50mm - what's the appeal?

[Wheatfield]

Originally Posted by vandamro

What hood do you use for FA 50 1.4? I've been looking all over the place for one!

I have a Takumar metal hood designated for 135/150/200 mm lenses. It's quite deep, but doesn't seem to vignette.

Originally Posted by Spock

I just saw new Nikon 50/1.8 and Canon 50/1.4 for about $150 (Australian) for sale in a shop today. I wish Pentax lenses were even half that cheap!

Pentax seems to be setting themselves up as a boutique brand. I think the long era of cheap Pentax lenses is pretty much done.

Originally Posted by Marc Sabatella

Right, and this is something that should be made clear to the OP: most of the comments about the advantages of 50mm lenses are not really about 50mm lenses specifically - they are about primes (single focal length lenses, as opposed to zooms) in general. It just happens that 50mm tends to be the cheapest prime you can get - often on the order of $20-$50 used (for manual focus).

I think some of the love also comes from the film era when the 50 was king. I still like my 50s, and with 12 in my kit, I suppose I am somewhat of a 50mm lens junkie, but I don't like them near as much on digital as I did on film.

But I agree, it isn't my favorite focal length. I've got eight primes, with a ninth on the way, and the 50 is the least used of these. But a 50 was also my first prime - specifically because it was so cheap - and they are often among the fastest (large maximum aperture = fast shutter speed) and sharpest lenses you'll ever use.

<hijack alert!>
I prefer the conventional "standard lens" field of view, I try very hard to love my 31, and I really am fond of it, but I wish it was smaller.

Funnily enough though, shooting with the 4x5 I always preferred the 210mm, which would be quite close to the field of view of the 50mm lens on APS-C once you cropped it to 4:5. Now the 50 seems a bit too short for a lot of stuff, and a bit to long for most everything else. It's too bad because they are almost all excellent lenses, even the much maligned M50/1.4 is pretty decent.
It is a very, very nice loose portrait length, which makes having one worthwhile, since most everyone shoots loose portraits at one time or another.

</hijack>

[Marc Sabatella]

Originally Posted by enoeske

My K f/1.4 is 52mm filter size while the m, a, f, and fa are all 49mm. I don't see how they can be the same optically

I have no idea if they are the same optically or not, but FWIW, the DA50-200 and DA50-200 are definitely the same optically (this has been confirmed by the head folks at Pentax), but they somewhow managed to make the WR version take a smaller filter. So I wouldn't take that as proof in itself.

[lithos]

Originally Posted by enoeske

My K f/1.4 is 52mm filter size while the m, a, f, and fa are all 49mm. I don't see how they can be the same optically

Well, for one...that's a difference of three mill. For two, filter size is irrelevant in regards to the optical formula used to in each lens. The optical formula is just the number of glass elements, how they're shaped, grouped, and what they're made from.

That's what the optical formula is.

The filter size is to do with how the whole lens - barrels, rings, mounts - is constructed - and vice versa. The K's were fairly big and chunky, and Pentax got smaller after that. What primarily determines the filter size is the whims of the manufacturer. The K series probably used 52mm rings because the Nikon F made them popular.

Notice that most lenses don't fill their barrels. They've got that retaining ring spacing the glass from the filter ring (the bit, on the K series, that has the writing on it.)

On the A series fifties, the writing was moved from the retaining ring to a ring between the focusing ring and a lens barrel (which has the handy effect of being readable even when there's a filter on the lens...free advertising.) That's a good way to cut down on filter sizes.

As for three, four, five, six and seven:

Pentax K f1.4 50mm:

http://kmp.bdimitrov.de/lenses/prime...s/50f1.4-i.jpg

M f1.4 50mm:

http://kmp.bdimitrov.de/lenses/prime.../50f1.4-ii.jpg

A f1.4 50mm:

http://kmp.bdimitrov.de/lenses/prime...50f1.4-iii.jpg

F f1.4 50mm:

http://kmp.bdimitrov.de/lenses/prime...50f1.4-iii.jpg

FA f1.4 50mm:

http://kmp.bdimitrov.de/lenses/prime...50f1.4-iii.jpg

These are from Bojidar Dimitrov's Pentax K-Mount Page, so check the formulas for yourself.

[Ratmagiclady]

Originally Posted by vandamro

What hood do you use for FA 50 1.4? I've been looking all over the place for one!

I use a pretty big old hard plastic one that, apart from taking up more than usual space in a bag, makes me happy. It's both deep and wide in diameter, which helps with just mundanely protecting the front element, and lets me shoot on full frame cameras without vignetting, should I need that. Only drawback is I can't tell you anywhere in particular to find one. But it's step-ringed. If you take the 49mm up to a more common filter size, you can both share filters with more lenses... and have more choice of what hoods to get.

It's not a lens I've found to be at all fussy about vignetting.

For the OP, As for what's the appeal, I had one of these FA 50 1.4's (and said step-rings and a couple hoods) on order before the K20d even arrived. (I'm a little odd because I use the FOV of a 50 on crop for *lots* of things: on film cameras I joke that if someone glued my 85mm down it's possible I wouldn't notice for several days. ) Unless you got your K-m extremely extremely cheap, you shouldn't have to pay that much for one, though.

[TourDeForce]

The fifty does just about everything well.

On a crop sensor DSLR like your KX, it is a sharp, sweet, 75mm portrait lens with wonderful depth-of-field control.

Need some macro work, add cheap accessories like a reversing ring or extension tubes & VOILA! The IQ really comes through in this use.

At a party or concert & not much light to work with? Bust out the 50!

There are darn few lenses that will, for so little money, offer the image quality & versatility of the beloved fast 50.

Unlike most DSLR users, the 50mm finds a lot of use on my camera.

[Dangermouse]

I'm definitely considering a Pentax-A 50mm f2 come payday. Yes I know the faster versions are more flexible, but the f2 can be had for next to nothing and it will not lose value so it's a good way for me to try one.

I have never seen an AF 50mm go for under £100, which is more than I'm willing to pay for something used without being able to inspect it. Unfortunately there is a shortage of camera shops near me stocking used equipment (Jessops having apparently lost interest in that side of the trade), so I'm rather stuck with ebay.

[Ash]

The A 50/2 is OK but is not as sharp as any of the other varieties. My suggestion is to wait for the next pay day to save a few more quid and get an A 50 f/1.7 or f/1.4 (if you have one available to you to buy). These are famed just as well as any other 50mm lens, a touch brighter in the viewfinder (making manual focusing easier) and render photos better in detail and general image quality.

[Wheatfield]

Originally Posted by TourDeForce

The fifty does just about everything well.

On a crop sensor DSLR like your KX, it is a sharp, sweet, 75mm portrait lens with wonderful depth-of-field control.

Actually, it's a sharp, sweet, 50mm portrait lens.

[raymeedc]

Originally Posted by TourDeForce

The fifty does just about everything well.

On a crop sensor DSLR like your KX, it is a sharp, sweet, 75mm portrait lens with wonderful depth-of-field control.

Need some macro work, add cheap accessories like a reversing ring or extension tubes & VOILA! The IQ really comes through in this use.

At a party or concert & not much light to work with? Bust out the 50!

There are darn few lenses that will, for so little money, offer the image quality & versatility of the beloved fast 50.

Unlike most DSLR users, the 50mm finds a lot of use on my camera.

I concur. Whenever I'm heading out for a shoot with only one prime, not knowing what situations I might encounter, I almost invariably reach for a 50.

[Marc Sabatella]

Originally Posted by Dangermouse

I'm definitely considering a Pentax-A 50mm f2 come payday. Yes I know the faster versions are more flexible, but the f2 can be had for next to nothing and it will not lose value so it's a good way for me to try one.

It's not so much that the faster versions are more flexible - it's that they are quite a bit sharper. The The A50/1.7 usually goes for only slightly more than th A50/2; I'd definitely hold out for that, or get the M50/1.7 instead of the A50/2 if you just can't make yourself part with the extra 15 pounds or so the A50/1.7 would cost.

[Dangermouse]

Well, an impulse buy has seen a Pentax-M 50mm f1.7 join the collection (attached to an ME Super and flash for £36, so something of a bargain if it's as good as the seller claims). Next problem is getting it working with my K-m, as I don't have the same displays/controls as the cameras used in the manual lenses guide.

If I enjoy the experience of using it I'll go after an A version, but I've always wanted an ME Super so this was too good a deal to pass.

[Damn Brit]

Originally Posted by Dangermouse

If I enjoy the experience of using it I'll go after an A version, but I've always wanted an ME Super so this was too good a deal to pass.

You do know that the A doesn't mean auto focus don't you? The only difference between the A and the M is metering.

[Dangermouse]

Yep, the A are still manual focus but will make metering easier on a modern camera, as there'd be no need to fiddle around with settings (just dial in aperture as you would with any modern lens).

[Marc Sabatella]

Originally Posted by Dangermouse

Well, an impulse buy has seen a Pentax-M 50mm f1.7 join the collection (attached to an ME Super and flash for £36, so something of a bargain if it's as good as the seller claims). Next problem is getting it working with my K-m, as I don't have the same displays/controls as the cameras used in the manual lenses guide.

Use the +/- button where other cameras use the Green button or AE-L button. If you see references to using the DOF Preview function, skip that part, a your camera doesn't have this.

[Dangermouse]

Thanks Marc, I'd tried it before reading that and it seemed to work perfectly assuming you left the aperture wide open on the lens. I'll have another go now I know which button equates to the green one, as that should get me a bit more control over depth of field.