this is the mini-series roundup. i've got to end this series so i can talk about other stuff, so i'm going to double post dynamic range with RAW/jpg shooting.
let's start with dynamic range. this is the range of intensities the camera can collect in a photo, from the darkest dark to the brightest bright. the best camera can only see about 15% of the amount of dynamic range than the human eye. God : 1, nikon : 0. this is why when you snap a picture of a bedroom with a window during the day you either get the room exposed properly and the window totally blown out, or you get the window exposed properly and the bedroom very dark.
there's a technique called HDR (high dynamic range) photography. in it's simplest form, you take multiple photos at different exposure settings without changing the camera position, aperture, white balance, or focal length. that leaves us with using the shutter speed to control the exposure. the idea is to take a photo that properly exposes the darkest darks, another photo that catches all the mids, and another photo that captures the brightest whites properly. you then take all the photos and blend them together so that every part of the photo is exposed. you can also tone-map the colors to give it a surreal feel. tone-mapping is another whole animal that probably only 1% of people would care about so i won't go into it. here's a couple HDR photos i took of the nylo hotel in warwick, ri
cool, huh? you can get some pretty cool looking shots if you do it right. HDR doesn't lend itself well to pictures of people or animals or anything that moves since all photos have to have the identical content but at different exposures.
enough of that. onto RAW and jpg shooting. this could get ugly, but i'm going to refrain from too much tech talk. here's the super basic version - RAW allows you to capture much more dynamic range in a photo. it is uncompressed, the data exactly as your camera sensor sees it. every camera shoots in "RAW" internally, but all point-and-shoots add some processing and convert it to a jpg before saving it to your memory card. it's kind of like the digital equivalent of a film negative. in post processing you can determine the white balance and exposure without any image degradation. a jpg will always degrade with every edit made to it. the drawbacks to RAW is that they take up a lot more room on your memory card, each camera manufacturer has their proprietary RAW protocol, and every RAW file needs post-processing in order for it to be useful. RAW files on their own are very bland, desaturated, and not so sharp. the possibilities they allow you in post-processing is the huge benefit. they take time to deal with and hard drive space to store.
i always shoot RAW. my camera has a RAW+jpg option which will capture both formats from a single shutter press. if i'm taking casual photos i'll use that option in case i catch something i really want to tweak so i'll have the RAW file. otherwise i can just store away all the jpg files and i'm all set.
there's more to the RAW/jpg debate, but it has to do with bit-depth and aliasing and histograms. hopefully the info in this post is enough for you to decide if you want to jump into the RAW world. adobe bridge and photoshop come with a background program called 'camera raw' which is capable of processing all the major manufacturers' RAW formats
just a note - i wouldn't recommend attempting HDR unless you're shooting RAW. there's not enough information in the jpg files to make the image come out nicely.
that's it! the mini-series is over. a bit of a relief for me, i've got other stuff i want to start blogging about. an easy way to find all the posts that were part of the mini-series is to look on the right hand side under "categories" and click on 'education'. all the posts are under that category. go crazy. thanks for sticking with me through all of these educational posts!Labels: education
