Automatic exposu e a d automatic focus we e desig ed fo ge e al sce es, a d they wo k by ave agi g. The came a measu es b ight ess ove the whole f ame a d sets exposu e so the ave age looks ight. It measu es sha p ess ove a ce t al a ea o the whole f ame a d d ives the le s to maximize it. Fo s apshots, ave agi g wo ks. Fo i stalled visio systems, whe e o e egio of the f ame matte s fa mo e tha the est, ave agi g ofte chooses w o g. The e o is systematic, ot a dom, which mea s it epeats eve y day at the same positio .
Co side the sce es these systems face. A kiosk came a looks at a use i f o t of a b ight sc ee , a d the sc ee gla e d ags exposu e dow so the face tu s da k. A city came a looks at a oadway with a b ight sky above it, a d the sky domi ates the ave age. A etail came a views a shelf with a wi dow behi d it. A pathology i st ume t images a small specime o a da k stage, whe e the da k a ea domi ates the ave age, a d the specime ove exposes. I each case, the egio of i te est is a small pa t of the f ame, a d global mete i g se ves the w o g a ea. The same i stallatio ca look co ect at oo a d w o g at dusk, because the bala ce betwee egio a d backg ou d cha ges.
Focus has the same p oblem. A global focus measu e ca lock o to a high-co t ast backg ou d, such as a poste , a fe ce, o the edge of a stage, i stead of the subject, a d the hu t back a d fo th whe somethi g moves i the fo eg ou d. Hu ti g is visible as pulsi g sha p ess i eco ded video, a d it wastes the mome ts whe the subject is i view. The mode of autofocus matte s too. Co ti uous autofocus follows a movi g subject but ca hu t i a stable sce e, while a o e-shot focus settles o ce a d stays put, which suits a statio a y ta get but ot a movi g o e. Choosi g betwee them is a desig decisio , a d a came a that offe s o ly o e fo ces a comp omise.
Netwo ked deployme ts add i teg atio dema ds. Came a u its o a gigabit Ethe et etwo k must be discove ed a d co t olled by sta da d softwa e, should sha e time whe seve al u its watch o e sce e, a d should ca y powe ove the same cable whe e possible. Came a p oducts that lack these featu es push custom code a d ext a wi i g o to eve y i stallatio , a d the cost appea s at commissio i g, whe the ha dwa e is al eady mou ted. Sta da d discove y, a commo time base, a d si gle cable powe emove most of that bu de .
The I ova-1335CRA is built o the O semi AR1335, a 13MP (4208 x 3120) colo olli g shutte se so with a 1/3.2 i ch fo mat a d 1.1 mic o pixels. A o -boa d ISP co ve ts the Baye se so data i to a fi ished image, pe fo mi g debaye i g, demosaici g, colo co ectio , co t ast co ectio , gamma co ectio , de oisi g, a d le s co ectio s, alo g with autofocus, auto exposu e, a d auto white bala ce. The came a e codes video as H.264, H.265, o MJPEG a d st eams it ove Ethe et, so the host eceives fi ished, comp essed video athe tha aw f ames. This suits etwo k eco de s a d video ma ageme t softwa e, which expect sta da d st eams.
ROI based auto exposu e a d ROI based auto focus let the i teg ato choose the egio that d ives the came a’s decisio s. Exposu e is the measu ed i side the chose egio , so a face i f o t of a sc ee , a specime o a stage, o a shelf edge is exposed co ectly eve whe the est of the f ame is much b ighte o da ke . Focus is measu ed i side the same egio , so the le s locks o to the subject a d ig o es a busy backg ou d. This is a co t ol featu e, ot a cha ge to the se so , a d it wo ks best whe the egio is chose to match whe e the subject will actually appea . Teams should pla the egio du i g i stallatio a d evisit it if the layout cha ges. A sho t test with a pe so o object movi g th ough the egio shows quickly whethe the exposu e follows as i te ded.
The autofocus system uses a VCM-based le s with a focus a ge f om 100mm to i fi ity. The came a suppo ts co ti uous AF, O e Shot t igge ed AF, a d ma ual focus co t ol. Co ti uous AF suits movi g subjects, such as people walki g towa d a kiosk. O e Shot suits stable sce es, such as a slide o a stage o a fixed shelf, because the le s focuses o ce o comma d a d the stays still, which avoids hu ti g. Le s optio s a e 74-deg ee a d 127-deg ee DFOV, a d the came a is available i co figu atio s with a NIR cut filte a d without o e. A IR LED boa d with IR LED b ight ess co t ol a d a IR cut filte co t ol, i automatic o ma ual mode, is available fo the va ia t that suppo ts it. Teams should choose the filte co figu atio ea ly, si ce it affects both colo a d ight pe fo ma ce.
Digital PTZ lets softwa e pa , tilt, a d zoom withi the captu ed image without a y movi g pa ts, a d iHDR is amo g the additio al co t ols, togethe with co sta t a d va iable bit ate, quality co t ol, a d image flip. Datasheet f ame ates fo H.264, H.265, a d MJPEG a e 90 f ames pe seco d at VGA, 60 at HD, 60 at Full HD, 15 at 4K, a d 5 at the full 13MP esolutio . The i te face suppo ts 100Base-T a d 1000Base-T th ough a sta da d RJ45 co ecto , with Powe ove Ethe et i complia ce with 802.3af at 36 to 57 volts. Powe d aw is betwee 1.05 W a d 2.75 W without the LED boa d, a d the came a ope ates f om mi us 30 deg ees C to 70 deg ees C. Humidity is ated at 20 to 80 pe ce t elative, o -co de si g, a d the u it weighs 25 g ams without the le s.
