f1.8 or f2.8??


Status
Not open for further replies.
Jan 8, 2006
330
0
16
Bukit Batok!
#1
Hi all.. i have a 50mm f1.8 lens, and im quite confused about the apertures.. under what circumstances will you use 1.8 or 2.8?

For those who dont wanna read, Concluding my question, for the 3 scenarios below, just between 1.8 and 2.8, which will you use?:
1. Good light (daytime)
2. Bad light (night time/indoor, cant use flash)
3. Using flash



Really need advice from the pros here..
Sorry for the long winded post, but i have to get things right..


Am i right to say that
at 1.8
- faster shutter speed allowed (since more light are let in)
- smaller dof, better bokeh
- dof too small, easy to get oof
- good for isolation of subjects
- good when taking photos in low light, where hand shake is a problem due to slow
shutter speed

However, i started comparing f1.8 with f2.8, and found f2.8 to be sharper and brighter than f1.8. Pictures look more appealing at f2.8.. Also, when taking photos with flash, those at f2.8 are brighter than those at f1.8. Is this normal? I will post comparison photos if required.

Thanks a million
 

zac08

Senior Member
Feb 21, 2005
11,755
0
0
East
#2
f2.8 is stopped down and thus you'd get better sharpness and image quality than from wide open at f1.8

And when you use flash, there is already light from the flashgun itself and thus, you can even stop down lower to say f4 or f5.6 to get better DOF and image quality.
 

Jan 8, 2006
330
0
16
Bukit Batok!
#3
thanks for the quick reply.
ahh.. so its best to use f2.8 for most circumstances?
and use 1.8 only when the lighting is very poor or when theres a need to isolate subjects?

ive always heard people talking about the POWER of the 50mm f1.8, and posting uber sharp photos taken with it. Thats why i wanna know the optimum settings for it.

Thanks once again.
 

ExplorerZ

Senior Member
Jan 9, 2006
7,752
0
36
West Legion
hkchew03.deviantart.com
#4
thanks for the quick reply.
ahh.. so its best to use f2.8 for most circumstances?
and use 1.8 only when the lighting is very poor or when theres a need to isolate subjects?

ive always heard people talking about the POWER of the 50mm f1.8, and posting uber sharp photos taken with it. Thats why i wanna know the optimum settings for it.

Thanks once again.
try them out yourself... it is 101% better than listening to anyone here. Try to understand when you will really need f1.8 and when to choose between f1.8 or 2.8
 

Jan 31, 2007
113
0
0
#5
I have a question too.
For f1.8 or f2.8 which is more expensive ?
 

Jan 8, 2006
330
0
16
Bukit Batok!
#7
yeah, i guess i have lots to learn.. for now, from some test shots taken at home, i prefer shots at f2.8.
I gotta go out experiment by taking more real-world shots..
 

zac08

Senior Member
Feb 21, 2005
11,755
0
0
East
#8
yeah, i guess i have lots to learn.. for now, from some test shots taken at home, i prefer shots at f2.8.
I gotta go out experiment by taking more real-world shots..
Well, you got your answer... even in dim light, I normally will still take pics at at least 1 stop smaller thant the maximum wide. E.g. f2.8 with a f1.8 lens and f4 with a f2.8 lens...
 

Jan 8, 2006
330
0
16
Bukit Batok!
#9
Well, you got your answer... even in dim light, I normally will still take pics at at least 1 stop smaller thant the maximum wide. E.g. f2.8 with a f1.8 lens and f4 with a f2.8 lens...
i see.. i took many pics at chinatown at f1.8 cos i saw yilishengxian taking mostly at f1.8 with what he called The One Lens. Hoped to get the results similar to his, but guess my skill is still waaaaay lousier. lol..

1 photo to share at f1.8.
 

zoossh

Senior Member
Nov 29, 2005
8,725
0
0
Singapore
#10
both are fast lens capable of shortening shutter duration. the overall brightness depends on your metering, exposure compensation and PASM mode.

what differs is the depth of field. depends on your focus subject, if perpendicular, can use 1.8. if straddle across a distance, 2.8 or more.
 

zac08

Senior Member
Feb 21, 2005
11,755
0
0
East
#11
You'd like to try f1.8 with a f1.4 lens... Also do take care on the handshake and very shallow DOF.
 

Jan 8, 2006
330
0
16
Bukit Batok!
#12
i think f1.4 is too shallow for my needs..
At the completely same settings (iso, exposure, metering etc), same focal length and same aperture, i found that the 50mm took much better pic compared to the 18-70mm kit lens at 50mm. Now i know why prime lens are so highly rated. Haha..
 

Vulpix0r

Senior Member
Oct 2, 2002
3,136
0
0
West
#13
BTW, just to answer the TS, aperture does not affect the quality of the bokeh. Many factors will affect the quality of a photo's bokeh, but most of the time it's the quality of the lens.
 

Jan 8, 2006
330
0
16
Bukit Batok!
#14
BTW, just to answer the TS, aperture does not affect the quality of the bokeh. Many factors will affect the quality of a photo's bokeh, but most of the time it's the quality of the lens.
oh! thanks for enlightening me! Ive always thought that the wider the aperture, the smaller the dof which leads to a better bokeh.. I see.. So a small dof doesnt always mean the bokeh is good, just that its blur.

thanks
 

ExplorerZ

Senior Member
Jan 9, 2006
7,752
0
36
West Legion
hkchew03.deviantart.com
#15
BTW, just to answer the TS, aperture does not affect the quality of the bokeh. Many factors will affect the quality of a photo's bokeh, but most of the time it's the quality of the lens.
actually it does affect, if you aperture diaphragm ain't a perfect circle, stopping down the lens might cause bokeh of spot of light to be in hexagon shape or etc.
 

Youhong

Senior Member
Dec 30, 2004
3,967
0
0
31
North
photofreak-alvinz.blogspot.com
#16
ive always heard people talking about the POWER of the 50mm f1.8, and posting uber sharp photos taken with it. Thats why i wanna know the optimum settings for it.

Thanks once again.
You should look at the pro's pictures... Really an expert of 50mm... :thumbsup:
http://www.pbase.com/teetoo/root
 

Jan 8, 2006
330
0
16
Bukit Batok!
#17
cool.. thanks for the weblink.
Certainly gives me the "push" to explore and experiment the lens in-depth
 

Status
Not open for further replies.
Top Bottom