Jun 17
HDR ghost removal in PS CS5
A while back I was being a bit sceptical about the new Photoshop CS5. Then I found out that there’s one feature that might actually be quite interesting for me, the improved HDR processing engine. HDR in CS4 was quite bad, actually, but this new version (HDR Pro) promised an option to remove ghosts that sometimes appear in your HDR pictures when something has moved between the frames, for example tree branches in the wind. I had one such HDR that I’ve been trying to fix on and off since last September, so of course I had to test if I could finally get it done in CS5.
In short – no.
If you look at the picture, the first sample shows the ghosting that appears when the image is processed normally (samples are not downsized or processed otherwise than the HDR, just cropped from originals). I then applied ghost removal and used the medium exposed frame as the base for it. And it actually does a pretty good job, but only with some of the branches. On the right side, things look fine. In the lower left corner, it’s a total disaster.
So I loaded the same HDR but using the under-exposed frame as the base for the ghost removal. Now it looks acceptable (let’s oversee the serious CA, it’s not the point of investigation here), but instead of the ghosting, there is now some weird pixelated splotches all over the place. Look at the tree trunk, there are some black dots that are not happening in the other samples. And on the right in the brances, some green dots.
I tried to adjust all of the processing settings to see if I could get these artefacts to disappear. But nix, it can’t be done.
This particular HDR could work with just two frames, but the ghost removal option is not available for a two frame merge. It probably wouldn’t help anyway because the un-needed overexposed frame is not used for the branches anyway.
Maybe this particular picture is just too much for HDR Pro. Let’s not forget that this is the first version of ghosting removal and first versions often just give you a taste of the tool. Just like the HDR tool in CS4 was crap and now it’s good, so there’s a reason to expect that ghosting removal will be improved in CS6!
But until then, I have to decide if I will keep this HDR or finally trash it after spending hours on trying to make it work. Currently my only option seems to be to combine the best bits from the two HDR versions with ghosting removal applied. After a while, I’ll probably decide that the picture wasn’t that good anyway!
5 comments
After getting over the “candy” phase of experimenting with Photomatix, I donated my licence to a Spanish friend of mine (I did not remember I paid quite a bit for it).
…and I bought a new camera with vastly wider DR. Now, I don’t bother with software solutions any more, unless it is something completely mad, like moonscape or so…
That said, I have not even had the time to fool around much in CS5 or LR3! That’s what you get when you change your job to get those software faster
Well, my fix was to ditch camera, shooting, playing WoW and image manipulation. Instead I bought a fly fishing rod, second, third and fourth and lotsa tying materials. Now I even bought classic fishing hat, English style ofc. I spend all my leisure time on the riverside, reading the current and trying to decide which tackle to use. I changed photographing forums to dedicated fly fishing ones. Look what I have become, a multitalented, rich, famous and handsomely thin real fly fisherman what those perverted spinners call “ojahomo”…
Now, I didn’t really ditch my cameras, mwahahahah!
Thanks guys, you’ve been really helpful. …now about this HDR Pro then…? Considering that buying a new camera or a fishing rod is not an option.
Not an option, eh, you should give it a try
Fish is healthy and fishing is fun!
I think those frames are impossible to merge, no matter what software you use
Sorry being a pessimistic horse related animal, but these are my two cents 
I’m allergic to fish so I’m afraid that I have to stick this camera and software I have.
Yup, I think I asked too much from HDR Pro to fix this. Considering that it did work on part of the image, I can say that in principle this new tool works – it just has its limits, which shouldn’t actually come as a surprise at all. But I will not be surprised either if the next version of the software can finish the HDR!