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02-10-2012, 08:01 PM   #31
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Sigma has a 28mm f1.8 I believe, if that floats your boat

02-10-2012, 08:10 PM   #32
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QuoteOriginally posted by NotaxPen Quote
If I wanted a slow or heavy zoom, yes they have those covered.
If I want relatively fast and light/small, not many options.
it sounds like you'd have gotten better responses if you had stated your question more clearly.
02-10-2012, 08:16 PM - 1 Like   #33
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QuoteOriginally posted by westmill Quote
Well you cant argue with any of that ! For most people though, normal is 50mm in 35mm terms and thought as such because it approximates our own feild of veiw with our eyes.
Actually, not. Our fields of view is *much* wider than what a "normal" lens produces. Our field of view is more like around 13-15mm on APS-C. It's the lack of perspective distortion on a *print* made from a 30mm-ish lens and viewed from a typical distance for that size print that is "normal" in some sense.

Last edited by Marc Sabatella; 02-11-2012 at 06:46 PM.
02-10-2012, 09:16 PM   #34
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QuoteOriginally posted by mikeSF Quote
it sounds like you'd have gotten better responses if you had stated your question more clearly.
Sorry I wasn't clear, for most of my life zoom lenses didn't exist and most 135 format cameras came with a fixed 40mm to 50mm lens so that was always considered "normal" or "standard"
When I say "normal lens" I'm referring to the normal field of view compared to a wide-angle or telephoto fixed lens.
I realize most consumers these days buy a "Kit" zoom with the camera and that is the norm now. For myself, zoom lenses are either too slow to accurately focus manually, or heavy/bulky beasts that I would like to avoid if possible and that's why I prefer smaller, faster fixed focal length lenses.

I'm just trying to find the digital equivalent of the tools that worked best for me in the film world.

02-11-2012, 04:17 AM   #35
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I actually like the 40mm FOV when I am going somewhere to take portraits but there isn't a lot of space. But I crave a nice 24-28mm DA ltd. The FA31 is big and it would require a new set of filters. For now my under appreciated M28/2.8 performs nicely. I'm usually at f8+ for landscapes though.
02-11-2012, 06:30 AM   #36
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QuoteOriginally posted by NotaxPen Quote
I'm just trying to find the digital equivalent of the tools that worked best for me in the film world.
As "normal" lenses on film,
I used a Summicron 35/2 on a Leica M2,
and an SMC-Takumar 55/1.8 on a Spotmatic, for many years.
The APS-C digital equivalents I use now (on K-x bodies)
are a K24/2.8 and ZK25/2.8 to replace the 35/2,
and a DA 35/2.8 Ltd to replace the 55/1.8.
The EV stop of slowness in the lenses on digital
is compensated by the high K-x IQ at 400ASA,
way better than pushing High-Speed Ektachrome!
02-11-2012, 10:10 AM   #37
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QuoteOriginally posted by RKKS08 Quote
I miss such a lens for APS-C badly: a SMALL full metal manual focus 2.0/30 with acceptable IQ at 2.0 and very good IQ from 4-5.6 on FOR NOT MORE THAN 100 ($125) new.
The problem is that it costs more to make a 30 f2 lens than a 50 f2 lens. The Pentax A 28/2 sold for around $200 in 1986. The A 50/1.7 sold for $55, almost a quarter the price of 28/2. Even the 35/2 sold for $150. The wider the lens, the more expensive it is to make. Hence, it's unlikely you'll see a 30 f2 lens sell for under $125, particularly one that's built out of metal.
02-11-2012, 11:15 AM   #38
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QuoteOriginally posted by Marc Sabatella Quote
Actually, not. Our fields of view is *much* wider than what a "normal" lens produces. Our field of view is more loke aroind 13-15mm on APS-C. It's the lack of perspective distortion on a *print* made from a 30mm-ish lens and viewed from a typical distance for that size print that is "normal" in some sense.
Our eyes dont even come close to that even taking into account perphirel vision, which is genrally used for detecting movement. We have binocular forward vision
in order to gain depth perception. It certainly has not
got anything to do with prints. Our eyes scan without us even realising it and our brain processes the info.
All this aside though.... My comment was that most people consider that 50mm in 35mm terms is considered as a standard lense. Some might have different ideas or thoughts or whatever but the statement is correct, as in most people. The ish bit you mention is very true, since there is no true defining line anyway, which is also why I said aproximate. A 30mm ish lens on APSC is around 45mm ish anyway. That in my book is a close enough ish.

02-11-2012, 11:25 AM   #39
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QuoteOriginally posted by dgaies Quote
The FA31/1.8 is pretty close to normal on aps-c.
at abnormal price
02-11-2012, 12:38 PM   #40
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QuoteOriginally posted by wlachan Quote
....., though I would love to have a metal DA28/2 w/o SDM for <$600. .....
QuoteOriginally posted by abieleck Quote
I would like to see a DA Limited pancake 28mm as well, one that's a bit faster than the FA 28mm f/2.8. ..... would love to fill it with a FA31 but it's a bit pricey for me. I am looking at getting a DA 21mm but that is still a big gap till I hit my DA 35mm, and it is a f/3.2

I would be interested in a fast DA 23mm pancake as well, maybe an f/2. To me that would probably be the ideal street/walk around/low profile lens.
Pentax has the design for their K 28mm f2.8 that is the same design as the Carl Zeiss 28mm f2 Distagon they made for their Contax line of cameras. The lens is legendary, has a cult following and commands a premium price, especially among Canon shooters.

A DA Ltd or even better DFA Ltd updated design could and would be a new replacement for the film 50mm lenses. They could produce both the f2 and f2.8 versions, which would be particularly fitting for their ASP-C sensor.

Last edited by interested_observer; 02-11-2012 at 12:45 PM.
02-11-2012, 01:45 PM   #41
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QuoteOriginally posted by dgaies Quote
The FA31/1.8 is pretty close to normal on aps-c.
This lens is still a wide angle design. Great for a wide angle prime pretty nice on APS-C, but nothing like a normal lens designed for APS-C a huge overaccomplishment for an APS-C sensor. The price is right considering it is a wide angle lens. He is right, there is no equivalent of a 1.8/50 in APS-C mount, or may a mention no equivalent for a 1.4/50 or 1.2/50...
Btw there is no equivalent of the 1.8/31 mm for APS-C format as well - that would be a large aperture 21 mm or so lens.

The 1.8 Sigmas are crap and not designed for APS-C. Why does nobody want to understand that anything below 40 mm focal length designed for a 35 mm SLR system requirs a retrofocus design which is turn means more glass, more distortion, more abberations...
02-11-2012, 02:25 PM   #42
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QuoteOriginally posted by Marc Sabatella Quote
Actually, not. Our fields of view is *much* wider than what a "normal" lens produces. Our field of view is more loke aroind 13-15mm on APS-C. It's the lack of perspective distortion on a *print* made from a 30mm-ish lens and viewed from a typical distance for that size print that is "normal" in some sense.
What he said...and what's more, our vision is not rectilinear. The projection is closer to the fisheye view of things. Our perception (brain doing the filtering to do a reasonable crop) is similar to that of a "normal" lens photo printed to a "normal" size and viewed at a "normal" distance. Translation: "Normal" focal length is determined by convention only and varies somewhat depending on the photographer.

Steve


BTW...has anybody noticed that the magnification of a 50mm lens is about the same as that of the human eye? With a 1:1 viewfinder, bring the camera to eye and what you see is what you get...
02-11-2012, 02:44 PM   #43
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QuoteOriginally posted by zapp Quote
Why does nobody want to understand that anything below 40 mm focal length designed for a 35 mm SLR system requirs a retrofocus design which is turn means more glass, more distortion, more abberations...
Huh? The Sigma 1.8 may well be crap, but it has nothing to do with the size of its image circle.

As for retrofocus design for APS-C vs. 35mm vs. 645 vs. you name it...if the camera has a mirror box, there will be a focal length threshold below which you need retrofocus to allow the rear element to clear the mirror. This is one of the big arguments in favor of mirrorless cameras.


Steve


BTW...who said that retrofocus = bad performance?
02-11-2012, 02:50 PM   #44
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QuoteOriginally posted by stevebrot Quote


BTW...has anybody noticed that the magnification of a 50mm lens is about the same as that of the human eye? With a 1:1 viewfinder, bring the camera to eye and what you see is what you get...
That's because viewfinders haven't changed since the film days. Try this sometime: Put a 50mm lens on a 35mm camera and note how it compares to the same lens on an APS-C camera.
I did a little research a while back, it turns out that the human eye has a focal length of ~22mm, and the diameter of the retina is also about 22mm. This is why, I suspect, that lenses in or around the diagonal of the format are considered normal lenses, and give a comfortable field of view and comfortable perspective, with nothing looking either foreshortened (telephoto) or elongated (wide angle).
02-11-2012, 03:32 PM   #45
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Other than a portrait lens, because we are very sensitive to face proportions, I see nothing superior in one focal length over another. It depends on what you want to photograph and how far away it is. There is nothing normal about a normal lens.
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