Photomatix Registration Redo

On my first posting about Photomatix HDR I mentioned that I was disappointed that the registration of the images wasn’t very good. The same images were very tight in the PS CS3 HDR conversion, but didn’t work well when I did it in Photomatix.

In Photomatix, there are two registration options:

  • By correcting horizontal and vertical shifts
  • By matching features

I processed that first image using the first option. I didn’t like the results. I decided to run it again and see how it did.

Here’s the first image I did:


Here’s the new one, I generated using the second option:


The registration is much better. I also played around with the image a bit now that I’m more familiar with the tool and the process. The final look is different, not necessarily better. But the registration was tighter and that’s what I was looking for.

I finally bought a copy of Photomatix, so now I’m committed. I believe I understand the basics enough to really start exploring what I can do with it, to use it. I also signed up for the Kelby Training. The first course I ran was Matt Kloskowski’s Real World of HDR course.  It did two things. It filled some holes in what I’ve learned piecemeal of the last few weeks and it confirmed the rest of what I have learned and my conculsions. Matt’s approach is very simple – how to spread the exposure latitiude – not necessarily how to come up with the hard-core HDR affect. But he does show how to do that, he just doesn’t dwell on it. All in all a good course.

FYI – if you’re considering purchasing Photomatix and signing up for the Kelby Training, hook up with Kelby Training first and check out the HDR course. They have a promo code that will save almost enough money on Photomatix to cover your first month of Kelby. I did it in the wrong order, but I stumbled across another promo code so I was good.

On a totally un-related subject – I’ve  been watching the BBC (I think) produced show ‘MI5′. What an amazing show. Gritty, real, touching. The production techniques remind me of 24 – I think they did it first. Either way – I’ve really enjoyed it to this point. Look for it on your local PBS station.

Summer Fun – a composite

A few weeks ago I was sitting in the back reading ‘Within the Frame’. Naturally, I had my camera in my lap while I read. Just to enhance the reading experience. My daughter and her cousin were jumping on the tramp. It hit me that there was a good opportunity to do a fun little composite. So I shot a bunch of pictures and put them all together. Nothing brilliant by any means, but it was some practice in selections and blending. Learned a few things.


I showed it to my 7 year old daughter fully expecting her to be thrilled with it. Instead she scrunched her eye brows together and said that she didn’t like it – she prefers her pictures to be ‘realistic’.

Oh well.

a Pseudo-HDR image

This is a follow up to my last post.

In that post, where I created an ‘HDR’ image from a single RAW file I lightly threw out the following statement:

I guess it isn’t technically an HDR, just the Tone Map.

That’s been eating at me ever since. First, was I full of it and Second, what did that really mean? So I read up on the process and here’s some clarification.

Generating an HDR in Photomatix is a two part process. The first generates the HDR from multiple images. After that is complete the merged image is Tone-mapped. Tone Mapping is where the ‘magic’ happens. Most of the enhancements happen there.

So when you generate an ‘HDR’ from a single image you’re creating a ‘Pseudo-HDR’ that is ready to be tone mapped. This is the explaination from the Photomatix User Manual (pg 7):

Photomatix Pro allows you to create a 32-bit HDR image from a single RAW file. To do this, open one RAW file using File >Open, and Photomatix will convert it into a pseudo-HDR image. It is important to note, through, that an image created with a single RAW file cannot really be considered High Dynamic Range. The important characteristic of this pseudo-HDR image is that it is unprocessed. Its dynamic range is not much larger than the range of an already converted file.

So 1- I’m not full of it and 2 – it means that when we’re processing a single image what we’re really doing (in the Photomatix view of the world) is generating a tone-mapped image.  When we’re processing from multiple images, the first step combines the multiple images, generating a single image with a wider exposure range, then we generate a tone-mapped image.

There is an additional feature within Photomatix – Exposure Blending. This feature allows you to blend images with multiple exposures without the HDR effect. Example – shooting a interior with windows where the outside exposure doesn’t match the inside. You could take an exposure that captures the inside of the room and another that captures the detail in the window and blend them into a single image. I tried that the first time I played with Photomatix just to see what it would do. I haven’t tried it since them. I’ll explore that more later.

HDR from a single image

As promised, here’s my next foray into the realm of HDR. I ran a single RAW image through the Photomatix Tone Map. I guess it isn’t technically an HDR, just the Tone Map. Still, I wanted to see the impact.

The following is from the FAQ section of the Photomatix web site:

You can still use Photomatix when you have shot only one exposure in RAW mode. The big advantage, of course, is that you just need one image, so there is no need to use a tripod or to remember to auto-bracket, and it will also work if the subject is moving

However, the range of “workable” exposures you can get from a RAW file is limited. If you are shooting a high contrast scene, you are unlikely to match the results you would have with taking the scene under different exposures that can cover the whole dynamic range.

There are three techniques for using Photomatix with one single exposure taken in RAW mode:

· Technique 1:Open your RAW file in Photomatix to convert it into a pseudo-HDR image, then tone map it.
· Technique 2:Convert your RAW file into a 16 bits/channel image in your favorite RAW converter, open it in Photomatix, and tone map it.
· Technique 3:Create two or three exposures in your RAW converter and combine them in Photomatix as it they were “real” bracketed shots

For good results with these techniques, it is important to ensure the lowest noise level at capture time. For that, set the lowest ISO possible (ISO 100 for instance) and expose for the shadows when taking the RAW image, i.e. overexpose your shot. Even though the histogram of your camera may indicate that highlights will be lost, you should still be able to recover them during RAW conversion (unless the scene is too high contrast, but then a single image will not be sufficient for good results with Photomatix).

Deriving “fake” exposures from a single RAW file (technique 3 above) is theoretically an improper way of creating a 32-bit HDR image. If you intend to use the HDR image file for 3D rendering, then you should not use this technique, as you will not get accurate linear pixel values required for image based lighting. However, if you are only interested in the tone mapped result, then creating “fake” exposures is a valuable technique, as long as you get improved results over technique 1 or 2.

I picked a shot I took a few weeks ago of a hillside of fox tails and other assorted weeds. I loved the texture and the subtle color shift.

I popped the white balance up in the Tone Map since the original exposure range was pretty narrow. This brightened it up a bit. And I popped up the saturation just a bit – because I liked it. I left the rest of the Photomatix settings at their default. After I processed it I pulled it into LightRoom and did the normal LightRoom adjustments – White Point/Black Point and I sharpened it quite a bit (0 to 50).

Then I compared it to my LightRoom adjusted original. The original was significantly brighter (my normal tendency is to over expose everything -comes from being a commercial/fashion photographer in the mid 80’s). So I pulled down the brightness just a tad to bring it closer to the Tone Mapped image.

This is a side-by-side comparison of the full image – the Tone Mapped image is on the right: 

 Again, the differences are subtle, but they are there (click to enlarge).


The Tone Mapped image is just a tad richer in color and when you get real close and personal you see just a touch more detail in the highlights. Here’s a close up of the bottom right corner of the image to help see that (click to enlarge):


The contrast is a touch less and the image just feels a bit more open.

I’ve created larger images and I’ll link them as soon as I figure out how to do that, then you’ll be able to see it better.

Again, what I love about this is the extra level of subtle detail it brings out in the highlights and shadows and the slight increase in richness of the color. It isn’t sharper, its more detailed.

I’m still keeping the HDR/Tone Mapping adjustments to a minimum so I’m not getting the ‘wow’ effect that most of the HDR out there is associated with. We’ll play with that another day. For now, I’m enjoying the subtle touch. And I expect that is what I’ll come back to.

Next time I’ll try Technique #3 – create 2 or 3 different exposures from a single RAW file and run those through Photomatrix.