Wednesday, 16 April 2014

Easter views

For an Australian Easter in Spring is something of an epiphany (not that this is my first one). All the (apparently hollow) symbolism actually has meaning when experienced here in the north. Perhaps even more so in the very far north (such as Finland) where the harsh colds and frozen water of winter gives way to the burst of growth of plants.

Reasons for flowers suddenly make sense as they symbolise the cyclic regeneration of the things which seemed to die and pass with the coming of winter, to be renewed with the cycles of the seasons.

So it makes sense for the the Christians to have hijacked this occasion with their Easter message of death and life after the everlasting life after death.

I must say that as one who does not believe in reincarnation (the variouso non christian views of it), and is also vexed about the idea that there is anything after life (but certainly not in outright denial), I have found over the years that the Christian messages at Easter are somewhat confusing and incomprehensible (such as the God who is man thing, the sacrifice of God himself as a part of Christ ... the list goes on). I lay the blame for that at the feet of those who so incapably teach it. Far more are called to serve Faith than seem to be able to teach. Perhaps too I as the student was not yet "prepared ground" to allow such things to grow.

Back at the end of 2012 I wrote that who I was and who I was becoming was dead. Of course this "death" is somewhat of a metaphor. Perhaps that post (or this one the year later) may go some way towards explaining that metaphor.

I re-watched Cast Away (Tom Hanks) lastnight (having put it off a few times for various reasons) to find that there was a message within that quite similar to my own journey.

My view is that while Chuck the human survived, so much of Chuck died that his survival grew him into a different version of himself. His epiphany came when he realised:
I couldn't even kill myself the way that I wanted to, I had power over nothing.
When he came back to "civilization" he was clearly a changed man. His perception of time "that ticking clock" was altered (perhaps forever) by those long years alone, where clocks had no real meaning. He had in some ways discovered things inside him which he never knew existed.

I think its fair to say that the Chuck who landed on the island died, but the Chuck who emerged was wiser stronger and visibly healthier than the dead Chuck.

Chuck had been reborn: that my friends is the message of Easter.

You don't get that singing in a church and  falling backwards in a bath (paying money for playing a role in a theatric event) you get it from emerging from suffering.

Let me tell you something obvious which many can repeat but don't grok: suffering fucking hurts.

Since Anita passed away I have been attacked at all angles (yet protected in some ways). I have had physical degradation from my the infection near my heart and the death of my wife (closest to my heart) and the constant and grinding loneliness to fill my every night.

So like Chuck I have been in a kind of survival mode since then. Where I just try to keep breathing, even though I have no reason to hope.

These last few months I have had no plan, no idea what tomorrow would bring and even thoughts of plans bring me nothing more than the reminder that my plans were all destroyed that moment when I got that phone call to say she was in hospital with a tumor.

Of course death does not come in an instant, it takes time for everything to sink in and even some days for things to happen. None the less I see that who I was is now gone.

But I have said this before, todays message is about the realisation that (even though I have totally no idea what will be in the furture, even though I still feel the pain of her absence) that life has not finished yet (despite me wishing that it had).

Unlike Chucks fiance Kelly, I have totally no hope to hold onto that Anita may be still alive, yet like her I feel that sense of hope, that the love that bound us still lives.

Somehow this taking a step every day has shown me that while plans can not be made with certainty; that the journey of a thousand steps is reached by taking that step every day.

The difference for me now is that I don't have a map and I don't care. Perhaps that means I will never be lost?

While in many ways the colour has gone from my life at the moment there is still beauty in texture (expressed black and white). The daffodil image to the left here was one I took with my "big camera" of some daffodils that Anita bought one Easter past for our home in Finland. Finns quite like these bright and beautiful plants at this time. If you click it a larger version will load and I hope you will enjoy the textures of that exploring the small beauties in that image.

If I have taken anything of Anita with me into my future I believe it is the understandings of the beauty of small things that she gave me.

The Cathedral at Tampere has some of the works of the artist Hugo Simberg (Anita loved his works and introduced me to them). Of all the churches I've ever entered this is the only one where behind the altar was a message that there is something beyond the grave. Not like the typical Catholic Cathedral: stagnant and brooding where ultimately a message of "pain and death hangs on a cross" looms ... but instead a message of hope beyond what seems hoplessness.

perhaps this is the most meaningful message of resurrection in our daily lives?

Happy Easter and may you find peace

[to Anita: forever your love]

Tuesday, 15 April 2014

noise about sensor noise

Just the other day I got a comment on a post about the validity of using my GF images to postulate how much better the Sony a7s may be at its high ISO setting.

I thought about this for a bit and realised that I'd not actually done such a side by side comparison myself but had just 'observed' the changes each time a new camera comes out and thought "oh, well ... nothing startling there". So with that in mind I thought I'd download a few images (as I don't have a more modern camera) and while at it download all datasets from the same source (to get some sort of consistency).

Well clearly its hard to get consistency in testing sources (especially when they get their money from ads and I don't get money). So with that in mind I pulled down GF-1 and GX-7 images from DPReview at 3200ISO to compare.

My view from the start was that sensors have not made any great leap forwards but that signal processing has. Physics would indicate that more pixels from the same size sensor (GF1 is 12MP GX7 is 16) would give more noise per pixel, but if done smartly the camera maker can probably do some pixel binning to use the information from the adjacent photo-sensor site to "settle" the noise a bit.

Then when looking at the data its important to not confuse advances in RAW processing (such as Adobe has built into ACR) and advancements in pre-write in camera, which do some adjustments in hardware on the data from the sensors. And yet again from those.

To sort that out cunning software tricks in demosiac to an RGB image I used DCRAW to produce linear 16 bit files of the images from both cameras.

Firstly lets look at the GX7

Interesting, I had to double check that I had not used the 'low light' version they now include. It looks very clustered to the left perhaps they were trying to extend the (known reduced HIGH ISO) dynamic range?


This image shows far less clustering and perhaps suggests a better actual dynamic range.

Processing the GX7 file with parameters to use camera white balance (and gamma) [dcraw -v -w -6 -T P1030049.RW2] I get this

where it seems they've chosen to skew the data away from the lower end of the recording spectrum (where floor noise will be the loudest) and then in demosaic time, strech the histogram to get it to fit keeping black is black.

Of course you'd never see this when looking at the JPG (or probably even a Lightroom or ACR image).
So when I've evened out the dark areas of the GX (as will happen in any processing) I get this:

I've chosen to look at the RED channel for each camera (which has more noise than green) to show the levels of noise. The noise in the GF is striking but there is quite a bit of noise in the GX too ...

Probably Panasonic could have reduced that by ignoring the bottom end (as they've done in the GX) and perhaps also by adding some pixel binning before writing it out to the RAW file with a bit of pixel binning.

To simulate that I've down sized the view of the GF1

Looks remarkably similar now to me. If I could take an image with the GF where I ramped up the sensor gain circut and ignored the bottom half and added some pixel binning then I'm sure they'd look about the same.

Why may they have taken this approach? Well if you are interested I suggest reading this article over at the University of Chicago (totally worth the read for the technically inclined). The author examines how you can keep apparent tonal range as long as you have enough noise to cover it up.

NB: from that page

To take his point a bit further, I've taken a stepped image and selectively added noise into the RED (top noise band), then BLUE (middle noise band) then both RED and BLUE (bottom noise band).

Now, do you see 'mottely' colour effect in your images like anything in that simulation? If so its the effect of colour nose between the channels. I discussed that some years ago over here. Actually to make it clearer than I understood in that page the JPG noise being 'funny kind of worse' in those images was the result the JPG noise reduction algorithm smoothing (smudging / wavelet blur) the noise and resulting in the colour channels being different. (then there is high frequency noise and low frequency noise ....).

So I expect that Panasonic is just more cunning than people give them credit for ... reduced the effective tonality of the sensor (by humping it right) and cutting out as much of the floor noise as they could.

So my view now is that there hasn't been any really big changes is sensors, just adding in more pixels and working the signal processing angle to wring out a few more bits of gain.

PS: I had a bit of a late brain wave and thought I'd go sus out what DxO said too..

Overall Ratings:

The GX and the GF1 are rated similarly while my GH1 (my preferred camera anyway) is rated higher than the 'newer sensor'

so then Signal to Noise ratios

again similar with the GH1 leading by a nose

then Dynamic Range

With the GH1 leading the pack at 100 - 200 ISO before the GF1 falls away a bit and the GX holds it with my old faithful GH1

So I feel that all round this backs up my view that there hasn't been much stunning change in Sensors and I really do hope for something excellent from the Sony a7s

Wednesday, 9 April 2014

but the NEXT Sony A7

Readers of my blog will know that while I was quite interested in many aspects of the last (two?) iterations of Sony's mirrorless full fame camera (like its a full frame mirrorless camera about the size of my GH1 and with all the lens adaption advantages conferred by mirrorless) I just wasn't totally moved.

However just the other day I stuck my head into a website and was greeted by news of the third variant of the Sony a7 full frame. The a7s. As soon as I read that the next version has a 12Mpix sensor and high ISO I had an Austin Powers moment...

The reason for this is the very welcome addition of high ISO performance : 409600 ISO.

I have long argued my reasons for desiring full frame on the basis of shallow normals and nicer wide angle lenses. Especially when it comes to wide angles and manual focus there is a wealth of single great lenses out there just aching to be married up to a great camera again. It is in this respect that 4/3 (micro or otherwise) and APS falls down.

My $20 Canon FD 50mm f1.4 (a beautiful lens) married up with this body would be superb. It would give the wonderful Bokeh I know it does and give better shallow DoF than the (commonly dribbled about by King Wangs subjects) Nocticron lens for micro43 (which costs nearly as much as just this body is likely to).

Assuming the actual results of this camera are good, then suddenly the 2 stops DoF advantage of micro43 disappears into the ISO haze and IBIS becomes far less significant (for stills, for video its still pretty dam good). Let me explain.

I like to take pictures with my camera, and digital has allowed me to use cameras in much lower light than I could ever have done before. Unfortunately despite this temptation there are limits imposed by the ISO. For instance: I took this shot with my GF-1 and the 14mm f2.5 pancake.

Even with f2.5 and ISO 3200 (max) the exposure was 1.6 seconds ... well out of the usefulness of IBIS (or Mega OIS...). Plus the amount of noise in the shot makes it look seriously grainy ... sometimes that works, sometimes that doesn't.

Now with this Sony things have changed, for instance:

Looking at this chart you can see that by upping the ISO from 3200 to 409,600 (God I get giddy just thinking about how high that is) you can see that I can get right up to 64th of a second exposure which is actually quite reasonable at capturing motion (no fast motion mind you) and the use of IBIS (for stills) is suddenly moot.

To me this opens up FAR FAR more photographic potential than giving me extra megapixels (which my lens won't resolve nor will I see if not using a tripod anyway).

For photographing my friends and family I totally HATE flash, its ugly (looking like a search light) and screams out to everyone in the room that you're taking photographs. Shots like my favorite shot of my niece would be rubbish with flash ...

This shot was taken during the day, but this Sony now opens up potentials for shots like this during the evenings (without looking like they were ink-jet printed onto sand).

I have argued that IBIS brings very little to my photographic table, and while it may be nice in assisting people to hand hold telephoto lenses, for normal to wide its sort of pointless. With shots like this:

Image Stabilisation brings nothing to the table (although I must say that the movement was nice and I've come to like it on occasion) as its clear that my camera technique has kept the subject sharp anyway IBIS would bring little to this image either.

Again this was at ISO 3200 and looks like a noise fest on the smaller sensor of 4/3. I would warrant that the new a7s will make much cleaner images at ISO 3200 than this, and probably much higher. Thus allow me to pick the ISO I want to capture movement or display it.

For example in that above shot the GF-1 had pixel level noise like this at (just?) 3200 ISO:

While the previous model a7 (in a shot I found on line) had pixel level noise like this @ ISO 12,800:

Which is about the same as the GF-1 at 2 stops higher ISO, so I expect that the a7s will be easily better for another 2 or more stops.

I wait with bated breath.

This does not mean I'll abandon micro4/3 as it will work with my Telephoto and Super Telephoto lenses (such as my FD300mm f4) to keep me getting the advantages of the crop factor and make my 300mm into a 600mm (which I like for nature work)

Bring it on!