====== Filter Type ====== * filter guide: * all pro expensive one comparison: http://forum.xitek.com/thread-1008967-1-1-1.html * UV filter * Polarize filter * Closeup filter * ND filter * color filter * other filter * Black card * black card technique as traditional way of Photoshop-like masking: http://hanjies.blogspot.sg/2009/10/black-card-photography-part-i.html ====== ND filters and How Many Stops You need ====== So when you consider a ND filter, there are mainly 2 purposes for it - reduce incoming light, and be able at using f1.4 like lens wide open, when you already hit lowest ISO, like 100, and also hit highest shutter speed, like 1/1000sec, to achieve **Corret Exposure** - reduce incoming light, and be able to use a extreme slow shutter speed like 10-20sec, after you already use f8 and ISO 100, to achieve **Corret Exposure** - or combination of both **Case Study** * Situation 1: Bright Day Light and Wide Open portrait shot, (Ambient Light: EV 15) * answer: at least 3 stop ND filter needed for this case. * extra answer: if you doing flash fill, and you stuck with 1/125 sync shutter speed,then you need additional 4 stop ND to bring 1/2000 sec to 1/125, that is total 7 stop ND filter. * extra extra answer: if you ^ case ^ F ^ Iso ^ Shutter ^ note ^ ^ normal correct setting | f16 | ISO100 | 1/125 sec | | ^ max wide open setting with 4 stop Pshift | f4 | ISO100 | 1/2000 sec | f16->f11->f8->f5.6->f4 \\ 1/125->1/250->1/500->1/1000->1/2000 | ^ max wide open with addition 3 stop ND | f1.4 | ISO100 | 1/2000 sec | f4->f2.8->f2->f1.4 | | | f2.8 | ISO100 | 1/500 sec | for f2.8 lens | ^ stuck with 1/125 sync speed, means to use 7 stop ND | f1.4 | ISO100 | 1/125 sec | f16->f1.4, 7 stops | | make ambient 1 stop darker than flash, means 7+1=8 stop ND | f1.4 | ISO100 | 1/125 sec | f16->f1.4, 7 stops + 1 stop flash fill | | | f2.8 | ISO100 | 1/30 sec | f2.8 lens | ^ if also with motion trail of background people, like 8 sec, \\ then it need to turn 1/125 into 20", means 8+10=18 stop ND| f1.4 | ISO 100 | 8" | 1/125->1/60->1/30->1/15 \\ ->1/8->1/4->1/2 \\ ->1"->2"->4" \\ ->8" | | if you able to stop down to f8, you just need 18-5=13 stops ND | f8 | ISO 100 | 8" | f1.4-f8, 5 stops | * Situation 2: Night time (Ambient Light: EV 3) * answer: Night is like a built-in ND for the sky, means it is 15-3=12 stops cut from day light settings. ^ case ^ F ^ Iso ^ Shutter ^ note ^ ^ normal correct setting | f1.4 | ISO100 | 1/4 sec | f16->f1.4, 7 stops; 1/125->1/4, 5 stops | ^ f8 landscape setting | f8 | ISO100 | 8" sec | f16->f8, 2 stop, 1/125->8", 10 stops | | 1/125 sync speed not affect slower shutter speed | f8 | ISO100 | 8" sec | no change | | flash has no impact on ambient,\\ flash => portrait, shutter => ambient | f8 | ISO100 | 8" sec | 1 stop flash fill | | for 20" or 60", 3 stops ND is enough or just blend 3 shots of 8" | f8 | ISO 100 | 8" | 8" -> 15" -> 30" -> 60" | **conclusion** * for a f2.8 lens, you need 3 stop of ND is good enough for day and night use * for a f2.8 lens with fill flash, you need 6 stop of ND to overpower the sun flash at wide open. * for a f1.4 lens, you need at least 6 stop of ND for day time use, and 10 stop ND for overpower sun flash at wide open. * 3 stop of ND is good enough for any night shots ===== ND filter brands and naming ===== * Haida Neutral Density Filters’ Factors: ^ Neutral Density ^ Exposure Adjustment ^ Light Transmission ^ | ND0.3 (2x) | 1 stop , reduces ISO by 1/2 | 50% | | ND0.6 (4x) | 2 stops, reduces ISO by 1/4 | 25% | ^ ND0.9 (8x) | 3 stops, reduces ISO by 1/8 | 12.5% | ^ ND1.8 (64x) | 6 stops, reduces ISO by 1/64 | 1.0% | | ND2.7 (400x) | 9 stops, reduces ISO by 1/500 | 0.25% | | ND3.0 (1000x) | 10 stops | 0.1% | * haida 6 stop and 10 stop ND * review: [[http://www.clubsnap.com/forums/showthread.php?t=1265784&highlight=haida|by edutilos]] * case: [[http://www.clubsnap.com/forums/showthread.php?t=1382377|photo by nitewalk]] * note about Haida海大 price * PROII级多层镀膜 vs normal (price increment factor) * 超薄 vs normal (price increment factor) * link * Haida海大超薄PROII级多层镀膜减光镜MC-ND1.8 (64x) 49mm (琪琪摄影俱乐部) 128 [[http://item.taobao.com/item.htm?spm=a1z10.5-c.w4002-9411363827.70.cCjsxl&id=41925012233|link]] * Haida海大超薄型 ND1.8 (64x) 49mm 中灰密度镜 减光镜 84 [[http://item.taobao.com/item.htm?spm=a1z10.5-c.w4002-9411363827.115.VhLpde&id=41924500829|link]]