SANAT
GÜZELLİK & SAĞLIK
ZANAAT
KÜLTÜR & TARİH
EĞLENCE
ÇEVRE
YİYECEK & İÇECEK
TERS MÜHENDİSLİK
BİLİMLER
SPOR
TEKNOLOJİ
GİYİLEBİLİR ÜRÜNLER
Cooke Triplet Lens
Nineteenth-century lens makers flattened the image with a stop placed in front of or behind the lens, at the cost of astigmatism at the edges. Harold Dennis Taylor, optical manager at T. Cooke & Sons of York, dropped that trick entirely. He showed that a negative lens images a flat object onto a surface curved exactly as much as a positive lens of equal power, but the other way - so one can cancel the other.
**US 540,122**, "Lens", Taylor, filed 5. February 1894, granted 28. May 1895, puts "a negative lens … between two positive lenses, the focal power of the negative lens being approximately equal to the combined focal powers of the two positive lenses". Three separated elements: the Cooke triplet, still the simplest well-corrected camera lens.
**You build one from stock lenses**, and compare how flat its image is with a single lens.
Orta
2 hours
Talimatlar
1
1
Choose three lenses
Choose three lenses
Two convex lenses of about 100 mm focal length (check each on a distant window) and one concave of about -50 mm. Powers: +10 and +10 dioptres against -20.
Bu adım için malzemeler:
Dışbükey mercek takımı1 takım
İçbükey mercek1 adetGerekli aletler:
Çelik Cetvel2
2
Mount the triplet
Mount the triplet
On the bench: convex, 20 mm gap, concave, 20 mm gap, convex. Centre all three on the same height.
Gerekli aletler:
Optik sıra ve ray
Mercek tutucu seti3
3
Light a grid
Light a grid
Tape graph paper to a window or light it from behind with a torch, 1.5 m from the lens. Put a tracing-paper screen behind the triplet and focus the centre of the grid sharply.
Bu adım için malzemeler:
Milimetrik Kağıt1 yaprak
Kalıp kopya kâğıdı rulosu1 yaprak
Maskeleme bandı1 ruloGerekli aletler:
LED muayene feneri
Şerit Metre4
4
Measure the edge refocus
Measure the edge refocus
Without touching the lenses, move the screen until the grid 15 mm from the image centre is sharpest. Note how far it moved. Replace the triplet with one convex lens, refocus the centre, and measure the refocus again at the same 15 mm image height.
Gerekli aletler:
Çelik Cetvel5
5
Petzval sum and design
Petzval sum and design
Jupyter defteri yükleniyor…
6
6
History & Context
History & Context
**What the patent specifies:** a negative lens between two positive lenses, its power about equal to theirs combined, each element free of diaphragm corrections, flattening the field and removing marginal astigmatism. **Modern build (derived):** three stock singlets on a bench.
Taylor's employer declined to make it; Taylor, Taylor & Hobson did, as the Cooke lens. Tessar and many later designs grew from it. Its limits: with only three elements the aperture and angle of view are modest before aberrations return.
Malzemeler
5- 1 takımYer Tutucu
- 1 adetYer Tutucu
- 1 yaprakYer Tutucu
- 1 yaprakYer Tutucu
- 1 ruloYer Tutucu
Gerekli Aletler
5- Yer Tutucu
- Optik sıra ve ray%10 komisyonYer Tutucu
- Mercek tutucu seti%10 komisyonYer Tutucu
- Yer Tutucu
- 1 vendor sell this, none ship to you yetYer Tutucu
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.