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03-05-2010, 10:33 AM   #1
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Questions for DA40mm/2.8 LE

I've got a DA40/2.8 LE, which is known as the famous "pancake" lens.
However, I found that, on APC-S, the 40mm becomes to the 60mm.

Under the 60mm, the angle is not longer wide as 40mm, and not in a good length for portrait (according to New York Photography Institution Book), moreover, f2.8 is not so quick for an indoor portrait.

It is a kind of dilemma, 40mm is not wide as 35mm and not so quick as some 50mm lens.

Anybody has the same questions like me?

03-05-2010, 10:56 AM   #2
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Not to be rude but you really haven't asked any questions in this post. You have a few statements from other sources about the Focal Length and Field of View. Take a look at the Pentax Photo Gallery:

PENTAX Photo Gallery

185 photos there taken with the DA40 with a lot of varying uses from indoor, portrait to landscape and closeup.
03-05-2010, 11:07 AM   #3
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QuoteOriginally posted by henryjing Quote
I've got a DA40/2.8 LE, which is known as the famous "pancake" lens.
However, I found that, on APC-S, the 40mm becomes to the 60mm.

Under the 60mm, the angle is not longer wide as 40mm, and not in a good length for portrait (according to New York Photography Institution Book), moreover, f2.8 is not so quick for an indoor portrait.

It is a kind of dilemma, 40mm is not wide as 35mm and not so quick as some 50mm lens.

Anybody has the same questions like me?
First, a lens doesn't become anything other than what it is.
I've always wondered how these lenses magically change focal length.
I know my 210mm Nikkor view camera lens is a 210mm lens even if I put my DSLR onto the adapter that I made for mounting it onto my 4x5.
I put a 300mm 6x7 format lens onto my DSLR one day, and surprisingly to me, it didn't change into a 450mm lens.
It just stayed a 300.

Perhaps the Limited's are more magical than I thought.

Anyway, the 40mm lens is a short telephoto on Pentax DSLR cameras. It was also designed for the DSLR, not for film, so I'm really not seeing any logic in your surmising that it has somehow become something else.
It is what it is.

Any lens can be a portrait lens. On the Pentax DSLR, the classic portrait length is closer to 55mm (hence the DA*55/1.4). I've shot portraits with everything from the 15LTD up to 300mm.
03-05-2010, 11:14 AM   #4
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Nice Website, thanks a lot.


QuoteOriginally posted by MrApollinax Quote
Not to be rude but you really haven't asked any questions in this post. You have a few statements from other sources about the Focal Length and Field of View. Take a look at the Pentax Photo Gallery:

PENTAX Photo Gallery

185 photos there taken with the DA40 with a lot of varying uses from indoor, portrait to landscape and closeup.


03-05-2010, 12:14 PM   #5
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QuoteOriginally posted by henryjing Quote

It is a kind of dilemma, 40mm is not wide as 35mm and not so quick as some 50mm lens.

But it is MUCH smaller than both!

And yes, I do share the same sentiment about the DA40. Actually, the speed never bothered me as much as the focal length. When asked to review my DA40, I usually say it is the perfect lens, and the only problem is the 40mm..

And despite the fact that I also have the FA35 f/2 (which offers a better focal length and speed), I keep the DA40 because of its size. It is the perfect carry around lens.


Later

BB
03-05-2010, 12:57 PM   #6
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Pentax knew that these lenses were to be used with APS-C cams so they designed the lens around it. They wanted somewhere around 60mm so they designed a "40mm" lens.

f/2.8 is fast enough for a lot of in-door shots. I have a 1.4 and where the 2.8 can't do, the 1.4 is typically not sufficient also - two extras stops won't get you to stop action, or to film the evening cityscape. Plus, at f/1.4 it was very soft.

I wouldn't worry about 60mm not being a good length for portraits, there's a lot more involved in a good portrait, like lighting, subject, background, etc... if you have a 12mm I'd worry about it, but 60mm is perfectly fine.

Shawn
03-05-2010, 01:05 PM   #7
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QuoteOriginally posted by shawnxji Quote
Pentax knew that these lenses were to be used with APS-C cams so they designed the lens around it. They wanted somewhere around 60mm so they designed a "40mm" lens.

f/2.8 is fast enough for a lot of in-door shots. I have a 1.4 and where the 2.8 can't do, the 1.4 is typically not sufficient also - two extras stops won't get you to stop action, or to film the evening cityscape. Plus, at f/1.4 it was very soft.

I wouldn't worry about 60mm not being a good length for portraits, there's a lot more involved in a good portrait, like lighting, subject, background, etc... if you have a 12mm I'd worry about it, but 60mm is perfectly fine.

Shawn
So if I wannna get my second lens, what will you recommand for me.
I am thinking of FA 31 limited, but the price is so high. Or anyone knows how to get the FA 35 f/2
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