Friday, 5 February 2010

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.

pentax-110-kitNaturally 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
P1070170

Standard Zoom
P1070169

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...

24-centerDetail

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
P1070177

the OM50mm @ f2.8
P1070179

which is of course not wide open so lets look at that too:
P1070178

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):
50-2-MresCenter

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.
50-2-3b-MresCenter

and again from a different section of the image:
50-2-3a-MresCenter

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
P1070181

OM50mm@f2.8
P1070183

OM50mm@f1.8
P1070182

Standard zoom 45mm@f5.6 (which is wide open as it gets)
P1070185
and certainly less shallow in DoF than either of the two above.

Comparing the center section of the Pentax and the OM
50-3-2a-MresCenter

and then tossing in the (noticeably smaller) Standard zoom:
50-3-3a-MresCenter

Some distance overviews

Pentax 110 50mm
P1070173

OM50mm @f1.8
P1070174

OM50mm @f2.8
P1070175

OM50mm @f5.6
P1070176


Pentax 110 50mm
P1070171

OM50mm @f2.8
P1070172

50-centerMres

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

6 comments:

The Justified Sinner said...

Amazing synchronicity! I bought a Pentax 110 system last weekend at a charity shop and it came with a batch of lenses. After doing a bit of research, I realised - like you - that the lenses could be attached to the G1... My adapter arrived from Taiwan today and I'll be spending tomorrow trying it out.

In case you are interested, my adapter came from Hawks_factory on Ebay, doesn't seem to have any light-leakage problems and the lenses seem to sit very tightly in the mount. It has to be said, however, that the adapter was more than twice the price of the one you got.

Thanks for the info and the shots. I'll be posting some photos on my Flickr photostream tomorrow.

hodad66 said...

Waiting for an adapter myself.... should be fun to try these lil devils out!!

Peter Werner said...

Thanks for the information and your thorough analysis.

I just got an 18mm/2.8 Pentax 110. Being a wide angle (36mm FF), it seemed the most interesting of the lot. A 24mm is on the way. I use it with the Hawk adapter on the G1.

While the sharpness and bokeh are good, it has a strong tendency to flare, even when using a hood.

You can find some examples and comments on

http://forum.getdpi.com/forum/showthread.php?p=186827

Cheers
Peter

Rodrigo Luiz said...

hi,i would like to know which adapter should i buy to use a 18mm lens on canon dslr, is this a K MOUNT? PK? M42?

Best Regards

obakesan said...

Rodrigo, to my knowledge there is none. The mount is simply called Pentax 110, but you see the lens must be held a specific distance from the film / sensor. The mount distance from the sensor is called the focal flange distance, and for a EOS camera it is 44mm. The distance for the 110 is 27mm. So it simply won't be able to work with that mirror flapping around in there.

It works on the Micro 4/3 cameras because (with no mirror) they can have a much shorter mount distance, it is 19.25mm ... this opens up a large access to lenses denied the EOS system (and one of my reasons for leaving it).

The next problem you face is coverage, the image circle of the 110 is too small for APS so the corners would darken. As it happens, 4/3 fits the 110 format perfectly so there is no darkening.

obakesan said...

Rodrigo, there is such an adapter for EOS M (although you didn't mention you had one). Search on ebay :-)