Pre HDR processing

Huujuu

Huujuu

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601
Name
Ian
Edit My Images
Yes
If you are making a HDR image, do you tweak the images before creating the combined overlay and if so how does that effect the programs ability to combine 3 or more images with more than just the original differences in exposure? i.e, at what point in the process do you look at white balance, sharpening, contrast etc. Ive tried making adjustments prior to loading images into photomatix which then asks what the exposure differences are. How do you decide what to tell it? Thanks.
 
I only adjust the white balance. If you start doing more then you're doing 3 times the work. There shouldn't be any issue of what to tell Photomatix about the exposure because they should be certain stops apart.
 
Usually photomatix just loads up the images and i guess it knows the differences between your original exposure settings but when i tweak things i often get a dialogue box up asking what the exposure differences were. Should i tell it the correct original values or is this an indication that ive overdone things already?

If the original images are no quite ideal would it not make it harder to adjust them in, say cs3, once they are combined (please dont say 'only use ideal images' i'm not at that stage yet!)

thanks for your help.
 
I do nothing. I let Photomatix suck in the RAW files and do it's thing on them. It takes noticeably longer as it has to convert each exposure (into TIFFs I imagine), but I haven't noticed any difference in output between doing it this way and converting the RAWs into TIFFs first before letting Photomatix at them. HTH :)
 
My camera will only take 1 RAW at a time. Ive tried manual adjustments and taking 3 seperate RAW images but, as yet the small differences in movement i get are not compensated for when they are lined up in photomatix. Quite often the 3 jpegs i can take dont quite line up either, but they are getting better (using 2 second shutter delay timing helps).

Ive noticed (call me dumb) the difference in quality between jpg's and RAW, didnt have a clue before, so are you saying RAW doesnt need adjusting the same way? Thanks
 
Jpgs are already 'processed' in camera and if you use auto settings for white balance then each photo could have a different colour temperature. Also if you're using auto focus, the focal point could change which would affect the end result.
Ideally, you want to use a tripod and remote release and manual focus ( you can auto focus and then turn it off so all shots remain the same) Shooting Raw means that you have no processing in camera and the images just raw data.
Does your camera not have auto bracketing available? That's the easiest way to get a set of images evenly spaced, based on the settings you create e.g. 2 stops difference. Anything you can do to avoid having to touch the camera between shots will help with alignment when processing the HDR.
 
Yup, i'm using auto bracket. It also hadnt occured to me about how the camera processed the jpg's, it's a very valid point.

The auto focus is also an excellent point i hadnt considered as i have used it quite a bit and that may have caused some of the problems. Thanks.

Have tripod...maybe need a better one!

(y)
 
If you're concerned about the stability of your tripod you may be able to steady it a bit more. Does the centre column have a hook at the bottom? If so, you can hang your camera bag on it and the weight helps steady the tripod.
 
Nothing as fancy as a centre hook but i can adapt, thanks very much, it's amazing what basic physics can do! All i need now is something heavier than just my instruction booklet to put in the bag. Dare not ask what you've got in yours in case lens envy creeps in. Maybe i should start putting my packed lunch in there.
 
Not sure how effective hanging your lunch would be, I suppose it depends on your appetite. Also, it would mean you could only take shots before you've eaten! :LOL:
There are little bags you can get with ribbons attached that you tie to the tripod and fill with stones. Alright if there are stones conveniently laying around. I suppose you could always take a shovel with you! :D
 
All i do is use the orig RAW file as the middle image, Over expose the image by 2 f stops for the lighter image and then underexpose by 2 f stops for the darker image and save each one with seperate names and then import the images into Photomatix. Photomatix will then do the work. At the mo i'm using Canon DPP to adjust the RAW image.

If you over or under expose the orig Raw file by more than 2 f stops, Photomatix will give an error message saying that a file or 2 are over/under exposed and it will adjust accordingly....which is nice! :D
 
You read my mind for the next question Andy. For a bit of practice i've been taking an old, single jpg and doing what you suggest just to liven it up a bit, so it's just started clicking (excuse pun) that if i did the same with the single RAW i can take on my camera, that the quality of my finished HDR image may actually be superior to 3 jpg's taken on auto bracket. Can't wait to get a proper DLSR, but not until ive wrung every last drop out of this one first.

All your advices really are very much appreciated and are being put to good use as we speak, minimise window, maximise window..............
 
Photomatix state that you can get very similar results using Jpg's but i would stick with the Raw files as i think there is more control.

Good Luck....................Fun innit! :LOL:
 
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