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Old Oct 2, 2007, 11:44 PM   #11
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superakuma wrote:
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I you can buy the Pentax version for cheaper then what they list for. I would rather go for the Tamron version if they are the same price because Tamron gives you 6 years warranty vs the standard Pentax 1 year.
Hi sk.

I think that there might be some other considerations involved if I were making the choice between the two. OEM lenses usually keep their value better than 3rd party ones, and are also more marketable because of perceived quality and original price, and I've yet to personally encounter a warranty problem with a lens that cropped up after 1year. Usually "defects" which would be covered are apparent right away, or relatively soon after receiving a lens, and the warranty won't usually cover damage or misuse which would be the more likely cause of problems long term -- tho SDM lenses might be a different animal, I have no experience with the longevity of these motors.

If Tamron's warranty is a "no questions asked" 6 yr replacement or repair, of course that would be a different story, but (knock on wood) I have yet to trash a lens, and I don't baby my gear.

To cover another base, I think that Harriet's DA50-200 problem is probably the exception rather than the rule.

Scott
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Old Oct 3, 2007, 12:14 AM   #12
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interested_observer wrote:
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This is just speculation, but since the current kit lens - the 18-55 is thought of so well, might this be the new kit lens? With a broad range across both the 18-55 and the 50-200, offering this as the initial kit, might move beginners up to the dual lens set and then maybe on to their new set of f2.8 lenses...

... also, if this were to be the new kit, then the K100D kit would really compete with the superzoom offerings from Canon, etc. with a 14x lens all in a single package with all the bells and whistles.....

Just thinking outloud...
Hi i o,

It's doubtful, tho an interesting thought. Think "inexpensive" for the kit lens, or you'd be talking about trying to market a $1000+ "entry level" camera which would probably turn people off -- people tend to look at the base price and not the details. Nikon did make a hit with their expensive VR consumer superzoom because of the good IQ, but I don't believe that they tried to market it as a kit with any of their bodies.

I think that the bottom-line price is what attracts the attention of potential new users. Couple that with an OEM, high quality, available "all in one" superzoom so the fear of dust on the sensor (which is a big factor, realistic or not) is effectively negated, and I think that more P&S shooters will be attracted, and the company will make more money overall. Pentax has this ability -- with SR in the body, the superzoom can be sold for considerably less than comparable C and N stabilized lenses, and since the bodies have already been shown to be at least competitive in price, the bottom line is that you can get equivalent performance at a significantly lower price with Pentax.

These are my impressions after spending a lot of time in Panasonic fora before taking the plunge into DSLRs a couple of years ago.

Scott
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Old Nov 5, 2007, 6:53 AM   #13
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As we all know now the DA 18-250 is just a rebadged Tamron 18-250 and like you say costs more and with less warranty, although for us poor folk in the UK the Tamron Warranty is only 1 year anyway, Doh!

I have currently sent my Tamron 18-250 back to Tamron UK (Intro2020) under Warranty as I feel the IQ is just unacceptable at anything less than f11, regardless of the focal length.

It exhibits severe left side softness, about 25% of the left side of all images shot at less than f11 are not so much soft, but plain blurred, vast diference between left and right sides, there was a Sigma zoom lens that had this same problem a while back if I remember rightly.

If it comes back from warranty service with no improvement then it will be back to the shop for a refund.

I wll post a sample tonight.
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Old Nov 5, 2007, 4:25 PM   #14
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As promised here are some examples of what a fine lens the Tamron 18-250 is:

All the images are full size crops, with the left half taken from the left side of the original image and the right side taken from the right side of the original image.

A18-1.JPG is the far left and right, full size crop portions of an image taken at:
ISO 100, 1/200 sec, f/3.5, 18mm.

A18-2.JPG is the far left and right, full size crop portions of an image taken at:
ISO 100, 1/125 sec, f/4.5, 18mm.

A18-3.JPG is the far left and right, full size crop portions of an image taken at:
ISO 400, 1/80 sec, f/11, 18mm.

As you can see the extreem left side softness does not get any better untill f/11 at the 18mm focal length.

And as can also be seen the distortion has to be seen to be believed.
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Old Nov 5, 2007, 4:27 PM   #15
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The image above is A18-1.JPG

This one is A18-2.JPG
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Old Nov 5, 2007, 4:28 PM   #16
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And here is A18-3.JPG
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Old Nov 5, 2007, 10:02 PM   #17
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If I understand your post - you are showing the extreme right and extreme left of a single shot, taken from the same part of the frame (in other words, both are from the bottom or from the top or from the center)? If so, then it looks to me like a real problem with the lens. It'll be interesting to see what it looks like when you get it back because I think your Tamron lens has the same problem my Pentax 50-200 has (which Scott has convinced me might be repairable and would be worth sending in to get a quote for repair).
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Old Nov 6, 2007, 2:31 AM   #18
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mtngal wrote:
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If I understand your post - you are showing the extreme right and extreme left of a single shot, taken from the same part of the frame (in other words, both are from the bottom or from the top or from the center)? If so, then it looks to me like a real problem with the lens. It'll be interesting to see what it looks like when you get it back because I think your Tamron lens has the same problem my Pentax 50-200 has (which Scott has convinced me might be repairable and would be worth sending in to get a quote for repair).
Yes thats correct the crops are from the left and right 25% of the original image and taken from the center, so they were not even croped from the worst part of the image, which would have been the corners at the top, or bottom.

Well the lens has just arrived back, so will collect it today and repeat the same tests over the weekend.
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Old Nov 11, 2007, 12:10 PM   #19
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Right here we are again then, got the lens back from Tamron UK (Intro2020) and collected it on Wednesday.
I finally managed to retest the lens on Saturday 10/11/2007 and here are the results.
A18-F1.JPG is the far left and right, full size crop portions of an image taken at:
ISO 100, 1/400 sec, f/3.5, 18mm.

[align=center][/align]


A18-F2.JPG is the far left and right, full size crop portions of an image taken at:
ISO 100, 1/250 sec, f/4.5, 18mm.

[align=center][/align]


A18-F3.JPG is the far left and right, full size crop portions of an image taken at:
ISO 100, 1/40 sec, f/11, 18mm.

[align=center][/align]


So as we can see and much to my surprise, everything now appears to be great.

In fact the left side is now so sharp that it makes the right side look a little soft, but that's just being picky.
So if there are any other disgruntled Tamron 18-250 owners out there, don't worry, just send the lens back to Tamron and get it serviced under warranty.
Here's what Tamron did to the lens to fix it:
Re-centered at the wide 18mm end and adjusted wide resolution power.
Adjusted light axis and focus shift to within standard.

Now I'm officially impressed and look forward to getting out there and shooting some of those autumn colours before they all disappear.
Here's the link to the full gallery again for convenience:
http://www.entsoft.co.uk/Web%20Album...les/index.html
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Old Nov 11, 2007, 4:47 PM   #20
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Significantly better pictures - glad to hear yours was repairable (and gives me incentive to send my Pentax lens in - maybe mine is repairable too!). Your tests are really pretty good for a lens with such a big range.
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