Comment on the use of certain lenses

[Tom Caldwell]

The GXR-M seems to work well with most lenses and the restrictions and results seem more a factor of the lens itself than the camera body and M mount module.

This seems a silly statement as most of the chatter is about loading up your GXR-M with the finest lenses that money can buy.

What I mean is that if you do put a very expensive lens of outstanding performance on the module then you might expect outstanding performance and perhaps even push the GXR-M to its limits. The lesser sung story is that it will happily play with kit zoom lenses and produce images quite convincingly within the performance of that lens design.many sales of this EVIL type style of camera are made with modern kit zooms. Consequently you might think that those that were happy with a kit zoom, or even a higher quality zoom performance might be using their GXR-M with a manual zoom lens. But they are obviously not. Why? - simply because almost everyone that buys a GXR-M combination is from a separate market area. Zoom lenses interest another market segment entirely.

But this was not the real purpose of starting this thread. My purpose was to note carefully that quality manual lenses for slr cameras work fine as well. I am not rigorous enough to know precisely if there is any loss of performance from these lenses on the GXR-M but I might think not. You sacrifice a larger size to be able to use some of these older gems but nothing much more I speculate.

However I have just noticed another characteristic last night. I was photographing a fast-moving Roller Derby event last night. A test of any camera. I was dutifully using my Canon gear and including a 50mm f1.2 and a 200mm f2.0 lens. ISO 1600 all the way if you please. No way that somethig like a GRDIII and even an A12 50mm f2.5 would be struggling. f2.8 is about as slow as will cope with the movement in the light conditions, and it is not really good enough as my 70-200mm f2.8 always tells me.

Intrigued I wondered whether the GXR-M with either the Samsung 85mm f1.4 or Pentax 50mm f1.4 might work well enough. Manual focus and Roller Derby? Anyway I might have a few images that worked . I have now posted an example image (later). I think Mode1 focus assist and concentration on smooth focus adjustment does make moving target photography possible. With a GXR-M manual focus is possible in these situations if harder and more a test of personal skills.

What was very plain to me though is that in the situations where you are continually adjustimg focus to capture a moving object then the Samsung 85mm f1.4's heavily damped focus action is far too heavy for this type of work. Smooth and certain for non moving objects it is far too stiff for moving ones. The Pentax on the other hand was just about perfect. Just the right blend of smooth knife through warm butter and accuracy. Too loose amd it would not be accurate enough, too well damped and heavy and you just cannot keep up focus with that moving subject. When I came home I had to try the focus ring movement "feel" on my Rikenon 55mm f1.4 M42. Just as smooth and creamy as the Pentax, I wished I had taken it with me. Not much difference in the technical specifications but the Rikenon is physically much larger and I suspect just that much a finer lens for it.

I was just experimenting with a new technique and have not worked up any skills in that area. My sole object was to see if it were possible to do at all and not to make practised quality images.

I think it important test as I think that the GXR-M is on the cusp of being at least a semi-professional all rounder camera unit. But forget any manual lens that does not come with a very smooth lower resistance focus ring. In this regard even such lenses that might have a tiny focus ring "band" like a pancake lens would not work well. Give me the big wide grippy Takumar-style focus ring grip and it might just be something possible on a regular and consistent basis.

Of course only oddballs would ever wish to consider taking images of fast moving subjects with manual lenses (grin).

Tom

[Wiener]

Hi Tom,
I guess in the good old days of only manual focus, one had to focus on a point and hope the action passed through it. So, being old enough to remember those days, I don't think you are at all mad!
Also, I have been following your thoughts and discusions concerning the GXR M-module with interest. I too would love to have a 'one system' approach to my photography for all the reasons you have suggested. Not sure if my pockets are deep enought for the M-module approach WITHOUT falling back on those lesser mortals which now languish in dusty second-hand camera shop windows. With the ability of good output from high ISO, some of the zoom-glass with f5.6 maximum aperture might become viable...or perhaps not! I would love to have a module for a week, just to play around to establish it's potential. Otherwise I am a little afraid that the M-mount will just have to float around in my dreams for a little while yet!
All the best,
Andy

[Tom Caldwell]

Andy

It is hard to exactly express what I mean. the GXR-M in many ways is "just" a mount for manual lenses and thus it picks up all the manual lens theory. What I am exploring right at the moment is that with focus assist and it's highlighted "ripples" it is possible to quickly see just what is in focus. Therefore if you have an appropriate lens on board that is fast enough, and seemingly above all, has a very soft smooth focus ring action then it is possible to "follow focus". But I think I would need a lot of practice to get good at it. However this takes the GXR-M more into the league where manual lenses are truly more useful than people generally realise.

Obviously in the circumstance I describe the action is far too fast to rely on screen magnification for focus. Mode1 seemed better last night as it showed the "true" image with highlights but now I am thinking that maybe if I had used the more weird looking but seemingly more easily used for accuracy Mode2 it would have been better with perhaps one eye looking over the camera to juggle real life framing against focus accuracy via the lcd.

With Roller Blading on a fixed course the action does pass through fixed points but unfortunately the "incidents", action and best images can be all over the place.

I think focus tracking on moving objects can be done with the focus assist on the GXR-M - harder than static objects but certainly do-able but much practice is going to be needed.

I mentioned zoom simply because the GXR-M does zoom just as well as whatever type zoom lens you like to fit. Zooms are always slower than equivalent prime lenses and good ones are usually larger and expensive. However you can get a handy enough knockabout manual zoom for the equivalent of US$60 that is more than worth it's money. So why not? There are times with "knockabout" photography where a cheap light serviceable zoom on board gives a compact unit and saves a bagful of "cracking good" primes rumbling about unnecessarily. We are not always out with the intention of getting that award-winning image - or am I out on my own little tree-limb?

Tom

[Tom Caldwell]

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An example of panning follow focus with a manual lens on the GXR-M. Might just be a lucky shot but I had been tracking the athlete down the straight and caught this as she passed around a turn.

Black and white makes the image stand out better from the background colours.

Image is at f1.4 and I think this was one of the instances where the Samyang 85mm f1.4 actually worked despite it's over damped focus ring. The Pentax 50mm f1.4 was a lot more comfortable and reliable with its less heavily damped movement. The Rikenon 55mm f1.4 is even smoother with less resistance still and this could be put down to it's larger diameter providing better leverage and control and it's larger shaped focus ring grip being more assured. I also note that the Rikenon has a longer throw of movement between 10 metres and infinity than the Pentax which is tiny. I had no real use-problems with the Pentax short throw but have not used the Rikenon yet for this type of work - it will be interesting to see what works better in a real life comparison.

Tom