1. RAW vs JPEG
Digital cameras can save images in two main formats: RAW and JPEG. This choice has a major impact on post-production flexibility.
JPEG
JPEG is a lossy compression format. The camera pre-processes the image (applying white balance, contrast boost, and sharpening) and then compresses it to reduce file size.
- Bit depth: 8 bits/channel → 16.7 million colors.
- File size: Small (3–10 MB).
- Pros: Ready to share immediately, no post-production needed.
- Cons: Difficult to recover blown highlights or blocked shadows; detail is lost when exposure is pushed heavily.
RAW
RAW is an uncompressed (or losslessly compressed) format. It is the raw sensor data — unprocessed. You have full control over white balance, contrast, and brightness in post-production.
- Bit depth: 12–14 bits/channel → 68 billion to 4.4 trillion colors.
- File size: Large (20–50 MB).
- Pros: Exposure can be pushed 4–5 stops while retaining detail. White balance can be changed with no quality loss.
- Cons: Requires dedicated software to view and process. Large files.
| Criteria | RAW | JPEG |
|---|---|---|
| Bit depth | 12–14 bit | 8 bit |
| Recoverability | High (±4 stops) | Low (±1 stop) |
| File size | 20–50 MB | 3–10 MB |
| In-camera processing | None (manual processing required) | Applied |
| Post-Production | Required | Optional |
| Best for | Professional work, printing | Quick shooting, web sharing |
"Shoot RAW. Storage is cheap. Missing a photograph because the shadows were too dark is expensive."
2. Histogram
Histogram is a chart showing the tonal distribution in an image. The horizontal axis represents brightness from 0 (black) to 255 (white), and the vertical axis represents the number of pixels at each brightness level.
How to Read a Histogram
- Left clipping (0): Shadow detail is lost — the image is underexposed.
- Right clipping (255): Highlight detail is lost — the image is overexposed.
- Peak in the middle: Ideal histogram for most scenes — a balanced tonal range.
- Peak shifted to one side: The image is dominated by bright or dark tones (which may be an intentional artistic choice).
Principle
Do not let the histogram touch the left or right edge — unless you intentionally want a silhouette (right clipping) or a low-key image (left clipping).
The histogram is the most objective tool for checking exposure. Do not trust the camera's LCD screen — it may appear brighter or darker than reality depending on ambient light.
"The histogram is the truth. Trust it more than your eyes on the back of the camera."
3. White Balance
White balance is the process of adjusting colors to neutralize color casts, so that white and neutral gray areas appear as the human eye sees them.
Color Temperature (Kelvin)
| Temperature | Light Source | Characteristic |
|---|---|---|
| 2000K | Candlelight, fire | Deep orange-yellow |
| 2700–3000K | Tungsten light | Warm yellow |
| 4000–4500K | Cool white fluorescent | Neutral white |
| 5000–5500K | Daylight | Standard white |
| 6500–7500K | Overcast, open shade | Slight blue cast |
| 8000–10000K | Blue hour, clear blue sky | Deep cool blue |
Inverse Rule
When selecting white balance on the camera, remember the rule: selecting a color temperature lower than the light source → the image becomes cooler. Selecting a higher temperature → the image becomes warmer.
Example: Shooting in daylight (5500K), if you set white balance to 3200K → the image will look cold and blue.
Auto WB vs Custom WB
- Auto WB: The camera guesses automatically — convenient but sometimes inaccurate.
- Custom WB: Shoot an 18% grey card under the same lighting → the camera measures accurately.
- RAW + flexible WB in post: With RAW, you can change white balance freely in post-production with no quality loss.
4. Post-Production Workflow
The standard post-production workflow consists of 4 steps:
Step 1 — Import
Copy images from the memory card to a hard drive. Create folders by date or event. Use a systematic file-naming convention.
Step 2 — Cull
Reject failed and duplicate shots. Flag the best images. This is the most time-consuming yet crucial step — professional photographers typically keep only 10–20% of what they shoot.
Step 3 — Develop
Edit the selected images: exposure, contrast, white balance, color, and sharpening. With RAW, this step is mandatory. With JPEG, it is optional.
Step 4 — Export
Export to the final delivery format. For web: JPEG at 80–90% quality, sRGB, 2000px on the long edge. For print: TIFF or JPEG at 100% quality, Adobe RGB, sized to print requirements.
5. Essential Lightroom Tools
Lightroom (or Capture One, or the free Darktable) is the most popular post-production tool. Below are the most important sliders in the Develop module:
| Tool | Function | Suggested Use |
|---|---|---|
| Exposure | Increase/decrease overall brightness | ±0.5 to ±1 stop |
| Contrast | Increase/decrease overall contrast | +10 to +30 |
| Highlights | Adjust highlights | -30 to -60 if highlights are clipped |
| Shadows | Adjust shadows | +30 to +70 if shadows are blocked |
| Whites | White point | ±10 |
| Blacks | Black point | ±10 |
| Clarity | Local midtone contrast | +5 to +20 |
| Vibrance | Intelligent saturation | +10 to +25 |
| Saturation | Global saturation | Use sparingly |
| Sharpening | Sharpening | +25 to +60 |
| Noise Reduction | Noise reduction | Only when needed |
"The goal of post-production is not to change the photograph — it is to reveal what was already there. Less is often more."
6. Demo: Histogram
Adjust Exposure and Contrast to see how the histogram changes with each adjustment. When the histogram touches the left or right edge, the image will clip and lose detail.
7. Summary
After this lesson, you have learned:
- RAW vs JPEG: RAW is 12–14 bit, uncompressed, recoverable by ±4 stops. JPEG is 8 bit, compressed, pre-processed.
- Histogram: Horizontal axis 0–255 (black–white), vertical axis is pixel count. Avoid clipping at either edge.
- White Balance: Color temperature in Kelvin. Candlelight 2000K → blue hour 10000K. Selecting a white balance lower than the source → cooler image.
- Workflow: Import → Cull → Develop → Export.
- Lightroom: Exposure, Contrast, Highlights, Shadows, Whites, Blacks, Clarity, Vibrance.
Practical Exercises
- Shoot the same scene in both RAW and JPEG. Process both in Lightroom with identical settings (push Exposure by +2 stops). Compare the degree of detail loss.
- Shoot a normal scene and check the histogram directly on the camera. Adjust exposure so the histogram does not touch either edge.
- Shoot the same scene at 4 white balance settings: Auto, 3200K, 5500K, 8000K. Compare color casts.
- Select 5 RAW images and run the 4-step workflow: import → cull → develop → export. Note down the steps you performed.
1. ETTR (Expose To The Right) technique when shooting: A digital sensor captures the most information in the right half of the histogram. When shooting on location, expose so the histogram waveform sits as close to the right edge as possible but never let the peak puncture the 255 wall. When you pull the Exposure slider down slightly back at home, the image will be remarkably clean with virtually no shadow noise while sky and cloud detail remains fully intact!
2. The Alt-key technique for setting black/white points in Lightroom: Hold down Alt (or Option on Mac), click and drag the Whites slider to the right until the black screen just begins to show a few tiny colored specks, then stop; continue holding Alt and drag the Blacks slider to the left until the white screen just begins to show dark specks, then stop. Your image instantly achieves deep, crystal-clear dynamic range with naturally crisp contrast!
Overusing the Clarity and Saturation sliders (+40 and above) creates messy glowing halos (halo effect) around subject edges and turns skin tones into a fake, orangey look. The second mistake: shooting 8-bit JPEG and then aggressively lifting shadows → the image will break apart into blotchy patches with unrecoverable clumpy blue-red color noise.