example. The sky area in the example you posted earlier in the thread seems much better to me, was that produced in the same way or is that the result of applying tonemapping to the resulting HDR image. If so I would argue that some of the tone we see in that other example is the grey infill that the plugin seems to apply to blown highlights.

I must admit I'm usually rather intriqued by what the CS2 merger coughs up in the initial preview. The histogram can of course be altered at the preview stage, though I've usually opened the unaltered preview version, converted to 16bit then used the "equalize histogram" or "local adaptation" - then done the tone-mapping.

The graveyard image is tone-mapped - that's how I retrieved the blue area above the roof..... after all, the components are there in the .hdr they are retrievable.

The Yew tree and churchyard were my first and only experiments at shooting a specific series (apart from that gate latch series) so I can't really claim to be any sort of expert. :D

I think maybe what I have concluded is that 3 shots at 1.5 or 2 stop intervals would probably be enough though - I reckon that should cover sufficient range. I think I probably overdid it with 5 and might be better trying bracketing another time.

What I actually did was started shooting with the shutter speed set at the reading from the sky - then worked down in 1 stop intervals until I reached the reading from the dark wall.

I suppose I could also convert the RAWs to 8bit jpgs then see what happenes if I create the hdr in the Photomatix basic freeware..... though the picci is just so boring I'm not sure if it's worth the bother. :(

I'd rather try to have another attempt only somewhere and something more interesting.

Pol

Well I'd be up for that :D

Stephen - here's something fascinating! I've just gone back and used ony 3 images for the merge. See the attached for what it produced in the inititial preview.

I think the upshot probably is that the creation of the .hdr is only a very crude starting point and it's what you do after the merge that really matters.

Pol

I think you must be right Pol, thanks for doing that

Yeah well. We can't all be sitting 3 hours in a traffic jam heading for somewhere interesting to shoot ........ and never arriving. :D

Better luck next time, m8. :D

Pol

I was just thinking to myself - maybe it is better to have an extra shot either side of the range (if possible) then you can be sure you have enough to experiment with - especially if you've travelled to a specific, distant location. Better safe than sorry!

I reckon it should also be ok to shoot fine jpgs for an hdr series too. Saves on CF space and you're not going to be using the ACR anyway - unless you decide you want to process a one-off image from one of the series.

Pol

No problem at all Stephen.

All very interesting stuff. Gets the little grey cells working.

Don

Special request then Stephen. :D

Part 2 here http://ronbigelow.com/articles/curves-2/curves-2.htm

Don

Goodness me is he really going to spin this out for another 3 parts :(

Stephen,

Only 2 more to go. :)
http://ronbigelow.com/articles/curves-3/curves-3.htm

Don

I feel like cutting my throat ;)

Stephen,

You will be pleased to hear only one more to go. ;)
Part 4 http://www.ronbigelow.com/articles/c...4/curves-4.htm

Don