Should I buy a 50mm f1.8 when I have a 17-70 f2.8?


maisatomai

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#1
If I shoot at 50mm, will the 50mm f1.8 stepped down to f4 have advantage over my 17-70 f2.8 @ 50mm f4. Will the depth of field be the same and will it have advantage in low light situtation?
 

daredevil123

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#2
If I shoot at 50mm, will the 50mm f1.8 stepped down to f4 have advantage over my 17-70 f2.8 @ 50mm f4. Will the depth of field be the same and will it have advantage in low light situtation?
At 50mm, and F4, on the same camera, both lenses will give you the the same depth of field, as well as low light performance. No low-light advantage whatsoever.
 

coolthought

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Jun 23, 2008
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#3
If I shoot at 50mm, will the 50mm f1.8 stepped down to f4 have advantage over my 17-70 f2.8 @ 50mm f4. Will the depth of field be the same and will it have advantage in low light situtation?
may i know what brand of lens is your 17-70 f2.8? thanks
 

SkyStrike

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#4
At 50mm, and F4, on the same camera, both lenses will give you the the same depth of field, as well as low light performance. No low-light advantage whatsoever.
Unless looking thru the viewfinder and see that it's brighter is an advantage.
 

mazeppa26

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#5
unless you wanna take photos at f1.8
or
you want a lighter smaller alternative for street photog
 

rhino123

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#6
If I shoot at 50mm, will the 50mm f1.8 stepped down to f4 have advantage over my 17-70 f2.8 @ 50mm f4. Will the depth of field be the same and will it have advantage in low light situtation?
Bro... I believe your 17-70mm is Sigma's 17-70... which is a variable aperture lens (of course I might be wrong). So if it was the case, then at 50mm on your 17-70mm, it will not be f2.8. however at f4, the DOF should be the same for both the 17-70mm at f4 and 50mm at f4. Sharpness wise differ but I am leaning towards the 50mm.
 

sfoto100

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#7
i feel that since 50mm f1.8 is so cheap, no harm getting it.. at least it is 1.25 stop faster than f2.8.. it will help in low light and bokeh..
 

digitalpimp

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#8
I can't count the times when I wish I brought my f1.x with me on a trip. Just two days ago I was trying to do night street photography in those narrow alleyways in Bangkok. f2.8 and ISO1600 just couldn't cut it. Ended up with a big fat fail. So yea, get it. It's cheap anyway.
 

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#9
digitalpimp said:
I can't count the times when I wish I brought my f1.x with me on a trip. Just two days ago I was trying to do night street photography in those narrow alleyways in Bangkok. f2.8 and ISO1600 just couldn't cut it. Ended up with a big fat fail. So yea, get it. It's cheap anyway.
Heard of manual focus during night shots?
 

digitalpimp

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#10
rvf79 said:
Heard of manual focus during night shots?
Not the focusing but the speed of the people walking I had problems with. I wanted faster shutter speeds to freeze motion. Heard of it?
 

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digitalpimp

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#13
rvf79 said:
U never say people walking ma.

Then increase the iso then pp lo.
Sorry, but don't take lessons from people who call a watermark 'name stamp'.

Trust me, I know what I'm talking about.

Your sarcasm isn't appreciated. You pushed, I just pushed back. :)

And yea, I don't need to explain anything to you. You're not even the thread starter.
 

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rhino123

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#19
I can't count the times when I wish I brought my f1.x with me on a trip. Just two days ago I was trying to do night street photography in those narrow alleyways in Bangkok. f2.8 and ISO1600 just couldn't cut it. Ended up with a big fat fail. So yea, get it. It's cheap anyway.
Just a tot, bro... if you step up your ISO to around ISO3200 or more, maybe f2.8 will cut it. As for the amount of noise in the pic, we can always use pp to cut away the chroma noise...

Just a tot. However if people are walking very fast or your speed cannot reach fast enough, then very difficult to freeze motion.
 

digitalpimp

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#20
rhino123 said:
Just a tot, bro... if you step up your ISO to around ISO3200 or more, maybe f2.8 will cut it. As for the amount of noise in the pic, we can always use pp to cut away the chroma noise...

Just a tot. However if people are walking very fast or your speed cannot reach fast enough, then very difficult to freeze motion.
Arggh 3200... Let's just say I'm not crazy about Sony's NR performance.:) Higher ISO will definitely help, but the noise is just too much at 3200 on the A700. I'll consider as soon as I upgrade. I heard the new algorithms can do magic. ;)

Not walking very fast lah. It's really a case to case basis and a different topic altogether.
 

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