20-40 ltd vs 21 ltd

yorik · 01-31-2016, 06:08 PM

Question: how does the 20-40 compare to the 21?

I'm thinking of purchasing the 20-40 as a wr 20mm f/2.8 ltd with bonus focal lengths, hence the question.

normhead · 01-31-2016, 06:27 PM

For me? It's bigger and heavier. Those are the salient points.

Outis · 01-31-2016, 06:27 PM

Oooh, I'm so glad you asked this question, because I've been wondering the exact same thing.

wstruth · 01-31-2016, 06:33 PM

They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2.

Driline · 01-31-2016, 06:39 PM

Originally posted by wstruth

They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2.

Wow that's really bad

**UncleVanya** · 01-31-2016, 06:57 PM

In multiple threads I have seen other people mention that the DA 21 was better than the DA 20-40 @ 20mm. I haven't seen any definitive test shots but the consensus seems to exist. But most have indicated modest differences not major ones.

aleonx3 · 01-31-2016, 07:10 PM

Originally posted by wstruth

They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2.

My copy of 20-40 is quite sharp wide-open at all focal lengths within that range....my be I am lucky...

excanonfd · 01-31-2016, 07:11 PM

20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me.

normhead · 01-31-2016, 07:16 PM

What's special about the 20-40 is 2.8 to f4. Couple that with a 15, 50 1.8 , 77, 100 and 200 and it really could be part of a nice set up. I tend to work in 2/3s of a stop, and 2.8 is two thirds better than the 3.5 starting point of many Pentax WAs zooms.

jeffryscott · 01-31-2016, 07:19 PM

Originally posted by excanonfd

20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me.

It is a strange focal length, but the WR vs that of the primes is intriguing. I have the 15, 21 and 77 Limiteds, and the honorary 100 WR, but have seriously considered the 20-40 for the WR (to replace my 16-50). Not sure I am there yet, but the flare resistance over the 16-50 is a very strong consideration.

longbow · 01-31-2016, 07:20 PM

Originally posted by wstruth

They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2.

Wow then I must have a very good copy, because I have no problem using my 20-40 sharp at f5-5.6 the whole focal range. The 21 is a great lens, but really are 2 different tools, at least was in my camera bag. My daughter now has the 21, because it fit her use better than mine.

Sandy Hancock · 01-31-2016, 07:24 PM

Like Bill, my DA20-40 limited was good in the centre wide open at the wide end, but fell away dramatically even half way to the edges - it took f/5.6 or smaller to be usable. The problem persisted until at least 30mm. I returned it.

20mm f/4.0

My DA21 limited is tiny, very flare resistant, and gives awesome starbursts if needed. It is quite usable wide open:

K52S7595

yorik · 01-31-2016, 07:32 PM

Originally posted by normhead

For me? It's bigger and heavier. Those are the salient points.

The size and weight don't bother me - it's about the same as the FA 77 and lighter than the FA 31...

Originally posted by excanonfd

20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me.

It covers my most commonly used range of focal lengths, with wr and no need to swap lenses. Together with the FA 77 I would rarely need anything else... if the optical quality is there, hence my curiosity.

I'm not baffled.

Originally posted by normhead

What's special about the 20-40 is 2.8 to f4. Couple that with a 15, 50 1.8 , 77, 100 and 200 and it really could be part of a nice set up. I tend to work in 2/3s of a stop, and 2.8 is two thirds better than the 3.5 starting point of many Pentax WAs zooms.

The 20-40 and the 100 wr macro would be a nice wr combo for me.

normhead · 01-31-2016, 07:41 PM

The biggest problem for me is my 21 and 40XS are tried and true keepers. By adding a 31 and my 50, I don't really need a zoom in that range. You don't have that issue. It's just I haven't heard that the 20-40 is going to give me what my 21 and 40 XS give me. I have the 18-135 for walking around and it's really strong from 20 to 40, and the 21 , 40 and 50 allow me to go from "very strong" to stellar. I'm thinking the 20-40 is another "very strong" lens without the reach of the 16-85, 17-70 or 18-135.

yorik · 01-31-2016, 07:41 PM

I had seen a lot of complaints early on about softness, especially on the edges of the 20-40, but it seems that lately people have been more inclined to praise it, at least in PF. Was there an early QC problem that has been resolved...?

Adam?

---------- Post added 01-31-16 at 06:43 PM ----------

Originally posted by normhead

The biggest problem for me is my 21 and 40XS are tried and true keepers. By adding a 31 and my 50, I don't really need a zoom in that range. You don't have that issue. It's just I haven't heard that the 20-40 is going to give me what my 21 and 40 XS give me. I have the 18-135 for walking around and it's really strong from 20 to 40, and the 21 , 40 and 50 allow me to go from "very strong" to stellar. I'm thinking the 20-40 is another "very strong" lens without the reach of the 16-85, 17-70 or 18-135.

I have also been thinking of the 18-135 (or 16-85), but I prefer the form factor of the 20-40 and don't really *need* the additional range... Happily I don't have to decide today.

01-31-2016, 06:08 PM	#1
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991	20-40 ltd vs 21 ltd Question: how does the 20-40 compare to the 21? I'm thinking of purchasing the 20-40 as a wr 20mm f/2.8 ltd with bonus focal lengths, hence the question.

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01-31-2016, 06:27 PM	#2
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	For me? It's bigger and heavier. Those are the salient points.

01-31-2016, 06:27 PM	#3
Outis Veteran Member Join Date: Apr 2014 Location: Cambridge, MA Posts: 935	Oooh, I'm so glad you asked this question, because I've been wondering the exact same thing.

01-31-2016, 06:33 PM	#4
wstruth Veteran Member Join Date: Nov 2010 Location: at my kitchen table Photos: Gallery \| Albums Posts: 1,294	They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2.

01-31-2016, 06:39 PM	#5
Driline Pentaxian Join Date: Dec 2012 Location: IOWA Where the Tall Corn Grows Photos: Gallery Posts: 3,705	Originally posted by wstruth They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2. Wow that's really bad

01-31-2016, 06:57 PM	#6
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,459	In multiple threads I have seen other people mention that the DA 21 was better than the DA 20-40 @ 20mm. I haven't seen any definitive test shots but the consensus seems to exist. But most have indicated modest differences not major ones.

01-31-2016, 07:10 PM	#7
aleonx3 Veteran Member Join Date: Jul 2007 Location: Brampton, Ontario Photos: Gallery \| Albums Posts: 3,996	Originally posted by wstruth They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2. My copy of 20-40 is quite sharp wide-open at all focal lengths within that range....my be I am lucky...

01-31-2016, 07:11 PM	#8
excanonfd Veteran Member Join Date: Jan 2010 Location: Vancouver, BC Posts: 1,421	20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me.

01-31-2016, 07:16 PM	#9
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	What's special about the 20-40 is 2.8 to f4. Couple that with a 15, 50 1.8 , 77, 100 and 200 and it really could be part of a nice set up. I tend to work in 2/3s of a stop, and 2.8 is two thirds better than the 3.5 starting point of many Pentax WAs zooms.

01-31-2016, 07:19 PM	#10
jeffryscott Senior Member Join Date: Jan 2012 Posts: 253	Originally posted by excanonfd 20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me. It is a strange focal length, but the WR vs that of the primes is intriguing. I have the 15, 21 and 77 Limiteds, and the honorary 100 WR, but have seriously considered the 20-40 for the WR (to replace my 16-50). Not sure I am there yet, but the flare resistance over the 16-50 is a very strong consideration.

01-31-2016, 07:20 PM	#11
longbow Veteran Member Join Date: Jan 2015 Location: NW Oregon Posts: 905	Originally posted by wstruth They're close at f/8 but my 20-40 is not usably sharp until f/8, the 21 is usable at f/3,2. Wow then I must have a very good copy, because I have no problem using my 20-40 sharp at f5-5.6 the whole focal range. The 21 is a great lens, but really are 2 different tools, at least was in my camera bag. My daughter now has the 21, because it fit her use better than mine.

01-31-2016, 07:24 PM	#12
Sandy Hancock Moderator Site Supporter Join Date: Feb 2012 Location: Adelaide Hills, South Australia Photos: Gallery \| Albums Posts: 11,275	Like Bill, my DA20-40 limited was good in the centre wide open at the wide end, but fell away dramatically even half way to the edges - it took f/5.6 or smaller to be usable. The problem persisted until at least 30mm. I returned it. 20mm f/4.0 My DA21 limited is tiny, very flare resistant, and gives awesome starbursts if needed. It is quite usable wide open: K52S7595

01-31-2016, 07:32 PM	#13
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	Originally posted by normhead For me? It's bigger and heavier. Those are the salient points. The size and weight don't bother me - it's about the same as the FA 77 and lighter than the FA 31... Originally posted by excanonfd 20-40mm, what kind of zoom range is that? It's not quite wide and it's certainly not long. The legacy prime lenses that exists in that focal range are widely available and faster, by the looks of it with superior IQ. Pentax has a long history of putting out odd focal length lenses but the 20-40 baffles me. It covers my most commonly used range of focal lengths, with wr and no need to swap lenses. Together with the FA 77 I would rarely need anything else... if the optical quality is there, hence my curiosity. I'm not baffled. Originally posted by normhead What's special about the 20-40 is 2.8 to f4. Couple that with a 15, 50 1.8 , 77, 100 and 200 and it really could be part of a nice set up. I tend to work in 2/3s of a stop, and 2.8 is two thirds better than the 3.5 starting point of many Pentax WAs zooms. The 20-40 and the 100 wr macro would be a nice wr combo for me.

01-31-2016, 07:41 PM	#14
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	The biggest problem for me is my 21 and 40XS are tried and true keepers. By adding a 31 and my 50, I don't really need a zoom in that range. You don't have that issue. It's just I haven't heard that the 20-40 is going to give me what my 21 and 40 XS give me. I have the 18-135 for walking around and it's really strong from 20 to 40, and the 21 , 40 and 50 allow me to go from "very strong" to stellar. I'm thinking the 20-40 is another "very strong" lens without the reach of the 16-85, 17-70 or 18-135.

01-31-2016, 07:41 PM	#15
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	I had seen a lot of complaints early on about softness, especially on the edges of the 20-40, but it seems that lately people have been more inclined to praise it, at least in PF. Was there an early QC problem that has been resolved...? Adam? ---------- Post added 01-31-16 at 06:43 PM ---------- Originally posted by normhead The biggest problem for me is my 21 and 40XS are tried and true keepers. By adding a 31 and my 50, I don't really need a zoom in that range. You don't have that issue. It's just I haven't heard that the 20-40 is going to give me what my 21 and 40 XS give me. I have the 18-135 for walking around and it's really strong from 20 to 40, and the 21 , 40 and 50 allow me to go from "very strong" to stellar. I'm thinking the 20-40 is another "very strong" lens without the reach of the 16-85, 17-70 or 18-135. I have also been thinking of the 18-135 (or 16-85), but I prefer the form factor of the 20-40 and don't really need the additional range... Happily I don't have to decide today.