What's the purpose of "Pancake" lenses?

Scrib · 01-14-2010, 09:11 AM

But if the 'pancake design' is actually a superior design, then why aren't all lenses pancakes?

asdf · 01-14-2010, 09:14 AM

Originally posted by Scrib

But if the 'pancake design' is actually a superior design, then why aren't all lenses pancakes?

Because as with everything in photography there are trade-offs. If you want large aperture and a sharp image wide open (correcting for spherical and chromatic aberration), you need a giant front element and a lot of optical elements in between. Take a look at Sigma 50 f/1.4. The small lenses are comparatively slow.

Laurentiu Cristofor · 01-14-2010, 12:53 PM

Also check this reference, for the earliest pancake lens design:

Tessar - Wikipedia

jeffrey r · 01-14-2010, 12:59 PM

Awesome form-factor and performance. Many people can better speak to the technical merits. Practically, in addition to the benefit of making your subjects more comfortable, I have found that when I have to hand my camera off for a shot, the other person (usually my wife) seems more at ease. When I hand her my K200D with my Tamron 28-75, or god forbid my Pentax 50-135, between the size, and the weight, and using the zoom (not flicking a lever like on a P&S), it's usually a lost cause. But when I hand her my K200D with my DA 40 or DA 70, it is small, and light, and I say "no zoom--what you see is what you get", she just shoots away and usually gets good shots.

jonlee · 01-14-2010, 01:57 PM

The Pentax "pancake" primes was the primary reason I bought into the Pentax system, which is quite a change for me, since I had given up on using primes in the past because of their inconvenience - more lenses to carry and more work to use. The ability to pocket 2 or 3 primes covering a useful range of focal lengths, along with the already compact, feature-rich K-7 makes it terrific on-the-go/travel/walk-around system.

When I need a zoom due to limited maneuverability or convenience, I'll take my D700 and 24-70 or 17-35 - but that adds more weight. There would be other reasons I'd use the D700 over the K-7, but that's another topic.

I started with the 40mm, then bought into the rest of the set, once I realized its performance fit my needs in terms of usage and output. Needless to say, I was very impressed with the 40mm - it is amazingly small with excellent overall image quality. I just started to compare the DA 70mm to my Nikon 105DC and thus far, they seem quite comparable in terms of image quality. I haven' t used the 15 or 21 very much yet, so can't comment on those. I like the size of the 21 more so than the 15, however. The 15, while still relatively small, isn't what I'd call a true pancake.

**DAKS** · 01-14-2010, 02:20 PM

Jeffrey R makes a very good point.

Sometimes I use my K7 with zooms (DA* 16-50, 50-135, and 55-300).
I usually have the grip in place for those and they are very comfortable.
Other times I'll just take the K7 without the grip and two (or three) limiteds for a very compact experience. I find the primes to be very sharp. While the DA limiteds may not be as fast as their counterparts, the FA limited are both fast and sharp.
I have the FA43 which is a 1.9 and I hope to someday get the FA31 limited which is a 1.8. While they are small, they are not "pancake" in size like the DA 40 is.
In addition to the FA43, I have the DA 21 and DA 70. I use the DA 70 for portraits and as others have said, it makes the subject more comfortable that a larger lens. The Da 21 has been a pretty good walk-around lens when I want to stay small and discreet. I keep trying to convince myself that I need the 31 to complete the package.

David

Frank B · 01-14-2010, 03:04 PM

Originally posted by little laker

Since you've heard about some, although probably not all of the advantages already I'll mention the only 2 downfalls of it.... that I can think of. Since I don't own one I'm just basing this on what I've heard

1. They're harder to focus manually, due to being soo close to the body.
2. Much easier to get your finger in the shot. I've seen this a couple of times in the lab, where I work.
Other than that, I understand that they're stellar lenses. I'd like to add one to my collection soon.

Since you mentioned that your comments were based on what you've heard - I have the DA15, DA21, DA40 and DA70, and can say from personal experience:

1. In actual use the DA Ltd lenses (including the DA40) are not at all difficult to focus manually, or at least not any more so than any other AF lens. You just have to get used to holding the camera and lens in the appropriate manner for a lens that short. Actually they have a pretty nice feel to manual focus when compared to the older F lenses like the 35 f/2 or 50 f/1.4.

2. I think you would really have to not be paying attention to get your finger in the shot with a DA Ltd, even with the DA40. Now, if you want to talk about fingers (and other body parts) in the shot with the DA10-17 Fisheye that's a whole different story.

GeneV · 01-14-2010, 03:28 PM

Originally posted by jonlee

The Pentax "pancake" primes was the primary reason I bought into the Pentax system, which is quite a change for me, since I had given up on using primes in the past because of their inconvenience - more lenses to carry and more work to use. The ability to pocket 2 or 3 primes covering a useful range of focal lengths, along with the already compact, feature-rich K-7 makes it terrific on-the-go/travel/walk-around system.

When I need a zoom due to limited maneuverability or convenience, I'll take my D700 and 24-70 or 17-35 - but that adds more weight. There would be other reasons I'd use the D700 over the K-7, but that's another topic.

I started with the 40mm, then bought into the rest of the set, once I realized its performance fit my needs in terms of usage and output. Needless to say, I was very impressed with the 40mm - it is amazingly small with excellent overall image quality. I just started to compare the DA 70mm to my Nikon 105DC and thus far, they seem quite comparable in terms of image quality. I haven' t used the 15 or 21 very much yet, so can't comment on those. I like the size of the 21 more so than the 15, however. The 15, while still relatively small, isn't what I'd call a true pancake.

Same reason I was buying the predecessors 30 years ago. You could pop an MX body or even two with compact M-lenses on them in a bag, and never need a zoom. Except for the K-7 on the body, that looks a lot like the rig I took all over. Even the new form of the K-7 is in line with what I liked about the Pentax line of the early 80s.

Gooshin · 01-14-2010, 03:33 PM

Originally posted by Scrib

I've been wondering about this as well. The advantage is obviously that they are small, but doesn't IQ suffer from this? I mean, I can't imagine Pentax stuffs all the expensive glass in the larger lenses just for fun. I'd think there is always a compromise... then again, I don't know much about optics.

the compromise is maximum aperture

the FA31 is F1.8, the DA40 is F2.8

Next time you have an F1.8 lens in your hand, stop it down to F2.8 and you realize how little glass you require.

also the reason Pentax gets away with having pancake autofocus lenses is due to the in-body motor and in-body stabalization.. since these no longer have to be in the lens!

In fact, take the FA31mm or the FA77mm lenses and compare them to any Canon or Nikon equivalent.. (remember they have to cover full frame), the size differences are still noticable.

SOldBear · 01-14-2010, 03:42 PM

See how compact they can be - replacing the DA 21mm's and the DA 70mm's hood with something simlar to the DA 40mm's hood and using double lens mount caps:

Marc Sabatella · 01-14-2010, 04:42 PM

A couple of other points:

For the most part, no, you haven't seen other lenses in the same focal length that were bigger - who makes a 21mm or 40mm that is *not* a pancake?

The two commonly cited tradeoffs are maximum / center sharpness and maximum aperture. that is, pancakes might be sharper overall - sharp wide open, sharp in the corners - but when you get down to it, other designs might be sharper in the center when stopped down. And as mentioned, pancakes are typically not as "fast" as larger designs.

A nice side bonus of smaller size is faster AF. MF might not be as nice as with larger lenses, but really, all AF lenses are pretty compromised in that respect, and I don't find even the 40 that much harder to focus manually than any other AF lens I've used. I rather liek that I can focus it with just one finger on my *right* hand.

**interested_observer** · 01-14-2010, 07:02 PM

Originally posted by Reportage

with the Kx, it fits inside ladies purse?

It all depends on the size of the ladies purse....

Its a relative small SLR, but I have seen small purses - no, and large purses - maybe.
I think your mileage may vary...

... my wife's purse - yes, if she emptied everything else out of it...

01-14-2010, 03:42 PM	#25
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	See how compact they can be - replacing the DA 21mm's and the DA 70mm's hood with something simlar to the DA 40mm's hood and using double lens mount caps: Last edited by SOldBear; 01-14-2010 at 03:47 PM.

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01-14-2010, 09:11 AM	#16
Scrib Junior Member Join Date: Jul 2009 Photos: Gallery Posts: 27	But if the 'pancake design' is actually a superior design, then why aren't all lenses pancakes?

01-14-2010, 09:14 AM	#17
asdf Veteran Member Join Date: Jan 2009 Location: Canada Posts: 1,252	Originally posted by Scrib But if the 'pancake design' is actually a superior design, then why aren't all lenses pancakes? Because as with everything in photography there are trade-offs. If you want large aperture and a sharp image wide open (correcting for spherical and chromatic aberration), you need a giant front element and a lot of optical elements in between. Take a look at Sigma 50 f/1.4. The small lenses are comparatively slow.

01-14-2010, 12:53 PM	#18
Laurentiu Cristofor Banned Join Date: Nov 2009 Location: WA Photos: Albums Posts: 3,055	Also check this reference, for the earliest pancake lens design: Tessar - Wikipedia

01-14-2010, 12:59 PM	#19
jeffrey r Veteran Member Join Date: Sep 2008 Location: New Jersey, USA Posts: 337	Awesome form-factor and performance. Many people can better speak to the technical merits. Practically, in addition to the benefit of making your subjects more comfortable, I have found that when I have to hand my camera off for a shot, the other person (usually my wife) seems more at ease. When I hand her my K200D with my Tamron 28-75, or god forbid my Pentax 50-135, between the size, and the weight, and using the zoom (not flicking a lever like on a P&S), it's usually a lost cause. But when I hand her my K200D with my DA 40 or DA 70, it is small, and light, and I say "no zoom--what you see is what you get", she just shoots away and usually gets good shots.

01-14-2010, 01:57 PM	#20
jonlee Forum Member Join Date: Nov 2009 Location: Southern California Posts: 51	The Pentax "pancake" primes was the primary reason I bought into the Pentax system, which is quite a change for me, since I had given up on using primes in the past because of their inconvenience - more lenses to carry and more work to use. The ability to pocket 2 or 3 primes covering a useful range of focal lengths, along with the already compact, feature-rich K-7 makes it terrific on-the-go/travel/walk-around system. When I need a zoom due to limited maneuverability or convenience, I'll take my D700 and 24-70 or 17-35 - but that adds more weight. There would be other reasons I'd use the D700 over the K-7, but that's another topic. I started with the 40mm, then bought into the rest of the set, once I realized its performance fit my needs in terms of usage and output. Needless to say, I was very impressed with the 40mm - it is amazingly small with excellent overall image quality. I just started to compare the DA 70mm to my Nikon 105DC and thus far, they seem quite comparable in terms of image quality. I haven' t used the 15 or 21 very much yet, so can't comment on those. I like the size of the 21 more so than the 15, however. The 15, while still relatively small, isn't what I'd call a true pancake.

01-14-2010, 02:20 PM	#21
DAKS Site Supporter Join Date: Jun 2008 Location: McLean, VA Photos: Gallery Posts: 97	Jeffrey R makes a very good point. Sometimes I use my K7 with zooms (DA* 16-50, 50-135, and 55-300). I usually have the grip in place for those and they are very comfortable. Other times I'll just take the K7 without the grip and two (or three) limiteds for a very compact experience. I find the primes to be very sharp. While the DA limiteds may not be as fast as their counterparts, the FA limited are both fast and sharp. I have the FA43 which is a 1.9 and I hope to someday get the FA31 limited which is a 1.8. While they are small, they are not "pancake" in size like the DA 40 is. In addition to the FA43, I have the DA 21 and DA 70. I use the DA 70 for portraits and as others have said, it makes the subject more comfortable that a larger lens. The Da 21 has been a pretty good walk-around lens when I want to stay small and discreet. I keep trying to convince myself that I need the 31 to complete the package. David

01-14-2010, 03:04 PM	#22
Frank B Senior Member Join Date: Aug 2009 Location: San Diego, California Posts: 149	Originally posted by little laker Since you've heard about some, although probably not all of the advantages already I'll mention the only 2 downfalls of it.... that I can think of. Since I don't own one I'm just basing this on what I've heard 1. They're harder to focus manually, due to being soo close to the body. 2. Much easier to get your finger in the shot. I've seen this a couple of times in the lab, where I work. Other than that, I understand that they're stellar lenses. I'd like to add one to my collection soon. Since you mentioned that your comments were based on what you've heard - I have the DA15, DA21, DA40 and DA70, and can say from personal experience: 1. In actual use the DA Ltd lenses (including the DA40) are not at all difficult to focus manually, or at least not any more so than any other AF lens. You just have to get used to holding the camera and lens in the appropriate manner for a lens that short. Actually they have a pretty nice feel to manual focus when compared to the older F lenses like the 35 f/2 or 50 f/1.4. 2. I think you would really have to not be paying attention to get your finger in the shot with a DA Ltd, even with the DA40. Now, if you want to talk about fingers (and other body parts) in the shot with the DA10-17 Fisheye that's a whole different story.

01-14-2010, 03:28 PM	#23
GeneV Veteran Member Join Date: Oct 2008 Location: Albuquerque NM Photos: Albums Posts: 9,830	Originally posted by jonlee The Pentax "pancake" primes was the primary reason I bought into the Pentax system, which is quite a change for me, since I had given up on using primes in the past because of their inconvenience - more lenses to carry and more work to use. The ability to pocket 2 or 3 primes covering a useful range of focal lengths, along with the already compact, feature-rich K-7 makes it terrific on-the-go/travel/walk-around system. When I need a zoom due to limited maneuverability or convenience, I'll take my D700 and 24-70 or 17-35 - but that adds more weight. There would be other reasons I'd use the D700 over the K-7, but that's another topic. I started with the 40mm, then bought into the rest of the set, once I realized its performance fit my needs in terms of usage and output. Needless to say, I was very impressed with the 40mm - it is amazingly small with excellent overall image quality. I just started to compare the DA 70mm to my Nikon 105DC and thus far, they seem quite comparable in terms of image quality. I haven' t used the 15 or 21 very much yet, so can't comment on those. I like the size of the 21 more so than the 15, however. The 15, while still relatively small, isn't what I'd call a true pancake. Same reason I was buying the predecessors 30 years ago. You could pop an MX body or even two with compact M-lenses on them in a bag, and never need a zoom. Except for the K-7 on the body, that looks a lot like the rig I took all over. Even the new form of the K-7 is in line with what I liked about the Pentax line of the early 80s.

01-14-2010, 03:33 PM	#24
Gooshin Veteran Member Join Date: Sep 2007 Location: Toronto, the one in Canada. Posts: 5,610	Originally posted by Scrib I've been wondering about this as well. The advantage is obviously that they are small, but doesn't IQ suffer from this? I mean, I can't imagine Pentax stuffs all the expensive glass in the larger lenses just for fun. I'd think there is always a compromise... then again, I don't know much about optics. the compromise is maximum aperture the FA31 is F1.8, the DA40 is F2.8 Next time you have an F1.8 lens in your hand, stop it down to F2.8 and you realize how little glass you require. also the reason Pentax gets away with having pancake autofocus lenses is due to the in-body motor and in-body stabalization.. since these no longer have to be in the lens! In fact, take the FA31mm or the FA77mm lenses and compare them to any Canon or Nikon equivalent.. (remember they have to cover full frame), the size differences are still noticable.

01-14-2010, 04:42 PM	#26
Marc Sabatella Veteran Member Join Date: Sep 2006 Location: Denver, CO Photos: Gallery Posts: 10,685	A couple of other points: For the most part, no, you haven't seen other lenses in the same focal length that were bigger - who makes a 21mm or 40mm that is not a pancake? The two commonly cited tradeoffs are maximum / center sharpness and maximum aperture. that is, pancakes might be sharper overall - sharp wide open, sharp in the corners - but when you get down to it, other designs might be sharper in the center when stopped down. And as mentioned, pancakes are typically not as "fast" as larger designs. A nice side bonus of smaller size is faster AF. MF might not be as nice as with larger lenses, but really, all AF lenses are pretty compromised in that respect, and I don't find even the 40 that much harder to focus manually than any other AF lens I've used. I rather liek that I can focus it with just one finger on my right hand.

01-14-2010, 07:02 PM	#27
interested_observer Loyal Site Supporter Join Date: Jun 2009 Location: Tumbleweed, Arizona Photos: Gallery \| Albums Posts: 5,707	Originally posted by Reportage with the Kx, it fits inside ladies purse? It all depends on the size of the ladies purse.... Its a relative small SLR, but I have seen small purses - no, and large purses - maybe. I think your mileage may vary... ... my wife's purse - yes, if she emptied everything else out of it...