Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Aug 27, 2009, 9:08 PM   #11
Senior Member
 
Join Date: Feb 2005
Location: East Central Vermont
Posts: 1,890
Default

This may be more than you wanted, but the kit lens is considered a "slow" lens. That means its most wide open aperture is not all that wide. (I'm not referring to the focal length; at 18 mm it's a reasonably wide-angle zoom lens.) Apertures are measured in f-stops, and if I remember correctly, the kit lens is f 3.5 at the wide end, and f 5.6 at the telephoto end. The f-stop is determined by a fairly complicated mathematecal formula, but in essence it describes the ratio of the lens diameter to the focal length. Imagine one lens that's the proportions of a cardboard tube at the center of a roll of paper towels; imagine anoher lens that's the proportions of a can of tuna fish. It's pretty obvious that the large diameter short lens (the tuna can) will allow a lot more light through than will the narrow, long lens (the paper towel tube). In my admittedly strange example, the tuna can is a fast lens; the paper towel tube is a slow lens. The lower the f-stop number, the larger the diameter of the lens, relative to its focal length. Lenses with low f-stop numbers are called "fast" because they transmit a lot of light, allowing a relatively fast shutter speed, while lenses with high f-stop numbers are slow lenses, since they don't transmit as much light to the sensor, and therefore require a slower shutter speed to get a proper exposure.

Unfortunately, it's difficult and expensive to design and manufacture a fast lens. It's fairly easy and cheap to make a slow lens. The Pentax 16-50 f 2.8 DA* lens will perform much better in low light than the kit lens, especailly at the long end of its range. That lens has a constant aperture of f 2.8 throughout its entire zoom range; the kit lens is f 5.6 at the long end. But the 16-50 f 2.8 costs about $650, while the kit lens costs only about $100. Naturally, there are other things about that lens that contribute to the price difference, but the fact that the f 2.8 lens is so much faster explains much of the price difference. Faster lenses are also more bulky and heavier.

Okay, lesson over. Bottom line: the kit lens is fine for general use. If you're planing to shoot lots of pictures in a dimly lit night club, without flash, you won't be happy with it. But if you're taking pictures of kids playing at the park, birthday parties, etc, the kit lens will probably produce completely satisfactory results, especially if you use an external flash for indoor shots. Pboerger has suggested a lens that has a much larger zoom range, and there's no question that it would probably be more versatile, but most people who are doing general photography of family events are happy with the kit lens.

I hope this helps.
mtnman is offline   Reply With Quote
Old Aug 28, 2009, 7:59 AM   #12
Senior Member
 
Join Date: Jul 2006
Location: Tumbleweed, Arizona
Posts: 1,381
Default

Quote:
Originally Posted by pboerger View Post
Skip the kit lens. The 18-55 range will not keep you interested very long. Get the Tamron 18-200 or better yet, if you have the money, get the Tamron 18-250 that works beautifully on my K2000 even in low light.
Photography is a series of compromises, everywhere you turn. Zoom range is a number that is the ratio of the long end divided by the short end, i.e., for the Tamron 18-250 it is 250/18= 13.8, which is rather large. pboerger has a valid point, that lenses with a larger zoom range are more versitle and overall you can do more with them, and use/carry/buy fewer lenses overall. That is the up side. The other side of the coin is image quality. Now, I am not saying that image quality of a large zoom lens is bad, it is just easier for the lens designer to design a lens with better image quality with a smaller zoom range.

The rule of thumb for zoom lenses is that a zoom range of 4 is reasonable. Anything substantially larger than 4, tends to have too many design compromises in order to achieve that larger zoom range. So in general a 18-55 lens (zoom range of 18/55 = 3) is a simpler design, easier to manufacturer, lighter in weight, physically smaller, less expensive to buy, and is capable of higher image quality, than a 18-250 lens. Ultimately, prime lenses with zoom range of 1 (no zoom) are capable of the highest image quality.

So, you can see - that right away, quite a few decisions are being made (consciously or not). The super zoom lenses provide you with a lot of capability as in not having to swap lenses as often, which reduces the opportunity for dirt and dust to get on the sensor, fewer lenses to carry, overall a lighter set of equipment to carry.

There is no "right" or "wrong" answer to this. There is just what appeals to you, your budget, the equipment you want to carry around, how you want to use your camera and lens combination.
interested_observer is offline   Reply With Quote
Old Aug 28, 2009, 5:09 PM   #13
Senior Member
 
mole's Avatar
 
Join Date: Mar 2009
Posts: 8,522
Default

Not much I can add to all the great advice already given in this thread. Just to say that I hope you enjoy your K-m/K-2000 as much as I have enjoyed mine. The kit lens is good, but I tend to stick with the Tamron 18-250, only because it best suits my needs. Got a great deal on it used at KEH.
mole is offline   Reply With Quote
Old Aug 28, 2009, 9:44 PM   #14
Senior Member
 
Join Date: Aug 2006
Location: Western Canada
Posts: 3,076
Default

Quote:
Originally Posted by anthony_b View Post
I'm looking to buy the Pentax kit mentioned above and I was wondering if the basic lense that comes with it would be enough (DA-L 18-55 Lens) for just general purpose stuff like the beach, indoor pictures and parks. Nothing fancy, just everyday memories of the kids. I figured I would get the best IQ by getting a slr instead of buying a high end p/s....due to my budget I don't see my self buying any lenses anytime soon....so, do you think this lense will do for what I need it for ?
I bought a KM (K2000 in the States) with the kit 18-55 lens. It has the internal flash, although not powerful has worked out well for me. Lights up group pix, birthday parties, etc. The kit lens goes from moderate wide angle to moderate portrait lens.

I've been very happy with my KM (K2000) and I bought it as a carry around daily camera. I have it in a small Lowepro baf (170AW) and it's not much heavier or bigger than the G10.

I also have a Pentax K10D and a number of lenses and accessories..the KM also functions as a another K mount body in my Pentax system.

I considered buying the highest end p/s...the Canon G10. That is till I compared picture quality vs the K2000(KM) and G10. Not much of a contest. The K2000 is better, capable of taking better pictures.

The sensor on a p/s is is smaller than the sensor , even on a entry DSLR like the K2000.

I'd get the K2000...you'll get a camera that is capable of getting better pictures, has an on board flash, a very good zoom lens.

The other thing, is that you will get a camera you can grow with. As money gets a bit better (I was a young father at one time, know budgets, etc.) you can expand the system by getting more lenses, a more powerful external flash, other accessories.

You can't grow with a p/s.






lesmore49 is offline   Reply With Quote
Old Sep 5, 2009, 11:35 AM   #15
Junior Member
 
nilescrane's Avatar
 
Join Date: Sep 2005
Posts: 9
Default

Hi-haven't got the K-m, but with the K100D I've used the Tamron 18-250 at concerts on the maximum zoom at ISO 3200. After running the images through a noise-reduction programme, I was happy with the results.

Any news on an update to the K-m? I saw rumours somewhere.
nilescrane is offline   Reply With Quote
Old Sep 5, 2009, 5:52 PM   #16
Senior Member
 
robar's Avatar
 
Join Date: Mar 2005
Location: D/FW area Texas
Posts: 7,590
Default

Quote:
Originally Posted by anthony_b View Post
due to my budget I don't see my self buying any lenses anytime soon....so, ?
YEAH RIGHT!!!!!
so naive
__________________
Roy
Passion is in all great searches and is necessary to all creative endeavors. - W. Eugene Smith
http://picasaweb.google.com/roysphoto/?pli=1
robar is offline   Reply With Quote
Old Sep 5, 2009, 6:45 PM   #17
Senior Member
 
NonEntity1's Avatar
 
Join Date: Jul 2006
Location: Lake Placid Florida USA
Posts: 2,689
Default

I see the original question was posted a few days ago, so you may have already made your purchasing decision. I am going to come down if favor of the 18-55mm and 50-200mm lenses, both of them offer a lot of performance for the money. There are certainly more expensive choices but the K2000 and those two lenses should give you results superior to nearly any point and shoot and make a very nice starting kit.

This summer my father bought a K2000, one week before he and my mother took a "trip of a lifetime" to Italy. I filled out his bag with the 50-200mm and an FA 50mm 1.4, gave him some quick lessons, and he was absolutely tickled with the results. My first two lenses were the 18-55 and 50-200 and both still give regular service on our K100.

Tim
NonEntity1 is offline   Reply With Quote
Old Sep 15, 2009, 10:16 AM   #18
Senior Member
 
anthony_b's Avatar
 
Join Date: Aug 2009
Location: Florida
Posts: 211
Default

NonEntity1, thanks for the reply...I still haven't purchased it becuase I'm still debating on which entry level slr to get, my choices are the (canon xs, sony a230 and the Pentax k2000).
anthony_b is offline   Reply With Quote
Old Sep 16, 2009, 8:30 PM   #19
Senior Member
 
NonEntity1's Avatar
 
Join Date: Jul 2006
Location: Lake Placid Florida USA
Posts: 2,689
Default

Well, we would obviously recommend Pentax but most everyone here would agree you can take great photos with any of those systems. I turned up here about three years ago researching my first Dslr and I have learned a ton from the fine folks on this forum. So if you do get the K2000, post some shots here and participate!

Don't discount the K20d either. It is a larger and heavier camera but at $699 for the camera and kit lens it is much more than an entry level camera for an entry level price. ($1100 18 months ago).

Tim
NonEntity1 is offline   Reply With Quote
Old Oct 22, 2009, 10:28 AM   #20
Senior Member
 
anthony_b's Avatar
 
Join Date: Aug 2009
Location: Florida
Posts: 211
Default

I've read about this camera not having a feature to let you know what part of the frame you're focusing on, and to remedy this you need to have it at "center" focus....but what if I'm taking a large family picture ?...what do you do then ?...is this a major drawback ?....is it the same with the K-X ?...Would you still consider buying this camera ?
anthony_b is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 4:53 PM.