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Polytrope
12-13-2006, 01:11 PM
How do I go about getting a moderately powerful telephoto lens for the K100D? When I try to find things on the web, I either don't find anything at all, or I'm bewildered and not sure whether what I've found would work.

Might help if I explain where I'm coming from. I've just bought the Pentax K100D after using a Canon PowerShot Pro Series S3 IS for the last many months. I love the Pentax and would like to make it my only camera - would love to sell the Canon and the converter lenses I have, too - but boy, the zoom capabilities of the Canon S3 are hard to part with, especially since I'm a bird watcher. The 12x zoom built into the S3 is said to be the equivalent of a 434mm lens; I'm not sure whether that's 434mm for a film SLR or a digital SLR, but either way, it's a decent lens. But I have the Canon 1.5x converter (bumps me up to about 650) and also the Raynox 2.2x converter (bumps me up to 26x or close to 900mm!). I can live without a replacement for the converter lenses, at least for a while. But I'd really like to be able to match that 12x built-in lens.

I don't care whether it's a zoom or a prime. (Hope I'm using "prime" correctly. I just learned the word. I understand it to be a fixed focal-length lens.) If I had, say, a 400mm lens of any sort, I'd probably pop it on only when I wanted to use every last mm of focal length, so a prime would, I think, be fine. Of course, a zoom lens that goes from 100-400 would be more versatile.

I understand that there is a wide variation in the quality of lenses. I'm not planning to shoot covers for National Geographic, and in any case, I don't have $2000 to spend on this. I would like to get a decent/usable lens, preferably for as much below $500 as possible.

I should mention that I'm sitting here waiting for UPS to deliver the Pentax 50-200mm lens. That will become my standard all-the-time lens. But I'd like a 400mm or better for birding, etc. I just don't know where to shop, or what to be looking for. Any advice you've got will be greatly appreciated.

Will Porter
Dallas, Texas (USA)

Reps
12-13-2006, 01:58 PM
DA 50-200 is a superb choice- You will love it at it's focal lengths... but birding is IMO another lifestyle- there You will definitely hit LBA with *marked lenses- no workaround here...

Best and happy shooting, JR

jeisner
12-13-2006, 03:52 PM
For birding I use a Pentax F*300mm (FOV equiv 450mm)....

You can then add a Tamron 1.4x AF teleconverter to that... works pretty well... You could also add a 2x teleconverter, does degrade a bit but still well ahead of the raynox (i did have one for my FZ20)..

Polytrope
12-13-2006, 05:32 PM
DA 50-200 is a superb choice- You will love it at it's focal lengths... but birding is IMO another lifestyle- there You will definitely hit LBA with *marked lenses- no workaround here...

Reps,

UPS delivered the 50-200 lens about an hour ago. My daughter thinks I'm crazy because I'm sitting in the living room taking pictures of the dishes in the display case, the cat on the couch, our CD collection, books on the bookshelves. It's too dark now to go outside. I am sure that YOU understand. :-)

Forgive me, though - I'm not good at acronyms. What does "LBA" stand for?

Will

Polytrope
12-13-2006, 05:47 PM
For birding I use a Pentax F*300mm (FOV equiv 450mm)....

You can then add a Tamron 1.4x AF teleconverter to that... works pretty well... You could also add a 2x teleconverter, does degrade a bit but still well ahead of the raynox (i did have one for my FZ20)..

Excellent - thank you so much for these recommendations. I have two questions.

First, is this (http://www.amazon.com/Tamron-Autofocus-Teleconverter-Pentax-Cameras/dp/B000068RUI/sr=1-1/qid=1166059704/ref=sr_1_1/002-0571465-4598453?ie=UTF8&s=photo) the Tamron 1.4x converter you're talking about? On Amazon.com, it's described as being for "Pentax SLR" cameras. Usually, if the lens is for the digital SLRS, they say "for Pentax DSLR". Do I have the right lens? I don't find an alternative labeled for DSLR....

Second, can this converter lens be used with the Pentax 50-200 lens that I just acquired? While the 300mm lens sounds like a must-have, I might like to get the converter first, then acquire the 300 later on. Would that work?

Thanks again,

Will

Polytrope
12-13-2006, 06:04 PM
For birding I use a Pentax F*300mm (FOV equiv 450mm)....

You can then add a Tamron 1.4x AF teleconverter to that... works pretty well... You could also add a 2x teleconverter, does degrade a bit but still well ahead of the raynox (i did have one for my FZ20)..

May I ask you (or anybody) about this lens: the Tamron Autofocus 75-300 f/4-5.6 LD (with hood) (http://www.amazon.com/Tamron-Autofocus-75-300mm-Pentax-Cameras/dp/B00005V8SA/sr=1-2/qid=1166061516/ref=sr_1_2/002-0571465-4598453?ie=UTF8&s=photo)? It's in my price range and the reviews on Amazon are generally about as good as I would hope for, in other words, it sounds usable and might even take some good pictures. I have looked at some other lenses that I'm SURE are good, but gosh, I could make a nice downpayment on a new car for those prices!

Anyway, I've already got the Pentax 50-200, would it make more sense to get the Tamron 75-300, or the Tamron 1.4x converter (which would, if my math is correct, give me roughly the same focal length)? I think I read somewhere that the converter doesn't do its best job when the base lens is zoomed to its full extent....

Will

SpecialK
12-13-2006, 08:10 PM
Hi Polytrope ("many-colored"?):

You already have the 50-200 which is great. I would not duplicate most of the range with with a 75-300.

I have a couple Sigmas which I like, and quite a few other people on the forum have them as well. You might try www.sigma4less.com as a starting point to see what is available. On the left side, click on "Lenses", then for the mount choose "Pentax".

I had a 600mm f8 mirror lens a long time ago in my film days. I wish it would come back in stock. Long focal length, reasonably short physical length, pretty light, and a fixed aperture of f8.

Hmmm, this has possiblities...
http://www.sigma4less.com/sess/utn;jsessionid=154580cd9a6e47a/shopdata/0040_Lenses/0010_Zoom/0040_Tele+Zoom/product_details.shopscript?article=1150_Sigma%2BZo om%2BTelephoto%2B170-500mm%2Bf%3D26slash%3D3B5-6%3D252E3%2BAPO%2BDG%2BAutofocus%2BLens%2Bfor%2BPe ntax%2BAF%2B%3D28SG170500F5DPX%3D29

As for "finding stuff on the web", I use Google and look up "brand name focal length lens review" (or "rating") once I know which lens I'm interested in.

Hope that helps.

Oh, I took pictures of my bookcase and TV the first night I had my camera :-)

Polytrope
12-14-2006, 12:30 AM
Hi Polytrope ("many-colored"?):

Not quite. Click here (http://www.polytrope.com/etc/polytrope.html) to read the explanation on my web site.



You already have the 50-200 which is great. I would not duplicate most of the range with with a 75-300.

Kind of what I decided myself. That's why I went with the 1.4x converter instead (that, plus it's cheap).



I have a couple Sigmas which I like, and quite a few other people on the forum have them as well. You might try www.sigma4less.com as a starting point to see what is available. On the left side, click on "Lenses", then for the mount choose "Pentax".

GREAT resource. Thanks.



Hmmm, this has possiblities...
http://www.sigma4less.com/sess/utn;jsessionid=154580cd9a6e47a/shopdata/0040_Lenses/0010_Zoom/0040_Tele+Zoom/product_details.shopscript?article=1150_Sigma%2BZo om%2BTelephoto%2B170-500mm%2Bf%3D26slash%3D3B5-6%3D252E3%2BAPO%2BDG%2BAutofocus%2BLens%2Bfor%2BPe ntax%2BAF%2B%3D28SG170500F5DPX%3D29


Oh, dear, I think I'm in love. Well, that will be the first item on my wish list for Christmas 2007.

Thanks a lot.

jeisner
12-14-2006, 02:54 AM
First, is this (http://www.amazon.com/Tamron-Autofocus-Teleconverter-Pentax-Cameras/dp/B000068RUI/sr=1-1/qid=1166059704/ref=sr_1_1/002-0571465-4598453?ie=UTF8&s=photo) the Tamron 1.4x converter you're talking about? On Amazon.com, it's described as being for "Pentax SLR" cameras. Usually, if the lens is for the digital SLRS, they say "for Pentax DSLR". Do I have the right lens? I don't find an alternative labeled for DSLR....

Yes but overpriced... This is the one at a much better price.. It is for SLR and works fine for DSLR as is the lens I mentioned...

http://www.bhphotovideo.com/bnh/controller/home?O=Search&A=details&Q=&sku=160579&is=REG&addedTroughType=search


Second, can this converter lens be used with the Pentax 50-200 lens that I just acquired? While the 300mm lens sounds like a must-have, I might like to get the converter first, then acquire the 300 later on. Would that work?

It will work but teleconverters degrade lens quality and its best to start with a prime not a zoom lens... it will otherwise degrade the picture noticably, like the raynox did in my experience..

jeisner
12-14-2006, 03:00 AM
Oh, dear, I think I'm in love. Well, that will be the first item on my wish list for Christmas 2007.

Stick with the 135-400mm version I have had both and the 135-400 is cheaper, lighter, better quality and still a great range... Also make sure you get the new model, it has 'DG' in its name.. It menas it has coatings optimised for digital...

http://www.sigma4less.com/sess/utn;jsessionid=1545812da294d4b/shopdata/0040_Lenses/0010_Zoom/0040_Tele+Zoom/product_details.shopscript?article=1050_Sigma%2BZo om%2BTelephoto%2B135-400mm%2Bf%3D26slash%3D3B4%3D252E5-5%3D252E6%2BAPO%2BDG%2BAutofocus%2BLens%2Bfor%2BPe ntax%2BAF%2B%3D28SG135400F45DPX%3D29

This is a pretty heavy crop out of the center of I shot I took with the Sigma 135-400...

http://www.pbase.com/joele/image/45309175/original.jpg

Polytrope
12-14-2006, 09:24 AM
Yes but overpriced... This is the one at a much better price.. It is for SLR and works fine for DSLR as is the lens I mentioned...

http://www.bhphotovideo.com/bnh/controller/home?O=Search&A=details&Q=&sku=160579&is=REG&addedTroughType=search


THanks. I stumbled on b&h's price myself last night and that's the one I ordered. It might not be perfect, but for $60, I could afford to take the risk.



It will work but teleconverters degrade lens quality and its best to start with a prime not a zoom lens... it will otherwise degrade the picture noticably, like the raynox did in my experience..

I'll do some tests as soon as it arrives (probably not until next week). If it's no worse than the Raynox 2.2x converter, I'll be delighted. I'm not expecting miracles for $60. :-)

Polytrope
12-14-2006, 09:26 AM
Stick with the 135-400mm version I have had both and the 135-400 is cheaper, lighter, better quality and still a great range... Also make sure you get the new model, it has 'DG' in its name.. It menas it has coatings optimised for digital...

http://www.sigma4less.com/sess/utn;jsessionid=1545812da294d4b/shopdata/0040_Lenses/0010_Zoom/0040_Tele+Zoom/product_details.shopscript?article=1050_Sigma%2BZo om%2BTelephoto%2B135-400mm%2Bf%3D26slash%3D3B4%3D252E5-5%3D252E6%2BAPO%2BDG%2BAutofocus%2BLens%2Bfor%2BPe ntax%2BAF%2B%3D28SG135400F45DPX%3D29

This is a pretty heavy crop out of the center of I shot I took with the Sigma 135-400...

http://www.pbase.com/joele/image/45309175/original.jpg

Looks great. Still a bit too pricey for me to acquire this week, but as soon as possible....

Thanks,

Will