Shutter Speed vs. FPS

Before this, I have a problem understanding the differences between shutter speed and frame per seconds while recording video in DSLR. So, I assumed it's not important. IT IS differs and important especially when you want to record fast moving action.

In short:
Shutter speed: How much each frame is exposed to the light source.
FPS: How many frames are recorded each seconds

See the details explanation below.







Thanks.

SIGMA 18-200mm F3.5-6.3 DC OS

Just got my hands on the Sigma all-purpose lens 18-200mm after been a while searching for it. This is by far the cheapest all-purpose lens available. I bought it at my local retailer.

The box

The lens mounted on my D3100

Things I like about this lens

• Cheap
• Good build quality
• Got optical stabilisation 
• Cover from wide all the way to telephoto in one lens
• Got zoom lock to avoid lens creep

Things I don't like

• Image a bit dark due to small aperture
• The zoom ring a bit tight especially at 50-80mm range..maybe just a while coz it's still new
• The stabilizer need some time to settle down especially at tele range

That's all. Thank you. Want to enjoy new lens..hehe

Photography: Depth-of-Field

Wow. Sibuk gilalah sempena amik intersesi ni. 2 subjek lagi tu. Memang hectic. Anyway, intersession dah pun habis and boleh rehat. XD Takut nak tau result :S

Anyway, untuk entry ni saya nak buat yang pendek je la..nak share about depth-of-field dalam bidang photography sebab recently ada rakan saya ni tanya:

"eh camane kau buat gambar belakang tu jadi kabur ea?"..and

"eh camane nak control brape banyak kabur kita nak ea?"..ha lebih kurang gitulah..

So, konsep yang dia tanya tu adalah berkenaan Depth-of-Field(DOF). Ia adalah term untuk menerangkan jarak antara depan dan belakang focus point yang relatively sharp. Untuk membezakan, kita guna term "shallow DOF" untuk jarak DOF yang pendek(means tempat yang dalam focus sikit je) dan "deep DOF" untuk jarak DOF yang besar(means tempat yang in-focus agak luas).

Source: http://images.cambridgeincolour.com/tutorials/dof_circleofconfusion.png

Apa yang penting sangat dengan depth-of-field ni? Penting sangat kalau:

• Nak buat bokeh
• Nak buat potraitization
• Supaya orang yang lihat gambar fokus pada objek bukan pada backgroundnya

Potrait - source: http://withfriendship.com/images/i/44403/Portrait-photography-image.jpg

Bokeh - source: https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgoob7sSKLgYrrfOQcTO0qcSVcyB2GdyhxZh17koKRTbb2ouxkTOYZCq5auwb8VA4CFuE_6lSNKjL0r2p-Q0ETL3dkKSC17-39BjYZC76V5X3SPjWRVNPsuCi_JgxQsSEW_rE9arxuVYVw1/s400/awesome+bokeh.jpg

Macamana nak kawal depth-of-field??

Ada 3 cara:

1. Aperture
2. Focal length
3. Distance

But usualy, people only focus pada aperture dan focal length so saya akan cerita pasal dua factors ni sahaja ok.

1. Aperture

Aperture adalah luas bukaan iris/lubang pada lens. Ia diukur dengan menggunakan f/stop seperti f1.8, f2.8, f5.6. Makin besar nilai f/stop, makin kecil bukaan aperture dan juga sebaliknya. Ramai orang silap tentang prinsip aperture number ni bila mereka ingat f number yang besar, besarlah bukaan aperture. Wrong.

INGAT: f-number besar, bukaan kecil
              f-number kecil, bukaan besar

Aperture and its value

Jadi, untuk mendapatkan shallow DOF macam gambar potrait di atas, pakai aperture yang besar(f-number kecil). Kalau hendakkan deep DOF pakai aperture kecil(f-number besar). Tapi ingat, kalau pakai bukaan aperture kecil, anda kena matchkan dengan shutter speed yang bersesuaian sebab bukaan kecil hanya membenarkan sedikit cahaya masuk ke sensor camera/filem. So kena try-and-error ;-)

Shallow DOF

Deep DOF

To conclude:

• shallow DOF = wider aperture = lower f-number = lesser lighting entering camera
• deep DOF = narrower aperture = higher f-number = more lighting entering camera

2. Focal length

Kalau ikut wikipedia:

The focal length of an optical system is a measure of how strongly the system converges (focuses) or diverges (defocuses) light.

Tapi untuk layman term, focal length adalah berkenaan zoom. To cut it short, the more you zooming in, you'll get shallower DOF and vice versa. Simple.

Zoom more = shallower DOF
Zoom less = deeper DOF

Focal length comparison - source: www.freshdv.com/wp-content/uploads/2007/10/dof_explained_tutorial.jpg

Ok. Simple as that. Tu je lah nak cerita nak share. Skarang nak cari kerja. huhu..

Papai!!