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11/28/2006 02:12:00 PM · #1 |
I've heard in the past that there are issues with the 50 f/1.4 when used wide open. I'm hoping to use it this weekend for a ballet performance though and I don't think my f/2.8 lens is going to cut it without severely jacking up my ISO. Any one have any tips or trick on how to "help" the 50 f/1.4 when it's wide open? Is there a filter I can get that will improve it?
The issues are that it looks like it has a soft focus screen on it and it blows highlights pretty bad with awful splotches.
Here's an example:
ISO 360
1/160 sec
f/1.4
WB - Incandescent
Only editing was the crop.
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11/28/2006 02:31:44 PM · #2 |
The problem isn't really that these lenses are 'soft'. The problem is that the depth of field is so shallow at f/1.4, a lot of it will appear soft. It's not a problem with the lens. It's the way the lens is designed. If your subject is far enough away from you, it won't be a problem at f/1.4.
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11/28/2006 02:39:48 PM · #3 |
Compared to my 30 f/1.4 the 50 f1/4 is noticeably soft and lacking contrast wide-open. From f/1.8 it is great, but I really don't like to use it at f/1.4).
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11/28/2006 03:14:13 PM · #4 |
Ok, here's 2 more examples I just went out and shot - 100% crops
f/1.4
f/16
These were taken at about 25 feet away.
Notice how the f/1.4 looks like it has a soft focus filter over it. Also notice how the detail of the white fur on his shoulder doesn't have much detail either.
The f/16 shot admittedly I missed the focus a tad but I don't want to go shoot it again and it actually illustrates my point between the difference between the "soft focus" of the f/1.4 and just plain "out of focus". |
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11/28/2006 03:27:47 PM · #5 |
Wideopen it simply isn't very good, not much you can do about it.
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11/28/2006 04:06:02 PM · #6 |
That "soft focus" effect, where there is still detail but with a soft halo, is either due to astigmatism or spherical aberration, or a bit of both. Neither are uncommon on very fast lenses, and both will be much more visible wide open.
Slight undercorrection for spherical aberration was a trick that some designers of portrait lenses used to obtain that "glowing" look to skin. A perfect example of this was the venerable Zeiss-Jena 75/1.5 Biotar. An outstanding portrait lens, but never, never try to use it for astrophotography :-P |
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11/28/2006 05:53:13 PM · #7 |
| Thanks Kirbic, I didn't know about that. Too bad there isn't a fix for it :( It doesn't look like anyone makes a 50 f/1.4 aspherical either. Sigma makes a 30mm but that'd be too short for what I need. Looks like I'm stuck with my 2.8 and bumping up the ISO. |
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11/28/2006 06:04:27 PM · #8 |
Originally posted by Megatherian:
...Looks like I'm stuck with my 2.8 and bumping up the ISO. |
Before giving up on the 50mm lens, I would try it at f/2.0. That's a whole stop away from f/1.4, and still a whole stop faster than f/2.8. Might be worth a try. |
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