SANAT
GÜZELLİK & SAĞLIK
ZANAAT
KÜLTÜR & TARİH
EĞLENCE
ÇEVRE
YİYECEK & İÇECEK
TERS MÜHENDİSLİK
BİLİMLER
SPOR
TEKNOLOJİ
GİYİLEBİLİR ÜRÜNLER
Photoelectric Exposure Meter
Photographers judged exposure by eye, by printed tables, or with extinction meters that asked them to read the dimmest visible number. Edward Weston (the instrument maker, not the photographer) used a photovoltaic cell that generates its own current in light and fed it straight into a sensitive meter marked in exposure terms. No battery, no judgement.
**US 2,016,469**, "Exposure meter", Weston, assigned to Weston Electrical Instrument, filed 31. December 1931, granted 8. October 1935: an instrument "for the direct determination of the correct exposure conditions", improving on earlier current-generating cell meters whose output was too small and whose construction was impractical.
**You build the same thing** from a small solar cell and a multimeter, calibrate it against a lux meter, and turn its readings into shutter speeds.
Başlangıç
90 minutes
Talimatlar
1
1
Cell and meter
Cell and meter
Clip the solar cell's two leads to the multimeter set to DC milliamps (or microamps). This short-circuits the cell through the meter - the current is what you read.
Bu adım için malzemeler:
Solar Cell Mini - 350mV1 adetGerekli aletler:
Multimetre
Alligator to Alligator Cables2
2
A hood
A hood
Glue a black card tube 30 mm long around the cell so it sees only light from in front, as Weston's meter did.
Bu adım için malzemeler:
Siyah mukavva1 yaprakGerekli aletler:
Maket Bıçağı
Sıcak silikon tabancası3
3
Calibrate
Calibrate
Hold the cell and the lux meter side by side, facing the same way, in four very different lights: a dim room, a lamp, a window, open shade outdoors. Note both readings each time.
Gerekli aletler:
Lüksmetre4
4
Current to exposure
Current to exposure
Jupyter defteri yükleniyor…
5
5
Use it
Use it
Stand at the subject, point the hood back towards the camera, read the current, and set the camera manually from the notebook's table. Compare with the camera's own meter.
Gerekli aletler:
Multimetre6
6
History & Context
History & Context
**What the patent specifies:** a light-sensitive current-generating cell connected to a measuring instrument reading directly in exposure terms. **Modern build (derived):** a silicon solar cell and a multimeter.
Weston's selenium-cell meters, sold from 1932, made metering routine; cameras later built the cell in. Its limits: selenium cells lose sensitivity in dim light and age, and any meter averages the scene - a snowfield or a black cat still fools it.
Malzemeler
2- Solar Cell Mini - 350mV%10 komisyon1 adet$2.22
- 1 yaprakYer Tutucu
Gerekli Aletler
5- Yer Tutucu
- Alligator to Alligator Cables%10 komisyon$3.58
- Yer Tutucu
- Yer Tutucu
- Yer Tutucu
Tahmini toplam
Yapan kişinin satın aldıkları. Fiyatsız görünen malzemeleri nereden alıyorsanız oradan temin edersiniz.
İlgili Blueprint'ler
Bu blueprint'ler bilgi paylaşır — teknikler, malzemeler veya ilkeler
CC0 Kamu Malı
Bu plan CC0 lisansıyla yayınlanmıştır. İzin almadan kopyalayabilir, değiştirebilir, dağıtabilir ve herhangi bir amaçla kullanabilirsiniz.
Planı üzerinden ürün satın alarak Maker'ı destekleyin, böylece Maker Komisyonu Satıcılar tarafından belirlenen komisyonu kazanırlar veya bu Planın yeni bir versiyonunu oluşturun ve gelir paylaşımı için kendi Planınıza bağlantı olarak ekleyin.