40mm F2.8 review in DP

[PentaxManiac]

I don't know if any of you have seen the current issue of Digital Photo but there's a group test of prime lenses which give a roughly equivalent effective focal length to an old 50mm on DSLRs. This includes the "Limited Edition" Pentax 40mm F2.8.

Of the six lenses tested, the Pentax comes out best for image quality and also gets top marks for features and build and overall rating, but loses out on first place to a Nikon 35mm F1.8. It seems what counted against the Pentax was the noise of the AF in action, although how Pentax are supposed to cut this down by putting a motor in a lens as physically small as this one is not clear.

What set me thinking was the obvious similarity of this lens to the old "Pancake" manual focus 40mm F2.8, even down to the very small front element. Has anyone tried one of those on a K10/20/7? How did the resulting shots look? Has anyone perhaps tried both the old one and the new one - and if so, is there a sufficient increase in quality to justify an outlay of £350 on the new one?

[Malcolm_Stewart]

I've got an original Pentax Pancake lens, and if someone's got a Pentax to Canon EF adapter to lend me, I could run a full frame check on my 5D. (and cropped checks on a 30D)

[johnriley1uk]

The M lens is a terrific lens, but without any electrical contacts on the mount. This makes it less convenient to use on DSLRs.

The DA Limited lens also has the Quick Shift feature which allows manual tweaking of the focus point whilst still in AF mode. This alone IMHO makes it worth it.

Try Amazon and see if any are left at the £230 or so that I found mine at.

[Benchista]

The old pancake is good, but I wouldn't say terrific - it's not a patch on the 50mm f1.7 IMHO. I would expect the new lens to trounce it, TBH.

[johnriley1uk]

I've had several SMC Pentax-M 40mm f2.8 lenses, and they have all been excellent, which is what Photo Technique found when they tested them in the 1970s. The SMC Pentax-M 50mm f1.7 is equally good, but I wouldn't say better.

[Benchista]

It depends how you're using it. Stopped down to f8 or more, I would agree, but at wider apertures, the 50mm is significantly better IMHO, and that chimes in with my recollection of tests at the time - that would've been AP and/or (What) Camera (Weekly). However, my pancake gets more use, as an MX plus pancake fits into a jacket pocket, and the quality is certainly good enough for most things. I might get a PK to EF mount convertor and give it a go myself on digital.

[Monobod]

I have (had) a perfect s/h Pentax SMC FA 50mm f/1.7 that is until I fell over in the icy weather recently and pushed the focusing element back into the body. I had only taken one image with it on my K-7, but this turned out to be pin sharp. At full pixels, I could read the mileage on a signpost that was just a small object in the distance. I was amazed by this.

Does anyone know anything about this autofocus lens? I am arranging to get it repaired as soon as funds permit.

[johnriley1uk]

In general, the f1.7 lenses have higher resolution than the f1.4 ones. They also have a flatter field, so take close up abuse better. That is, when used on bellows, extension rings, with close up lenaes and so on.

[Monobod]

Thanks John, that has reassured me that the repair is worth it.

[Done_rundleCams]

Evening David,

I specifically bought a s/h FA 50/1.7 just when the IST*D came out (spring 2003) -- knowing that it
only a matter of time before I picked up a Pentax DSLR ( IST*Ds - Dec 2004) -- and thinking I would
have a perfect short tele lens (75/1.7) Sadly, however, it has been my least used lens over the
last 5 plus years BUT, when I have put it into to use ...it has yet to fail me ..weird, eh Mind you, I have never used in the style of Mr. Riley and, truth be told, never
new of it (close-up) capabilities -- thanks John -- but ........... [i]Oh Cr@p, I just lost my train of
thought (if I had one ) .... on well, get it fixed cuz you can't get 'em knew anymore (at least)
not in Canada and, hopefully, ...................... A screw it .....sometimes I shouldn't even attempt to post
anything other than emoticons

Jack