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08-03-2011, 02:50 PM   #31
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QuoteOriginally posted by paperbag846 Quote
That is preposterous!

There is no way the 1.7 is 10x sharper than the 1.4. What a silly thing to say. The only way you would feel that way is if you have only ever used the 1.4 in autofocus mode, and never bothered to calibrate the autofocus.
actually you misunderstood what I meant by the sharpness ratio or I might not made it clear. what I meant by that is the number of f1.4 lenses that would support that it is sharper than the f1.7 at certain fast apertures or vice versa. the general consensus and majority of such users would validate that the f1.7 is sharper than the f1.4. now that ratio is more of a 10:1 in terms of actual use and comparison by people who actually used such lenses without the benefit or influence of individual MTF tests on the web conducted by certain users.

however, I believe that it is erroneous to say that the 1.4 is soft at wide open and I refute anyone who would say it is. it is sharp but not at the same degree as that of the f1.7 at similar apertures not until f2.8 and lower apertures which had been validated or noticed by actual users, including myself.

now, if the question of preference would come to mind, there are things to be considered on choosing either lens. the f1.7 pop sharpness rendering at wide open and color or the f1.4 fast aperture and bokeh. these are two lens that are not similar unlike the 55/1.8 and 55/2. so basically, this is more of an apple to orange comparison rather than a same fruit variety.

08-03-2011, 02:51 PM   #32
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QuoteOriginally posted by paperbag846 Quote
That is preposterous!

There is no way the 1.7 is 10x sharper than the 1.4. What a silly thing to say. The only way you would feel that way is if you have only ever used the 1.4 in autofocus mode, and never bothered to calibrate the autofocus.
Calibrate the autofocus? How would you go about doing that? I have a Kr (not sure if that matters).

I finally got my FA 1.4 in the mail today and I must admit that I'm a bit disappointed. However, I am confident that I am disappointed because of user error and not because of the lens. I've been testing it out around the house and cannot get any consistent sharpness. I took a pic of my dog and part of him came out sharp (the body) while his face is very soft, almost out of focus (I think I'm explaining that correctly).

Any ideas from anyone?
08-03-2011, 03:04 PM   #33
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QuoteOriginally posted by reivax Quote
I finally got my FA 1.4 in the mail today and I must admit that I'm a bit disappointed. However, I am confident that I am disappointed because of user error and not because of the lens. I've been testing it out around the house and cannot get any consistent sharpness. I took a pic of my dog and part of him came out sharp (the body) while his face is very soft, almost out of focus (I think I'm explaining that correctly).
I'll let others help with calibration; that might be a FF/BF issue.

But your sharpness problem is due to the very wide aperture at that focal length. Any 50/1.4 lens has VERY thin DOF wide-open, especially when shooting close. Tell your dog to SIT just one yard/meter away. Aim at one eye. Shoot. Chances are, the nose and ears and other eye and everything else will be OOF. Shooting wide-open and close requires great care.

As I've said, you don't shoot a 50/1.4 wide open for edge-to-edge sharpness, but to grab light and/or action, and for the creative control of thin DOF. Stop-down for thick DOF; stay wide-open to surgically isolate a subject from their surroundings, or to shoot in very low light, or to catch fast movement. That's what the lens is for -- to capture otherwise-impossible images.

Last edited by RioRico; 08-03-2011 at 03:12 PM.
08-03-2011, 03:08 PM   #34
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QuoteOriginally posted by RioRico Quote
I can't help with calibration; that might be a FF/BF issue.
How do I know if I have a FF/BF issue?

Sometimes my pictures do come out with great sharpness and in perfect focus. Do FF/BF issues come and go? Or would they appear in all pictures.

08-03-2011, 03:14 PM   #35
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aside from the user error and possible BF/FF issues of the f1.4, as riorico mentioned has a very thin DOF that makes it tough for someone who is not acquainted with such fast lens. it would be advisable for you to shoot at f2 or f2.8 for now.
08-03-2011, 03:21 PM   #36
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I haven't had BF/FF issues, but here's what I think I know. Cameras and AF lenses are calibrated for focus within certain specifications. Any particular pairing might together be beyond specs. So our dSLRs let us adjust the back/front focus per lens. See your manual under FOCUS ADJUSTMENT. No, BF/FF issues don't come and go with a particular lens -- it either back/front focuses, or not.

If your focus seems variable, that's either a User Issue (you're not aiming right!) or a Focus Point issue. See your manual under FOCUS POINT and try different settings. With a fast lens, I don't trust Matrix AF -- I'll set Spot focus and make sure my subject is centered in the frame. If I don't like the composition, I'll crop in PP, after I'm done fixing my exposure / WB / contrast / sharpness / other goofs!
08-03-2011, 04:01 PM   #37
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QuoteOriginally posted by RioRico Quote
If your focus seems variable, that's either a User Issue (you're not aiming right!) or a Focus Point issue. See your manual under FOCUS POINT and try different settings. With a fast lens, I don't trust Matrix AF -- I'll set Spot focus and make sure my subject is centered in the frame. If I don't like the composition, I'll crop in PP, after I'm done fixing my exposure / WB / contrast / sharpness / other goofs!
+1.

I also think that the FF/BF thing comes out of every camera being calibrated slightly differently. It does not show, though, unless you are autofocusing a very fast lens.

Anyways you can do it in custom options... just play with it. But most importantly... stick to f2 for the most part, and centre-point focus.
08-03-2011, 05:18 PM   #38
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QuoteOriginally posted by paperbag846 Quote
+1.

I also think that the FF/BF thing comes out of every camera being calibrated slightly differently. It does not show, though, unless you are autofocusing a very fast lens.

Anyways you can do it in custom options... just play with it. But most importantly... stick to f2 for the most part, and centre-point focus.
So you recommend sticking to f2 or higher? Any reason why I would ever want to go lower? (other than really low light situations?)

08-03-2011, 05:34 PM   #39
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QuoteOriginally posted by reivax Quote
So you recommend sticking to f2 or higher?
Until you get the feel of the lens, anyway. Maybe not even that long. Practice practice practice.

QuoteQuote:
Any reason why I would ever want to go lower? (other than really low light situations?)
To capture fast action; and to exploit very thin DOF, like to surgically isolate a subject from their surroundings.
08-03-2011, 05:37 PM   #40
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QuoteOriginally posted by RioRico Quote
Until you get the feel of the lens, anyway. Maybe not even that long. Practice practice practice.


To capture fast action; and to exploit very thin DOF, like to surgically isolate a subject from their surroundings.
Do any of you have any night shots with your FA 50 1.4? I'm really curious what settings you guys used. I hope to be able to take some night shots with it.
08-03-2011, 06:01 PM   #41
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QuoteOriginally posted by reivax Quote
Do any of you have any night shots with your FA 50 1.4? I'm really curious what settings you guys used. I hope to be able to take some night shots with it.
not really shot at f1.4 but at f1.2, but atleast you get the idea what it would look like using at fast lens at night. this was taken at almost pitch black. the only light source visible is the cauldron.



btw, I wouldn't recommend using this lens either unless you are pretty committed and would really want to get accustomed to such lens.
08-03-2011, 08:29 PM   #42
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QuoteOriginally posted by Pentaxor Quote
btw, I wouldn't recommend using this lens either unless you are pretty committed and would really want to get accustomed to such lens.
Not really sure I understand, why wouldn't I want to get used to this type of lens? What's wrong with it? What lens should I be using?
08-03-2011, 10:24 PM   #43
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QuoteOriginally posted by reivax Quote
Not really sure I understand, why wouldn't I want to get used to this type of lens? What's wrong with it? What lens should I be using?
A 50mm f1.2 allows you to shoot in extremely dark conditions, and allows for some pretty extreme DOF control. However Pentax has never made an autofocus version of this lens, and they are pretty expensive. Very advanced, and not much advantage over the 50mm f1.4s in the common aperture range (f2.8 and smaller).

---

Some examples of f1.4:

As you can see, it's good for very low light (the bowling alley shots), or abstracts. I'm still learning this lens myself, but I can say that no lens has given me more enjoyment than my 50's (1st 55mm f1.8, then 50mm f1.7, and now my favourite, the 50mm f1.4).

You can see my settings with "View Picture EXIF"
Attached Images
View Picture EXIF
PENTAX K20D  Photo 
View Picture EXIF
PENTAX K20D  Photo   
View Picture EXIF
PENTAX K20D  Photo 
View Picture EXIF
PENTAX K20D  Photo 

Last edited by paperbag846; 08-04-2011 at 07:27 AM.
08-04-2011, 02:29 AM   #44
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QuoteOriginally posted by reivax Quote
Not really sure I understand, why wouldn't I want to get used to this type of lens? What's wrong with it? What lens should I be using?
(ssst... it's a conspiracy to keep you from buying a great, exclusive lens...)

There is fast, and there is FAST. There are relatively few f/1.2 lenses, very very few that are faster (and those get mighty expensive). F/1.2 is like at the junction of extremity and afford-ability. Extreme, because they can be tricky to use wide-open; and affordable, because for instance I got a K50/1.2 for US$250 shipped a few months ago, and that's about market rate.

AFAIK there are no AF f/1.2's made for Pentax. That leaves either A-type or M-type MFL's. My K50 is M-type, no aperture automation, so I must use it either wide-open, or in M(anual) mode for stopped-down metering and shooting. So that's 3 degrees of trickiness beyond an FA50/1.4: no autofocus, and no auto-aperture, and thinner DOF. Yes, it takes a bit of practice.

The K and A50/1.2 are both top-flight lenses, literally among the best ever made by anyone. (The auto-aperture A50 is much more expensive.) The micron-thin DOF wide-open and tremendous light-gathering capability allow great effects. Stopped down slightly, they're exquisitely sharp and clean. Ah, that thin DOF isn't unique to 50/1.2's. You'll get thinner DOF from an 85/2 and even the common-as-dirt 135/2.8 and 200/4. But because those are longer, the effects aren't as extreme.

So keep shooting your 50/1.4 at various distances and apertures. Find how your camera-to-subject distance affects the feeling of depth and focus in pictures. After awhile the 50/1.4 will seem almost ordinary... and then you'll lust for a 50 or 55/1.2. Wait, that's not thin enough! Gotta get a 58/1.2!! No, a 50/1.0!! No, a 50/0.9!! Ooh ooh! How far can you go?!?!?
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