if you dont mind Mac OS X and small screen
there you go...

MacBookAir 11", i5-4250U + Intel HD5000 + 128GB SSD@RM2999[1.08kg], 4GB, backlit keyboard, Mac OSX
MacBookAir 11", i5-4250U + Intel HD5000 + 256GB SSD@RM3599[1.08kg], 4GB, backlit keyboard, Mac OSX

Apple
MacBookAir 13", i5-4250U + Intel HD5000 + 256GB SSD + (1440x900)@RM3899[1.35kg], 4GB, backlit keyboard, Mac OSX
MacBookPro 13" (Retina Display), i5-4258U + Intel Iris 5100 + 128GB SSD + (2560x1600)@RM4199[1.57kg], 4GB, backlit keyboard, Mac OSX

Dell
XPS13, i5-4200U + Intel HD4400 + 128GB SSD + (1920x1080; Touch)@RM3999[1.37kg], 8GB, W8.1, backlit, 55Whr

Sony
Vaio SVP13213SGS, i5-4200U + Intel HD4400 + 128GB SSD + (1920x1080)@RM3799[1.06kg], 4GB, W8SL

prices are RRP and negotiable.

Apple Macbook Air
+ Very thin
+ Light
+ Good battery life
+ Amazing build quality
+ Backlit keyboard
+ Good warranty service
- Small screen resolution
- Limited storage with SSD

Apple Macbook Pro
+ Light
+ Good battery life
+ Amazing build quality
+ Good graphics performance (medium settings)
+ Backlit keyboard
+ Good keyboard
+ Massive screen resolution
+ Good warranty service
- Expensive (need to negotiate to get your price range)
- Limited Storage with SSD

Dell XPS 13
+ Light
+ Good battery life
+ Good build quality
+ Backlit keyboard
+ Full HD screen resolution
+ Good warranty service
+ 8GB of RAM as base spec
- Average keyboard
- Weak graphics performance
- Limited storage with SSD

Sony Vaio Pro 13
+ Extremely light for a 13 incher
+ Good battery life
+ Good build quality
+ Very thin
+ Good warranty service
+ Backlit keyboard
- Average keyboard
- Weak graphics performance
- Limited storage with SSD
- Useless touch screen, could save up the cost with a Full HD screen
- Weak graphics performance
- Limited storage with SSD

all are just based on my opinions towards the specs.

Illegear
RE-13 Pro, i5-4200M + Nvidia GTX765M + (1920x1080 IPS)@RM3999[2kg][Onkyo, SoundBlaster Cinema], 4GB, 500GB(7200rpm), Backlit Keyboard, FreeDOS, [CPU Options: i5-4200M - i7-4900MQ]
RE-15, i5-4200M + Nvidia GTX765M + (1920x1080)@RM3499[2.6kg][Onkyo, SoundBlaster Cinema], 4GB, 500GB(7200rpm), FreeDOS, [CPU Options: i5-4200M - i7-4900MQ]

MSI
GE40-2OC, i7-4702MQ + Nvidia GTX760M + (1600x900; anti-glare)@RM3499[1.8kg], 4GB, 750GB(7200rpm), W8
GE60-2OC, i7-4700MQ + Nvidia GT750M(GDDR5) + (1920x1080; anti-glare)@RM3599,8GB, 750GB(7200rpm), W8, steel series KB

Lenovo
Y510p, i7-4700MQ + Nvidia GT755M(GDDR5) + (1920x1080)@RM3399[2.7kg], 8GB, 1TB, W8.1, red backlit, swappable ODD, 120w psu, 2 yrs

the Illegear RE-13 and MSI GE40 are another example of light gaming notebook which did not mentioned earlier. however, they are power hungry, so the battery life is not part of your consideration if you go for gaming. to add another, is the cooling. the smaller and thinner the laptop, the poorer its cooling system.

in before this i recommended him 2 macs, a dell and a sony.

well, not much know why they design it like dat.    as long as the heat flow inside the laptop and keep the palm rest area cool... its ok for me.. 
price provided in the brochure of the brands product. some of the price are provided by seller from garage sales.    have a look and visit. 
Y510p graphic card and N56JR graphic card is on par.. the different is not much..

The GeForce GT 755M and the GeForce GTX 760M have the same amount of video memory, but are likely to provide slightly different experiences when displaying game textures at high resolutions.

The GeForce GT 755M has 16 GB/sec greater memory bandwidth than the GeForce GTX 760M, which means that the memory performance of the GeForce GT 755M is slightly better than the GeForce GTX 760M.

In terms of overall gaming performance, the graphical capabilities of the Nvidia GeForce GTX 760M are massively better than the Nvidia GeForce GT 755M.
so..between lenovo y510p and asus n56jr.. i gonna pick n56jr.. cz have 12gb ram. (8gb x 2).

illeager re-15 also good. may i know your  budget? so, i assume you prefer i7 processor isnt it..?

Macbook Pro 13 (im a mac hater). even though it uses ULV processor, the Iris graphics equipped is good enough for med gaming. it is light and has an amazing build quality. just if you wanted to play games, you need to do bootcamp.

by the way, i would still suggest you to go an experience the laptops yourself, because you dont know how the laptop looks like, you never experience it, hold it etc. so what i suggested here, is just to make a choice of list for you and do a research.

Dell
Vostro 5470, i5-4200U + Nvidia GT740M@RM2249, 4GB, 500GB(5400rpm), W8, 3-cell

Lenovo
U430T, i5-4200U + Nvidia GT730M + (1600x900; touch)+ 8GB SSHD + 500GB HDD@RM2799, 4GB, W8, 2 yrs

both definitely suit your requirement.

How serious are you in photo editing?

I highly suggest you seek a person who can "loan" or colour calibrate your laptop for a fee, I was doing this service quite regularly last time but stopped already when I sold the device. Btw, the device cost around RM400+ for a basic one, I'm using the Spyder 4 Pro which costs close to RM700. That was how serious I was about photo editing lol. Plus, the prints that I do is from a Master Printer who prints for Malaysia's top wedding photographer After calibrating my Dell U2311H desktop monitor, colours were perfect, 99% sRGB and everything came out exactly as what I see on the computer. Simply fabulous when you see your own work on print. It's just awesome

Colour accuracy after calibration will depend on the quality of the monitor itself. The higher the quality of the monitor, the close it gets to near 100% colour accuracy. Also, it depends on the colour gamut of the monitor itself.

But of course, the most important point in colour calibration is to correct the White balance first, as this is the most disastrous thing. You think you are editing a person's face to slightly brown, but in reality it's very brownish (almost orangy). Why? Your monitor is too bluish (cold White balance), vice versa.

The other points are correcting blacks/whites, contrast ratio,etc

Most laptop monitors typically have 60-80% sRGB values, the better quality monitors should have higher sRGB values, maybe like the Macbooks or the Ultrabook IPS monitors.

p/s: Don't get me wrong, the sRGB values are constant. It just shows how much colour data your monitor can display with respect to sRGB (almost anything you see on the internet is sRGB). My monitor which has 94% sRGB for example can display 4 shades of orange, while let's say your monitor only has 60% sRGB, it can only display like 2 types of orange maybe?

These are all that I know lah, don't really know the details...

Do you think i should just get this laptop ( or give me more recommendations ) and use an external monitor for photoediting, or increase the budget and get a macbook pro 13" w/ retina display?

3. Usage-
Photoediting, browsing, college work, light gaming (dota 2), movie, light video editing (got a desktop)

4. Preferred laptop/screen size
Light weight (if possible) , long battery life

Dell
Vostro 5470, i5-4200U + Nvidia GT740M@RM2249, 4GB, 500GB(5400rpm), W8, 3-cell

Lenovo
U430T, i5-4200U + Nvidia GT730M + (1600x900; touch)+ 8GB SSHD + 500GB HDD@RM2799, 4GB, W8, 2 yrs

both definitely suit your requirement.

Apple
MacBookAir 13", i5-4250U + Intel HD5000 + 256GB SSD + (1440x900)@RM3899[1.35kg], 4GB, backlit keyboard, Mac OSX
MacBookPro 13" (Retina Display), i5-4258U + Intel Iris 5100 + 128GB SSD + (2560x1600)@RM4199[1.57kg], 4GB, backlit keyboard, Mac OSX

Dell
XPS13, i5-4200U + Intel HD4400 + 128GB SSD + (1920x1080; Touch)@RM3999[1.37kg], 8GB, W8.1, backlit, 55Whr

Sony
Vaio SVP13213SGS, i5-4200U + Intel HD4400 + 128GB SSD + (1920x1080)@RM3799[1.06kg], 4GB, W8SL

prices are RRP and negotiable.

Considered these already?
10"
Microsoft
Surface Pro, i5-3317U + Intel HD4000 + (1920x1080;touch) + 64GB SSD@RM2749[680g], 4GB, W8P
Surface Pro, i5-3317U + Intel HD4000 + (1920x1080;touch) + 128GB SSD@RM3049[680g], 4GB, W8P
*Prices are outdated

13"
HP
Split 13-M005TU x2 PC, i5-3339Y + Intel HD4000 + 128GB SSD + (1366x768;touch)@RM2899[2.22kg], 4GB, W8

Lenovo
Yoga 11s, i3-3229Y + Intel HD4000 + 128GB SSD + (1366x768, IPS touch)@RM2599[1.19kg], 4GB, W8, 2 years; colors: grey/orange
Yoga 11s, i5-3339Y + Intel HD4000 + 256GB SSD + (1366x768; IPS touch)@RM3299[1.19kg], 8GB, W8, 2 years; colors: grey/orange

But if you want top notch warranty service, I suppose it'll be better to opt for an Apple MBA11/13 

. Preferred Brand-
Any, build quality and service must be top notch
Apple might work as well.

2. Budget-
RM <4k

3. Usage-
Photoediting, browsing, college work, light gaming (dota 2)

4. Preferred laptop/screen size
Light weight (if possible) , long battery life roughly 4-5 hours, mainly for college work and photoediting, FHD , 15.6" screen for photo editing.

HP ENVY TS 15-j053TX
does this have long battery life?

vs

Dell Inspiron 15-7000 series- 7537