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01-13-2010, 12:49 PM   #1
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rokinon 85mm f1.4 vs pentax fa 50mm f1.4?


I'm looking for a new lens that can shoot with a lot more light and I was looking at either the Rokinon 85mm f1.4 and the pentax fa 50mm f1.4. They are roughly the same price ($250-$300) so I was wondering which would be a better choice.

One thing to note is that one of the big reasons for wanting a wider lens is so I can shoot better indoor/night/lowlight videos with my new Pentax K-x. My hope is that a wider lens with reduce some of the noise/grain issues I've been having with lowlight video.


01-13-2010, 01:07 PM   #2
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First of all "wider" lens is a lens that gets more into the picture, i.e. low mm numbers.
You are talking about a "faster" lens.

I have a Pentax-A 50mm/1.7 and a Rokinon 85mm 1.4 clone.
The Rokinon and clones are a tad softer than the fast 50s, I believe. Even stopped down to 2.2.
Part of that is that the subject isolation with a 85mm lens is quite big. This can be an interesting thing to play with.

But generally, if it is your first prime, I would go with the FA 50mm, because it is autofocus and more useful. If you find you need something longer, I would buy the Rokinon later.

01-13-2010, 01:31 PM   #3
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I have both. I would think that the focal length of the 85mm would be too long for most indoor situations...unless you are doing theater, concerts, or something similar. Even the FA 50 is a tad long indoors for me. Both are good lenses. I feel that the FA 50mm is a little soft until about f/2, maybe f2.5. The Rokinon is VERY sharp from f1.4 to around f/4 (give or take). The FA 50mm will beat the Rokinon 85mm after f4 for sure. It is pretty much confirmed that the 85mm was made to be sharp wide open and as a result suffers just a bit at medium apertures.

Both lenses are great and should make you happy. Obviously the FA is auto focus, which is nice.
01-13-2010, 01:50 PM   #4
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I have a vivitar 85m F1.4 and super tak 85mm F1.9 as well as SMC and Super Tak 50mm F1.4 lenses.

I find 85 mm a little long for indoor portraits. I think today, for Indoor work you need 50mm and perhaps 35 mm, depending on head and shoulders shots or full body, and obviously the size of room / studio you are in.

for outdoor, and candid shots, I like both 85mm and 135 mm as good focal lengths for portraits, but you need space.

01-13-2010, 10:16 PM   #5
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The Rokinon has a minimum focus distance of 1 meter, which may also be a problem. The FA50/1.4's distance is 0.49 meters.
01-14-2010, 05:02 PM   #6
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Ther 85 would be if all you want are head shots. The 50 would be if all you want are head and shoulder / shots. Neither would be my first choice for basic indoor shooting - you need something wider. I'd say you're better off with a 28 or 35, even if "only" f/2.8 (that's still twice as good as the kit lens).
01-20-2010, 01:35 PM   #7
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Like Marc mentions above, for indoor shots I'd recommend a different lens (The 16-50mm DA* 2.8 comes to mind), but if I had to choose (as you've set forth) I would go with the FA 50mm 1.4 hands down.

I have both lenses and the 50mm is much more usable based solely on a slightly wider focal range AND of course the Auto focus.

Since you're primarily focusing on Video - also keep in mind that a wider focal length lets you get closer to the subject - in the case where you're using the in-camera mic.


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