Sunday, 6 October 2013

newer bigger better faster

Sometimes you can't have everything (well, where would you put it?), and just like my title of 4 words you don't always get all togther.

As mentioned in previous posts I like my compact camera to be compact. Sometimes when I'm out and about I like to have another lens around in case the opportunity arises and my compact 14mm wide angle is not what is needed. With the GF series cameras I like that lens to be small too, something in keeping with the cameras philosophy.

Sometimes bigger isn't better and newer isn't always better either. My case in point today is a small review of my newly purchased Pentax 110 70mm lens. Introduced by Pentax sometime in the late 70's early 80's this little lens is perhaps the best of the 110 series lenses in terms of manufacture quality and feel.

One thing is true this lens sure isn't newer.

In this post I'd like to show the lens to those who may not have seen it, discuss the lens handling and feel and then examine some images made with it. This is not a review in the normal modern manner. There'll be no shots of brick walls to show its ability to hold a square, or MTF curves ...

The lens is made of a mixture of metal and plastic. The lens barrel is metal and the focus grip is beautiful to work with, its rubber which is still looking good more than 30 years later ... I can't say the same of my kit 14-45 (which is an optically good lens btw). The focus turns nicely and with a sense of precision.

Sat beside the more modern more plastic feeling (not that that's any sort of problem for me) Panasonic 14-42 zoom we can see that the little Pentax is quite compact.

Please excuse the softness of this shot it was taken with my FD50 f1.4 on my GH camera, wide open because I was too lazy to get better artifical lighting .... None the less it shows that the lens is really small. This is in my view quite in keeping with the philosophy of the micro 4/3 system compact concepts.

Interestingly the 14-42 zoom extends quite a bit when zooming. Even though it only gives a focal length of 45mm (significantly less than 70mm) it ends up looking like this when zoomed:

With that lens on the camera it starts to look like more of a big lens on a small camera than a than a compact camera system.

To me its looking decidedly less compact ... but then I guess thats what people want ... bigger compact things, because it couldn't possibly be any good if it was small right?

Personally I feel that the GF series cameras (as distinct from my SLR alike GH series camera) benefits from a more compact lens ... and actually the little 70mm looks and feels really nice on the GH too. The Pentax 110 70mm lens is actually not only a compact lens, but a high quality lens that follows the philosophy of small cameras with big image quality.


so what's the fuzz with faster. For reasons I don't really know people seem to get all confused about this. Well I think that the simplest way to understand this is to do something no one does anymore, and that's look at my light meter. For a given exposure an f5.6 lens will need a shutter speed of 1/30th of a second while the f2.8 lens will snap the shot in a mere 1/125th of a second (that's 4 times faster).

So not only is this little guy faster he's way faster.

But wait, someone says:
Oh who needs speed I can hand hold at a 30th with OIS 
 well sure you can, but if you're photographing people they just might move...

The lens is not only nice to hold but has a very smooth damped feel to the focus and (importantly) a long throw. This means that you have to turn the lens more to get a change in focus. When you're dealing with wanting shallow depth of field smaller movements make it much easier to get exactly what you want in focus.


When taking portraits one wants to be a little further away (to not intimidate the subject) and get a smoother rendering of their face. In case anyone is still of the "zoom with your feet" school of thought I would argue that there are differences in portraiture. This shot was done in just such a manner with the subject staying in exactly the same spot and me just 'zooming with my feet' to show what mild telephoto VS wide angle in closer does to a persons face.

so if you want your friends and family looking like the portrait on the right, go on using your iPhone and stop reading this post now ;-) (and yes that's my shadow in the image on the right)

Noone volunteered for being subject on this lens test so sorry to say you won't be getting any people shots with this lens. None the less there are two things I look for in a portrait lens ...
  • shallow Depth of Field
  • soft out of focus rendering
So I thought that I'd explore this with some images. First this one:

shot in available light (because setting up lighting is just so spontaneous) and hand held at about the perfect framing for a head head and shoulders shot. Background is quickly out of focus and yet at the critical point of focus the lens is sharp. A segment of that image shows this.

Sharp enough to see the threads ... Now I have not added any sharpening or contrast control here, so you have room to do some local area masking and selective sharpening also. Ultimately this is not bad for hand held and shows the advantages of that faster lens (so I suppose this means I look for 3 things in a lens then ...)

So next I'd like to answer two questions:
  • is it sharp on the edges
  • is there any point in going from 45mm to 70mm as they're both tele (and how much tele do you need?)

To answer both these questions I took the following shots with the focus at the edge of the image (probably further to the edge than you'd realistically put a portrait) and also use the 14-45 at the 45 end (which btw isn't really fast as its f5.6 at that length) the 70mm in question and for the heck of it a 50mm 110 lens which I also have which at f2.8 is much faster than the 45 end of the zoom while not being that much more telephoto. I wrote a little bit about the 50 in a few pages, for instance in the last blog post here and quite a bit more back a few years ago here, where I compared it to the kit 45 and an OM 50mm f1.8.

So, anyway rendering of depth of field (how it looks). It could be said that because one is in closer with the 45mm that even though its slower that f5.6 may give a similar rendering to the 70mm further away *(since we know that as you move away from the subject DoF around the subject increases)

Now in all these shots I moved back from the position that one needs to be in for the 45mm to see keep the composition of the portrait the same and to see what happens to the image. My focus in all images was the white wooden edge of the house.

The 45 @ f5.6

The 50mm @ f2.8

The 70mm @ 2.8

I think its pretty clear that the DoF between the images varies remarkably and focus is more keenly had on the place where I wanted it. 

I included the 50mm f2.8 to show that even with its more shallow depth of field that by moving further back and using the more telephoto did indeed give a better out of focus effect. Personally I very much like the rendering of the 70mm to give good background / subject separation.

Lets look then to edge sharpness.

The 45mm

The 50mm

The 70mm

Personally I reckon that the edge sharpness (the white board) is plenty, probably more than is needed for portraiture (when the ladies will be asking you to use some Photoshop 'love' to cover the wrinkles and any skin pores).


So there you have it the Pentax 110 70mm from a time long gone does a great job on the micro 4/3 (which is the same size sensor as the  110 film area was BTW) and makes a great lightweight compact lens to add to your micro 4/3 kitbag.

Now I know that Olympus makes a very similar lens (75mm f1.8) which is actually a native lens. This means it will have:
  • auto focus
  • a working aperture
  • better optics
  • is slightly faster at f1.7 (consulting our light meter about double, so 300th)
why not just get that one?

Sure ... if you feel like putting down $1000 for the Olympus I'm quite sure you'll be very pleased with it. But this lens cost only $50. Yes that's right fifty dollars vs a thousand dollars.

I'm a hobby photographer ... so for me if I get 90% of the benefits for 5% of the costs thats only good right? I don't have clients to impress, just family. Of course if you were a business photographer probably you'd be able to build a better business case for the returns on investment on the Olympus 75mm f1.8

Even if you were thinking of getting the Oly, but you weren't sure, well you could try the Pentax and see if you are actually getting much use out of it after a few months.

Won't cost you much ;-)

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