Pentax pancake lens reign ending?


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airconvent

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Apr 12, 2005
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#1
While pancake lenses are not exclusive the pentax, theirs are the most common and popular.
So it seems odd that only recently that both Olympus and now Panasonic has jumped on the bandwagon to offer fast pancake lenses considering their compactness. The new ones for the new Panasonic camera include some as did the Oly EP1. I wonder if Pentax will introduce faster version of their classic 40 2.8...eg 40 1.4? :)
 

scorpioh

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Jul 17, 2007
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#2
the f-stop is the main compromise of pancake size. 50 1.4 pancake is not possible.
 

Jan 16, 2009
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Olympus and Panasonic can make pancake lens for the micro 4/3 system because of the technical aspects of the 4/3 system. They will not be able to do so easily for the 4/3 system, and pancake lenses are still exclusive to Pentax when it comes to APS-C systems.
 

airconvent

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Hi Cyrn.. Welcome back again!
I am not sure if its true but there is a limit as to how much you can bend the light without distortion, hence if the depth of the lens is too shallow, you can't squeeze in the complex optics assembly to achieve a fast ratio. At least that is what I thought. Do you have other literature that says otherwise?
 

darrrrrrrrrr

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Sep 19, 2006
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#8
interesting, perhaps you could share what you've read?

here's what i've seen so far..

image linked from DPR


pentax's fa50/1.4 is about as small as autofocus fast fifites go, i think?

also to quote from http://photo.net/equipment/pentax/pentax-limited-lenses

Pancake lenses were originally based on the Zeiss Tessar design developed a century or so ago. It was legendary for its sharpness, small size, and high speed compared to other lenses of the time. While pancake lenses are no longer considered "fast" (their design places limits on maximum aperture), they still have the advantage of being compact in size. The Pentax Limited 40/2.8 protrudes almost no further than a thick body cap.
 

CYRN

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#11
Hi Cyrn.. Welcome back again!
I am not sure if its true but there is a limit as to how much you can bend the light without distortion, hence if the depth of the lens is too shallow, you can't squeeze in the complex optics assembly to achieve a fast ratio. At least that is what I thought. Do you have other literature that says otherwise?
interesting, perhaps you could share what you've read?

here's what i've seen so far..

image linked from DPR


pentax's fa50/1.4 is about as small as autofocus fast fifites go, i think?

also to quote from http://photo.net/equipment/pentax/pentax-limited-lenses

Pancake lenses were originally based on the Zeiss Tessar design developed a century or so ago. It was legendary for its sharpness, small size, and high speed compared to other lenses of the time. While pancake lenses are no longer considered "fast" (their design places limits on maximum aperture), they still have the advantage of being compact in size. The Pentax Limited 40/2.8 protrudes almost no further than a thick body cap.
it's not impossible in the future perhaps.
I had the lensbaby 2G in mind. Simple 50mm. If not for the need to "bend" it's physical size could be much smaller.... that is why I mentioned 50mm f1.4 pancake is possible....

Furthermore, 50mm lenses are generally the most "compact" category, if Pentax can have pancakes from 15mm to 70mm with 40mm the most compact... so why can't a 50mm (or 40mm) f1.4 be like the size of 70mm pancake... still considered pancake, right?

Mabbe I left out aperture module which might take up quite some space in pancake design. :dunno:
 

night86mare

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Aug 25, 2006
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#12
I had the lensbaby 2G in mind. Simple 50mm. If not for the need to "bend" it's physical size could be much smaller.... that is why I mentioned 50mm f1.4 pancake is possible....
lensbaby 2G = inferior soft optics + not pancake actually
 

Apr 5, 2007
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#14
Furthermore, 50mm lenses are generally the most "compact" category, if Pentax can have pancakes from 15mm to 70mm with 40mm the most compact... so why can't a 50mm (or 40mm) f1.4 be like the size of 70mm pancake... still considered pancake, right?
The flattest fast lens from Pentax I know of is the FA 43mm / 1.9 Ltd (without the hood) - does it count as a pancake?

Even so, the FA 43 is probably at least twice as fat as the DA40. You do realise that the DA Ltd pancakes are relatively "slow" lenses, don't you? I do agree that a 50 / 1.4 pancake is impossible at this point in time, simply due to the laws of physics, which airconvent and darr brought up.

Unless in the future Pentax or some other lens maker comes up with a new form of ultra aspherical or some other wonder glass that makes flat and fast glass possible. Til then, there will always be a trade off somewhere.
But why the need for a pancake anyway? I appreciate small lenses yes, but you can achieve small and fast lenses (FA 50 1.4, FA ltds) without having to go for pancakes.
 

darrrrrrrrrr

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#15
But why the need for a pancake anyway? I appreciate small lenses yes, but you can achieve small and fast lenses (FA 50 1.4, FA ltds) without having to go for pancakes.
because they're so uber cool :bsmilie:
 

CYRN

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#16
The flattest fast lens from Pentax I know of is the FA 43mm / 1.9 Ltd (without the hood) - does it count as a pancake?

Even so, the FA 43 is probably at least twice as fat as the DA40. You do realise that the DA Ltd pancakes are relatively "slow" lenses, don't you? I do agree that a 50 / 1.4 pancake is impossible at this point in time, simply due to the laws of physics, which airconvent and darr brought up.

Unless in the future Pentax or some other lens maker comes up with a new form of ultra aspherical or some other wonder glass that makes flat and fast glass possible. Til then, there will always be a trade off somewhere.
But why the need for a pancake anyway? I appreciate small lenses yes, but you can achieve small and fast lenses (FA 50 1.4, FA ltds) without having to go for pancakes.
Nevermind.... My point was missed.
 

darrrrrrrrrr

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#17
Nevermind.... My point was missed.
Your point wasnt very clearly stated, that's why i had to ask you what it was.. perhaps you could share what you've read that suggests a 50/1.4 pancake is realistically possible?

I've seen photos of an old nikon 50/1.8 pancake.. Series e or something. For film, so i guess it can be done? However it's mf only while the da ltds are af and i think tt takes up some space too?
 

darrrrrrrrrr

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#18
one last thought, image quality should be a priority, esp with the premium da and fa limited lines. no point forcing a pancake design if it severely compromises iq, turning the lens into a silly gimmick.

The fa50 isnt stellar at large apertures, i think it'll only get worse in a pancake configuration.
 

airconvent

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Apr 12, 2005
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#19
because they're so uber cool :bsmilie:
yup...People thought its a PnS when I'm using it and I need a smaller compartmentation in my bag when its being used. :bsmilie:
 

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creampuff

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Jul 11, 2006
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#20
Thinking backwards, the design brief to produce a small compact lens would invariably have the Pentax lens designers to opt for the simpler Tessar design comprising of 5 or 4 elements in 4 groups. The Tessar design has been around a long time (about 100 years) and is characterised by good contrast and sharpness but at the expense of having a large maximum aperture. Moreover it is simple and cheap to produce. As a matter of comparison, Pentax is not the only company to have made a pancake lens of around 40mm focal length. Konica's 40mm, Contax T* 45mm, Nikon 45mm, Cosina 40mm Ultron, Olympus Zuiko 40mm and Minolta 45mm come to mind and some are definitely superior to our own Pentax 40mm, whether M or DA version.

Now all the standard lenses that a f/2 and faster are without exception based on the Zeiss Planar design that's usually 7 or 6 elements in 6 groups. The design exhibits excellent peak sharpness and is superior to the Tessar design because of it's light gathering ability and higher resolution. Because of the large number of air surfaces in the design, the old complaint of flare and lower contrast is all but absent with superior lens coatings nowadays.

Now comparing the DA 40mm f/2.8 Limited with the FA 50mm f/1.4, the DA 40mm shows even sharpness across the apertures whereas the FA 50mm definitely shows higher overall sharpness when stopped down. As to whether a 50mm f/1.4 can be made into a pancake is actually irrelevant in my opinion. The lens barrel design and overall dimensions is dictated by the lens optical design.

Personally the only thing going for the pancake lenses is the compact size period. In my book, if one wants a prime setup, large maximum apertures is the way to go, that's probably why for me, after getting over the euphoria of having a pancake lens like the DA 40mm and M 40mm, I began to be more conscious about the f/2.8 limitation and promptly dumped it. I do realize some of you may feel it's the best thing since sliced bread, but it just got no love from me... sorry. :sweat:
 

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