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07-31-2018, 04:56 PM - 1 Like   #16
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The bad name that first generation of SDM got for themselves means you can pick 'em up from frustrated sellers at a good price, Samoht.

The 50-135 is absolutely glorious, I understand the 16-50 is not as good but I might get it one day to complete the pair, even though I have the Sigma 17-50.

08-06-2018, 10:06 AM - 1 Like   #17
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I ended up buying a used DA* 16-50 already converted to screw drive, paid about 320 USD including shipping costs. I've already checked with the local service center what the cost is to fix the SDM, since it's made prior to the updated sdm both sdm motor and electronics needs to be replaced at a cost of around 215 USD. Will use it with screw drive to start with, really no need for silent focusing since it's mainly gonna be used for landscape photography.
Thanks for the advice's!
08-06-2018, 11:27 AM   #18
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The Tamron 17-50mm f/2.8 has very high field curvature, while the Sigma 17-50mm f/2.8 EX DC HSM is very unique, especially among zoom lenses, in having virtually none. It is also better built and has better AF.

Nothing wrong with using screw drive with the Pentax DA* 16-50mm. You also get WR, and an excellent build quality. From reports, the screw drive AF is also faster.
08-06-2018, 12:17 PM   #19
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The field curvature of the Sigma at 17mm is about 3% as measured at optical limits....
Sigma AF 17-50mm f/2.8 EX DC HSM OS - Review / Test Report - Analysis

The Tamron is 3.34. YOu're quibbling over 0.4% field curvature when both afar from perfect.
Tamron AF 17-50mm f/2.8 SP XR Di II LD Aspherical [IF] VC (Canon) - Review / Test Report - Analysis

QuoteQuote:
At 17mm it shows very pronounced barrel distortion (~2.9%) and a slight pincushion distortion at longer focal lengths
I'm interested in knowing what your source is for saying the Sigma is significantly better.

The 1.5 star 18-135 at 18mm... 3.5% barrel distortion,

Apples to Apples compared on the samer canon Sensor
Tamron max centre resolution is 2488 ƒ5.6 at 24mm
Sigma max resolution 2652 @ ƒ4 and 24mm

You might be able to see the difference, but most of the time you won't. It's about a 7% difference in resolution. Most of us won't consider less than 10% worth picking one lens over another and that's if they are both the same price This to my mind is a case where you pick the one you get the best price on.

The really funny thing would be that at 24mm the 18-135 is probably better than both of them. SO you pick a lens and you pick your poison.

But honestly, for lenses of this quality, just buy the one you want. Saying one is better than the other just begs the question "better for what?" Show us the image that prove your point. Now when i see a lens like the Canon 24mm and it gets better resolution than any other lens in it's class, by at least 30%, that kind of difference is worth buying a lens for.


Last edited by normhead; 08-06-2018 at 12:38 PM.
08-06-2018, 01:38 PM   #20
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QuoteOriginally posted by normhead Quote


.

The really funny thing would be that at 24mm the 18-135 is probably better than both of them. SO you pick a lens and you pick your poison.
To quote your own post "Show us the image that proves your point" or qualify your statement with "IMHO based on ??"
08-06-2018, 02:02 PM   #21
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QuoteOriginally posted by timb64 Quote
To quote your own post "Show us the image that proves your point" or qualify your statement with "IMHO based on ??"
You can read the tests on Optical Limits like I have and try and extrapolate across platforms, as I did. It's clear from the numbers the lenses are pretty close so It's not like my post is based on no evidence. If you want to do it yourself and see if you come to different conclusions have at ehr. But mine, is more than my opinion. It's backed up by test site data. I know that rots your socks but learn to live with it.

I don't doubt that you like the 16-85, my wife likes the tamron 17-50. People like different lenses probably based on their shooting styles/, I have no idea why. I've studied the charts, I've look at the images on the forum, it's not about the lenses in question, it's more about the people who use the lenses, and why that particular lens suits them.

It' not about one being better. They are all mid range quality lenses, not DA* or DFA *s, better than kit, It's about why it's better for you.

Last edited by normhead; 08-06-2018 at 03:43 PM.
08-06-2018, 03:15 PM   #22
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QuoteOriginally posted by normhead Quote

It' not about one being better. They are all mid range quality lenses, not DA* or DFA *s. It's about why it's better for you.
Except that in your opinion the 18-135 is “better” than them both at 24mm,that’s what you said in post #19.
08-06-2018, 03:46 PM - 1 Like   #23
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QuoteOriginally posted by normhead Quote
The field curvature of the Sigma at 17mm is about 3% as measured at optical limits....
Sigma AF 17-50mm f/2.8 EX DC HSM OS - Review / Test Report - Analysis

The Tamron is 3.34. YOu're quibbling over 0.4% field curvature when both afar from perfect.
Tamron AF 17-50mm f/2.8 SP XR Di II LD Aspherical [IF] VC (Canon) - Review / Test Report - Analysis



I'm interested in knowing what your source is for saying the Sigma is significantly better.

The 1.5 star 18-135 at 18mm... 3.5% barrel distortion,

Apples to Apples compared on the samer canon Sensor
Tamron max centre resolution is 2488 ƒ5.6 at 24mm
Sigma max resolution 2652 @ ƒ4 and 24mm

You might be able to see the difference, but most of the time you won't. It's about a 7% difference in resolution. Most of us won't consider less than 10% worth picking one lens over another and that's if they are both the same price This to my mind is a case where you pick the one you get the best price on.

The really funny thing would be that at 24mm the 18-135 is probably better than both of them. SO you pick a lens and you pick your poison.

But honestly, for lenses of this quality, just buy the one you want. Saying one is better than the other just begs the question "better for what?" Show us the image that prove your point. Now when i see a lens like the Canon 24mm and it gets better resolution than any other lens in it's class, by at least 30%, that kind of difference is worth buying a lens for.
I certainly agree regarding the virtues of the Pentax DA 18-135mm. It is very under-rated in tests. In practice it is an outstanding lens especially for the range it offers.

As to the field curvature difference between the Tamron and Sigma 17-50mm f/2.8 lenses, there was apparently a variant of the lens produced when they designed the VC for the Canon version and likewise for the Nikon mount. The test you quote by opticallimits is this newer variant from 2010. The former version is the one still available for Pentax. Just google Tamron 17-50mm XR Di II without the VC, OS, etc. to get the former version, a 2006 report, where they go into the field curvature issue. The distortion figures were different between them too, with the newer one this time being the worst.

The opticallimits report of the Sigma (for Canon I believe) comments regarding the very low field curvature they measured, and again more comments about that in their conclusion.

In researching, I also came across reports of there being a slight shortcoming of max aperture in the Tamron, so that it seems to be actually more like f/3.2 wide open. Along with that is my finding that the Sigma, while being good to very good wide open at f/2.8 does indeed improve very, very quickly upon the least stopping down. I find this is true. Very acceptable wide open at the edges, but even at f/3.2 (maybe equal to f/2.8 on the Tamron), even the edges are already very good indeed. The AF is quiet and fast.


Last edited by mikesbike; 08-06-2018 at 03:52 PM.
08-06-2018, 06:18 PM - 1 Like   #24
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QuoteOriginally posted by mikesbike Quote
I certainly agree regarding the virtues of the Pentax DA 18-135mm. It is very under-rated in tests. In practice it is an outstanding lens especially for the range it offers.

As to the field curvature difference between the Tamron and Sigma 17-50mm f/2.8 lenses, there was apparently a variant of the lens produced when they designed the VC for the Canon version and likewise for the Nikon mount. The test you quote by opticallimits is this newer variant from 2010. The former version is the one still available for Pentax. Just google Tamron 17-50mm XR Di II without the VC, OS, etc. to get the former version, a 2006 report, where they go into the field curvature issue. The distortion figures were different between them too, with the newer one this time being the worst.

The opticallimits report of the Sigma (for Canon I believe) comments regarding the very low field curvature they measured, and again more comments about that in their conclusion.

In researching, I also came across reports of there being a slight shortcoming of max aperture in the Tamron, so that it seems to be actually more like f/3.2 wide open. Along with that is my finding that the Sigma, while being good to very good wide open at f/2.8 does indeed improve very, very quickly upon the least stopping down. I find this is true. Very acceptable wide open at the edges, but even at f/3.2 (maybe equal to f/2.8 on the Tamron), even the edges are already very good indeed. The AF is quiet and fast.
There's a lot of good digging there. Although odd, that the VS version has more distortion than the older version. That's something you really have to be student of the lens to know.

---------- Post added 08-06-18 at 09:21 PM ----------

QuoteOriginally posted by timb64 Quote
Except that in your opinion the 18-135 is “better” than them both at 24mm,that’s what you said in post #19.
And it may well be, the information is inconclusive. I certainly don't discount the possibility. But lets not forget our positions, I regularly recommend people look the 18-35, the 16-85, the two 17-50s. I don't guide people one way or the other, just suggest possibilities. You on the the other hand proudly proclaim your undying love of the 16-85 without reservation. And tell everyone how you didn't like the 18-135, as if that's relevant to anyone but you.

The simple fact is these lenses are different enough that each has it's strengths and weakesses and in the end it all be one's persoanal biases in the way they shoot that will decide. The question is not that the lenses will deliver, they all do in their own way. The question is do they deliver on the images you think is right.

The 18-135 is the best of the above mentioned lenses for this image.


If that image interests you, then you should consider the 18-135, not the 16-85, not one of the 17-50s, not a 17-70. Now if that is not enough to make up for whatever weaknesses the lenses have (and test charts and images can help) then it's not for you. If on the other hand if you can look at the image and say, that's an ability I'd like to own, and I can live with the rest of it, it's the best lens for you.

There is no "best lens." It's nonsense. They all have their strengths, and you can buy even a kit lens because you like it's small size and weight and IQ combination over anything else that other lenses offer. If you have to resort to saying "this lens is a better lens" without saying what its better for, because it's not better for everything. then better to say nothing.

Last edited by normhead; 08-06-2018 at 07:21 PM.
08-06-2018, 09:00 PM   #25
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QuoteOriginally posted by normhead Quote
There's a lot of good digging there. Although odd, that the VS version has more distortion than the older version. That's something you really have to be student of the lens to know.

---------- Post added 08-06-18 at 09:21 PM ----------


And it may well be, the information is inconclusive. I certainly don't discount the possibility. But lets not forget our positions, I regularly recommend people look the 18-35, the 16-85, the two 17-50s. I don't guide people one way or the other, just suggest possibilities. You on the the other hand proudly proclaim your undying love of the 16-85 without reservation. And tell everyone how you didn't like the 18-135, as if that's relevant to anyone but you.

The simple fact is these lenses are different enough that each has it's strengths and weakesses and in the end it all be one's persoanal biases in the way they shoot that will decide. The question is not that the lenses will deliver, they all do in their own way. The question is do they deliver on the images you think is right.

The 18-135 is the best of the above mentioned lenses for this image.


If that image interests you, then you should consider the 18-135, not the 16-85, not one of the 17-50s, not a 17-70. Now if that is not enough to make up for whatever weaknesses the lenses have (and test charts and images can help) then it's not for you. If on the other hand if you can look at the image and say, that's an ability I'd like to own, and I can live with the rest of it, it's the best lens for you.

There is no "best lens." It's nonsense. They all have their strengths, and you can buy even a kit lens because you like it's small size and weight and IQ combination over anything else that other lenses offer. If you have to resort to saying "this lens is a better lens" without saying what its better for, because it's not better for everything. then better to say nothing.
Get your facts straight,I have never said I didn’t like the 18-135.On the contrary I have also frequently recommended it as a good budget walk around option and took numerous pictures I was very happy with (look back at posts in the relevant thread),

It’s just that,when asked, I am able to state ,having owned both lenses,that the 16-85 is better and for some reason my having that opinion gets your goat!

Anyway this thread isn’t about the 18-135 despite your obsession!
08-07-2018, 07:50 AM   #26
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I swear, when you see any mention of the 18-135 in any context, you must turn red and start spitting.

When i tested the the ways i have to take a 35mm image, some people preferred the images of the FAJ 18-35, or the kit lenses over the DA 35, Tamron 17-50 or SMC 35 3.5. Not a majority. I always approach these subjects as if the OP is capable of selecting any one of the lenses mentioned.

Comments on your opinion of the 18-135 are pretty much irrelevant. There is absolutely nothing to suggest that more than 30% will share your opinion, in fact the odds are against it. I say that because I've done the test images, Your constant negativity, and declaring that you sold a lens is definitely negativity and away to try and influence the OPs decision.

ANd I use the 18-135 as my favourite example of a lens trashed by test sites forum members etc. that is a lens that many really love. That's it. I'm not advocating anyone buy it. I'm advocating that people look at it. "If this is what you are looking for you might like this." The fact that it sets you off every time I mention it in that context is unfortunate. You it be easier for you if I mentioned the kit lens instead? Why?, it's just an example, that happens to be a lens a lot of people like.

My point is, dig deeper than the test charts. Look at some images, Sorry that's something you can't let pass. My other point would be, don't depend on opinions to make your decision. Look at some charts look at some images, look at what the lens does others don't do and decide what you need. Simply stated if 99% of the opinions on the forum don't like your favourite lens, it's still the best lens for you. Don't listen to them.

In your case, because all you ever state is a personal opinion, that's a problem. I know you like your 16-85 more than you liked your 18-135, but I have no idea why. You provide nothing. Given my starting position that there is a 70% chance i won't agree with your opinion, a little bit of "why" would be nice and preferable to your usual "pronouncement from the throne."

Saying one lens is better, you really have to ask "better at what?" There is simply is no lens that's better at everything. And picture is worth a thousand words.

Last edited by normhead; 08-07-2018 at 08:22 AM.
08-07-2018, 08:52 AM   #27
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QuoteOriginally posted by normhead Quote
I swear, when you see any mention of the 18-135 in any context, you must turn red and start spitting.

When i tested the the ways i have to take a 35mm image, some people preferred the images of the FAJ 18-35, or the kit lenses over the DA 35, Tamron 17-50 or SMC 35 3.5. Not a majority. I always approach these subjects as if the OP is capable of selecting any one of the lenses mentioned.

Comments on your opinion of the 18-135 are pretty much irrelevant. There is absolutely nothing to suggest that more than 30% will share your opinion, in fact the odds are against it. I say that because I've done the test images, Your constant negativity, and declaring that you sold a lens is definitely negativity and away to try and influence the OPs decision.

ANd I use the 18-135 as my favourite example of a lens trashed by test sites forum members etc. that is a lens that many really love. That's it. I'm not advocating anyone buy it. I'm advocating that people look at it. "If this is what you are looking for you might like this." The fact that it sets you off every time I mention it in that context is unfortunate. You it be easier for you if I mentioned the kit lens instead? Why?, it's just an example, that happens to be a lens a lot of people like.

My point is, dig deeper than the test charts. Look at some images, Sorry that's something you can't let pass. My other point would be, don't depend on opinions to make your decision. Look at some charts look at some images, look at what the lens does others don't do and decide what you need. Simply stated if 99% of the opinions on the forum don't like your favourite lens, it's still the best lens for you. Don't listen to them.

In your case, because all you ever state is a personal opinion, that's a problem. I know you like your 16-85 more than you liked your 18-135, but I have no idea why. You provide nothing. Given my starting position that there is a 70% chance i won't agree with your opinion, a little bit of "why" would be nice and preferable to your usual "pronouncement from the throne."

Saying one lens is better, you really have to ask "better at what?" There is simply is no lens that's better at everything. And picture is worth a thousand words.
Norm,there are several things in the world today that make me "turn red and start spitting" but the discussion of the relative merits of camera equipment isn't anywhere close to being one of them.That's an utterly laughable statement and goes to show,once again,that you're incapable of carrying out a reasoned discussion without losing it totally.

There's a danger of this exchange degenerating further and we both have previous with the mods on that score so I'm going to take no further part in this thread.

Last edited by timb64; 08-07-2018 at 09:19 AM. Reason: Grammar!
08-07-2018, 09:03 AM   #28
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QuoteOriginally posted by timb64 Quote
There's a danger of this exchange degenerating further and we both have previous with the mods on that score so I'm going to take no further part in this thread.
Well there you go, you can have the last word. I've made my points.
08-07-2018, 01:25 PM - 1 Like   #29
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My 16-50 has better center sharpness than my 16-85. However the 16-85 has better borders. There are times when f2.8 is definitely handy. I had a copy of the Sigma 17-50 but I preferred the color rendering of the 16-50. I primarily use the16-85 now. My 16-50 took a fall so it is not in the best shape. If I had to pick one I would get the 16-85. Unless you really need the constant f2.8 apeture the 16-85 is the way to go. Used 16-50's are going for cheaper than the 16-85 though. I did a comparison between the 16-50, 16-85, 18-135, and 28-105. The clear winner for me was the DFA28-105, that little lens just blows me away. Next was the 16-50, 16-85, and the 18-135. In the real world, stopped down, all these lens will produce excellent shots. The 16-50 and 16-85 were about tied. However for a one in all walkaround lens the 18-135 can not be beat. I typically will take my K3, the 16-85, 55-300, and sometimes the 10-17. With those I am covered for about anything and the weight does not break my back.
08-07-2018, 02:21 PM   #30
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QuoteOriginally posted by Scorpio71GR Quote
My 16-50 has better center sharpness than my 16-85. However the 16-85 has better borders. There are times when f2.8 is definitely handy. I had a copy of the Sigma 17-50 but I preferred the color rendering of the 16-50. I primarily use the16-85 now. My 16-50 took a fall so it is not in the best shape. If I had to pick one I would get the 16-85. Unless you really need the constant f2.8 apeture the 16-85 is the way to go. Used 16-50's are going for cheaper than the 16-85 though. I did a comparison between the 16-50, 16-85, 18-135, and 28-105. The clear winner for me was the DFA28-105, that little lens just blows me away. Next was the 16-50, 16-85, and the 18-135. In the real world, stopped down, all these lens will produce excellent shots. The 16-50 and 16-85 were about tied. However for a one in all walkaround lens the 18-135 can not be beat. I typically will take my K3, the 16-85, 55-300, and sometimes the 10-17. With those I am covered for about anything and the weight does not break my back.
Now that has always been the weird thing about the 16-50 to me. For me, it would be a landscape lens, I prefer 70mm for portraits. SO what were they thinking with those soft borders? To me it's one of those mysteries that helps define the random nature of the universe, there are all these good edge to edge 16-50 type lenses, and then there's this odd lens out, super sharp centre, soft edges, just over there in the corner all by itself. Was it actually designed for a purpose?? And what was the purpose?
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