Here and there, I hear people saying a photo is "technically correct". How can I tell whether a photo is technically correct or not?
For start, one should be aware that technical correctness is no substitute for artistic vision. Here are some technical criteria in no particular order:
- The exposure is correct, shadows are not lost, highlights are not clipped
- The parts that need to be in focus, are in focus
- There is no motion blur (caused by camera shake)
- The photo does not have a color cast (probably because of incorrect white balance)
- The colors are correct (what you usually see, not oversaturated or changed)
- The noise/grain is not dominant
- There are no sensor dust spots
- There are no scratches, dust spots, interference patterns in case of scanned images
- There are no obvious digital artefacts (sharpening halos, banding, compression artefacts)
- Post-processing is not too obvious (think of overcooked HDR)
- There is no obvious distortion, chromatic aberration, lens flare, vignetting
- There is enough depth of field (important parts of your subject are not out of focus)
- There is enough contrast (the photo is not flat nor overdone)
- Orientation is correct, vertical objects are vertical and not leaning because of bad shot angle, horizontal objects are horizontal (usually horizon)
- Skin tones are correct (in case of portraits/people shots)
- The retouching marks/feel are not noticeable (think of visible cut edges in cases where different parts of image are from different photos or "Playboy skin" where all the detail is lost)
Any of these can be part of your concept or meant to create the mood, then they can be discarded.
Whether you're following this or not depends largely on the purpose - standards are higher when you sell your images or large prints, enter contests, etc and lower when you only do them for family album.
The essentials of a "Technically Correct" image would be:
- Correct Exposure
- Correct Focus (Auto-focus should take care of this)
For the most part, if you use good equipment in auto mode and avoid things like camera shake, your camera will take care of the technically correct part. As long as you know how to avoid the big issues, you can take a picture that is technically correct, the hard part is taking one that tells a story.