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01-31-2010, 09:57 AM   #31
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I just received my Tamron 17-50 on Thursday. Have played around with it and pictures look better compared to the kit lens, but really I bought it for the f2.8 aperture and certainly that does not disappoint.

I'm looking forward to JnM_in_VT's tests...I shot a few comparison shots myself but primarily to compare the Pentax Kx+17-50 with my Canon system.

This is my first ever lens shootout test, and so expect a number of rookie mistakes. Anyway, I'll post the results soon.

01-31-2010, 10:14 AM   #32
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QuoteOriginally posted by taurus9 Quote
I just received my Tamron 17-50 on Thursday. Have played around with it and pictures look better compared to the kit lens, but really I bought it for the f2.8 aperture and certainly that does not disappoint.

I'm looking forward to JnM_in_VT's tests...I shot a few comparison shots myself but primarily to compare the Pentax Kx+17-50 with my Canon system.

This is my first ever lens shootout test, and so expect a number of rookie mistakes. Anyway, I'll post the results soon.
welcome and where are you from b.c. ?

btw, were you refering to the Canon kitlenses? coz those ones aren't of any good even when compared to the Pentax kit lenses.
01-31-2010, 10:18 AM   #33
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Rafalas:

Huh, sorry, but I think you are being a bit anal. Were you using the kits in full auto? I think you have some great images and maybe you need to refine your technique.
01-31-2010, 11:01 AM   #34
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QuoteOriginally posted by Ahab Quote
Rafalas:

Huh, sorry, but I think you are being a bit anal. Were you using the kits in full auto? I think you have some great images and maybe you need to refine your technique.
That's not being anal, that's being very wise to ask such a question. Step outside the M and at least move over to Av for a while, play around with what you like...then onwards!

Jason

01-31-2010, 03:37 PM   #35
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This test took much longer to go through than originally thought...

I have learned lots so please bear with the limitations of this test.
All tests shots were focused manually via Live View (magnified) on a Kx. The two second self timer was used and shot on a tripod. The point of focus is the right red cheek on the sunshine toy. Exposure was manual @ ISO100. A surprising amount of variation in the exposures from both lenses; more so on the Tamron. Although part of it was vignetting, I still had to bring the exposures 'by eye' in post. I chose to do the equalization in post rather than making changes in the shutter speed.

All pictures were shot in DNG format, and converted via Photoshop CS3. Settings left at default with the exception of WB and exposure (as described above). I should note that the AWB of the Kx is VERY impressive with the lights at home.

The two lenses being compared are a Pentax mount Tamron 17-50 and an SMC DA L 18-55 Kit lens that came with my Kx.

Here is the overall test scene.

Last edited by taurus9; 05-07-2011 at 08:00 AM.
01-31-2010, 03:41 PM   #36
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50mm Comparison

Top set of crops are Tamron. From Left to Right, f2.8, f4, f5.6 and f8.
Bottom set of crops are Pentax. From left to right, f5.6 and f8.

First picture is centre crop.

Second picture is bottom crop

And last one is the right side crop.

Last edited by taurus9; 05-07-2011 at 08:01 AM.
01-31-2010, 03:47 PM   #37
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35mm Comparison

whoops, did not shoot f8 here...

Again, top set of crops are Tamron at f2.8, f4, and f5.6
Bottom set of crops are Pentax at f4.5 and f5.6. (at 35mm, f4.5 is wide open)

First set of crops are centre. Second set of crops are bottom, and last set are right side.

Last edited by taurus9; 05-07-2011 at 08:01 AM.
01-31-2010, 03:53 PM   #38
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Wide Angle Comparison

Rather than try to obtain the same field of view between the two lenses, I just shot them at the widest setting. If you're looking for a truly scientific experiment, then I'm afraid this isn't it. In reality, you're more likely to just rack the zoom to its widest setting anyway.

By now you should know the drill, but here goes again

Tamron @17mm top set of crops. Left to right are f2.8, f4, f5.6, and f8
Pentax @18mm bottom set of crops. Left to right are f3.5, f4, f5.6, and f8

First set of crops are centre. Second set are bottom, and third set are right side.


Last edited by taurus9; 05-07-2011 at 08:02 AM.
01-31-2010, 04:10 PM   #39
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Well, I hope this is useful for the OP and for any curious onlookers. As I mentioned, this is my first lens shootout. I prefer to compare lenses by taking pictures in the field and looking at them on a computer screen and then get general impressions.

As an FYI, I shot the same scenes with my Canon Xti with a Tamron 28-75 @35mm and @50mm. I will probably post the crops later but not now, as I've had enough of staring at crops for half a day.

Pentaxor: I live in Burnaby the bedroom community of Vancouver
01-31-2010, 04:12 PM   #40
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thank you for your test Taurus. I appreciate it. it does appear that the kitlens is truly is weak in the contrast department. even at small apertures. the difference is just noticeable evidently.

not to undermine the kitlens, it is a good lens, but it needs some degree of post-processing inorder to make outstanding results.

in conclusion, the 17-50 is worth the upgrade from the kitlens.
01-31-2010, 06:40 PM   #41
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??? If anything, I see *more* contrast in the kit lens pictures at smaller apertures, although at the larger apertures toward the edge of the frame, it is noticeably softer. Hard to say how much of that might be different field curvatures or focus points, though.
01-31-2010, 08:03 PM   #42
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I would prefer to say that the Tamron lens is stronger.

That does not look like a particularly weak performance for the kit lens to me. In fact, I wonder for how many people the difference would matter, especially with pp or in-camera sharpening and contrast.
01-31-2010, 08:50 PM   #43
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QuoteOriginally posted by taurus9 Quote
Well, I hope this is useful for the OP and for any curious onlookers. As I mentioned, this is my first lens shootout. I prefer to compare lenses by taking pictures in the field and looking at them on a computer screen and then get general impressions...
It's kind of cold in the field, though.

I thought that was a great comparison test. Good work. GeneV does have a point - is this difference enough to show in real pictures? I am almost afraid to run a similar test with my kit vs. the DA 16-45. I think I see better photos but I could be imagining it.
01-31-2010, 10:58 PM   #44
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QuoteOriginally posted by GeneV Quote
I would prefer to say that the Tamron lens is stronger.

That does not look like a particularly weak performance for the kit lens to me. In fact, I wonder for how many people the difference would matter, especially with pp or in-camera sharpening and contrast.
the question is how much workflow is needed or the person wanted to invest with?

I appreciate the love for the 18-55 kit lens, especially when post-processed. but comes the question why people still upgrade inspite of the fact that post-processing could help the lens' shortcomings.

aside from aperture speed, what other factors or obvious advantage that a faster lens have over the kitlens and why person prefer them? if there isn't really a significant difference or advantage that either better primes or zooms have over the kit lenses + pp have, then we would had been seeing most of us being contented with an 18-55 + 55-200 combo. do we really think that this is all about marketing a product which have certain characteristics that can be easily copied or recreated?
02-01-2010, 03:46 AM   #45
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QuoteOriginally posted by Ahab Quote
Rafalas:

Huh, sorry, but I think you are being a bit anal. Were you using the kits in full auto? I think you have some great images and maybe you need to refine your technique.
Nothing to be sorry about. My two main shooting modes are M or Av. To be honest, I can't remember the last time I shot in Auto, apart of just testing how the camera will behave in certain conditions.
In my travel to Egypt, I often found myself shooting at low shuter speeds, resulting in trepidation and unusable photos. I'm very reticent of user ISO values above 100; I would even say I'm a purist of 100 ISO, and that I do what I can to don't gove above that. I'm starting to think that might be the problem, and that I should be starting to shot without fear at 400 and even at 800 ISO, giving me two or three more shutter steps in comparison.

Thanks a lot to taurus9. Those field test are great, and they do really show the difference between two lenses. Nothing more "scientific" is needed. They really do the work.

I'm starting to be in GeneV's side. I've been in photography for around 10 years already, not proffesionally, but on a high amateur level. I do really care for image quality and technical superiority, and I do recon that the Tamron is superior to the Pentax kit, but these differences will only be seen in big prints or by very critical eyes. It's although undeniable the fact that the Tamron is a faster lens, constant f2.8 , and because of that I will still consider it as a worth buy, giving the fact that the K10D is not specially good at ISO speeds, and that I find that being my most common problem. I'm still thinking about it.

Regarding the technique, I don't fully understand your advice around that. What do you mean by improving my technique? I do understand the principles behing the relations between ISO, Shutter and Focal. How to use and select them. I don't know much about AF techniques though. Is it something I should be taking care of ?

Well, thanks a lot for your opinions. This is being a great threat for me.
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