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Old Sep 27, 2007, 6:53 PM   #1
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I've decided on the K10D after Christmas but I need a fast 50 or 70-200 zoom lens to do what I need. Being new to DSLR's the lenses confuse me. I think the 18-55 kit lens will work for me butdoes anyone makes a fast 200 AF zoom lens for this camera? I would really like a f2.8 but everything I see is way over a $1000.00. I do need the auto focus on the lens also. If you have a suggestions I would appreciate it and could be watching e-bay for the lens even before I bought the camera.

DonR
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Old Sep 27, 2007, 9:51 PM   #2
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Unfortunately, an f2.8 200mm AF lens is going to be very expensive, even if you should find one used on e-bay. I was in the bidding for one a few days ago and dropped out when it topped 575-dollars, and it looked very used. It wound up selling for 695-dollars. The choices in this type of lens are limited, and none of them come cheap.

You say the kit lens will handle most of your short range work. There are a number of good zooms in the same f-stop range as the 18-55 (most are f4.0-5.6). These are no nearly so expensive as a 2.8.


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Old Sep 27, 2007, 10:55 PM   #3
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The reason I need a fast 200 zoom is that I take pictures at two indoor rodeos and the light is really bad and the action is very fast. I used my V-LUX 1 this year and the fastest shutter speed I could get at 165mm - f3.6 - ISO 800 was 1/80sec. Not fast enough to freeze the action and I still had to brighten the pictures. Needless to say they are also very noisy. I'm hoping the Pentax K10D with a fast zoom will get faster shutter speeds but I saw a Nikon 70-200 f2.8advertized and it cost $1600.00 andone like that is absoutely not in my budget. Any other suggestions are welcome.

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Old Sep 28, 2007, 1:38 AM   #4
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Prime lenses are generally faster than zooms but can be a bit more restrictive as they do not allow the instant flexibility of the zoom.

I have a Vivitar Series 1 200mm f3 that I use for sports late in the afternoon or on really overcast days.

With my DS I confidently shoot at ISO 1600 and above without noise being too obvious.

Then I use Noise Ninja to finish them off. It batch processes so once the initial culling is done it is easy and relatively quick to operation.

A bonus is that my original sports shots are jpeg, but noise ninja can save the processed files as TIFF in another folder for editing.

This pic, while not a sports shot, is an example of ISO 3200, with dark areas to really show the noise.

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Old Sep 28, 2007, 2:28 AM   #5
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There's a Sigma 70-200mm f2.8 for Pentax, and there is the new Pentax DA* 50-135mm f2.8, if you don't mind a few mm shorter.

Both are under 1000$

There's a Tokina AT-X Pro 80-200mm f2.8 aswell I think, but it's hard to find.

The FA* 80-200mm f2.8 goes well over 1000$...

Tom
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Old Sep 28, 2007, 8:17 AM   #6
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Not having knowledge of DSLR lenses I need to ask a dumb question. Can you buy a lens that was not factory made for a Pentax and adapt it to fit or does it specificaly need to be made for a Pentax?

Also: Can someone explain the difference in the types of lenses shown on the Pentax website? Whichtypes fit the K10D and are auto focus? I guess I'm dense, but the more I read the more confused I get.

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Old Sep 28, 2007, 10:12 AM   #7
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There are quite a few third party lenses made for Pentax, in addition to the Pentax brand. What you want is a K banet mount, which is the part that attaches to the camera. The Pentax bodies are backward compatable so you can use a wide variety of old lenses that were made for film bodies just fine. Some are manual (manual aperature and focus), while others have various levels of automation (aperature and focus ) supported.

The third party lens that have been cited here have the Pentax K mounting, and then you need to read the description to see what level of automation they support. The main third party lens are
  • Sigma[/*]
  • Tameron[/*]
  • Tokina (which is owned by Hoya who just bought Pentax)[/*]
30 years ago the M42 mount (screw) was used and with an adapter ($5 to $10 - K to M42) you can still use these lens on the current Pentax bodies.

Also for comparison to a 35mm film lens, you need to adjust the focal length by a factor of 1.5 thus a 200mm focal length lens on the K10D is really a 300mm lens when expressed in 35mm terms. So your really looking for a 133mm lens if your V-Lux at 165mm is being expressed in 35mm terms. Confused yet???

For a long but not nearly extensive list of lens brands take a look at
http://forums.steves-digicams.com/fo...mp;forum_id=94



TDN use to have a very good web page that explained all the various lens types and what exactly they did and did not do, but I can't seem to find it.....
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Old Sep 28, 2007, 10:39 AM   #8
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d-sr wrote:
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the fastest shutter speed I could get at 165mm - f3.6 - ISO 800 was 1/80sec. Not fast enough to freeze the action and I still had to brighten the pictures.
Ok, this is very telling.

First off - you really are going to want 200mm even on your current crop camera. When shooting at high ISOs you need to frame VERY tight - you can't crop nearly as much as you can at say ISO 100.

But, back to the above. 3.6, ISO 800 1/80 was underexposed. For the sake of argument let's take aperture down to 2.8 for a correct exposure. This is assuming you did only SLIGHT lightening. So, 2.8 ISO 800 1/80. That means at ISO 1600 you'd only have 1/160 - still WAY too slow. You need at least another stop to get halfway decent shots. That means either ISO 3200 or a 2.0 aperture lens.

I know the rodeo I shot a month ago OUTDOORS I was shooting ISO 3200 / 6400 and 2.8 - and that was outdoors at dusk with lights.

As I recall the k10d wasn't as clean at higher ISO so a 3200 exposure might not yield great results. But you might have to accept it - assuming you can find an autofocus lens. The sigma 70-200 2.8 is a great lens (sells for around $850) but it is difficult to find in a Pentax mount.

I'm not sure what autofocus primes are available but if you could find one - say a 135mm 2.0 type of lens it might work - BUT you'd have to shoot from the side of the chute and not across from it to have the subject close enough for decent shots. Hopefully someone much more knowledgable than I on pentax lenses can let you know what autofocus 2.0 or 1.8 primes there are for pentax around the 135-150mm range.

Best of luck!

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Old Sep 28, 2007, 12:58 PM   #9
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TDN wrote:
Quote:
There's a Sigma 70-200mm f2.8 for Pentax, and there is the new Pentax DA* 50-135mm f2.8, if you don't mind a few mm shorter.

Both are under 1000$

There's a Tokina AT-X Pro 80-200mm f2.8 aswell I think, but it's hard to find.

The FA* 80-200mm f2.8 goes well over 1000$...

Tom
Not to be picky, but I thought that the Sigma 70-200 f2.8 didn't appear in the Pentax mount.



Please show website to prove me wrong, as it may be what I am after.



Dal
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Old Sep 28, 2007, 2:21 PM   #10
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Short course in Pentax lens capability:

K or M lenses = manual exposure, manual focus
A lens = auto exposure, manual focus
F = auto exposure, auto focus
FA = auto exposure, auto focus (with some other differences that mean more with film cameras)

If you want AF, limit your search for lenses (Pentax or third party) that say F or FA.

The one indoorhunter/jumper horse show I shot was with the DA 50-200. I was in the stands (notbig ones, and not that far fromringside)and shot most of the pictures around 150mm. If I wanted to catch a cowboy's face as he was coming off a bull or in the midst of tying off a calf,I would have wanted something longer than 200, but for hunter/jumpers my 300mm lens was way too long. I definitely would NOT recommend the DA 50-200 - it was way too slow at f4.5 and ISO 1600. You would need at least a 2.8 lens (look for the FA*80-200 2.8on ebay, won't be cheap though). If I were going to shoot indoor hunter/jumpers on a regular basis, I could probably get away with the DA*50-135 2.8, since the lens is sharp at 2.8 (not sure about rodeo though). This lens is still fairly expensive - if you aren't sure of the focal length/aperture you can usually pick up a K-Mount Takumar 135mm 2.5 lens for under $30 and that would give you some idea of whether the DA*50-135 would really work or not, without shelling out much money (this particular lens is a low-contrast, uncoated manual lens that was sold as a kit lens in 1980. It has a poor reputation and Roy had one in the paperweight category, but mine is really sharp. I suggest it not as a suitable lens for your purpose, but a cheap one to experiment with to see what you would get at that focal length and f2.8 ).

As an aside - this is one of the cases where the K100 might have suited you better. While I got acceptable pictures with the K10 at 1600, the K100 has less noise and I would have been happier with mine if I had used it. One suggestion with the K10 and high ISO - try (if at all possible) to slightly over-expose, as long as you don't blow out the highlights. Noise is most noticeable in dark/underexposed areas and willget worseas you lighten the picture. Also remember that the longer your lens focal length is, and the bigger the aperture, the smaller the DOF is and so focus becomes absolutely critical. Take lots of pictures.
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