Is it worthy to upgrade from 50mm f1.8 lens to f1.4 lens ??

[prabir008]

Hello folks... I have a question or rather say a doubt and need of a suggestion. I have my canon 50mm f1.8 II which is just awesomest. Now the thing is i need another prime lens with fast AF. have chosen out canon 50mm f1.4; canon 85mm f1.4 n sigma 50mm f1.4. No the doubt is having a f1.8 lens, is it really worthy to upgrade to f1.4 lens considering the fact sigma cost more but image quality is far better????? possibly it will be take another 2years of saving to buy a f1.2 lens so i nearly cut it out..!! help me out


P.S : I have a APS-C camera..!!!

 

[bhop]

Do you ever feel like the 1.8 is limiting you? Or is it just a "want the fastest" kinda thing?

 

[prabir008]

Do you ever feel like the 1.8 is limiting you? Or is it just a "want the fastest" kinda thing?

yupp thats correct. 1.8 is just tooo slow and the buzzing AF sounds just piss me off sometimes no doubt its a bang for its buck.. so help me in this regard..!!

 

[Big Mike]

Overall, yes...I would say that it is worth the price to upgrade from the F1.8 to the F1.4 50mm. But if auto focus is your main concern, then it might not be worth it.

The 50mm F1.4, while it does have a 'USM' focus motor, it's not the good 'ring type' USM motor that most high end Canon lenses have. It is a USM motor, but it still uses gears to drive the focus elements, so it isn't super fast or silent.

The Sigma does have an HSM ring type focus motor...so if focus sound & speed are an issue (and you can't afford the Canon L) then the Sigma may be a good option.

Keep in mind that the Sigma is much bigger and much heavier than the Canon 50mm F1.4, which may be an issue for some people.

 

[prabir008]

Thanks alot @Big mike... that clears alot of my doubt. considering the prices of both canon 50mm/85mm f1.4(in my country its almost same price), which one should i go for as I am planning for a full frame(for aps-c; 85x1.6=135mm focal length)..!!! I asked this regarding the internal mechanism of 50/85mm... are they both same except their focal length??? image quality and bokeh??

 

[Big Mike]

Either the 50mm or the 85mm will work equally well on an APS-C or full frame camera.

The 85mm does use the better 'Ring Type' USM motor.

 

[Big Mike]

(for aps-c; 85x1.6=135mm focal length)..!!!

No. the 50mm is always 50mm on any camera....and the 85mm is always 85mm on any camera.

The crop factor you are referring too, only changes the field of view because an APS-C camera will crop the edges off.

 

[Dao]

By the way, the Canon 85mm lens should be f/1.8 (the L version is f/1.2). I owned both Canon 50mm f/1.4 and 85mm f/1.8. As for the AF speed, the 85mm is better than the 50mm. And the out of focus blur image that rendered by the 85mm f/1.8 lens seems to be smoother. The build quality of the 85mm lens also better than the 50mm.

 

[prabir008]

Sorry @Dao, your are correct. its Canon 85mm f1.8. Thanks @Big mike n @dao. that's the help i was in need for. Now i think 85mm as my next prime lens will serve me better in AF speed..image quality..bokeh n low light..!! thnks alot guys. :thumbup:

 

[STM]

I cannot speak for Canon, having used Nikon all my life, but the difference in lens speed between f/1.8 and f/1.4 is a less than 1/2 stop so you don't gain much in that department. I do know that the 50mm f/1.8 AIS Nikkor does beat the 50mm f/1.4 AIS Nikkor somewhat handliy in the corners, so the same may be true for the Canon. Unless something about the f/1.8 is holding you back, I would stick with what you have. As for any f/1.2 lens, unless you do A LOT of shooting in very dim interiors, there is no advantage to a lens that fast. They are big, very expensive and usually do poorly in the corners compared to f/1.4 and f/1.8 lenses

 

[Big Mike]

but the difference in lens speed between f/1.8 and f/1.4 is a less than 1/2 stop so you don't gain much in that department.

Actually, it's more than half a stop, it's somewhere around 2/3 to 3/4 of a stop difference.
Still not a huge difference though.

 

[KmH]

F/1.8 to f/1.4 is 2/3 of a stop.

[TABLE="class: wikitable"]
[TR="bgcolor: #e5d1cb"]
f/#[TD]0.7[/TD]
[TD]0.8[/TD]
[TD]0.9[/TD]
[TD]1.0[/TD]
[TD]1.1[/TD]
[TD]1.2[/TD]
[TD]1.4[/TD]
[TD]1.6[/TD]
[TD]1.8[/TD]
[TD]2[/TD]
[TD]2.2[/TD]
[TD]2.5[/TD]
[TD]2.8[/TD]
[TD]3.2[/TD]
[TD]3.5[/TD]
[TD]4[/TD]
[TD]4.5[/TD]
[TD]5.0[/TD]
[TD]5.6[/TD]
[TD]6.3[/TD]
[TD]7.1[/TD]
[TD]8[/TD]
[TD]9[/TD]
[TD]10[/TD]
[TD]11[/TD]
[TD]13[/TD]
[TD]14[/TD]
[TD]16[/TD]
[TD]18[/TD]
[TD]20[/TD]
[TD]22[/TD]
[/TR]
[/TABLE]

 

[Big Mike]

If you look at a chart in 1\4 stop increments, it's 3/4 of a stop.

f/# 1.0 1.1 1.2 1.3 1.4 1.5 1.7 1.8 2 2.2 2.4 2.6 2.8 3.2 3.4 3.7 4 4.4 4.8 5.2 5.6 6.2 6.7 7.3 8 8.7 9.5 10 11 12 14 15 16 17 19 21 22

http://en.wikipedia.org/wiki/F-number#Typical_one-quarter-stop_f-number_scale