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06-10-2011, 06:51 AM   #31
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QuoteOriginally posted by Blue Quote
Yeah I am aware of that, but what you are overlooking is that the aperture mechanism was completely redesigned with rounded blades. It also has the SP on the front element as well as the weather seals and a metal barrel. IT is also ever so small and lighter than the already small earlier version. The only downside is it lacks an aperture ring.
I suppose one could also cite the lack of a clamp on the 100WR as another difference between it and the older DFA100. However, the 100WR has a much nicer feel to the focus ring than the previous DFA100 version has, with or without the clamp engaged. But as Blue said, the only real downside to the 100WR is the lack of an aperture ring, assuming that is something you would want/need.

06-10-2011, 09:55 AM   #32
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QuoteOriginally posted by Blue Quote
Yeah I am aware of that, but what you are overlooking is that the aperture mechanism was completely redesigned with rounded blades. It also has the SP on the front element as well as the weather seals and a metal barrel. IT is also ever so small and lighter than the already small earlier version. The only downside is it lacks an aperture ring.

None of which is likely to have much effect on the MTF measurements I referenced, eh?

I do not suggest the Pentax does not have positive attributes. For my use, though, spending more for less optical acuity is not an attractive opportunity. For your use, things may be different.
06-10-2011, 09:58 AM   #33
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QuoteOriginally posted by civiletti Quote
None of which is likely to have much effect on the MTF measurements I referenced, eh?

I do not suggest the Pentax does not have positive attributes. For my use, though, spending more for less optical acuity is not an attractive opportunity. For your use, things may be different.
No, but it will effect the bokeh and the K-5 does in fact effect the mtf and as I said, they never tested the WR on the K10d nor the tam 90 on the K-5 yet. It is a lot like comparisons of the D FA to the FA and F 100mm macro when it came out. The other thing to keep in mind is that PZ tests lenses at infinity focus.

Last edited by Blue; 06-10-2011 at 10:35 AM.
06-10-2011, 10:35 AM   #34
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QuoteOriginally posted by civiletti Quote
None of which is likely to have much effect on the MTF measurements
Then again, buying a lens solely based on MTF measurements is probably not a great idea. It's similar to buying a car based solely on the horsepower output of the engine. There are many other things to consider besides the MTF number, especially since both lenses offer a ton of resolution and it's not likely that either one is going to let you down in that respect. So if that is of primary concern to you, and the other features of the 100WR aren't important to you, then I would certainly suggest you buy the Tamron 90. As I said in a previous post, you just can't go wrong with either lens IMO.

06-10-2011, 01:31 PM   #35
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QuoteOriginally posted by civiletti Quote
The WR version is the same optical design as its predecessor. The Tamron would yield better numbers on the k-5, to the same extent the Pentax would.
Same optical design does not guarantee same performance in MTF tests, particularly when the tests use different cameras. Nor does same optical design even guarantee identical performance by lens. MTF tests of several M 50/1.4 and A 50/1.4 lens show the A 50/1.4 scoring higher, despite have the same optical design of the M 50/1.4.

QuoteOriginally posted by stanic Quote
according to lenstip, the DA 100/2,8 WR is the same (or even better in some areas like light fall-off) than Canon 100/2,8L
Popular Photography chose the Canon as their "best in class" (I assume this means best 100mm macro). Yet the Pentax scored better on the "SQF" tests: "[With the Pentax DA 100 macro], SQF results held on to an Excellent rating all the way to 16x20óbetter than the Canon 100mm f/2.8 IS, which only held this rating to 11x14."
06-10-2011, 04:00 PM   #36
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QuoteOriginally posted by dgaies Quote
Then again, buying a lens solely based on MTF measurements is probably not a great idea. It's similar to buying a car based solely on the horsepower output of the engine. There are many other things to consider besides the MTF number, especially since both lenses offer a ton of resolution and it's not likely that either one is going to let you down in that respect. So if that is of primary concern to you, and the other features of the 100WR aren't important to you, then I would certainly suggest you buy the Tamron 90. As I said in a previous post, you just can't go wrong with either lens IMO.
As I wrote, your priorities may differ from mine, but I buy lenses based on image quality and price, as long as a lens can be expected to function reliably. The Tamron 90mm has been around a long time and has a decent reputation for reliablilty.
06-10-2011, 04:05 PM   #37
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QuoteOriginally posted by Blue Quote
No, but it will effect the bokeh and the K-5 does in fact effect the mtf and as I said, they never tested the WR on the K10d nor the tam 90 on the K-5 yet. It is a lot like comparisons of the D FA to the FA and F 100mm macro when it came out. The other thing to keep in mind is that PZ tests lenses at infinity focus.
You are correct about PZ's test focal distance, and there may be some differences in close-focus image measurements. Modern Photography used to do close-up resolution and contrast tests, but I don't know who does these days. Informal test are usually not worth much as small inconsistencies can effect results in a big way. I imagine many of those inconsistencies would be magnified at close focal distance.
06-10-2011, 04:18 PM   #38
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QuoteOriginally posted by northcoastgreg Quote
Same optical design does not guarantee same performance in MTF tests, particularly when the tests use different cameras. Nor does same optical design even guarantee identical performance by lens. MTF tests of several M 50/1.4 and A 50/1.4 lens show the A 50/1.4 scoring higher, despite have the same optical design of the M 50/1.4.



Popular Photography chose the Canon as their "best in class" (I assume this means best 100mm macro). Yet the Pentax scored better on the "SQF" tests: "[With the Pentax DA 100 macro], SQF results held on to an Excellent rating all the way to 16x20óbetter than the Canon 100mm f/2.8 IS, which only held this rating to 11x14."

Pentax lens guru Yoshihiko has claimed that the M50/1.4 and A50/1.4 do not have identical optical design. As to camera used, lenses usually change consistently. If you look at PZ's retesting on the k-5 of lenses that were previously tested on the k-10, you will find mostly consistent results. I calculated the average difference in MTF numbers to be ~1.13 greater for the k-5.

As to Pop Photo's lens preference, that's their choice and I have never put much faith in their reviews. I the old days, Modern's testing seemed more complete, useful, and consistent with my own experience. Today, I think PZ, photodo, and some others are better.

06-10-2011, 07:05 PM - 1 Like   #39
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QuoteOriginally posted by dgaies Quote
Well, let's keep things in perspective. The OP of that thread may or may not have an issue with his 100WR as it's not clear from reading the thread whether or not he actually has an issue or not.
Clearly the OP does not share your opinion as he writes... I guess this thing should probably be sent in for repair or replacement.

Hands down the Tamron is better value. Better price with a better warranty. I don't know why people feel the need to defend and support everything Pentax makes. I cannot comprehend blind loyalty.
06-10-2011, 07:36 PM   #40
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QuoteOriginally posted by JHD Quote
Clearly the OP does not share your opinion as he writes... I guess this thing should probably be sent in for repair or replacement.

Hands down the Tamron is better value. Better price with a better warranty. I don't know why people feel the need to defend and support everything Pentax makes. I cannot comprehend blind loyalty.
The OP is sending it in because it's under warranty. I would send it in as well if I had doubts and it was under warranty. Besides, I never said the OP didn't have an issue, I merely said it was unclear whether he had an issue (even the OP in his initial post stated he was unsure if he had an issue). You accusation that I blindly defending everything Pentax out of a sense of blind loyalty makes leads me to believe you don't actually read what I post. If you did, you might have read this direct quote that I made earlier in the thread: "That said, I agree the Tamron is the better value at about a third to half the money." (post #13)
06-10-2011, 08:07 PM   #41
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QuoteOriginally posted by JHD Quote
Clearly the OP does not share your opinion as he writes... I guess this thing should probably be sent in for repair or replacement.

Hands down the Tamron is better value. Better price with a better warranty. I don't know why people feel the need to defend and support everything Pentax makes. I cannot comprehend blind loyalty.
#1: Wasn't that a used lens in that thread?

#2: I actually use a Sigma 105 EG DG macro and have 2 of the original Tamron 90mm lenses (52B and 52BB). I felt the Sigma was better than the D FA 100mm but I am not so sure about the WR. I hope to soon find out. I originally got the Sigma to replace my Vivitar Series 1 105mm Macro that had died and the repair was going to cost half the price of the new Sigma at the time.
06-10-2011, 08:19 PM - 1 Like   #42
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They're 100ish macros for goodness sake!

They focus slowly because of the internal travel, they have flat filed curvature because of their intended use at large # apertures, and they are all pretty much equally, blazingly, painfully sharp as a result.

They all have superb reps for IQ and I doubt anyone posting here can tell the difference in a real life shot. Macros almost defy pixel peeping because of their near-standard, magnify, magnify, magnify, and magnify some more design. Other than fast 50's, they're as close as one comes to clones in lens design.

The main differences:

10-15 mm (not much in the scheme of things)
a longer, better warranty
cost

Other than that, you pay more for the one that lets you photograph mushrooms in the rain. How many times you do that will determine the value to you and you alone.
06-10-2011, 08:28 PM   #43
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QuoteOriginally posted by Aristophanes Quote
They're 100ish macros for goodness sake!

They focus slowly because of the internal travel, they have flat filed curvature because of their intended use at large # apertures, and they are all pretty much equally, blazingly, painfully sharp as a result.

They all have superb reps for IQ and I doubt anyone posting here can tell the difference in a real life shot. Macros almost defy pixel peeping because of their near-standard, magnify, magnify, magnify, and magnify some more design. Other than fast 50's, they're as close as one comes to clones in lens design.

The main differences:

10-15 mm (not much in the scheme of things)
a longer, better warranty
cost

Other than that, you pay more for the one that lets you photograph mushrooms in the rain. How many times you do that will determine the value to you and you alone.

#1 That 15mm is equivalent to a DA 15mm Ltd.

#2 I am in the process of getting one for work on a spring fed river. We have temperatures here in the upper 90s with > 90% RH on top of that. It is more about shooting aquatic weeds and insects (as well as having a tele) on the river and in cypress swamps.

#3 Whether or not I keep or sell the Sigma will remain to be seen. However, I like using the Sigma on my MZ-3 and I suspect the D FA WR will sukk on the MZ-3.

sarcasm

Edit: In all seriousness, the D FA WR is incredibly light and small plus its made out of metal.

Last edited by Blue; 06-10-2011 at 08:46 PM.
06-11-2011, 08:55 AM   #44
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I had the same choice, and went for the Tamron for the following reasons:

I found a Canon website where it was voted the best lens under £500 (or may have been under $500). And it also came high in the vote for best lens at any price (possibly even in the top 10, but can't remember).

It is cheaper than the Pentax.

It has a focus limiter.

I have a K-r (no longer have my K20D), so the weather resistance isn't much of a benefit - for me.
06-12-2011, 12:05 PM   #45
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QuoteOriginally posted by Blue Quote
#1: Wasn't that a used lens in that thread?

#2: I actually use a Sigma 105 EG DG macro and have 2 of the original Tamron 90mm lenses (52B and 52BB). I felt the Sigma was better than the D FA 100mm but I am not so sure about the WR. I hope to soon find out. I originally got the Sigma to replace my Vivitar Series 1 105mm Macro that had died and the repair was going to cost half the price of the new Sigma at the time.
I am leaning toward the Sigma, but the Pentax WR is out of the picture because I can't use it with my older film bodies.
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