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07-17-2017, 05:58 PM   #31
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QuoteOriginally posted by Na Horuk Quote
they have the same optic schematic.
They have the same schematic, but actually the fa has a slightly larger front element (I have both).

07-18-2017, 01:44 AM - 1 Like   #32
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QuoteOriginally posted by Na Horuk Quote
I think some reports were that the f2.4 lens is actually a little brighter than f2.4, according to DoF and brightness tests. But I may be misremembering,it was long ago. I don't know how big the actual pupil of both lenses is. Would be interesting to compare to see where that 'aperture' difference comes from, since they have the same optic schematic. DA 35mm f2.4's front element has diameter of 3cm and the back element is 2,4cm, just measured. Is the FA 35mm f2's front or back bigger? Does it have different aperture inside? Just wondering
The front element is 3.5cm on the FA35, and just under 2.4cm on the rear.

Last edited by ScooterMaxi Jim; 07-18-2017 at 02:53 AM. Reason: Oops - measuring the FA; I don't have the DA.
07-18-2017, 01:44 AM - 2 Likes   #33
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Have owned the smc Pentax-DA 35mm F2.8 Macro Limited since 2012 and shot it on K-7 and K-3 bodies. Don't use it as much as my other lenses (except the 18-55mm kit zoom, which has largely fallen out of use with me), but that's due to the standard focal length more than anything else.

Whenever I do use this little gem, I return consistently pleased with its beautifully defined rendering. With its short working distance in macro, it may not be the answer to all my macro wishes, but I have always viewed it as a standard prime that lets me get really close to my subject if need be. With the smc version, you even get the lovely starbursts familiar from the smc DA15 and 21 Limiteds.

Since I've had it in my kit, I've never experienced any serious gear lust for any other 35 on the market, Pentax-branded or third-party. The DA35 Limited is that good.
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Last edited by Madaboutpix; 07-18-2017 at 08:54 AM.
07-18-2017, 02:48 AM   #34
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QuoteOriginally posted by northcoastgreg Quote
I've never heard that and am rather skeptical that early ghostless coatings are dull or inferior. Sure, the application of coatings between one lens and another will not be absolutely identical in all respects; but that's because the coatings are fine tuned to create similar color rendering among the entire lens series. That's different from using inferior coatings. I own two of the early ghostless coated lenses, the FA 20-35 and the FA 24-90, and both lenses share the excellent contrast and color of other ghostless coating FA lenses, such as the three FA limiteds, the FA 200 Macro, and yes, the FA 35. If the FA 35 suffers veiling flare in some situations, it's either due to (1) not being back coated; and/or (2) the design of the lens. Film lenses generally are not back coating and flaring is not just a consequences of lens coating technology, or lack thereof.
All are agreed that the schematic of the two lenses are similar, and - of course - neither lens has issues with the flat rear element design that can contribute to sensor hot spots and other issues. The idea that the FA 35 - one of the more respected lenses of that era - would not have back coating is just a bit breathtaking. You seem to have no idea about the lens. (The lens tests out fairly well for work against the light - I just find its performance not up to expectations compared to its overall strengths.) In any event, a close inspection of the FA 35 coatings show it to be very different from the DA 50, DA 40xs, SMC 21, and I could go on and on. The coatings regimen for zoom lenses is entirely different than for prime lenses, so let's not be mixing our pudding with Jello.

Finally, for those who are willing to look at the extensive reviews done by Simon at Lenstip 13 months apart entirely on crop sensor bodies, I will rest my case. Highlights include that the DA 35 has best in class distortion, and the FA 35 ranked middle of the pack when tested against various other 35s (Canon, Nikkor). Light fall off testing showed the FA best in class (fairly easily) while the DA trailed the Nikkor by a wide margin; at f/2.8 testing shows FA fall off 9%, DA fall off 22% (crop sensor designation for good reason). Take care in comparing the resolution and CA numbers from one lens to the other because different sensors were used, but the characteristics are not similar - as the center and edge resolutions wide open are very similar on FA (impressively so), while the DA is sharper in the center but the edge is much weaker; most users of both lenses also tend to note this.

Bottom line, these are two considerably different lenses and the myth that they are optically similar does not square with the facts. And that isn't even taking into account the vast physical differences.

07-18-2017, 05:46 AM   #35
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My DA 35 2.4 is sharp edge to edge wide open. Who am I going to trust, someone on the internet who does not have the lens or my own lying eyes?
The fact is that DA coatings are different than FA coatings - the former being more contrasty hand warmer in general. Also, you can't compare both lenses wide open because one is limited to a smaller aperture. If you compare at similar apertures the results in terms of sharpness and light fall off should be similar.

Last edited by ChristianRock; 07-18-2017 at 05:52 AM.
07-18-2017, 05:53 AM   #36
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QuoteOriginally posted by ScooterMaxi Jim Quote
Bottom line, these are two considerably different lenses and the myth that they are optically similar does not square with the facts.
DA


FA


FACTS
07-18-2017, 08:14 AM   #37
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QuoteOriginally posted by D1N0 Quote
DA


FA


FACTS
Now I see even the schematic is somewhat different - though nothing in the schematics tell us differences in glass or coatings, and the point that the claimed schematics are similar was never contested. Look a bit more closely (not that it really matters). We have measured the front elements and the rear elements - showing very clearly that the ratios are different. Yep, undeniable facts.

---------- Post added 07-18-2017 at 10:43 AM ----------

QuoteOriginally posted by ChristianRock Quote
My DA 35 2.4 is sharp edge to edge wide open. Who am I going to trust, someone on the internet who does not have the lens or my own lying eyes?
The fact is that DA coatings are different than FA coatings - the former being more contrasty hand warmer in general. Also, you can't compare both lenses wide open because one is limited to a smaller aperture. If you compare at similar apertures the results in terms of sharpness and light fall off should be similar.
Well, they aren't similar. Regarding the light fall off, Simon indicated that FA was at 9% at f/2.8 (one stop down); the DA indicated 22% at f/2.4 (wide open), and 11% f/4 (1.5 stops closed). This isn't terribly surprising when you consider that the front objective is around 20% larger! I don't know about warmer, but we have generally seen higher micro contrast in the DA lenses. Possibly mostly related to their newer design.

The sharpness argument on the edges would be more debatable based on sample variation. However, for those of you who read these thorough Lenstip tests, we always get clues about copy quality in the Astigmatism/Coma section. The DA had virtually no corner coma (although Simon was a bit brutal in pointing out that plastic mount lenses often don't hold together well over time and heavy use). The FA had a pretty healthy dose of corner coma not shown in the center, indicating (most likely - all other things being equal) that the lens was slightly decentered. Yet, the FA was the stronger edge performer, especially wide open. I am sure the DA is adequate on the edges, but the FA is really impressive in this regard (keeping in mind that the edge of crop is a long ways away from a FF edge).

I'm just going by the known facts. You would really have to attack the testing methodology of Lenstip to win this argument (claiming that the lens performance is essentially similar), but the light fall off side of it is an especially simple measurement that is not subject to much in the way of sample variation. And that light fall off differential is significant.

Last edited by ScooterMaxi Jim; 07-18-2017 at 08:48 AM.
07-18-2017, 09:32 AM   #38
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Well I just measured my Sigma 30mm f/1.4 Art front element at 36mm - smaller than the older DC EX version of the Sigma 30 1.4. Yet Imaging Resources writes, "vignetting has been much improved in this new model compared to the old one". Clearly there is much more to vignetting than the size of the front element.

Of course the DA optical formula is a "tweaked" version of the old FA optics. Nobody is contesting that, I think. The first two elements are slightly different and the aspherical element is different (hybrid on the DA, molded glass on the FA). The real world results, however, are going to be similar. It's not like the difference between a Tessar and a Planar... it's still the same lens design philosophy with minor tweaks to it. The warmer, contrastier DA coatings vs the cooler FA coatings, I think, make more of a difference than anything else... both lenses are very good optics. IMHO.

---------- Post added 07-18-17 at 12:32 PM ----------

Well I just measured my Sigma 30mm f/1.4 Art front element at 36mm - smaller than the older DC EX version of the Sigma 30 1.4. Yet Imaging Resources writes, "vignetting has been much improved in this new model compared to the old one". Clearly there is much more to vignetting than the size of the front element.

Of course the DA optical formula is a "tweaked" version of the old FA optics. Nobody is contesting that, I think. The first two elements are slightly different and the aspherical element is different (hybrid on the DA, molded glass on the FA). The real world results, however, are going to be similar. It's not like the difference between a Tessar and a Planar... it's still the same lens design philosophy with minor tweaks to it. The warmer, contrastier DA coatings vs the cooler FA coatings, I think, make more of a difference than anything else... both lenses are very good optics. IMHO.

07-18-2017, 10:51 AM   #39
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QuoteOriginally posted by ChristianRock Quote
Of course the DA optical formula is a "tweaked" version of the old FA optics. Nobody is contesting that, I think. The first two elements are slightly different and the aspherical element is different (hybrid on the DA, molded glass on the FA). The real world results, however, are going to be similar. It's not like the difference between a Tessar and a Planar... it's still the same lens design philosophy with minor tweaks to it. The warmer, contrastier DA coatings vs the cooler FA coatings, I think, make more of a difference than anything else... both lenses are very good optics. IMHO.
But I think that proves it. Tweak means differences. Yes, you are right, they are not massive differences, but there are still some. And I can believe that the DA is optimized for digital, whereas the FA is from a previous era. SMC has been silently updated numerous times since its conception. We simply don't know about things like coatings, glass materials, production line improvements..
so I can believe there are differences between FA and DA, especially since it looks like the FA actually has a larger front element, so there have to be differences. Can some average Joe on the street spot differences in the photos? Probably not. Can a discriminating photographer? Maybe. Comes down to the buyer's priorities. Im glad this thread was so thorough, hope it helps more future buyers.

I'm quite happy with my DA 35mm, though. Don't have FF camera, will stick with the DA 35mm f2.4 a bit longer
07-18-2017, 02:03 PM   #40
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07-18-2017, 02:11 PM   #41
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QuoteOriginally posted by Na Horuk Quote
But I think that proves it. Tweak means differences. Yes, you are right, they are not massive differences, but there are still some. And I can believe that the DA is optimized for digital, whereas the FA is from a previous era. SMC has been silently updated numerous times since its conception. We simply don't know about things like coatings, glass materials, production line improvements..
so I can believe there are differences between FA and DA, especially since it looks like the FA actually has a larger front element, so there have to be differences. Can some average Joe on the street spot differences in the photos? Probably not. Can a discriminating photographer? Maybe. Comes down to the buyer's priorities. Im glad this thread was so thorough, hope it helps more future buyers.

I'm quite happy with my DA 35mm, though. Don't have FF camera, will stick with the DA 35mm f2.4 a bit longer
DA 35 f/2.4 works in full frame, it's been demonstrated here on this site many times...

Also, tweaks are different from changing optical formulas... every generation of the 50 f/1.4 had tweaks to the next one for example (as well as coatings changes) from K to M to A F and FA, but people consider the optical formula to be basically the same.
07-18-2017, 10:07 PM - 1 Like   #42
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So, we have it... They share an awful lot in common regarding the optical groupings and diaphragm design. They are just slightly different because the FA has less light fall off, the front objective is larger, it is a half stop faster, resolution is more consistent edge-to-edge wide open, the coatings are different (by most reports), metal ring, physical aperture ring; the DA has less measured distortion, is considerably lighter, and has greater contrast (by most reports). Other than the several fairly significant physical and imaging differences, they are quite similar. Certainly more similar than the macro, but we have a pretty good idea that they are not essentially similar.
07-18-2017, 11:09 PM - 1 Like   #43
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I haven't tried the FA, but I have the DAL 35/2.4 and the DA 35/2.8 macro. Of those two, the limited lens is far superior in every way bar speed, and in fact when I tested them I found that the 35/2.4 is only a quarter or a stop faster than the 35/2.8, not a half stop as claimed.

The 35/2.4 has a lot of fans but that's mostly due to the price. You may disagree, but in my opinion the limited is better value because it's leagues better than the 35/2.4, far more enjoyable to use and produces much better results.
07-19-2017, 03:15 AM   #44
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Agreed on price being the motivator for DA35 f2.4 purchasing, in my case anyway, otherwise I'd have tried the FA35.
07-19-2017, 06:36 AM - 1 Like   #45
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So here's the resolution for the DA 35 2.4. Center is excellent and borders are very good from wide open.


Distortion is not field relevant, CA is tested to be very well controlled. Vignetting isn't an issue either:


And despite having gotten thousands of pictures from it and always being pleased with it, the only reason I could possibly like it is because it's cheap. It's true, I just learned that on this thread... or maybe it's because I have no idea what a good lens should actually look like. That is always a very strong possibility

Last edited by ChristianRock; 07-19-2017 at 06:43 AM.
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