Pentax 110 lenses on the Panasonic G1

For some time I have been tinkering with various legacy lenses for my G1. I started muckin about with the C mount lenses and while one of them has some utility for me, ultimately I decided that the kit zoom lens is best for those focal lengths. Especially when you consider that the standard zoom comes with all the lens corrections needed to be applied built into the camera, just like the software PT Lens will do for you, but already applied for you. Its worth pointing out at this point that the kit zoom is not so great when you convert RAW files with a converter which is not able to handle these lens corrections. Of course the RAW file is not corrected and contains meta data to be applied to the final image.

Before I had completely given up on this path I had "invested" €7 into a Pentax 18mm lens designed for the 110 cameras. Its important to stress here that these lenses have no aperture iris in them, that is in the camera on the Pentax 110 system ... thus each will be wide open or nothing. That's ok by me, as if I wanted to stop down I'd use the standard zoom because of its other advantages (Image Stabilization, automatic iris, auto focus). I had intended to mung up an adaptor but decided that with all the excitement someone was bound to make one. Well they did, and it was so well priced I thought I'd buy it to try the lens out.

Naturally I could not pass up the temptation to pick up a couple more of the Pentax 110 lenses as KEH had them for nearly nothing (well I had to pay postage to Finland too).

So in the name of experimental science (and just having to know myself) here we are :-)

The first thing which struck me about the lenses was how bloody small they are. The MONSTER of a lens you see sitting to the left of the Pentax lenses and adaptor is the relatively compact Olympus OM 50f1.8 lens

Actually with the OM 50mm mounted on the camera it certainly doesn't feel bad, it feels good in fact. The Pentax 50mm feels really compact ... almost tiny. Its certainly smaller than the kit zoom. So when it comes to camera bag there isn't a difference, but if you are wanting to go out with just the camera on your shoulder and perhaps a small lens in your pocket the Pentax 50mm fits the ticket perfectly.

Gosh these little guys are small. The itty bitty weeny one on the right of the adaptor is actually the 24mm f2.8 lens ...

Pancakes anyone?

This isn't a pancake lens, its a bloody pikelet lens.

Which really makes me wonder just why oh why the Panasonic 20mm f1.8 lens gets so much bullshit and poppycock about it being some sort of "gosh that's fantastic" thing when it is in fact an ordinary "normal lens" that happens to have Auto Focus and integrated automatic aperture.

Given this here Pentax lens was designed back in the late 1970's why do we have to pay €399,00 for the Panasonic 20mm lens, to get what is more or less straight forward technology? (I suspect the answer is that far far too many of the target market group are well funded and just say "what the hey" and justify it after buying it). The lens design for this little fella is found in the Pentax lens guide:


I'm not sure, but it seems to be a modification of the Tessar design, perhaps someone can fix me up straight on that one.

But I digress

Firstly, one of the reasons I decided to acquire more 110 lenses for the G1 was that I had been considering the above mentioned 20mm lens comparing this with existing lenses. Sort of dipping my toe in without committing the big bucks.

I have compared it to my FD28 and found it quite close, and kind people have been helpful enough to post some samples for me to see. What I've seen was not exactly the sort of thing I'd been looking for, but I wasn't willing to rule it out just yet.

You see the reason that I want the Panasonic 20mm is to get a shallow normal. It is well covered in the standard zooms range, which performs optically quite well enough for my personal needs. It does not have any image stabilization and thus all it has going for it to me is the shallow depth of field and the compact nature.

So my question is "is that worth €399 (or about AU$650)?". Anyway, I had an epiphany the other night "say, the Pentax 110 24mm is f2.8 that's much closer in focal length than the FD 28mm, perhaps it would make a good comparison?

So, first off the block, I thought I would compare it with the standard zoom at 24mm:

Pentax 110


Standard Zoom


No doubt about it, the standard zoom is better corrected, has less vignetting and seems to allow the camera to make better exposure decisions. No surprises there.

But what about the extra 2 stops in aperture, does this blur better than the zoom? It doesn't jump out at me, so lets look at a section of the middle of the images...



a little, but not really much there is there.

Which leaves me thinking that the one extra stop provided by the Panasonic 1.8 (over the Pentax f2.8) will be only a little more obvious than it is here between the Pentax @ f2.8 and the zoom @ f4.9 which is 2.5 stops ...

So all I'll gain by spending €400 is a more compact auto focus lens.

Hmm ... the temptation seems to evaporate.

While I was on the phone to KEH (and since I was paying US$35 postage on a US$11 lens) I thought I'd ask about the 50mm. Of course they had one, so I got that bundled just cos. Since its a real feather weight I thought that if its any good I'll get and it might make a good lens to leave in the bag ...

I thought it might be interesting to not only show that lens, but put it in context of the Olympus OM 50mm f1.8 and also the standard zoom (which is a bit shorter being 45mm and it shows).

If you refer to that diagram above, the Pentax 110's 50mm design looks more like that of a telephoto, compare it to this image of the design of the Olympus 180mm.

This shouldn't be much of a surprise really as the lens is intended to cover a much smaller format (110 film, which is essentialy the same as the 17x13mm sensor of 4/3) and thus a 50mm is a telephoto lens.

Its really interesting to me to see how similarly the image created by the Pentax looks to a 100mm telephoto on a 35mm full frame system.

So, here's the Pentax 110 50mm @f2.8


the OM50mm @ f2.8


which is of course not wide open so lets look at that too:


notice how the Bokeh of the OM starts looking harsh (like it or hate it is up to you) at 1.8 but is smooth at 2.8? I prefer the OM50@2.8 so its worth the extra weight over the 50mm.

Also, one thing which stands out to me, is that compared to the OM lens, the Pentax 50mm is a little more contrasty. This is apparent more in the shots towards the bottom.


Looking at the centers (the top image being the Pentax 110):


it seems to me that the everything is quite close, except for the bokeh

adding the 50mm at f1.8 into the middle it sits between the extremes of the two lenses, starting to show harsh blurs, but being more diffuse all the same.


and again from a different section of the image:


to me they look very similar in their medium contrast handling.

If you don't have any legacy lenses, the I'd say go for the Pentax 110 50mm as its really really compact and way lighter to carry. Adaptors and lenses cost about the same as each other, so if you're not planning any other OM lenses then the Pentax 110 50mm is well worth the US$11

:-)


I took some other images, which I'll place here with descriptions, and you can make your own calls on them, in all cases below I follow the convention of the top image being the Pentax 110:

Pentax 110


OM50mm@f2.8


OM50mm@f1.8


Standard zoom 45mm@f5.6 (which is wide open as it gets)

and certainly less shallow in DoF than either of the two above.

Comparing the center section of the Pentax and the OM


and then tossing in the (noticeably smaller) Standard zoom:


Some distance overviews

Pentax 110 50mm


OM50mm @f1.8


OM50mm @f2.8


OM50mm @f5.6



Pentax 110 50mm


OM50mm @f2.8

NOTE: except for resizing all images are out of the camera, taken JPG so as to get image corrections on standard zoom.