Tuesday, 26 May 2009

lens tilt on a Panasonic G1

One of the things which seems to be completely incomprehensible or ungraspable by the majority of photographers is the benefits of not having a stiff lens - body coupling. To a large format photographer such a restriction would render the camera all but useless.

Before I go much further I guess that I should explain what this is about to those readers who have never used anything else but compact cameras, 35mm and DSLR cameras (although there will be a few 35mm and DSLR users who know what I'm talking about already.

The image on the left is taken with a 'standard' lens at about f2.8.

As you see in the image focus is towards the bottom of the image around where I've drawn a blue ellipse.

The "depth of field" runs out due to the large aperture and as the table top moves away from the camera (towards the top of the image) things get out of focus or blurry.

Most photographers who were never trained on or used a view camera will say "sure, you just move the focal point further away to the middle of the image and stop down to f16 or f22.

Voilla ... its all in focus!

Well those of us who were trained on view cameras know that there is another way which is actually better (heck, classical education has merits?), that is to apply some tilt either to the lens or the back of the camera. View cameras have lots of movement aside from just focus you know. Check them out if you don't know much about them. They don't all have to be funny old stuff either, as you may be surprised to find that they are still used today for the top end photographic work on stuff such as jewelry or products.

So what doe the alternative look like?

Well, like this image.

Here I've held the lens in my hand and just tilted it manually (un-attached to the camera) to show that I can move the focal plane away from the normal "parallel plane".

You can see that focus goes up the table and even at a diagonal (gosh, I haven't taken takky images like this since I first played with a view camera decades ago in my student daze). I could have tried to just get the whole table in focus, but then how would you know it wasn't just kept in focus by depth of field at f22

This allows the photographer to not only better control of focus, but also gives control of composition giving the power to direct where the viewer places attention and remove items of distraction from attention.

Its well worth clicking on that image and looking around at the detail of where the focus goes.

Now despite there being no secret in this it is one of the best kept secrets of photography since rigid cameras came out. For years some photographers know about this and really long for such flexibility in rigid cameras and Canon provided their first Tilt lens with the TS 35 and then with the EOS system expanded it to include the TS-E 24, 45 and 90mm lenses (check them out on the Canon Camera museum). While I started using them as soon as I could afford it much to the marketing divisions annoyance they remain misunderstood and unknown.

Perhaps the problem was that serious photographers thought that 35mm was a 'toy' format ... there were some offerings in the medium format (MF) area such as the now gone Hassleblad ArcBody (reviewed here) and Flexbody. But MF being the expensive area it was I guess that most photographers who needed such things kept using view cameras.

Enter Digital

The digital age has brought us digital cameras which exceed the ready quality of 35mm and often come close to what was once MF quality. With photographers now using DSLR in earnest Tilt lenses are now entering a popularity never had before. With a TS-E lens on a DSLR camera you can do great things, for example I found that a fellow called Keith Cooper has a good review here.

Canon has has added a 17mm lens (perhaps to attract the APS sized sensor groups) and even Nikon has introduced (finally) Tilt lenses.

These are lovely devices but the problem is they're real dear. The Canon TS-E series lenses will set you back a grand ($1000) and even the old TS 35 (which is neither wide enough or standard enough to be useful) still fetches about US$500 on eBay.

lovely, but whats this got to do with the G1?

a good question, and I'm getting to that! You see to allow movements and tilt having a bigger "image circle" is essential. Large format lenses produce an image much larger than the film to facilitate this. This makes those lenses expensive and its also the reason that the TS-E lenses are expensive. They have to make an image to cover more than the 35mm frame.

Now, the sensor of the G1 is a 4/3rds sensor which is around 18mm x 13mm in size. A 35mm frame is 36mm x 24mm in size. So any lens which was designed to work on 35mm has plenty of coverage for a G1 and the short flange distance give the designer plenty of space for the mechanism.

Are you already using 35mm lenses on your G1 by an adaptor? I know I am. Heck its the main reason I bought the G1.

Right now, the only 'alternative' to the expensive TS lenses is stuff like the Lens Babies (which are essentially not good optics) and cost about $250 anyway. Imagine using an adaptor like that on any or all of your 35mm optics. Great (and cheap) lenses like 28mm and 50mm become equal to lenses like TS-45 and TS-90.

So if we could get an adaptor to allow tilt then the G1 would become one of the bargain of the year cameras for product and creative photograhpers!

In case you don't know the G1 well, the major thing which differentiates it from a conventional DSLR is the lack of a Mirror. The design is much more similar to cameras like the Bessa L which simply have a shutter behind the lens.

This means that to allow mount of 35mm SLR lenses that an adaptor must space off the lens by some 24mm. Looking at the picture to the left you can see that is quite a lot (this is a actually an FD 50mm f1.8).

I've drawn in some curves to show where a tilt to effect a nice easy to deal with center tilt would pivot around for such a lens.

Clearly there is plenty of space for a mechanism to mount to the G1 and attach a lens.


Whats in it for me?

Well, while I'm an ideas man, I'm a photographer not an entrepreneur and I'm also a great believer in the free market. Since the internet gives us (buyers) the possibility to form a community and become a cohesive buyer group we can start to have a say in what gets made for our needs (rather than just be consumers buying what ever gets served up). To some extent this is already happening with eBay sellers like this guy, and this guy are already making great adaptors (and cheaply) for the G1 before Panasonic even offered them.

I've had communication with both of these guys on the topic (one was interested the other didn't reply with much) but I'm sure that if they knew they'd sell some they'd be turning them out soon.

So, if you're as keen for this sort of development as I am why not send them an email and express your interest or even place a comment here on this article (as I'll be sending them this link too).

I've suggested some possible ideas such as this one (which is adapted from the Canon TS 35 mount by a Russian maker)




and another based on the simple mount system of the lens baby design. I don't know if that ball pivot is "patented" but it might not be when applied to an adaptor
or perhaps something like this?



anyway ... certainly heaps of other designs are possible.

Lastly for those interested in how I've done this without an adaptor, here it is.

I've put my smallest extension ring (12mm) onto my 28mm to force the lens iris to be fully open, then I've gaffer taped some rubber onto the bottom to light seal flexibly and neatly against the lens mount ring (and protect the camera too).

This allowed me to focus by simply pulling and tilting the lens to where I wanted the focal plane to be while looking in the view finder.

simple but neither precise or easy to use.

I've added 2 more samples of what can be done. In this image I've moved the focal plane to be parallel with the the bottle of cleaner but twisted it a little away so that even at the foot of the bottle the marker is blurred.



and then in this one I've tilted the focal plane back to get the table top in (nearly) in focus (plane runs from the mat in front to the middle of the salt shaker.


inexperience graphics people who may be experienced in photoshop and the use of selective blur with a gradient should note that the de-focus on the top of the bottle is impinging on the less de-focused items in the background (top) of the picture. You just can't get this kind of fully 3D de-focus after you've got a 2D image. This means you need to do it in the camera. And why not, with the right tools its easy!

10 comments:

Anonymous said...

Very good idea, if purchase price could be around ~$200. I imagine you would sell a few thousand units over a few months time. I would prototype it, and send it out for bid in the Shenzhen City of China, I bet you could get quotes for build under $30 with an initial run of 1000, then market, build a website with video's as well (the GH1). I will be one right away ! design it so that tilt could exceed the standard 8. Really like your idea, keep us posted

Anonymous said...

I think the ideal configuration would be at tilt shift adapter between micro 4/3rds camera and 4/3rds lens mount. There are many adapters already for major 35mm brands and 4/3rds.

You might also want to contact these guys. They seem to be in the tilt/shift lens and adapter business already.

http://araxfoto.com/

obakesan said...

nice idea ... I've contacted them

thanks :-)

Jeff said...

I'd be quite interested in purchasing one of those should they become available. I've looked at the lensbabies and just really don't like the quality of their bokeh at all.

rex said...

I'd definitely buy one for the GH1. Anyone check if any of the Newport lab optical positions might be adaptable for this use?

Anonymous said...

I just have the same idea of having tilt-shift adapter for G1 (m4/3)... M42/FD/OM all have much longer flange focal distance than m4/3 format.

Recently I have sent emails to two eBay adapter sellers but I haven't got any reply from them yet.

I think it's definitely practical, but the problem is the difficulties of making such tilt-shift adapter, and if the cost is too high, people may not buy it.

Anonymous said...

Yes, sign me up for this too. I'd love to have a tilt lens for the GH1.

Anonymous said...

I would buy one immediately

Anonymous said...

Me too, but the tilt and shift axes should be able to rotate independently relative to the camera and to each other.

For instance, the mechanisms of the NEW Canon TS-E 24mm F3.5 L II and TS-E 17mm F4L are like that: the tilt and shift mechanism rotates +/-90°, allowing shift in any direction, and in addition the tilt mechanism independently rotates +/-90°, allowing tilt in any direction relative to the shift. Another example is Hartblei's Super Rotator design.

Johnny Lim said...

Believe there is already one such adapter made by some italian guys.

http://43rumors.com/tilt-lens-adapter-for-microfourthirds/