Why are DAs made with slower glass than FAs?

loganross · 03-05-2007, 01:24 PM

Hi,
I am trying to choose between FA and DA limiteds. I take many shots indoors so lens speed is important to me. I have come to rely heavily on my 50mm for this reason. But I am looking for a shorter and longer lens to enable "life" type portraits and candids, respectively.

Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)?

I understand that digitals have SR, but that doesn't help with moving subjects such as people. So why did Pentax choose to make the successors to the FAs slower?

If anyone can shed some insight I would appreciate it.

joele · 03-05-2007, 01:36 PM

The DAs you mentioned are all compact (pancake) models.. Being slower is just a trade-off of the compact design...

loganross · 03-05-2007, 01:42 PM

hmm, thats too bad for buyers who need the speed if they decide to no longer sell the FAs.

I think I would select the 70 over the 77 because the speed difference is minimal. I would select the 31 over the 21 because the speed difference is great and I have read some reviews that are disappointed in the 21's image quality. I would choose the 43 over the 40 solely due to speed and minimal price/size difference.

joele · 03-05-2007, 02:02 PM

31 and 21 have a very different focal length though, so hard to pick one over the other based on speed..

The FA35/2 is still in production and is a great lens IMO if you want speed and a decent size and price..

I also think the upcoming DA55 will be a faster lens too.. so there will still be fast 35 and 50ish

Last edited by joele; 03-05-2007 at 07:16 PM.

Adam · 03-05-2007, 02:03 PM

Remember to consider FF coverage, too! The FA 77 IMO is far superior to the DA 70, and I agree with you on the 31.

I've never used the FA 43, but I have the DA 40, and although it rarely use it, it's a great little piece, especially compared to the M 40.

loganross · 03-05-2007, 02:16 PM

joele,

I am looking to create a kit of wide, normal, and telephoto so that is why i was comparing the 21 and 31.

Mo,
do you mean "full frame" when you say "FF"? If so, I only have digital cams so I don't think that will be an issue.
Also why do you find the 77 superior to the 70 (other than FF)? I have seen many posts that show them to be virtually identical in IQ.

Adam · 03-05-2007, 03:27 PM

Yeah, I meant Full-Frame.

I suppose it's because the FA's corners aren't being used when mounted on a DSLR. The 77mm is also beased on the trusty optical design of the A* 85mm

BTW- thread moved to the lens section. Please remember to post in the correct category.

Adam
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roentarre · 03-05-2007, 06:43 PM

Before defection to pentax gear, the first ever glass I want to get is Fa77 ltd. I never regret getting this lens despite its hype and some crazy flowers including me.

Fa 77 ltd is quoted not as fast comparing to Da 70. I had a consideration to obtain Da 70 on the basis of faster AF as trying to do candids require faster AF speed rather than aperture ...

I would not mind having 3 Da ltd as reliable compact lenses to carry around in a small waist bag. It is really understanding for photographers who do not want to lug around lenses like doing some archeology expedition...

While I do not have any Da ltd primes, it is always at the back of my mind to acquire them soon or later. After all, they are specialty lenses aimed at a specific group of "easy" photographers.

I read a lot of reviews posted by Godfrey and some half hearted reviews from some commerical websites. Da 70 seemed to have wider view than true field of view of corresponding designated focal length (APC sensor speaking) and its aperture at f2.4 being more equivalent to the aperture of f2.8 with Fa 77 ltd.

I am not whining but I preferred Da 70 ltd for faster AF speed; otherwise they are both good anyway.

I seemed to have this feeling that Da ltd tend to produce less contrast overall from pbase shots .... Do not kill me over this; just a general gut feeling from browsing (Sailor has a Da 70; same as Volosong - they could add more comments for sure)

Few shots from my weekend shooting with Fa 77

Cheers

loganross · 03-05-2007, 08:35 PM

roentarre,

thank you for your reply. Excellent pictures. When I mean fast I am referring to aperture and not AF speed. I am concerned about low light photography.

roentarre · 03-06-2007, 01:53 AM

I am not too sure how well Da 70 does in low light as I hardly see any images shot in that kind of condition from that lens.

What I do know about Fa77 ltd is that it performs better in low, revealing vivid colour and texture in its own images even when viewfinder does not reveal such details.

However, the problem with Fa 77 in low light really really hunts with AF, A pain in the ass. I would usually just manual focus instead - much quicker

Fa 31 ltd is certainly a winner. Joel did a test of his Fa 35/2 against my fa 31 ltd. In a crude controlled test, the image sharpness in the centre to corner are roughly the same in bright or ambient lighting. However, Fa 31 ltd gives some sort of sparkle to protraits, more 3d feel in certain situations. It seems to do with certain subject distance to the camera, rendering that effect... This does not sound like science but it is certainly a feeling from my past 5 months use of this lens.

I am sure there will be more lenses coming out of pentax R&D department in the near future. I want to get primes with brighter and brighter apertures - this is an addiction not a necessity kind of thing

I am receiving my Fa 43 tomorrow - more lenses to play with

fast50 · 03-06-2007, 03:09 AM

Originally posted by loganross

Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)?

I don't know but I mentioned this to the distributor who didn't seem to get my point. The K10 isn't a small camera, so why put so much effort into making tiny tiny lenses? The FA Limiteds are all fantastic - no question - but the DA Limiteds seem to be favouring physical size over speed.

I would much rather have the extra stop or so for a bright viewfinder image and occasional wide-open shooting.

Given the mixed reviews the 21 has been getting, I think Pentax are losing focus (sorry) with the Limited concept.

RiceHigh · 03-06-2007, 07:09 AM

The truth is slower glass are easier to make and cheaper in manufacturing cost. Since Pentax are selling the DA Pancakes around the same prices as their old FA Limited, they can make more money, especially consider also that the DA pancakes are now made in Vietnam rather than in Japan where the FA Limited are made (so that Pentax can even have much more profit margin by further cutting the labour cost).

Originally posted by loganross

Hi,
I am trying to choose between FA and DA limiteds. I take many shots indoors so lens speed is important to me. I have come to rely heavily on my 50mm for this reason. But I am looking for a shorter and longer lens to enable "life" type portraits and candids, respectively.

Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)?

I understand that digitals have SR, but that doesn't help with moving subjects such as people. So why did Pentax choose to make the successors to the FAs slower?

If anyone can shed some insight I would appreciate it.

pentaxkat · 03-06-2007, 03:22 PM

Since all the recent digital bodies have SR then in some respects their 'speed' is 'equivalent' (because you can handhold at slower speeds), rather like 200mm lenses being 'equivalent' to 300mm lenses on film. Of course different max aperatures means different depth of field etc. so this isn't strictly true, but for a lot of uses I believe it is.

I think it boils down to people wanting the 'fastest' or the 'longest' they can have.

I like the limiteds for their small size, even though my DS doesn't have SR. Can always carry a fast 50 for low light. Have to say performance wide open of my 21mm limited is very impressive. Only thing I've noticed is a slight bit of vignetting wide open with a very white snow scene.

They are a good compromise IMHO and I wouldn't trade them for an FA limited (nor could I afford to).

loganross · 03-06-2007, 06:33 PM

pentaxkat,

The issue is that it is more important to have the faster lens to deal with the movement of the subject, thus SR does not serve as a substitute for faster lenses

RiceHigh · 03-06-2007, 06:45 PM

Originally posted by loganross

pentaxkat,

The issue is that it is more important to have the faster lens to deal with the movement of the subject, thus SR does not serve as a substitute for faster lenses

Yes, exactly.

It should be noted also that SR does NOT *always* work but fast lenses do, that is, SR only works *sometimes* and even it works, it does not give perfect images like a tripod does (and actually far less ideal than a monopod, too).

03-05-2007, 01:24 PM	#1
loganross Forum Member Join Date: Jan 2007 Location: SF Bay Area (CA) Posts: 86	Why are DAs made with slower glass than FAs? Hi, I am trying to choose between FA and DA limiteds. I take many shots indoors so lens speed is important to me. I have come to rely heavily on my 50mm for this reason. But I am looking for a shorter and longer lens to enable "life" type portraits and candids, respectively. Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)? I understand that digitals have SR, but that doesn't help with moving subjects such as people. So why did Pentax choose to make the successors to the FAs slower? If anyone can shed some insight I would appreciate it.

03-05-2007, 02:03 PM	#5
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Remember to consider FF coverage, too! The FA 77 IMO is far superior to the DA 70, and I agree with you on the 31. I've never used the FA 43, but I have the DA 40, and although it rarely use it, it's a great little piece, especially compared to the M 40. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-06-2007, 07:09 AM	#12
RiceHigh Veteran Member Join Date: Nov 2006 Location: Hong Kong Posts: 1,934	Simple.. The truth is slower glass are easier to make and cheaper in manufacturing cost. Since Pentax are selling the DA Pancakes around the same prices as their old FA Limited, they can make more money, especially consider also that the DA pancakes are now made in Vietnam rather than in Japan where the FA Limited are made (so that Pentax can even have much more profit margin by further cutting the labour cost). Originally posted by loganross Hi, I am trying to choose between FA and DA limiteds. I take many shots indoors so lens speed is important to me. I have come to rely heavily on my 50mm for this reason. But I am looking for a shorter and longer lens to enable "life" type portraits and candids, respectively. Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)? I understand that digitals have SR, but that doesn't help with moving subjects such as people. So why did Pentax choose to make the successors to the FAs slower? If anyone can shed some insight I would appreciate it.

03-06-2007, 03:22 PM	#13
pentaxkat Inactive Account Join Date: Jan 2007 Location: UK/Canada/wherever work takes me Posts: 95	But aren't the DA's equivalent? Since all the recent digital bodies have SR then in some respects their 'speed' is 'equivalent' (because you can handhold at slower speeds), rather like 200mm lenses being 'equivalent' to 300mm lenses on film. Of course different max aperatures means different depth of field etc. so this isn't strictly true, but for a lot of uses I believe it is. I think it boils down to people wanting the 'fastest' or the 'longest' they can have. I like the limiteds for their small size, even though my DS doesn't have SR. Can always carry a fast 50 for low light. Have to say performance wide open of my 21mm limited is very impressive. Only thing I've noticed is a slight bit of vignetting wide open with a very white snow scene. They are a good compromise IMHO and I wouldn't trade them for an FA limited (nor could I afford to).

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03-05-2007, 01:36 PM	#2
joele Veteran Member Join Date: Sep 2006 Location: Melbourne, Australia Photos: Gallery Posts: 1,308	The DAs you mentioned are all compact (pancake) models.. Being slower is just a trade-off of the compact design...

03-05-2007, 01:42 PM	#3
loganross Forum Member Join Date: Jan 2007 Location: SF Bay Area (CA) Posts: 86 Original Poster	hmm, thats too bad for buyers who need the speed if they decide to no longer sell the FAs. I think I would select the 70 over the 77 because the speed difference is minimal. I would select the 31 over the 21 because the speed difference is great and I have read some reviews that are disappointed in the 21's image quality. I would choose the 43 over the 40 solely due to speed and minimal price/size difference.

03-05-2007, 02:02 PM	#4
joele Veteran Member Join Date: Sep 2006 Location: Melbourne, Australia Photos: Gallery Posts: 1,308	31 and 21 have a very different focal length though, so hard to pick one over the other based on speed.. The FA35/2 is still in production and is a great lens IMO if you want speed and a decent size and price.. I also think the upcoming DA55 will be a faster lens too.. so there will still be fast 35 and 50ish Last edited by joele; 03-05-2007 at 07:16 PM.

03-05-2007, 02:16 PM	#6
loganross Forum Member Join Date: Jan 2007 Location: SF Bay Area (CA) Posts: 86 Original Poster	joele, I am looking to create a kit of wide, normal, and telephoto so that is why i was comparing the 21 and 31. Mo, do you mean "full frame" when you say "FF"? If so, I only have digital cams so I don't think that will be an issue. Also why do you find the 77 superior to the 70 (other than FF)? I have seen many posts that show them to be virtually identical in IQ.

03-05-2007, 03:27 PM	#7
Adam Administrator Site Webmaster Join Date: Sep 2006 Location: Arizona Photos: Gallery \| Albums Posts: 51,595	Yeah, I meant Full-Frame. I suppose it's because the FA's corners aren't being used when mounted on a DSLR. The 77mm is also beased on the trusty optical design of the A* 85mm BTW- thread moved to the lens section. Please remember to post in the correct category. Adam PentaxForums.com Webmaster (Site Usage Guide \| Site Help \| My Photography) PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

03-05-2007, 06:43 PM	#8
roentarre Veteran Member Join Date: Oct 2006 Location: Melbourne, Australia Posts: 11,783	Before defection to pentax gear, the first ever glass I want to get is Fa77 ltd. I never regret getting this lens despite its hype and some crazy flowers including me. Fa 77 ltd is quoted not as fast comparing to Da 70. I had a consideration to obtain Da 70 on the basis of faster AF as trying to do candids require faster AF speed rather than aperture ... I would not mind having 3 Da ltd as reliable compact lenses to carry around in a small waist bag. It is really understanding for photographers who do not want to lug around lenses like doing some archeology expedition... While I do not have any Da ltd primes, it is always at the back of my mind to acquire them soon or later. After all, they are specialty lenses aimed at a specific group of "easy" photographers. I read a lot of reviews posted by Godfrey and some half hearted reviews from some commerical websites. Da 70 seemed to have wider view than true field of view of corresponding designated focal length (APC sensor speaking) and its aperture at f2.4 being more equivalent to the aperture of f2.8 with Fa 77 ltd. I am not whining but I preferred Da 70 ltd for faster AF speed; otherwise they are both good anyway. I seemed to have this feeling that Da ltd tend to produce less contrast overall from pbase shots .... Do not kill me over this; just a general gut feeling from browsing (Sailor has a Da 70; same as Volosong - they could add more comments for sure) Few shots from my weekend shooting with Fa 77 Cheers

03-05-2007, 08:35 PM	#9
loganross Forum Member Join Date: Jan 2007 Location: SF Bay Area (CA) Posts: 86 Original Poster	roentarre, thank you for your reply. Excellent pictures. When I mean fast I am referring to aperture and not AF speed. I am concerned about low light photography.

03-06-2007, 01:53 AM	#10
roentarre Veteran Member Join Date: Oct 2006 Location: Melbourne, Australia Posts: 11,783	I am not too sure how well Da 70 does in low light as I hardly see any images shot in that kind of condition from that lens. What I do know about Fa77 ltd is that it performs better in low, revealing vivid colour and texture in its own images even when viewfinder does not reveal such details. However, the problem with Fa 77 in low light really really hunts with AF, A pain in the ass. I would usually just manual focus instead - much quicker Fa 31 ltd is certainly a winner. Joel did a test of his Fa 35/2 against my fa 31 ltd. In a crude controlled test, the image sharpness in the centre to corner are roughly the same in bright or ambient lighting. However, Fa 31 ltd gives some sort of sparkle to protraits, more 3d feel in certain situations. It seems to do with certain subject distance to the camera, rendering that effect... This does not sound like science but it is certainly a feeling from my past 5 months use of this lens. I am sure there will be more lenses coming out of pentax R&D department in the near future. I want to get primes with brighter and brighter apertures - this is an addiction not a necessity kind of thing I am receiving my Fa 43 tomorrow - more lenses to play with

03-06-2007, 03:09 AM	#11
fast50 Forum Member Join Date: Feb 2007 Posts: 86	Originally posted by loganross Why are DAs (21 3.2, 40 2.8, 70 2.4) slower than the FAs they replace (31 1.8, 43 1.9, 77 1.9)? I don't know but I mentioned this to the distributor who didn't seem to get my point. The K10 isn't a small camera, so why put so much effort into making tiny tiny lenses? The FA Limiteds are all fantastic - no question - but the DA Limiteds seem to be favouring physical size over speed. I would much rather have the extra stop or so for a bright viewfinder image and occasional wide-open shooting. Given the mixed reviews the 21 has been getting, I think Pentax are losing focus (sorry) with the Limited concept.

03-06-2007, 06:33 PM	#14
loganross Forum Member Join Date: Jan 2007 Location: SF Bay Area (CA) Posts: 86 Original Poster	pentaxkat, The issue is that it is more important to have the faster lens to deal with the movement of the subject, thus SR does not serve as a substitute for faster lenses

03-06-2007, 06:45 PM	#15
RiceHigh Veteran Member Join Date: Nov 2006 Location: Hong Kong Posts: 1,934	Originally posted by loganross pentaxkat, The issue is that it is more important to have the faster lens to deal with the movement of the subject, thus SR does not serve as a substitute for faster lenses Yes, exactly. It should be noted also that SR does NOT always work but fast lenses do, that is, SR only works sometimes and even it works, it does not give perfect images like a tripod does (and actually far less ideal than a monopod, too).