[Smolk]

I have that adapter and tried the FA645 45/2.8 and the FA645 75/2.8 on 35mm slide film. I compared them to the 43 Limited and the FA* 85/1.4, respectively. Theres no contest; the K-mount lenses are significantly better.
MF lenses doesn't need to be as good as 35mm lenses although many are. The larger the format the less lens qualities matter for in the final image quality. For small formats you really need good lenses to get great results; for larger format more of overall quality is provided for by sheer real estate....

The 645 45mm is known to be the weakest link in the 645 system. I have no access to the limiteds, but tried the 645 35mm A on my K-x, and the results were so much better than my Pentax-M 2/35mm, 2.8/35mm and (the vastly underestimated) 3.5/24-35mm that I sold all three M-lenses. I vaguely compared the 75mm (A) to my M 2/85mm and saw little difference, but if there was any, the 645 lens was better. If the 77mm is as good as rumoured, however, as the FA 1.4/85, I suspect the 645 75mm will be beaten. It is a very good lens, but not top notch. It doesn't shake you like the 35mm, 120mm or FA 150mm.

NOTE: of course, testing a 645 lens on a APS-C camera means that you only see the very centre of the lens, the sweet spot. In truth, the 35mm lens has been tested and found very good in the corners as well, but it may not apply to every 645 lens.

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Last edited by Smolk; 07-25-2010 at 01:10 AM.

[rparmar]

Intriguing info Smolk.

[Winder]

You haven't provided any kind of constructive criticism but claim that some of the best lenses ever made, as stated by countless of tests and user reports, aren't good enough for you. Instead you buy Sigma lenses, but expect Pentax to make ultrafast lenses better than the current state of the art and sell them cheaply. Your criticism is completely without basis in reality.

The majority of the reviews that people bring up to show the quality of Pentax Limited lenses were written before Pentax had a digital camera. They are based on result achieved with film. Film is much more forgiving in many regards.

I bought the Sigma because IMHO it is a better lens than the 55mm. I pre-ordered the 85mm because there is no Pentax lens in production that fits this focal length. As I said, I would have preferred the extra focal length of the 55mm and the WR, but the SDM motor is not of equal quality to the HSM, and sharpness at f/1.4 was more important that sharpness at f/5.6. I never said I wanted Pentax to make cheap lenses. I said I wanted Pentax to make better lenses. If the Pentax is going to cost $200.00 more than the Sigma then it needs to be $200.00 better than the Sigma. Coming from Canon I have always avoided Sigma because they have had a lot of trouble with Canon AF.

There is not a single review that I have read that has felt that them Pentax 55mm is better than the Sigma 50mm. Just because is says Pentax on the barrel does not make it a better lens. If I wanted cheap glass I never would have invested in the Olympus 4/3 system to begin with. There are no cheap SHG lenses.

[Kunzite]

How about slrgear.com?
"The 55mm ƒ/1.4 is one of the sharper Pentax lenses we've had the opportunity to test. One of the hallmarks of this lens is its wide ƒ/1.4 maximum aperture; happily, sharpness performance at this setting is very good, just about 2 blur units across the frame."

[Aristophanes]

The majority of the reviews that people bring up to show the quality of Pentax Limited lenses were written before Pentax had a digital camera. They are based on result achieved with film. Film is much more forgiving in many regards.

Ned Bunnell has said the same thing. The FA Ltd's on a 21MP FF sensor may have "issues" with resolution. The newer DA Ltd's are capable of superb resolution in their own right, and on digital, may outresolve and preserve colour clarity better than their FA predecessors.

[rparmar]

The majority of the reviews that people bring up to show the quality of Pentax Limited lenses were written before Pentax had a digital camera. They are based on result achieved with film. Film is much more forgiving in many regards.... If I wanted cheap glass I never would have invested in the Olympus 4/3 system to begin with.

If you are this concerned about ultimate detail then buying into a system with a smaller sensor than APS-C was really the wrong move. Better to get a Nikon D700. Or better yet, a Pentax 645D. These can resolve detail no smaller sensor possibly can. Results I have seen with the 645D are exactly what one would expect of medium format -- stunning.

It's not all about sharpness; more important is acuity.

[Pål Jensen]

Ned Bunnell has said the same thing. The FA Ltd's on a 21MP FF sensor may have "issues" with resolution. The newer DA Ltd's are capable of superb resolution int heir own right, and on digital, may outresolve and preserve colour clarity better than their FA predecessors.

He may have said so but it ain't true. Theres hardly any leses made that won't outresolve 21mp.
The myth that digital sets higher demands on lenses is just that; a myth (with the exception of edge definition on some sensors due to the angle of light). This myth is due to pixepeeping. Pixelpeeping is like putting a piece on film under a microscope; nobody did that. In the film days nobody shot branches in front of a complete blown out sky in order to look for fringing of some sort either....

[rparmar]

Pål: There are other issues here as well. No doubt standards are now much higher in terms of technical perfection. (Whether they are in fact lower in terms of artistic interpretation is a matter of debate!) But some people took loupes to shots in film days as well -- their version of pixel peeping.

It may not be digital that sets higher demands on lenses, but certainly higher pixel densities do. This is a matter of physics. Loads of MP in a small APS-C sensor requires extremely careful lens design and manufacture, since every little fault is magnified.

[Aristophanes]

He may have said so but it ain't true. Theres hardly any leses made that won't outresolve 21mp.
The myth that digital sets higher demands on lenses is just that; a myth (with the exception of edge definition on some sensors due to the angle of light). This myth is due to pixepeeping. Pixelpeeping is like putting a piece on film under a microscope; nobody did that. In the film days nobody shot branches in front of a complete blown out sky in order to look for fringing of some sort either....

Pixelpeeping in an earlier era was simply printing or enlarging! It's been around longer than digital sensors.

A case can be made that new developments in lens design allow for superior lens construction today and in the coming years that previous. The MTF's from some of the FA Ltd's are not as good as those from the DA Ltd's (Photozone). Other brands demonstrate similar trends. The actual lens bodies may be less artisan and metal, more plastic and mass produced, but the glass itself may have gotten substantially better in materials, design, and assembly.

CAD, CAM, and ashperical glass have all played their part. It's something to note going forward.

[Winder]

If you are this concerned about ultimate detail then buying into a system with a smaller sensor than APS-C was really the wrong move. Better to get a Nikon D700. Or better yet, a Pentax 645D. These can resolve detail no smaller sensor possibly can. Results I have seen with the 645D are exactly what one would expect of medium format -- stunning.

It's not all about sharpness; more important is acuity.

I have been using the 5D (12MP) and E-3 (10MP) for several years and there are advantages to both in terms of IQ. With good light the high pixel density of the E-3 gives me more detail than the 5D. The 5D however gives me cleaner files and a more pleasing image "most" of the time.

I am not necessarily interested in ultimate detail as I am sharpness. As pixel density increases (and Pentax is going to increase it) then the shortcomings of the lenses will become more and more apparent.

Photozone ran two reviews of the Sigma 50mm f/1.4. One on an 8MP 350D and one one the 15MP 50D. The higher pixel density really challenged the Sigma lens.

"It's quite obvious that the lens has more trouble with the 15mp of the EOS 50D compared to our initial test based on the EOS 350D @ 8mp."

Sharpness plays a big role in how much an image "pops" and how how well a lens isolates the subject from the background. While the smaller APS-C sensor may not give you the shallow DoF of the full-frame, but with a really sharp lens (good focus), with great bokeh, you can achieve very good subject isolation.

Because I like a larger aperture to keep ISO down, improve subject isolation, and keep shutter speed up I am very critical of how a lens performs wide open. If I shot landscapes or macro I would be less critical of this, and less critical of the Limited lenses.

[robjmitchell]

I have been using the 5D (12MP) and E-3 (10MP) for several years and there are advantages to both in terms of IQ. With good light the high pixel density of the E-3 gives me more detail than the 5D. The 5D however gives me cleaner files and a more pleasing image "most" of the time.

I am not necessarily interested in ultimate detail as I am sharpness. As pixel density increases (and Pentax is going to increase it) then the shortcomings of the lenses will become more and more apparent.

Photozone ran two reviews of the Sigma 50mm f/1.4. One on an 8MP 350D and one one the 15MP 50D. The higher pixel density really challenged the Sigma lens.

"It's quite obvious that the lens has more trouble with the 15mp of the EOS 50D compared to our initial test based on the EOS 350D @ 8mp."

Sharpness plays a big role in how much an image "pops" and how how well a lens isolates the subject from the background. While the smaller APS-C sensor may not give you the shallow DoF of the full-frame, but with a really sharp lens (good focus), with great bokeh, you can achieve very good subject isolation.

Because I like a larger aperture to keep ISO down, improve subject isolation, and keep shutter speed up I am very critical of how a lens performs wide open. If I shot landscapes or macro I would be less critical of this, and less critical of the Limited lenses.

All the Fa Limiteds have very good centre performance wide open and are excellent by 2.8. They are known for that very thing you desire, the ability to make images pop in a 3D like way. There so sharp at F4 that very little background blur is required to make your subject stand out.
If your worried about high shutter speed and ISO (low noise) then you need a flash or d700!

[Adrian Owerko]

Or Pentax decided not to release more DA*. It's my wishful thinking that no more pro grade crop lenses will be released since the upcoming pro camera will be FF. But again, it's in my own mind

Pentax needs to complete the DA* line, it is half done IMO.. Need a DA* 11mm f2.8, DA* 35mm f1.2, DA* 90mm f1.8, DA* 180mm f4 Macro, DA* 250-500mm f4.5, DA*14-60mm f4 DA*10mm f3.5 Fisheye..

[philippe]

Pål: There are other issues here as well. No doubt standards are now much higher in terms of technical perfection. (Whether they are in fact lower in terms of artistic interpretation is a matter of debate!) But some people took loupes to shots in film days as well -- their version of pixel peeping.

It may not be digital that sets higher demands on lenses, but certainly higher pixel densities do. This is a matter of physics. Loads of MP in a small APS-C sensor requires extremely careful lens design and manufacture, since every little fault is magnified.

This is somewhat similar to what happened in the last century with Leitz bringing out the 35 mm camera. The demands of the small format film where more important than LF due to, among manny others, the higher enlargement of a smaller negative. Even special film emulsions and — developers where created.
Leitz and Zeiss showed the way to others in designing lenses, the DA limiteds are the perfect answer to the demands of APS-C…

[ogl]

Ned Bunnell has said the same thing. The FA Ltd's on a 21MP FF sensor may have "issues" with resolution. The newer DA Ltd's are capable of superb resolution in their own right, and on digital, may outresolve and preserve colour clarity better than their FA predecessors.

I don't believe it. All users which use FA LTD at 5D MK II can tell - no any problems at all. The resolution of FA43 is one of the best in the world. FA31 and 77 have no any weaks in terms of resolution.

[Adrian Owerko]

I don't believe it. All users which use FA LTD at 5D MK II can tell - no any problems at all. The resolution of FA43 is one of the best in the world. FA31 and 77 have no any weaks in terms of resolution.

The big Question is will a Pentax FF have contacts for old FA glass?