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06-07-2011, 06:25 AM   #76
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QuoteOriginally posted by paperbag846 Quote
Correct me if I'm wrong, but hasn't the optical formula of the FA 50 remained about the same since the M era (or earlier?) I know the coatings have changed, but thats not exactly the same as designing a whole new lens (like the FA 43).

This is what I meant by "old design"... it's heritage is about 50 or 60 years.

----

Both the 50/1.4 and the 50/1.7 both have their optical layout and element design roots in the Takumar line. That said, most mtf comparisons seem to favor the F and FA series over the M and A series. The FA 43mm was influenced that way as well. The designer tweaked the arrangement and redesigned an element to get that "look" that has been debated in ump-teen threads including several Pixie dust threads. Plus, it was the first 35mm lens to get the Ghostless Coating. Both the FA 50/1.4 and FA 43/1.9 share that same 7/6 arrangement with those darn 2nd Model Super Tak 50/1.4 .

FA 43 (dimitrov)




FA 50/1.4 (dimitrov)







Last edited by Blue; 06-07-2011 at 06:34 AM.
06-07-2011, 11:50 AM   #77
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QuoteOriginally posted by Blue Quote
Both the 50/1.4 and the 50/1.7 both have their optical layout and element design roots in the Takumar line. That said, most mtf comparisons seem to favor the F and FA series over the M and A series. The FA 43mm was influenced that way as well. The designer tweaked the arrangement and redesigned an element to get that "look" that has been debated in ump-teen threads including several Pixie dust threads. Plus, it was the first 35mm lens to get the Ghostless Coating. Both the FA 50/1.4 and FA 43/1.9 share that same 7/6 arrangement with those darn 2nd Model Super Tak 50/1.4 .

FA 43 (dimitrov)




FA 50/1.4 (dimitrov)





Very interesting, Blue. I remember reading somewhere that the 43 shared some things in common with the 50 1.7, but it appears it is actually very similar to the 1.4 (but corrected for better flat-field sharpness).

Would this be accurate?
06-07-2011, 01:22 PM   #78
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I started with the 50 and then picked up the 43, expecting to replace it - but as has been mentioned a lot in this thread, they are different pieces of glass and perspective matters

Here are two shots I did for my own testing today, First the 43, then the 50, both at f2



and the 50

06-07-2011, 01:26 PM   #79
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QuoteOriginally posted by paperbag846 Quote
Very interesting, Blue. I remember reading somewhere that the 43 shared some things in common with the 50 1.7, but it appears it is actually very similar to the 1.4 (but corrected for better flat-field sharpness).

Would this be accurate?
That would be accurate. The f1.7 lenses actually have their design related to the 55/1.8 Taks.

06-07-2011, 01:41 PM   #80
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QuoteOriginally posted by Blue Quote
The f1.7 lenses actually have their design related to the 55/1.8 Taks.
hmmmm...interesting. I'm not sure if the 55/1.8 Taks are the same with the K counterparts. from what I noticed, the K55/1.8 is sharp and the 1.7 slightly sharper. and the 55 has a consistently smooth bokeh to that of the 1.7 which on some instances have far less desirable busy bokeh. also the difference in color temp.
06-07-2011, 02:01 PM   #81
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QuoteOriginally posted by LenWick Quote
I started with the 50 and then picked up the 43, expecting to replace it - but as has been mentioned a lot in this thread, they are different pieces of glass and perspective matters

Here are two shots I did for my own testing today, First the 43, then the 50, both at f2



and the 50
Re: The two shots of the elephant. Exposure is ever so slightly different, but the FA43 is noticeably sharper and shows more detail and tonal gradations on the surface of the stone (marble?) Bokeh is a toss-up and really a matter of personal taste. It's not as though the 50 shot looks bad, but the 43 looks better, and I don't think it's a close call. Thanks for posting this. I realize that it is not a definitive comparison of the two lenses.

Edit: Those who think that the FA43 is soft wide open and has ugly bokeh should take note of this sample.

Rob

Last edited by robgo2; 06-07-2011 at 02:07 PM.
06-07-2011, 02:08 PM   #82
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QuoteOriginally posted by LenWick Quote
I started with the 50 and then picked up the 43, expecting to replace it - but as has been mentioned a lot in this thread, they are different pieces of glass and perspective matters

Here are two shots I did for my own testing today, First the 43, then the 50, both at f2
and the 50
Interesting result - flies in the face of the MTF data, but what are the shooting conditions?

I can see that they both have similar FOVs for the scene, but were they both shot with the same exposure settings, and on a tripod with 2sec shutter delay? Was the PP work the same for both images?

I don't doubt 43 images look more pleasing overall than the 50, though I have seen f/2 images from the 50 look slightly sharper than this.

Last edited by Ash; 06-07-2011 at 02:14 PM.
06-07-2011, 02:48 PM   #83
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QuoteOriginally posted by Ash Quote
Interesting result - flies in the face of the MTF data, but what are the shooting conditions?

I can see that they both have similar FOVs for the scene, but were they both shot with the same exposure settings, and on a tripod with 2sec shutter delay? Was the PP work the same for both images?

I don't doubt 43 images look more pleasing overall than the 50, though I have seen f/2 images from the 50 look slightly sharper than this.
Possibly, focus calibration is slightly off for the 50, although I doubt it, because the elephant does seem to be the sharpest object in the frame. I think the results really speak to the excellence of the FA43.

Rob


Last edited by robgo2; 06-07-2011 at 03:03 PM.
06-07-2011, 02:57 PM   #84
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QuoteOriginally posted by Pentaxor Quote
hmmmm...interesting. I'm not sure if the 55/1.8 Taks are the same with the K counterparts. from what I noticed, the K55/1.8 is sharp and the 1.7 slightly sharper. and the 55 has a consistently smooth bokeh to that of the 1.7 which on some instances have far less desirable busy bokeh. also the difference in color temp.
Exactly my experience. The 55 isn't really a master of anything, but it makes a great little portrait lens due to it's smoother bokeh. I find the lack of insane sharpness acceptable in portrait settings (and it actually gives the photos a bit of a natural vibe to combat digital perfection... does that make sense)?

The 50 1.7 was one of the best low-light lenses I have used because it was so very sharp wide open (I took my best concert photos with that lens). However, the look of it is rather... boring.

---

RE: the 43 vs 50 shots. Interesting. Noticed:

1) Can clearly see increased DOF for the 43 due to focal length. I think that plays a role in sharpness determination.

2) Can see increased contrast in 43 photo. Flare resistance or perhaps something else?

3) I think the 50's shot is misfocused... there is no point of critical sharpness on the elephant. My K20d required a +8 calibration... perhaps this has skewed the results.

Also, was the 50 used with a hood? I find this lens pretty much needs one to even look half-decent (large, exposed element = flare).

In general it looks about right though - the 43 is much sharper in the f2-f4 range when compared with the 50, while the 50 has the creamier bokeh.
06-07-2011, 03:01 PM   #85
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Both shots taken within a few minutes of each other in an office with nice green light from above and good window light camera left. Both images manually focused – you can see the exact plane by examining the purple to green line transition on the left lower edge of the stone (often found with alabaster deposits, not sure what it is exactly) the 50mm is focused a little behind the 43mm image. Images taken on a tripod (no 2 second delay, sorry), and moved in to keep the subject similarly sized when switching lenses – unfortunately this also changes the perspective a little between the images.
06-07-2011, 03:12 PM   #86
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It's reasonably comparable.
The 2 sec delay isn't critical unless shutter speed was less than 1/60 or so.
Confirms that where it matters in thin DoF work, 43 results are generally more pleasing.
06-07-2011, 03:18 PM   #87
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QuoteOriginally posted by Pentaxor Quote
hmmmm...interesting. I'm not sure if the 55/1.8 Taks are the same with the K counterparts. from what I noticed, the K55/1.8 is sharp and the 1.7 slightly sharper. and the 55 has a consistently smooth bokeh to that of the 1.7 which on some instances have far less desirable busy bokeh. also the difference in color temp.
I didn't say they were the same. They do share the same number of elements and arrangement. Those Asahi lens designers were around over a long period of time.

Go here and scroll down to the cut-a-way of the SMC 55/1.8 Die Cast Pro - Super-Multi-Coated Takumar 55mm f/1.8 and compare it to this from Dimitrov's site and they share the 6 elements in 5 group layout.

06-07-2011, 03:34 PM   #88
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I still think there is a focusing problem with that 50. Cropped to show detail (f2, handheld).

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Was the 50 used with a hood? Could explain the softness. That image from the 50 does not look how it should. The 43 would still be sharper but this difference would not be this great.
06-07-2011, 03:53 PM   #89
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Not my intention to slander the 50 in any way I moved the focal plane forward a little (manual) then also set a 2sec timer, still on tripod. Time of day has adjusted the lighting a little bit

06-07-2011, 04:08 PM   #90
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Slightly sharper looking than the previous shot, but still not as good as the 43 both in sharpness and in rendition. It's what I expected, but not what the MTF data indicates.

As the lens designer said, the FA ltds were not designed for lab testing, they were designed for real-world shooting.
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