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06-04-2011, 02:36 PM   #16
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QuoteOriginally posted by robgo2 Quote
Could you please tell us the apertures used in the FA43 and DA40 shots? If it is f1.9 vs. f2.8, then it is not a meaningful comparison.

Rob
QuoteOriginally posted by paperbag846 Quote
Could you explain this one? We aren't comparing sharpness.
QuoteOriginally posted by v5planet Quote
They were both wide open, and I agree, that makes it a considerably less meaningful comparison. Optical eyesores that are visible in a lens wide open often resolve themselves when the lens is stopped down -- what we'd really need to see is the FA43 at f/2.8 vs the DA40 at f/2.8 in this situation. Presently the only thing these images tell us is that the 43 is capable of f/1.9 and the 40 is not.
Well, recently I only have access to DA 40 f/2.8 -- it found its way back to me. Thus, I cannot do a truly fair comparison myself.

06-04-2011, 02:51 PM   #17
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QuoteOriginally posted by v5planet Quote
They were both wide open, and I agree, that makes it a considerably less meaningful comparison. Optical eyesores that are visible in a lens wide open often resolve themselves when the lens is stopped down -- what we'd really need to see is the FA43 at f/2.8 vs the DA40 at f/2.8 in this situation. Presently the only thing these images tell us is that the 43 is capable of f/1.9 and the 40 is not.
Well by your logic these lenses should be compared at f4, then.
06-04-2011, 06:39 PM   #18
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QuoteOriginally posted by paperbag846 Quote
Well by your logic these lenses should be compared at f4, then.
No, but I think comparing them at f2.8 would be more reasonable. There was a thread back awhile ago where dgaies compared a bunch of really nice lenses wide open. The problem with the comparison is that for some lenses the max aperture was 2.8, while for one, it was f1.2.

It is nice to know how lenses perform wide open, but lenses really should be compared at similar apertures.

From what I have seen, the FA 43 does smooth out quite a bit at f2.8. I own the DA 55 and it has similar behavior (although a stop faster). It gets pretty busy at f1.4, but by f2, it really smooths out in the out of focus areas and looks nice.
06-05-2011, 12:39 AM   #19
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QuoteOriginally posted by kdre Quote
According to the test, Da40 has a focus shift. Did you notice it in real world situations?

Or did they test a bad copy?
I noticed it in 2 copies, enough for me to let it go. Most obvious in mid distance (4-6 meters, stoped down to f/4). Can be corrected, but will shift the focus in near limit range instead.

But, the lens is great lens and makes stunning image qulity though!

06-05-2011, 01:25 AM   #20
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QuoteOriginally posted by the swede Quote
I noticed it in 2 copies, enough for me to let it go. Most obvious in mid distance (4-6 meters, stoped down to f/4). Can be corrected, but will shift the focus in near limit range instead.

But, the lens is great lens and makes stunning image qulity though!
It's probably not an issue of a "copy," but rather of design. Canon 50mm f/1.2 and other nice fast lenses "suffer" from focus shift, by design, as well. Sometimes, you just have to learn to live with it or work around it.
06-05-2011, 05:38 AM   #21
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I don't understand what focus shift with a fixed focal length lens. What is it, when is it a problem?
06-05-2011, 06:20 AM   #22
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QuoteOriginally posted by audiobomber Quote
I don't understand what focus shift with a fixed focal length lens. What is it, when is it a problem?
Check the photozone analysis. Especially have a look at the ruler at the bottom of the analysis section.

When stopping down, the focus point shifts slightly to the back, instead of being where you want it to be. This makes it more difficult to focus properly with a small DOF within close distances.
06-05-2011, 08:58 AM   #23
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QuoteOriginally posted by Rondec Quote
No, but I think comparing them at f2.8 would be more reasonable. There was a thread back awhile ago where dgaies compared a bunch of really nice lenses wide open. The problem with the comparison is that for some lenses the max aperture was 2.8, while for one, it was f1.2.

It is nice to know how lenses perform wide open, but lenses really should be compared at similar apertures.

From what I have seen, the FA 43 does smooth out quite a bit at f2.8. I own the DA 55 and it has similar behavior (although a stop faster). It gets pretty busy at f1.4, but by f2, it really smooths out in the out of focus areas and looks nice.
The aperture used in the comparison is very significant. If the FA43 exhibits a somewhat nervous bokeh with a busy background at f1.9, it may be lovely at f2.8. Even so, with a relatively smooth background, it may be lovely at f1.9, which is not even available on the DA40. (And it is lovely under those circumstances. I know from personal experience.) Different shots present different challenges, and one has to learn how to use one's equipment optimally to get the best that it can deliver. Learn when you have to stop down a bit and when you do not. Very simple.

Rob


Last edited by robgo2; 06-05-2011 at 09:19 AM.
06-05-2011, 11:31 AM   #24
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QuoteOriginally posted by robgo2 Quote
The aperture used in the comparison is very significant. If the FA43 exhibits a somewhat nervous bokeh with a busy background at f1.9, it may be lovely at f2.8. Even so, with a relatively smooth background, it may be lovely at f1.9, which is not even available on the DA40. (And it is lovely under those circumstances. I know from personal experience.) Different shots present different challenges, and one has to learn how to use one's equipment optimally to get the best that it can deliver. Learn when you have to stop down a bit and when you do not. Very simple.

Lens bokeh tends to be subpar wide open. This would go for the DA 40 as well. So, you must compare both lenses at f4, to erase any disadvantages.

If you compare at f2.8 the DA 40 suffers the same disadvantage that the FA 43 does at f1.9. How has this escaped your attention?
06-05-2011, 01:27 PM   #25
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QuoteOriginally posted by paperbag846 Quote
Lens bokeh tends to be subpar wide open. This would go for the DA 40 as well. So, you must compare both lenses at f4, to erase any disadvantages.

If you compare at f2.8 the DA 40 suffers the same disadvantage that the FA 43 does at f1.9. How has this escaped your attention?
Yes, there is a reason these two lenses do not cost the same amount. That the DA40 would have a disadvantage relative to the FA43 when both are set to f/2.8 is precisely the point.

Complaining about the bokeh when the FA43 is at an aperture that isn't even possible on the DA40 doesn't make any sense unless you are interested in illustrating that the DA40 is not capable of f/1.9.
06-05-2011, 02:38 PM   #26
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QuoteOriginally posted by v5planet Quote
Yes, there is a reason these two lenses do not cost the same amount. That the DA40 would have a disadvantage relative to the FA43 when both are set to f/2.8 is precisely the point.
And we could go the other way with it: let's compare the FA 50 and FA 43 at f2 for bokeh and sharpness. Is there now justification for the FA 43 costing twice as much?

No, but if we were to stop each lens down to f2.8 (a fair comparison), then we could be able to see the strengths of both lenses, and how different they are.

Therefore the DA 40 and FA 43 should be compared above f2.8. Anything else would be an unfair comparison.
06-05-2011, 04:26 PM   #27
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QuoteOriginally posted by paperbag846 Quote
Lens bokeh tends to be subpar wide open. This would go for the DA 40 as well. So, you must compare both lenses at f4, to erase any disadvantages.

If you compare at f2.8 the DA 40 suffers the same disadvantage that the FA 43 does at f1.9. How has this escaped your attention?
OK, so how do these two lenses compare at f4.0? I only know that the bokeh of the FA43 is superb at that aperture. I do not have access to the DA40, so I can say no more on the subject. Can someone with too much time on his hands post sample images?

Rob
06-05-2011, 06:45 PM   #28
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QuoteOriginally posted by robgo2 Quote
OK, so how do these two lenses compare at f4.0? I only know that the bokeh of the FA43 is superb at that aperture. I do not have access to the DA40, so I can say no more on the subject. Can someone with too much time on his hands post sample images?
I imagine the difference will more be that the FA 43 will be sharper at pixel-peeping levels, bokeh should be more or less the same.
06-06-2011, 08:19 AM   #29
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QuoteOriginally posted by paperbag846 Quote
I imagine the difference will more be that the FA 43 will be sharper at pixel-peeping levels, bokeh should be more or less the same.
Oh, I was hoping that you would have the definitive answer to my query. To return to an earlier point, if the FA43 can render pleasing bokeh at f1.9 with a relatively smooth background, that is a distinct advantage that it holds over the DA40, which cannot go below f2.8. It is a difference that matters in real world usage, not theoretical speculation. I don't see how anyone can argue that point. Not to mention the fact that bokeh is only one aspect of a lens's performance, and people can differ in their opinions of what constitutes pleasing bokeh.

Is it just me, or do other people think that this discussion is getting a bit tiresome? I think that I will bow out.

Rob
06-06-2011, 11:36 AM   #30
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QuoteOriginally posted by robgo2 Quote
Oh, I was hoping that you would have the definitive answer to my query.
I don't have the money to own all of these lenses at once, and I've only ever played with the FA 43 once. I sold my FA 50 to buy the DA 40, and again sold my DA 40 to buy a FA 50.

However I can tell you a few things about bokeh and sharpness. The DA 40 is very sharp corner to corner, but at pixel peeping levels, it's not as sharp as the FA 43 or 50 stopped down. The DA 40 has some nippley bokeh at f2.8, but nothing too noticeable. In general, the bokeh of the 40 is pretty subtle (due to the focal length and aperture).

The FA 50 has some funny looking bokeh at f1.4, as well (similarly to the FA 43). The 50 is never as sharp as the FA 43, but once again, you would have to be looking very hard to see the difference at f4 - f8. The real difference is between f2 - f4, where the FA 43 is clearly sharper. On the other hand, the FA 50 tends to deal with busy backgrounds in a more pleasing way then the FA 43.

Part of this advantage is due to the speed of the FA 50, which is almost a full stop over the FA 43. So compared at f2, the 50 has a 1 stop advantage of smoothing going on. Another is the focal length... for the same reason the FA 77 beats the pants off of the FA 50. The third is that the FA 50 is not as corrected for sharpness as the FA 43. So the FA 50 is not as sharp (center or corner) as the 43, but it tends to smooth out backgrounds better.

Truth be told, both lenses are compromises. If they cost the same amount, I think people would be more willing to admit this, although I could understand why one would prefer the 43's rendering over the 50. In the end, the truth is that you pay handsomely for the fit and finish of an FA limited. There is no question that manually focusing the 43 is a nicer experience than it is with the 50. IQ differences, however, are more a matter of subjectivity than objective advantages.

---

The point, though, is that comparing one lens wide open to another lens stopped down, isn't really that fair. And in this discussion, I noticed the comparisons tended to be done in such a way as to favor the 43, which isn't the point of a comparison.
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