Forgot Password
Pentax Camera Forums Home
 

View Poll Results: Best Limited Lens in terms of Price-For-Performance?
SMC Pentax-FA 31mm F1.8 AL Limited 2818.92%
SMC Pentax-FA 43mm F1.9 Limited 3120.95%
SMC Pentax-FA 77mm F1.8 Limited 4429.73%
SMC Pentax-DA 21mm F3.2 Limited 138.78%
SMC Pentax-DA 40mm F2.8 Limited 5235.14%
SMC Pentax-DA 70mm F2.4 Limited 4429.73%
Multiple Choice Poll. Voters: 148. You may not vote on this poll

Reply
Show Printable Version Search this Thread
03-12-2008, 09:10 PM   #31
Pentaxian
Jimbo's Avatar

Join Date: Dec 2007
Location: Maple Ridge BC Canada
Photos: Gallery
Posts: 11,361
Great Picture twinda1

03-13-2008, 03:39 PM   #32
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
i agree, that's a great shot twinda! Any other photos that would show off the performance of the 31mm more?
03-13-2008, 04:42 PM   #33
Veteran Member
selar's Avatar

Join Date: Jul 2007
Location: Sydney, Australia
Photos: Gallery | Albums
Posts: 2,035
DA70 Limited

DA70 LTD at f2.4


03-13-2008, 06:04 PM   #34
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
Why oh why do I bring up the PhotoZone reviews just now??

Pentax SMC-DA 21mm f/3.2 AL Limited Review / Test Report
Pentax SMC-FA 31mm f/1.8 AL Limited Review / Test Report
Pentax SMC-DA 40mm f/2.8 Limited Review / Test Report
Pentax SMC-FA 43mm f/1.9 Limited Review / Test Report
Pentax SMC-DA 70mm f/2.4 Limited - Review / Test Report
Pentax SMC-FA 77mm f/1.8 Limited Review / Test Report

Anyway... just some quickstats:

3 limiteds got a "Highly Recommended" stamp from PZ: FA31,DA40 & DA70
3 limiteds have a 4-star "Price/Performance" rating from PZ: DA21,DA40 & DA70

In terms of optical quality, PZ has it like this:
FA31 - 4.5 stars
DA40 & DA70 - 4 stars
FA34 & FA77 - 3.5 stars
DA21 - 3 stars

In terms of mechanical quality, PZ has all limiteds on equal footing at 4.5 stars.

interesting...

03-16-2008, 07:20 AM   #35
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
Does anyone think that having the DA15 (when it comes out) and the DA21 would be redundant?
03-16-2008, 07:38 AM   #36
Veteran Member
Gooshin's Avatar

Join Date: Sep 2007
Location: Toronto, the one in Canada.
Posts: 5,611
QuoteOriginally posted by lastdodobird Quote
Does anyone think that having the DA15 (when it comes out) and the DA21 would be redundant?
the difference between the FOV of 15 and 21mm is very great, so no... iit would not be redundant.
03-16-2008, 10:37 AM   #37
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,576
FA77 ltd, front yard, not much light, a few minutes after purchase

http://nostatic.com/photos/twistLily1024.jpg
03-16-2008, 10:42 PM   #38
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
QuoteOriginally posted by Gooshin Quote
the difference between the FOV of 15 and 21mm is very great, so no... iit would not be redundant.
Really?

Am I correct in saying that as you go longer, the difference in FOV becomes more negligible?

I mean... is it correct to say that the difference in 15mm and 21mm is greater than the difference between, say, 75mm and 81mm?

Are there any general rules to remember that could be useful regarding FL and FOV?

03-16-2008, 11:23 PM   #39
Veteran Member
Kguru's Avatar

Join Date: Jun 2007
Location: Perth - WestAust
Posts: 602
QuoteOriginally posted by lastdodobird Quote
I mean... is it correct to say that the difference in 15mm and 21mm is greater than the difference between, say, 75mm and 81mm?
Yes that is correct.
Easier to think in terms of percentage change. 21 over 15 is 1.4 ie. 40% change; whereas 81 over 75 is only 8% change.

Back to the poll, if I leave out the DA40 (due to its exceptionally low price) the 77 and 70 are currently joint 1st. That's quite remarkable.
03-17-2008, 12:56 AM   #40
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
I'd choose the FA43 & FA77 Limiteds.

FOV increases tangentially. In short, this means that as focal length progressively gets shorter, the field of view increases dramatically. So comparing say a DA 16-45mm versus the Sigma 17-70mm wide angle zooms for example, that 1 mm difference works out to about 10 degrees at the wide end.

Specifically the formula is:

2 x tan-1( l / (2 x f) )

where ' l ' is the length of the frame in the direction that you want the reading and ' f ' is the focal length of the lens.
03-17-2008, 01:12 AM   #41
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
QuoteOriginally posted by Kguru Quote
Yes that is correct.
Easier to think in terms of percentage change. 21 over 15 is 1.4 ie. 40% change; whereas 81 over 75 is only 8% change.

Back to the poll, if I leave out the DA40 (due to its exceptionally low price) the 77 and 70 are currently joint 1st. That's quite remarkable.
oooh...that's a useful piece of information there.

I put it into a spreadsheet laying out all the limiteds (including the DA15, but excluding the DA35-Macro)

So in terms of percentage-chage, this is what it looks like:


so I dunno... putting it this way, it sure changes my POV about the 15mm and 21mm being redundant... Having both the 31mm & 43mm is even more redundant in terms of %-change compared to the 15mm & 21mm.

QuoteOriginally posted by creampuff Quote
I'd choose the FA43 & FA77 Limiteds.

FOV increases tangentially. In short, this means that as focal length progressively gets shorter, the field of view increases dramatically. So comparing say a DA 16-45mm versus the Sigma 17-70mm wide angle zooms for example, that 1 mm difference works out to about 10 degrees at the wide end.

Specifically the formula is:

2 x tan-1( l / (2 x f) )

where ' l ' is the length of the frame in the direction that you want the reading and ' f ' is the focal length of the lens.
wow. that looks interesting, but is there any way to simplify it a bit? Do you have an example where you can put values to 'l' and 'f'?

Thanks a lot! This is very informative.
03-17-2008, 04:43 AM   #42
Veteran Member
Kguru's Avatar

Join Date: Jun 2007
Location: Perth - WestAust
Posts: 602
QuoteOriginally posted by lastdodobird Quote
so I dunno... putting it this way, it sure changes my POV about the 15mm and 21mm being redundant... Having both the 31mm & 43mm is even more redundant in terms of %-change compared to the 15mm & 21mm.
A common approach is spacing FLs by a factor of about 1.5x

Someone has been more precise and suggested 1.4x for wide and 1.8x for tele. You see, the 31/43/77 falls exactly into this mould.

But I hear you argue 31 is not wide to use 1.4x? Well ... it was wide back in film days that the FAs were intended for.

Now with dSLRs 31 is normal, the next tele step up is ... guess what, 31x1.8= 55. Wow wow isn't that coming out soon?
03-17-2008, 06:33 PM   #43
Senior Member




Join Date: Oct 2007
Posts: 128
Original Poster
QuoteOriginally posted by Kguru Quote
A common approach is spacing FLs by a factor of about 1.5x

Someone has been more precise and suggested 1.4x for wide and 1.8x for tele. You see, the 31/43/77 falls exactly into this mould.

But I hear you argue 31 is not wide to use 1.4x? Well ... it was wide back in film days that the FAs were intended for.

Now with dSLRs 31 is normal, the next tele step up is ... guess what, 31x1.8= 55. Wow wow isn't that coming out soon?
Very interesting. I've learned quite a bit of info over the last several posts.

So considering that I already have the DA40...

40 * 1.8 = 72 (I'm thinking either the DA70 or FA77 will do the trick for this)
40 / 1.4 = 29 (FA31?)
40 / 1.8 = 22 (DA21?)
40 / 1.5 = 27 (??)

LOL =p
03-17-2008, 06:53 PM   #44
Veteran Member




Join Date: Jan 2008
Location: Brooklyn
Photos: Gallery
Posts: 316
I've got the 21, 31, 43, and 77.

My vote for price/performance went to the 43 and 70 (my guess is that the 70 is really close to the 77).

My favorite lens is the 77, but the 31 never really leaves the camera.
03-17-2008, 07:32 PM   #45
Veteran Member
nostatic's Avatar

Join Date: Feb 2008
Location: socal
Photos: Gallery
Posts: 1,576
QuoteOriginally posted by a a i b Quote

My favorite lens is the 77, but the 31 never really leaves the camera.
Well, then does price really matter?

I have a 31mm showing up Wed. The 77mm is my favorite so far...but that is compared to a couple zooms. Thinking seriously about the 21, but I wish the mythical 15mm ltd would appear. I'd love to ditch the 16-45...
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
k-mount, limiteds, pentax lens, slr lens, terms
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quick question regarding going price for mint 35mm limited. Vertex Ninja Pentax SLR Lens Discussion 3 10-19-2009 08:31 PM
what is a reasonable price for a mint used FA31 Limited? nuaabill Pentax SLR Lens Discussion 3 08-12-2009 02:17 PM
Pentax DA 15mm Limited Price RonMexico Pentax SLR Lens Discussion 16 03-25-2009 03:03 PM
Macro lens infinity performance bc_the_path Pentax SLR Lens Discussion 3 08-15-2007 03:57 AM



All times are GMT -7. The time now is 03:32 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top