Sekonic C-800 SpectroMaster
by Sekonic
Photo and film spectrometer with a Class A illuminance meter, spectrum display, CRI and TM-30. It shows no melanopic value and cannot export spectra.
Specs
| Range | 1–200,000 lux |
|---|---|
| Accuracy | JIS C 1609-1 Class A |
| Cosine corrected | Not stated |
| Melanopic reading | No |
| Sensor | Built-in spectrometer |
| Spectral range | 380–780 nm |
| Cct | 1,600–40,000 K |
| Color metrics | CRI (Ra, R1–R15), TM-30, SSI, TLCI |
| Flash | 20–20,500 lux·s |
| Memory | 99 readings |
| Power | 2 × AA or USB |
| Weight | 230 g |
Specs from the manufacturer and the sources listed below. Last verified Oct 20, 2026.
Good
- Class A illuminance meter under the Japanese JIS standard
- Shows the spectral distribution, so you can see how much blue a lamp puts out
- Color rendering in CRI, TM-30, SSI and TLCI
- Runs on AA batteries or USB power
Not so good
- No melanopic lux or melanopic EDI readout
- Sekonic reserves 1 nm and 5 nm CSV spectrum export for the C-7000, so you cannot calculate melanopic values yourself
- $1,899, mostly for photo and film features
- Sekonic's own store showed a notify-me button on the check date, so you may need to buy from a camera dealer
The C-800 is the spectrometer most people find when they search for one, so it is worth being clear about what it does for circadian use. It measures illuminance to JIS Class A, shows the full 380 to 780 nm spectrum on screen, and reports color temperature and color rendering in four systems. It does not report melanopic light.
That is a real limitation. The 2022 expert consensus targets for daytime, evening and night light are in melanopic EDI (Brown 2022). With raw spectral data you could calculate it yourself using free tools. But Sekonic’s product page says 1 nm and 5 nm CSV spectrum export is available only on the C-7000.
What you can still learn: the spectrum graph shows at a glance whether a “warm” bulb still has a blue spike, and the illuminance reading is good enough to check a SAD lamp. The color temperature reading gives a rough steer, since warm white LEDs deliver about half the melanopic light per lux of daylight.
It also measures flash, takes AA batteries or USB power, and stores 99 readings. Those features exist for photography and film.
For circadian checks alone, it is the wrong tool at this price. If you want melanopic numbers, the UPRtek MK350S Premium reports them directly. If you want accurate lux, the Extech LT300 costs about an eighth as much. The C-800 makes sense if you already work in photo or video and want one meter that does both.
Sources
Alternatives
- Best overallExtech LT300$244
- Best budgetDr.meter LX1330B$45
- Best for melanopic lightUPRtek MK350S Premium$4,125
- Best for LED lampsExtech LT45$359