legacy Olympus lens on EOS camera (digital or film)

to Raita ... may your photographic journey be fun

Today I'd like to put a quick tutorial on how to mount and use an Olympus OM lens on an EOS camera.

This is essentially done using a small metal adaptor which mimics the camera side for the lens being used, and then mimics the lens side of an EOS lens so that it can be put on the camera.

Now, EOS lenses are fully electronic, meaning that all of the control of the lens by the camera is done by an electronic interface (you can see this on the camera when you take a lens off as a bunch of little golden buttons).

Since the OM lens is fully mechanical it has no capacity for this sort of thing.

Now, keep in mind that lenses are essentially simple creatures, despite all the mystery that modern lenses seem to have, they focus and they have an aperture iris (which is just like the iris of your eye, and gets smaller to allow less light through to the film / sensor).

Quite simple really.

Ok, firstly lets cover mounting the adaptor onto the lens. Most camera systems have some red dot on the body and on the lens to guide you as to exactly where to hold them to orient them bring them together and lock ... so match the dots, bring the two together and turn till it clicks




So, now the lens is fitted to the adaptor, its ready to be used. You can check that it operates and you can see the iris stop down as you change the aperture control ring on the camera (remember, its not electronic-magic, its mechanical)



Remember, it doesn't just get dark as you stop down, the depth of field (what in and out of focus) gets wider ... so if you stop down with the lens on the camera focused on something you may see this in the viewfinder (I say may, because some people can't get past seeing that it just gets darker)

Now, as we see, adjusting the aperture actually stops down the iris (makes it smaller). On modern cameras (electronic or mechanical) we have a cunning system which would allow the lens to be fully open (making it bright to see, and easier to focus) and stopping it down just as you press the shutter. Of course the EOS camera has no such mechanical control, so the adaptor simply keeps that lever pulled and stops the lens down to exactly what f-stop you've set on the lens.




Now, lets put it onto the EOS camera ...




So because this lens now works in a pre-automated way (you know, things weren't always automatic...) it means that as you stop down the viewfinder will get darker. This will confuse your electronic camera which does not know that

• it can't control the lens
• what aperture the lens is set to
  

so you need to tell the camera that the lens is wide open. This is because the camera will only be able to control the shutter. Sure, you're making it darker by stopping the iris down, but the camera doesn't know that.

Depending on the camera you may need to tell the camera that there the lens attached is out of its control or you may not. You can tell by seeing how the camera reacts to having the lens mounted.

Keep it simple: use Av mode

First, lets keep this simple by putting your camera in Av mode. Now I picked that because in Av the camera does what its told regarding to aperture and picks the right shutter speed (lets assume it gets thing right ;-) for the aperture you have chosen. We will be picking the aperture (set on the lens) only this time the camera just won't know what its going to be.

Now just before you rush off, we need to check something (though if your camera isn't an old EOS you may be in the clear), there are two different behaviors for EOS cameras that are fitted with a mechanical lens:

If the display reads “1.0” (or any number other than “00”) then you have the old stop-down metering style.

If the display reads “00” then you have the new stop-down metering style.

I think its quite likely that you will have "00" showing with the Olympus on your camera. Anyway this is covered at this link on EOS stop down metering. Recommended reading for a rainy day ... when you can't be taking pictures.

Ok, on my EOS camera I need to manually set the aperture in Av mode to 1.0, be sure to check yours.

So, I can only use my camera in Av mode or Manual (but I have to remember not to change the aperture). The newer EOS cameras (and I think all the EOS digital cameras) use the "new method" which allows your camera to work in:

• P (program),
• Av (aperture priority) and
• M (manual).

Check your cameras "stop down" behavior and if you need to set it, set it, but probably you will not need to worry about anything.

So, just set Av and go take some pictures.


Ohh ... and don't forget to focus :-)

One of the reasons AutoFocus cameras have become so common is that most people completely forget to do this ... in the heat of the moment. Manual focus offers you control but with that comes responsibility ... you can't blame the camera for a blurry photo if you didn't focus.

Many cameras have diopter adjustment, which compensates for if you need glasses or not.

So just as it may be difficult to focus your eyes when wearing grandad's glasses, if the diopter adjustment has been knocked off center it maybe impossible for you to see anything clearly in the viewfinder too.

This is normally located on the back of the finder, and you'll see a little wheel with a + and - on it ... as in this figure.

When focusing (if you haven't ever done it before) keep the lens wide open (f1.8 on this lens) for easiest and brightest view. Focus by turning the lens as I did in my above video and when the subject looks sharp then its focused.

Don't forget, those numbers with m and ft on the lens are actually accurate. You can measure (or guess) the distance to your subject and 'prefocus' the lens to that point and just take.

Heaps of photographers who like to "snap on the street" use exactly that technique for their candid photography (when you haven't got time to focus but you want to get it right).

Stuff like this candid from the 1950's by Vivian Maier were undoubtedly done in just this manner.

For example, from Philip Greenspun's pages on photogrpahy we find this advice on zone focusing:

"The classic technique for street photography consists of fitting a wide (20mm on a full-frame camera) or moderately wide-angle (35mm) lens to a camera, setting the ISO to a moderate high speed (400 or 800), and pre-focusing the lens."

Its easier with wide angle lenses of course ... but if the subject is further away (like 5 meters) its not so hard ... either way its something worthwhile to know about

Simple.

To me the greatest benefits of these lenses come between f1.8 and f5.6 ... I prefer to use these lenses at f1.8 through to 2.8. The image may look a little nicer at 2.8 but 1.8 will give you a little more than 1 stop more shutter speed (thus these lenses are called fast lenses). That can make the difference between needing 1/30th of a second and getting 1/90th ... if your subject won't sit still that'll make all the difference.

Its actually still bright enough to focus at f4 on the lens (if you ask me) so you don't need to open and close it all the time, but if you're going to close down to 5.6 or smaller then you may as well use a zoom anyway.

The real advantage of these lenses is how bright (and thus how fast) they are as well as their lovely shallow depth of field, so keep it at 1.8 or 2.8. for maximum benefit :-)

Taken with my 50mm wide open (that means f1.8 ;-)

the naked truth

meaning naked as in uncovered ...

For ages there has been something separating digital photographers from film photographers. People don't often even know its there and those who do often don't even remember its there.

In management we talk about glass ceilings that prevent advancement, but in digital photography I'm wondering if the glass ceiling is indeed all the filters.

These are required to prevent the ugly aliasing effects which are associated with Bayer arrays or the heavier filters applied to prevent the sensors from seeing IR (which will disturb the colour as we perceive it), where they are quite sensitive, and to further limit the spectrum to Red Green or Blue as each respective sensor needs to be to assemble colour from the Bayer Array.

In my recent post about the 2010 Shootout I had some thoughts about this issue, and some of the comments I got reminded me of another digital camera of the distant past which seemed to side step many of these issues and take advantage of the technology with a different philosophy and design criteria.

That was the Kodak 760M camera.

Back in 2004 the above review of this camera made a simple statement which seems to have become lost:

Without an anti aliasing filter and no Bayer color matrix, the resolution of a 6 mega pixel monochrome camera is astonishing. In monochrome, 6 mega pixels effectively does what it takes 12-24 mega pixels with a color matrix

So forgetting for a moment any of the issues of how many more megapixels we can cram into a sensor, think for a moment about how much light is lost putting the sensors behind all those filters. Think about it, its well documented that a Wratten 25A deep red filter kills 3 stops.

In fact in that above review of the "special" Kodak camera (nothing more special than not munging up the sensor) Pete Meyers found his ISO was way way higher than he expected:

Correct exposure for my work meant not clipping the whites. I ended up in shock at watching exposure times go from 1/60 or 1/125 of a second with my Leica M6 and film, to 1/800, 1/1200 and even 1/1600 of a second for the same aperture with the DCS 760m. With a base ISO of 400 exposures times are brisk – another advantage of a digital monochrome over a color based sensor.

very interesting, thats a 3 or 4 stop increase.

So (if you ask me) the cost of colour digital is we get sensors which are 1600ISO but if you could just filter IR out and get rid of the other crap (I've got an IR filter anyway, and I'm sure Leica M8 users are familiar with using one too) we'd have black and white digital cameras which would give us jaw dropping image clarity and be equivalent to 12800 ISO all with existing technology.

Considering that Canon and Nikon are already putting out sensors which are 12,800 ... well that's 102,400 ISO imagine the stage photographer's joy of being able to use fast shutter speeds or even stop down a little to get better contrast.

The mind boggles ... so you guys in at Nikon and Canon, try to keep in mind that not everyone wants colour and munged black and white..

david vs goliath: spending the R&D money wisely

Its an old story, big vs small.

While this blog post is ostensibly about images, its also about how producers spend their R&D budget for products and what goes into production.

Let me start with an analogy.

This is my Ducati, its a 1989 750 Sport and was made by Ducati before the modern SS series really took hold of the market.

It was made at a time when their budget was small and they were owned by Cagiva. The company was trying hard to catch up with the Japanese bikes which had long since stopped being the wobbly things which took a genius gifted rider like Mike Hailwood to tame and bring to fame.

Based on the frames used in the race proven 750 F1 bikes, the 750 Sport had a real packet of problems to present for the owner. It was in many ways as frustrating to own as it was fantastic to own.

After decades of ownership of Hondas and Yamaha motorcycles owning the 750 Sport was an elegant exercise in understanding what it was the separated the two philosophies and the budgets. Yamaha no doubt had a small group of people dedicated to solving specific issues such as where to put the battery. Ducati on the other hand had clearly just a couple of hours to sort out where to put a battery in the frame (and undoubtedly the race bikes did not have them) and chose perhaps the worst possible location imaginable.

Check out how many 750 Sport owners have the knee of their jeans speckled with holes from battery acid spitting out ...

Just like motorcycles, camera makers have similar production and design issues and looking at an image from my friend over at Soundimageplus, I think I am seeing one. He posted this image recently on his blog, to examine what he finds on his Leica M9 (the lucky lucky bastard)


Looking at a strip he has placed on Flickr, he's photographed a scene at a variety of ISO's and then compared camera JPG to what he can get with LR and no particular massive amount of work.

Its interesting to see just how much better the LR images are compared to the in-camera JPG images.

Now, looking at this thumbnail set to the left here they all show really similar colour rendition, and that's a good thing. The JPG thumbnails also seem to be punchier. But its when you look at the image carefully you start to see that the JPG engine employed by Leica is really not anywhere near as good as those of companies like Canon (who are finally starting to get theirs in good order) Nikon or Panasonic (whom I'm getting more and more respect for with every RAW file I process).

Lets look first at a moderate sample, not this is not incredibly zoomed in or pixel peeped in any way.

First, this is an overview (yes, just an overview) of the red channel of the
in camera JPG image


that amount of noise is not a good thing at this magnification and you can hardly even read the name of M-AUDIO on the end of the keyboard there

what... didn't see it? Well look at the the RAW sourced LR image


So its not going to be any surprise that looking at a segment of the JPG file is going to show "noise" in the smooth tones like the shelf...



while the RAW image will make a beautiful smooth big print



just like any stock agency wants....

This comes back (in my view) to the same sorts of problems that earlier cameras from the big companies (in this case Nikon) had with in camera JPG vs RAW. I wrote that back in about 2005. In that (pre blog days) I wrote the following:

Considering that

• most people plug their cameras into the computer via USB and the proprietary software
  
• the software performs transformations on the images in many cases on transfer
  
• Media cards are now no longer a major limiting factor on the number of images
  
• computer software upgrades are easier than camera firmware upgrades
  
• alternative systems exist for advanced users
  
• JPG costs the makers, whereas a raw format like DNG would perhaps be cheaper for them to implement
  

Actually, this could serve to make the cameras cheaper, as the camera makers would not have develop and include proprietary embedded image processors for their cameras.

so it seems to me that its still true, although while we lack any "conduit" to pipe our images though to download, perhaps software like Lightroom works out better anyway ...

Anyway, if Leica have managed to shave thousands off their camera by minimising the on-board processing and focus on the hardware that's fine with me ... as I get better images from my Canon 20D RAW images now with the software tools I have than I did back in 2005 when I first got it.

As Canon has long since given up developing the hardware engine of that camera (like you could only ever tweak it with firmware anyway) I'm glad that I used RAW, as years later when I want to get a print of this:




I can do it better than the JPG from the camera....

funny things

I am in the midst of packing up my stuff go back to Australia and was packing my Epson 4990 scanner for the journey. While sealing the box, I noticed something on the original shipping document. You see I bought my Epson 4990 used on eBay ... there being nearly nothing like this in Finland I bought it in Germany and paid (don't ask) to get it shipped here. The funny thing is that according to the shipping consignment note, it seems like I bought it from Noritsu Deuctschland.

Funny, after being a fan of the Noritsu scanning process often associated with 35mm mini-labs to find I buy a used Epson flat bed from them.

go figga