which is better ?

whufee

hi, i am going to buy a wild angle lens for my pentax k10d, after 2 days research on net, there are 2 lens i prefer to buy, but i need more advise.
personally i shot i lot of landscapes and portrait, and i already have a 18-55mm, 50-200mm.

first one is: Pentax smc P-DA 12-24mm F4.0 ED/AL [costs about 580 euro]
second one is: Pentax SMC DA* 16-50mm f:2.8 ED AL IF SDM Lens [550 euro]


thx for you help :D

ThOnda

I will buy the 16-50 because I don't have wider lens. You have already similar one, so go WIDER :-)

It's easy... unless you need less wide, but with smaller aperture. Or bigger? I don't know. Just with the bigger hole :-)

snellers

12-24mm IMO if you are into Lanscape shots....I love the 12-24 on my Nikon - the extra 6mm will make a huge amount of difference to you

best of luck in whatever you decide upon!

Borderfox

12mm for sure.

whufee

ThOnda wrote: »

I will buy the 16-50 because I don't have wider lens. You have already similar one, so go WIDER :-)

It's easy... unless you need less wide, but with smaller aperture. Or bigger? I don't know. Just with the bigger hole :-)

so, is there a big difference between F2.8 or F4 ?

Thirdfox

I don't own either lenses but speaking from my knowledge of aperture and focal lengths I'd guess that with a wide angle lens there wouldn't be too much depth of field difference between the two (nearly everything is in focus at wide angles)

But there may be a shutter speed difference (important in lower light situations to prevent image blur and also if you want to "stop" a subject that is in motion).

snellers

F2.8 really comes into its own in low light conditions (in a nutshell it means you can handhold the camera and still take pics at a fast enough shutter speed to take sharp pics without any blur)- you mentioned that landscape and portraiture are your main interest.....landscape shots typically are made on a tripod with a wider aperture
to enable larger depth of field so you are ok there,as for portraiture unless you shoot a lot of candid stuff, lighting can be controlled by yourself thus negating the absolute need for a faster lens

thats not of course to say all lens' are equal and aperture is the only consideration....but this is another huge topic which their are many discussions about here on boards and across the internet over which lens is best and why!

as a general rule of thumb a lens with a constant aperture of 2.8 or better
e.g. Nikon 70 - 200mm F2.8 - tends to be a higher specification model with improved glass (thus improving the overall image quality) and build - a 'pro' lens (and also a hell of a lot more expensive!) -

Thirdfox

but he's looking at wideangles... using the reciprocal rule the 12mm (18mm equivalent on 35mm) would only need a 1/15 - 1/30 sec shutter speed to prevent hand shake. 1/15 is a really long shutter speed already.

But if you're looking at a normal range zoom 18-x mm then f2.8 is the professional grade while the cheaper consumer ones invariably are of the f3.5-f5.6 variety.

Mellor

snellers wrote: »

landscape shots typically are made on a tripod with a wider aperture to enable larger depth of field so you are ok there,as for portraiture unless you shoot a lot of candid stuff, lighting can be controlled by yourself thus negating the absolute need for a faster lens

I take it you mean narrow here, not wider.

amcinroy

Another one to consider is the Pentax 14mm DA Prime.

Somebody could glue this lens on to my camera and I wouldn't mind one bit. It's about as wide as you'd probably want to go for landscapes and the advantage of the prime is the resistance to flare when shooting into the sun

The 12-24mm zoom is an exceptional lens and the sharpnesss matches the 14mm prime. But you already have 18mm and above covered and would you really miss 2mm on the wide end? The 14mm would probably be wide enough with all the advantages of a prime (smaller, lighter, marginally sharper, better resistance to flare, faster aperture).

Check out my webpage for loads of examples of shots taken with the 14mm.

Andy
www.skyandstone.com

whufee

thank you so much!!!
but i think, there are few pentax dealers in ireland. two lenses i found are all come from ebay. uk shops have those two lenses but selling approx 750 euro for
16*50mm F2.5 !!!
so can anybody tells me an irish pentax seller.