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12-31-2010, 01:44 PM   #91
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QuoteOriginally posted by Cambo Quote
Film...?



What's that, grandpa?



Cheers,
Cameron
C'mon now. It really wasn't that long ago was it?...
Only a decade ago Pentax came out with its first dSLR, and even I'm old enough to have shot film before digital photography became mainstream...

12-31-2010, 02:18 PM   #92
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QuoteOriginally posted by Ash Quote
C'mon now. It really wasn't that long ago was it?...
Only a decade ago Pentax came out with its first dSLR, and even I'm old enough to have shot film before digital photography became mainstream...
.

I guess someone got lost in time.

but anyways, the dslrs never did went mainstream not until the MP pixel wars began and the costs for owning one became more consumer friendly.

film was still popular in the late 90's and even the early 2000 (around 2003 to be more precise. so to be honest, the dslr was only able to make sense at the turn of the century which was only about 10 decades ago. it only overtook film's popularity after 5 years. as far as digital PS cams are concerned, they started along the same as the dslrs.
12-31-2010, 03:44 PM   #93
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since your OT...I thought Id add MY OT experience along this vein.

the other day I handed my DSLR to a friends wife , who immediately held it at arms length and looked at me strangely when the LCD didn't show a picture....I had to explain the whole "SLR" thing to her .

just shows were we are now..most P&S camera dont even have VF's these days
12-31-2010, 09:47 PM   #94
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QuoteOriginally posted by Tommot1965 Quote
since your OT...I thought Id add MY OT experience along this vein.

the other day I handed my DSLR to a friends wife , who immediately held it at arms length and looked at me strangely when the LCD didn't show a picture....I had to explain the whole "SLR" thing to her .

just shows were we are now..most P&S camera dont even have VF's these days
how sad.

12-31-2010, 10:13 PM   #95
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QuoteOriginally posted by Pentaxor Quote
how sad.
Given all the talk of EVIL technology it's hardly unexpected, though.
08-05-2011, 10:07 AM   #96
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The only DA limited I own is the 35 mm macro. I have the M 50 macro and used it extensively in the film era. I wanted that same "normal" lens in digital format.

The results are stunning. Although I have a variety of lenses, the one that I carry around the most is the DA 35. It is small, takes sharp pictures and lets me focus from infinity to REALLY close. Can't comment on FA lens except to say they don't have a 35 mm macro.
08-05-2011, 12:01 PM   #97
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QuoteOriginally posted by clem Quote
The only DA limited I own is the 35 mm macro. I have the M 50 macro and used it extensively in the film era. I wanted that same "normal" lens in digital format.

The results are stunning. Although I have a variety of lenses, the one that I carry around the most is the DA 35. It is small, takes sharp pictures and lets me focus from infinity to REALLY close. Can't comment on FA lens except to say they don't have a 35 mm macro.
The DA 35mm LTD has been my primary prime since 2008 (of course I only have 1 af zoom).
08-05-2011, 12:08 PM   #98
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While the preference might be subjective, I can't help but notice the startling difference in colour between the DA ltds and the FA ltds (the FAs are quite warm and do not render very saturated blues compared to the DA ltds).

08-05-2011, 12:26 PM   #99
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QuoteOriginally posted by paperbag846 Quote
While the preference might be subjective, I can't help but notice the startling difference in colour between the DA ltds and the FA ltds (the FAs are quite warm and do not render very saturated blues compared to the DA ltds).
That would be more from the lenses themselves and not so much from the coatings given those are essentially the same except for all the LTD lenses except the DA 40 get SP, but that is for protection from dirt etc. Plus, I am not sure color differences can be said to be different from one LTD series vs. the other.

Last edited by Blue; 08-05-2011 at 12:33 PM.
08-05-2011, 12:41 PM   #100
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QuoteOriginally posted by Blue Quote
I am not sure that this can be said for one series vs. the other.
That's exactly what I'm saying, but I don't have the expertise to know whether it is the coatings, optical design, or both. I'm inclined to believe that it is both, since the coatings of DA lenses are generally bluer than FA lenses, but regardless, that is a major difference between the two lines (other then lens speed, size, quickshift, FF-compatibility, manual-focus feel, etc).

In pictures, it is easy to tell the two apart (at equivalent apertures) from two things: bokeh smoothness, and colour. DA is much more modern looking with high-contrast and even colour saturation between RBG. FA lds favour RG and render a more natural contrast, perhaps more true to life.

You can see this difference between the DA 40 and the FA 50 / FA 43, but not between the FA 43 and 50. The 43 has more micro-contrast / resolution available, but global contrast / colour is much more similar than when compared with the DA 40.

You can even see these differences if you compare the DA kit lens with an FA kit lens...
08-05-2011, 01:09 PM   #101
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QuoteOriginally posted by paperbag846 Quote
That's exactly what I'm saying, but I don't have the expertise to know whether it is the coatings, optical design, or both. I'm inclined to believe that it is both, since the coatings of DA lenses are generally bluer than FA lenses, but regardless, that is a major difference between the two lines (other then lens speed, size, quickshift, FF-compatibility, manual-focus feel, etc).

In pictures, it is easy to tell the two apart (at equivalent apertures) from two things: bokeh smoothness, and colour. DA is much more modern looking with high-contrast and even colour saturation between RBG. FA lds favour RG and render a more natural contrast, perhaps more true to life.

You can see this difference between the DA 40 and the FA 50 / FA 43, but not between the FA 43 and 50. The 43 has more micro-contrast / resolution available, but global contrast / colour is much more similar than when compared with the DA 40.

You can even see these differences if you compare the DA kit lens with an FA kit lens...
The interesting thing is that the FA 43 ltd, DA 40 ltd, FA 77 ltd were designed by Hirakawa Jun. (He also designed the FA 35/2, FA 28/2.8, DA 14/2.8, DA 10-17mm, DA* 55/1.4 as well as the FA* 85/1.4 and FA* 80-200/2.8.)

The FA 77 was released in 1999 and the DA 40 was released in 2004. While he didn't design the F A31 ltd, it was released a mere 3 years before the DA 40! People don't realize that in the 90s Pentax was a major player in digital street light cameras which is why the Ghostless Coating 1st used on the FA 43 ltd was designed initially (as well as for military applications). Coatings are really designed to minimize reflection and flare and are water clear in the visible spectrum. Optical design deals with color correction so that all colors are focused at the same point.

Here is an interesting read on the subject by Rick Oleson.

How Lens Coating Works

I personally think the improvement we have seen in the last 8 to 10 years hasn't been as much with the actual glass part of the designs as much as it has been with sensor improvement (including firmware/software).
08-05-2011, 01:42 PM   #102
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QuoteOriginally posted by Blue Quote
I personally think the improvement we have seen in the last 8 to 10 years hasn't been as much with the actual glass part of the designs as much as it has been with sensor improvement (including firmware/software).
I'm not sure what you mean here, but thanks for the link. Interesting.

The link you sent does suggest that colour of a coating would affect the colour of an image. "Colour-Correcting" that you see mentioned near the end refers to the correction of CA.

The differences between FA and DA colour are pretty easily seen on the same camera, regardless of age (including film, actually). Different coatings for the FA and DA series make sense, since baysian sensors and film see the world differently. I'm also not sure that just because the designer for a lens is the same, that all of his lenses would have the same coating. Especially if the designer believed that there are appropriate lens coatings for digital and film.

The funny thing is this: The FA lenses look way better on film, where post-processing is not really in my reach. They tend to look best out of the box. The DAs do not, they look almost over-processed. However, in RAW format, these lenses retain lots of detail which allows for some nice post-processing, to get whatever look you might desire.

In other words - FA ltds look the best to me for out of the box, and DA ltds look the best when you process them. I prefer the DA rendering personally BECAUSE I love post-processing. If I was shooting JPEGs or wanted to keep my post-processing to a minimum, the FA ltds would win for sure.
08-05-2011, 06:05 PM   #103
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QuoteOriginally posted by paperbag846 Quote
"Colour-Correcting" that you see mentioned near the end refers to the correction of CA
Chromatic aberrations are the result of the lens being unable to focus red/blue wavelengths of light on the same plane - only apochromatic lenses can do this.Lens coatings have nothing whatsoever to do with these optical aberrations. All the coatings do is reduce flare/ghosting and by doing that they increase the contrast of the images and as a consequence: any CA present in the optical design will be exacerbated because of the heightened edge contrast.
08-05-2011, 06:47 PM   #104
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QuoteOriginally posted by Digitalis Quote
Chromatic aberrations are the result of the lens being unable to focus red/blue wavelengths of light on the same plane - only apochromatic lenses can do this.Lens coatings have nothing whatsoever to do with these optical aberrations. All the coatings do is reduce flare/ghosting and by doing that they increase the contrast of the images and as a consequence: any CA present in the optical design will be exacerbated because of the heightened edge contrast.
Hmm, you misunderstood me.

From the article:

"So, if coated lenses are purple, won’t my photos have a purple tint?

No…. actually, they’ll have a slight yellow-green tint – the extra light that didn’t get reflected passes on through to the film, and there’s a little more of the 550nm yellow-green than there is of the other colors."

and

"One last, unrelated question: Does coating make a lens “color-corrected”?

No. Color correction is a function of the optical design of the lens, and is not affected in any way by coating."
08-06-2011, 08:35 AM   #105
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Let me reiterate that the Ghostless Coating was developed and patented in 1992 and first used on the FA 43 ltd and all subsequent ltd FA and DA ltd lenses have it in addition to some others such as the FA 35/2 (but not the FA 50/1.4). It was developed for digital traffic and military high res cameras. Also, SMC coating is SMC coating. There isn't a special one for film and a special one for digital. They have tweaked the formula a few times over the years, but only Pentax knows these trade secrets. Lastly, light transmission by these optics are ruled by the laws of physics regardless if its ccd, cmos, or various types of film.

My point about sensors earlier is that they have been improved and so some of the ghosting issues etc. early on had more to do with the sensors than the lenses. The lenses did what they always did, focus and image. Sure, inherent properties of sensors forced designers to develop better performing lenses.

Also, "developed for digital" doesn't really mean much given Pentax hasn't designed a film camera since the *ist and MZ-S. Therefore any lens currently developed can be stated to be made "for digital" but that doesn't mean it is going to automatically out perform the FA 50/1.4 or the F 28/2.8 on digital. Case in point, the DA 18-55 AL WR.

As pointed out in the linked article, each element can be designed to adjust the color effect of the coating. This has as much to do with the optical design, i.e. the number of elements than anything else.


QuoteQuote:
Every lens has at least two reflective surfaces, the front and the back. In lenses used for practical photography, there are generally at least six, and there can be 18 or more in complex wide angles or zooms. Each surface presents an opportunity to adjust the color effect of the coating: with, say, six surfaces to coat, the designer can specify six slightly different thicknesses of coating, each corresponding to a different point in the spectrum. If one surface transmits a little extra yellow-green, another a little extra blue-green, a third a little extra orange and so on, the total lens can be balanced to pass a very neutral color of light through to the film. This is why, in some lenses, you will see a number of reflections in different colors: each coating layer is the same Magnesium Fluoride material, each is a single layer, but each is a slightly different thickness to correspond to a different color within the visible spectrum to optimize balance. Not all designers did this – some felt it was better to optimize the entire lens in the center of the spectrum for best overall efficiency, and their lenses tend to have a uniform blue-violet color on every surface.
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