Sunday, 17 September 2017

Snapseed and noise (but from where?)

The other evening I was out walking (to watch the ISS go over) and took this image with my Oppo F1 phone (it being the only camera I happened to have with me) while I was out. (Note, blogspot seems to be causing posterisation on the images I load with its recompression of gradients ... Uhgg)


I took it with the phone/cam set to RAW so that I'd be able to play with the image later (cos I already know how much better that can be). I put it into Snapseed (which has become my default phone image processing tool) and applied my basic preferred steps and was disappointed by then noise it had in the image. I wanted it for Facebook so knowing it was going to be scaled back anway (meaning noone would notice) I cropped it a bit and resized it down and loaded it up. So wonding if the processing of HDR Scape was introducing the noise I pulled this image out of the same DNG file and had a look around. Even at this scale the noise is clear..


so lets have a pixel peep ... (cos even scaled back it looks a bit 'rough')


quite noisy ... and applying a little HDR (I've found gentle HDRI to adjust the brightness and at a low filter level cleans up a lot of vignetting) to it only made this worse.


I tried a few tools to remove the noise and was resigned to it being "how it is" at an ISO over 1000 (1229 actually) in low light.

Then it occured to me "I wonder what DCRAW Mobile would render" as I know DCRAW has wavelets for noise control. So while I was unable to see any difference using those parameters, DCRAW did a significantly better job.


without seeming to make the image any softer really (no sharpening applied, but I think Snapseed always does a bit).

So while this makes me feel comfortable that I can push my phones limits that bit more, it also makes me wonder what Snapseed are doing. I suspect that they may be adding noise in their process because (to save space) they may work with lower bit depths. Its well known that adding noise can cover gradient posterisation caused by inadequate bit depth. 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 with reduced bit depth (faster to process) as long as you have enough noise to cover it up.

NB: from that page




Given how fast Snapseed processes my DNG files (compared to DCRAW) it makes me wonder if they are not doing something like that. I already know (from asking the developer) that once the conversion from DNG to a demosiaced image occurs they only work in 8 bit ... hmmm ... I for one would be very interested to know why there is so much more noise even without the HDRI filter.

So I have reached out to the developer of DCRAW Mobile to ask if the wavelets are actually doing anything and hopefully they'll comment back here. Perhaps even answer if the slowness of demosaic in DCRAW is exacerbated by lack of threading on phones.

Meanwhile, my final image is this one, which somehow I find not quite punch enough but anyway:



Friday, 15 September 2017

The Kicked Down Sand Castle Effect

Imagine you are a kid down at the beach building an elaborate sand castle. Your family gets there early in the day and in between swims you build this great structure.

You spend hours between swims and a bit of belly boarding adding to this castle.

Then someone (like your mean brother) comes along and kicks it over and you're in tears about it.

Depending when it happens in the day (say early) you may start again and build on that foundation and make a better castle. If it was nearly time to go home you may just give up and walk away, being mad at your brother all the way home (and perhaps for some time to come).

This is how I have come to currently understand my own grief at the loss of my wife.

The metaphor is not too far from the truth because we are all only here on this "beach" for an amount of time. We eventually "go home" and must leave behind all we have made here. Yet when we are building our sand castles we are not thinking of "when we leave" we are absorbed in the the thing we are making, in making it better, in making it "just right". Sometimes we've only seen the sand castles of others, and we shape our own on that. Other times we've also had a little experience in building them in previous summers when we were younger, so we can do a better job.

Although we know that we must eventually leave them, we may harbor the idea that it will be there again tomorrow (sometimes it is). When the time comes to pack up and go home many will plead for a little more time, no matter we always look back at what we made as we are leaving the beach. But if we have it leveled down before our eyes it somehow hurts more, because we are attached to it and because it seems so unfair.

Past the initial shock and spending time in reflection (not just being upset, although there is surely a time for doing only that)  I came to see that without Anita, all that I'd built was smashed and meaningless. I soon also saw that my time on the beach was drawing to a close and there seemed less point in trying to rebuild.

Unlike sand castles much of what we have in life is needed to live comfortably; the houses we live in, the furniture we use, the stuff we have. Much of it is needed to make our lives comfortable, easier and doing things more convenient.

I don't believe I have enough time to ever make a castle again but I'm trying now to make something. Its not easy and I'm always struck with "what's the fucking point" ... I regularly think "fuck, can I just go home early". Of course some do just that.

As I've reflected earlier this happened to me at an awkward time, too old to really ever be able to build a decent sand castle again, too young to just "go home early".

So now I've bought another house, in a different place. There is much that needs doing to it, but its actually livable right now. Its small enough that I don't need to attempt anything grand, but enough work to keep me "on task" for some years.



Many times I feel like its all too hard, and I wonder "what the fuck have I done". But having kicked the can down the road for some 5 years now, I have decided its time to try. Its a total break from where I've been and in some ways like nothing I've ever done before.

Lets see what I make of it.

Wednesday, 13 September 2017

Camping Cooking at Home

I haven't been camping for a while now (just day trips), mostly because of the unsettled life I currently lead (indeed I feel like I'm camping most of the time sometimes). So I thought I'd share some cooking ideas which I essentially adapted from what I make and eat when I go camping.

Camping cooking is (well for those who aren't packaged food types) identified by the following points:

  • easy to make and serve
  • easy to be carried (no need for refrigeration)
  • easy to clean up
  • good nutrition (energy which you need and vitamins too)
Oats features in my cooking a lot actually. Not "instant" oats, but just good stout rolled oats, which look like this in the pan:


For this recipe I basically use a non-stick frypan (to minimise my efforts needed in stirring). 
So one of my favorites: savoury oats


Ingredients: chopped leek, sliced salami, sesame oil, chilli flakes, oats, water.

Method: Fry the chilli and leek in the oil for a bit, toss in the salami. 
Mix a wet slurry of Oates and pour that in. 
Cover and reduce heat / flame to minimum. 5 minutes later whack on the plate, add a little Tabasco sauce if you like ...



For an extra dash of colour add a quick sprinkle of Paprika powder at the frying stage (helps release the aroma of the paprika)

Enjoy

Saturday, 2 September 2017

keeping away the "GrassHoppers"

In my family at least we have a tongue in cheek way to call Kangaroos "grass hoppers", not the least because they hop out of the grass at you.

So motorcycling around up here at the moment the use of a tool for that is intended to make encounters with the little furry lovelies less likely by making them aware of me sooner. They are little ultrasonic "whistles" and look like this.



A quick video



I'll let you know how it goes

Thursday, 31 August 2017

Flogging a Dead Phone (for pixels)

well my Oppo F1 is not exactly dead, but it is in the view that they are no longer sold new by Oppo (perhaps you can get one somewhere).

The reason for this post (which will be of little interest to even less people than usual) is to provide an answer to a question which was asked of me recently:

Which is better: DNG (*and then process the DNG, with say Snapseed) or the Ultra HD mode
So I set about to answer this question...

Firstly lets look at some images, the overview I took, which has plenty of "natural detail" and is at a distance where the blur caused by atmosphere isn't going to effect things (like a mountain range):



I took (essentially) 3 shots the Ultra HD, then a DNG (which then automatically takes a) JPG.

Basically the Ultra HD mode uses some upscaling and combines (as near as I understand it) a number of images and attempts to work out the sharpest portions of each image to:

  1. jam together the best bits to make an over all
  2. upscale it and save it to a JPG

Lets take a look

So lets dive into the pixel peeping now shall we? First lets look at a segment of the OOC (Out Of Camera) JPG and the Ultra HD at the same level of detail (which means that the UHD will be shown at 50% so they are effectively comparable.


To me there are no surprises ... the two images look close, with the usual "over sharpened look" to the OOC JPG. Nothing screams out at us however.

I've never understood the mental masturbation over MegaPixel Madness, and I'm willing to bet that 99% of the images from these phones will end up on Facebook or some other social media and therefore scaled down ... very very few will end up being printed taking advantage of the 4000 pixel width ... but most of the "selfieObsessed" users attracted to the King Wang name will not even understand any of the above anyway ...

The next step is to look at the UHD more closely and compare that to the OOC JPG. To make this easier I did a bicubic upscale in Photoshop of the JPG so we can see clearly:


This makes it pretty clear (to me at least) that the final written JPG just doesn't have the "right stuff" to make an upscale work ... meaning that this is a win to the UHD image. Probably because the image is upscaled prior to the mushy crummy JPG algorithm that Oppo uses is applied to the OOC JPG (meaning its likely it does it in an uncompressed image space, perhaps even RAW).

Ok, so now lets take the DNG (which I've already established to be heaps better than the OOC JPG in so many previous posts it does not bear repeating), Starting with the DNG (processed in Snapseed with not much more than a straight conversion, which is of course then saved as a JPG by Snapseed) and then upscaled in Photoshop to compare to the UHD at 100%



Which is very close, but to me actually gives better tonals in the ridge of the rear wheel arch (the rust and cracked paint more clearly defined). So even upscaled the DNG is competitive to the UHD

As well (as a side benefit) we have the opportunity to do more post processing (without getting posterisation of the sky)  from the DNG than we would from the UHD (because we're dealing with more bits at starter).

For the hell of it I thought I'd downscale the UHD to compare it at 100% with the Snapseed to see if there was something in that:



Which to my eye looks pretty good (although I prefer the colour balance of the DNG over the UHD).

So what's the point and what's the benefit to a photographer? Are there drawbacks?

Advantages , Similarities and Drawbacks

As it happens the DNG is about the same physical size as the UHD shot (even though its a JPG), but the nod goes to the DNG because its actually a little smaller (should you be pushed for space on your phone) at 25Mb vs 26Mb (for the UHD) : advantage DNG

A drawback of each is that you have to remember to engage that mode (either RAW or Ultra HD), however the UHD has the additional drawback that (because it takes multiple images) you have to hold the camera steady longer ... or get a crummy shot. advantage DNG

Because the UHD is a JPG, you can (assuming you want to) just get a big print made directly from it and know that (printing to 140cm monster prints) you'll get a much crisper print than from a regular OOC JPG and won't need to bother with processing software or mussing up your hair : advantage UHD

Myself I'll keep using DNG because I happen to be OK with the use of Snapseed (or other future advances in DNG processing), however I hope this has helped you to work out what you'd like to do and why.

:-)

Friday, 25 August 2017

Stupid stuff I buy

It was fun




So now I can reveal more of that minor purchase


:-)

Tuesday, 22 August 2017

religious nonsence (or the media selling the electric car barrow)

Sadly sustainable development has gone all out to attract the "Public" for some years, and while I did my Masters in Environmental Science I must sadly admit there is quite a few in the "cohort" who are neither scientific nor rigorous. The Electric Car Advocacy is prime among them.

Recently I see that the ABC has become a mouthpiece for the push in this direction as if they've already decided. Sadly rather than present unbiased information they unashamedly promote stuff that doesn't even add up ... for instance:

http://www.abc.net.au/news/2017-08-21/can-electric-cars-go-the-distance-on-aussie-roads/8827926

This unashamed piece can't even present the facts reasonably and chooses to cherry pick its data. It starts by asking the obvious question of: Are electric cars cheaper to run


and comes up with the quick answer of yes and yes, but as they indicate its not really that simple because it quickly emerges that its No and NO.

For instance they present this "analysis"



I would take issue that the "average" fuel economy is 11.1L/100Km ... shit my 1989 3L V6 Pajero 4WD station wagon gets that. My friends Subaru gets more like 8 and a Hyundai i30 more like 6 ... so you can half that figure for the cost to travel 100km for a petrol vehicle straight away.

However its even more disingenuous because they themselves are talking about longer distances, and in their own article say: "However, the RAC-installed recharging stations on WA's Electric Highway cost the user 45 cents for each kilowatt-hour of electricity, plus a $1 transaction charge."

So if we substitute the more correct 45cents for a highway journey it becomes more like $8.10 plus the $1 transaction charge making $9.10

So for the Electric car its $9.10 and for a modern car using 8L/100Km its $10.40 ... suddenly less attractive isn't it. It only gets worse when you factor in modern diesel engines in the 2L category are regularly delivering 4.5L/100km.

This does not mention how long it takes to "fuel up" while we know that to fill up and get going on the highway is usually a matter of minutes, for the electric its going to be longer.

Watt does it all mean?

People will fuzz out on this, but a kilowatt is a thousand watts, so assuming you have the need to put 18,000 Watts for an hour (that's what watt hours means) into your car and you can use the three phase 410 volt supply you will be needing to suck 45amps  (Watts = Volts x Amps and so 410 * 45 = 18450 )... for an hour ... Inconvenient this truth stuff isn't it.

Of course you can drop that to half an hour if you punch in 90 amps.

That would pretty much max out the capacity of the service station to supply (and keep its own lights on).

Imagine if there was 2 or even (shock) 4 cars attempting to fill up ... of course you've never seen so many cars in the servo have you ...

The truth - inconvenient isn't it ...

The article tries to suggest that you can make it even cheaper if:
The cheapest option for electric car owners is recharging at home using the electricity from solar panels and stored by a home battery.

So, you'll need to have a good 4Kw system on your roof running all day to charge your car to drive 100Km ... meaning you will negate that solar electric advantage of the house ... ohh, and you'll need at least 18Kw of battery too ...

Truth in Costs

Most car organisations will say that the true cost of ownership of a vehicle must I clude repayments and depreciation, meaning what you paid for it minus what you sold it for. The cost of fuel is often insignificant.

So if you buy an electric car you'll also suffer greater depreciation because they cost more in the first place too .. expect 30% drop in the first year. The Nissan Leaf (a mid range car equivalent in spec to an i30) will set you back $51,000 while the Hyundai will set you back $20,950

So 30% loss on $51,000 is $15,000 ... most of the entire price of the Hyundai.

fuck


The article goes on to mention in one sentence:

Unless you are recharging using a renewable energy source, the power electric car owners are using still comes from burning traditional fossil fuels which, in WA at least, is primarily coal.
Yes, that's right ... it still means CO2

So like the article says near the end:
Electric future of the automotive industry 
Owners of electric cars say their cars are not the future, they are the past, because electric cars have been around since the mid-19th century.
Nothing has changed since then either, for in the past Electric cars have been the realm of the wealthy.

As is typical of propaganda, simply tell enough stuff that looks to be true (even though it won't pass scrutiny) and avoid all those inconvenient facts that get in the way of pushing your agenda.

Ask youself this: who actually benefits from electric cars? Would it be the electric car makers, or are they really "just doing it for society".

Here's some evidence:


So despite selling a fraction of the cars, Tesla is worth as much as GM in terms of Market Capitalisation while running a loss not a profit.

Hmmm

Lastly I'll add that the real reason to promote electric vehicles has nothing to do with anything mentioned in the usual public sell-job, its more about moving pollution from one place (cities) to another place (perhaps to someone elses back yard).

I encourage you to think critically and act with conservation in mind. My method is to walk more, use public transport in cities, ride my motorcycle and use my car last.

Think about it with the facts clear in mind

Monday, 21 August 2017

Eating Grass Seeds

Probably few people think about it, but wheat, rice and oats are all from the same family of plant: Grass.

Being a bit different I often try cooking things "outside the dots" and substitute one grain for another. In this case I use oats as many cultures use rice. So while may think of Paella as being a Spanish dish, it relies on rice which originates from Asia.

In Europe Oats has a much longer history. Its hard to imagine that my earlier European ancestors did not cook more interesting things with Oats than the modern western (god help me, American) idea that oats = porridge.

So, without further adieu I'd like to present my Savory Oats "Asian style" with

  • Oats,
  • Fish, 
  • Ginger, 
  • Garlic,
  • Spring Onions,
  • Capsicum (or as it can also be called Paprika, but not the spice..)
  • Sesame oil
  • Rice bran oil (or other vegetable oil, like sunflower, rapseed, peanut ...)
  • perhaps a touch of paprika (dried spice like Hungarian) for colour,
  • and a touch of Tabasco sauce
So we start with frying up the chopped garlic, ginger, fish, spring onions and capsicum. Gentle heat, not "immolation" material ...



next, we have the amount of oats we want (for a single serve I go with half a cup), ready to tip into the mix.


So we tip this in and then add an amount of water to make sure its all wet but perhaps not totally covered ...


Adding the water cools the pan but the residual heat will bring it back to the boil soon, so we cover it and keep an eye on it to reduce the heat as soon as it starts to gently boil ...


usually 5 or 6 min is about right, but its important to keep an eye on it till you get the hang of this so as to make sure its always a bit moist in there ..


At about the 6 min mark, lift the lid and give it a quick stir around, breaking up the fish.

Myself I usually want the oats to still be whole and visible, not turned to porridge, but to each their own.


So then serve it (or add a little more water and let it cook longer if you want  the porridge thing) and add a dash of Tabasco sauce (for those who like a more spicy touch) and some soy sauce.


and remember ... Oats is better for glycemic index than is rice, and is also accociated with lower cholesterol in the diet.

Have a glass of white wine with it too ;-)

processing the bird

I was out in the back yard today and there was this crested pigeon sitting on a branch, so I happened to be holing my GH1 and the FD300mm f4 (because the bird I was actually wanting to photograph flew away as soon as I tuned my camera on), and thought well ... lets photograph you.

So I came inside, pulled the SD card and moved the RAW file onto my phone and processed it with Snapseed. Here is a scaled version of that


This made me think ... hmmm ... I wonder what I'd have got with a PC based editor ... so I had a quick whirl in a photoshop alike product called RawTherapee


so its not ball tearing difference is it. In fact I kinda like what I could do with Snapseed and (drum roll) it took less time!

Lets zoom in

Snapseed:


RawTherapee:


Not that this is the first  time to really see this or present it, but it is at least entirely different subject matter and shows that Snapseed stacks up across a variety of uses.

Like this guy...


Tuesday, 15 August 2017

The night sky

Living up in the hills over a hundred km from the lights of a city the skies look lovely..


But one only has to look in that direction to see things on the horizon...



I read that soon half of humanity won't even know the Milky Way exists soon

Sunday, 6 August 2017

Minor purchase...

I suppose its funny in and of itself, but it does remind me of the (to me) annoying penchant for the Millennials to not just lather things with superlatives but really over do it


: maximum King Wang

Tuesday, 25 July 2017

Views from the other side

Growing up on one side of the range, some how I never spent much time on the other side.


So it's been nice to explore a bit of that this week



Nice place

Saturday, 22 July 2017

Friday, 21 July 2017

a new T-Max

After such a good experience with the last one I couldn't resist



We shall see how I find it .. already there has been a few changes to this which I'm not fond of (removal of practicality for "king wang"). I can't for the life of me understand why every single bike has to appeal to the "scratcher" set ... I mean if you want one of those, go buy a R6 or something


naturally I had to buy another orange helmet ...

Wednesday, 28 June 2017

Cold Inside the House

this is an older post from another blog of mine, but its quite relevant again to me (having just come back from Finland...

One day, walking around the shopping center I saw this advert for cold and flu medicine. It reminded me of one of the mysteries of life in Australia

That while its not typically cold here during the day we get quite cool in winter overnight. A lack of thermal insulation in most homes means that the heat leaves quickly over night and the radiant insulation (slowing the sun from heating the house) means that in winter we tend to be cold inside our homes, despite pouring a few kilowatts of electricity into the home.

I can only assume that its a tradition we have followed from the English.

Academics ponder the issue but builders keep churning out the same designs and Aussies keep buying them.

They then sit around inside complaining about how cold it is while just having argued that "it doesn't get cold in Australia". They even defend the perpetuation of this ... Strange how its often actually warmer outside ...

Why don't we laugh at Australian chimney and fireplace design next

:-)

Thursday, 1 June 2017

of waves and motion (and bell curves)


I've been considering an idea of modelling society based on what we know in two areas; social science and physics.

As a picture paints a thousand words I'll leave my description of my diagram brief.

The levels intelligence within society are described by a bell curve (lets not discuss how skewed that is here). Knowing that society is a dynamic thing I looked to the behaviour of waves to see what happens as society becomes more shallow.

A standard wave changes shape as it moves into shallow waters



and eventually as the wave reaches the "social media shallows"  the mediocre and dumbos form a dumper that pummels the higher intelligence groups.

An intelligent person (surfing the wave) must observe this formation and know when to "flick back" and not get smashed against the rocks by the rest of the wave.

I cite the "Cultural Revolution" as a clear example.

Tuesday, 30 May 2017

the camera you have with you ...

despite my overwhelming urge to pound my phone into a rock every time I try to type on the fucking thing (only those who can't type, have never used a decent QWERTY keyboard and can tolerate so many spelling errors and interpretation errors could confess they like on screen keyboards) the phone makes a good camera. Not least because its always  with you. Like today, I was out wandering around and enjoying the beautiful weather when I looked back (in anticipation of some good backlighting) and found just that:


These days I reflexively put the camera into RAW and then I've got that too. I've earlier found that this combination is about 85% of the quality my GF1 (with the 14mm f2.5 lens) gives.

The camera app did a pretty decent job of this challenging lighting situation (I'd tapped on the brightest cluster of leaves over there mid lower right) but RAW and Snapseed enabled me to pull the highlights down in development and sharpen up a good image.

Here is a full segment



Based on my experience with printing I reckon this'll be good for 52.6 x 71.1 cm (20.69 x 27.97 inches).

I reckon this'll go nicely on a wall back in Australia (to remind me of here when I'm there).

Wednesday, 24 May 2017

bicycle usage preference in Finland

Growing up in Australia I've pretty much always had "derailleur" style gears. I say "pretty much" because as a kid under 10 I had a "Dragster" style bike (like this, but I don't have a picture of mine)


 which pretty much got changed into something which would later become (yes, I'm old) BMX.

One thing about that bike that non of my other bikes (until I came to Finland) had was a "Sturmey Archer" style "internal hub" gear system.  For those unfamiliar with them (and mistakenly thinking that that shifter was just for looks because "that bike doesn't have gears" this is what they look like:



Clean, and simple, with no requirement to bend the chain as it moves across the lower cassette.

I quickly discovered (with my first 10 speed bike) how sensitive the rear hanger was (riding though bush all the time) to impacts and how often one needed to tune the system (something many folks could never properly do) or it wouldn't shift properly, would make a "rattle" sound all the time (while it was partially attempting to climb up or drop down on the cluster.

A great example on how you need to adjust your derailleur:
www.parktool.com/blog/repair-help/rear-derailleur-adjustment

My last bike in Australia was a Giant Yukon, which I loved and rode to work (and on trails as well as for general exersize) quite a bit for many years. Finally after some thousands of Km (literally) I needed a new rear cluster, but the Shimano Deore with "Rapid Change" worked great for me with only occasional adjustments and I loved the ability to keep a decent cadence and constant energy irrespective of slope or headwind.

Gears work. But most riders just don't know the first thing about how to use their gears properly, especially with a Derailleur system. For instance you can't just sequentially shift UP or DOWN, as you need to keep the rear sprocket more or less in line with the front sprocket, especially if you have more than 5 gears on the back sprocket. So as you shift up you eventually move from the smallest sprocket on the front to the middle, but you should do that before you've gone to the smallest on the back. Probably this will mean you'll need to change back down on the rear before changing up on the front ... which the rapid change system allows you to do (but you still need to be careful to not make a tangle of it).

It may sound complex but eventually it becomes second nature (or you just fluff it around like most people do).

Then I came to Finland where "entry level bikes" have most commonly got no gears (meaning a single gear fixed gear but with a coaster clutch / brake system not a "fixie") or a (most commonly Shimano Nexus) 7 or 9 speed hub. By most commonly I mean most of them.

These systems have the advantage that you just shift up or down with no thought of "do I need to change the front sprocket" ... just change.

Dead Simple ...

To show how common this system is here, here is a "for instance" just walking along and decided to film "poll" at my local small supermarket:




Note the number of mudguards and racks in that video. Its easy to see that bikes here aren't like most Australian bikes, they are clearly fundamentally practical transport. Because (unlike Australia) many people ride bicycles all the time, in all weathers for most of their daily stuff (like going to the shops or stuff like that).

After using my hub now for a few years I totally love it. Actually it was pretty much love at first pedal. Indeed while I see that "derailleur" style has some advantages in competition, almost none of that translates to street.

I have seen occasional posts on bicycle forums in Australia enquiring about these systems and usually they're regarded as "expensive" ... which is weird because in Finland they are fitted at almost the bottom end of the market. I expect its just another example of Australians being shagged up the butt for stuff because (either) the retail system just wants to simplify and have one thing to pedal (or the bike shops are populated by dedicated enthusiasts who just can't see the point of not being "comitted").

My bike (with the Nexus 7) has been a great transport unit and I paid 50 buck for it second hand (in really good condition. A real "low maintenance practical work horse" and my daily driver over here since 2013 (without as much as a screw driver put to it).



I wish Australians were as wise as Europeans.

PS: lastly if one is to get hung up on issues like efficiency , then I suggest reading this good reply on a forum here, its a good one.

Sunday, 21 May 2017

Getting DoF at a distance

one of my pet "disturbances" is people taking pictures of a tiny toy on their keyboard from 5cm away and going on about the DoF and Bokeh of their new lens, especially when its clearly going to be useless at "normal focal distances"

The only way to get DoF is by pupil diameter, not "f stop" ... the bigger the pupil the shallower the DoF

Of course to get that pupil bigger for the same angle of view one needs either a bigger f stop OR a larger format. For instance a 50mm lens on a FullFrame camera has a pupil diameter that's about 25mm at f2 ... while the pupil diameter of a 25mm lens on a 43rds camera (capturing the same view from the same spot)  will be 12mm. Meaning less DoF

So I thought that (not having a full frame or a good 50mm f1.4 lens handy) that using my 45mm f1.7 would do the job at imaging my favourte tree if I stitched together an array of 4 shots (as it would approximate a 50mm on a full frame single frame grab).

Here that is:



Seems that while its better than my earlier attempt with the 20f1.7 (single shot with m43) it looks like its not really doing what I want ... a pixel peep (or a big print) shows that it does indeed have better DoF popping it out of the background, but not as much as my 4x5 had (standing pretty much in the same spot).


Well its better and shows more "separation" from the background.

So, I was right but there was a lesson to be learned

On a larger (again) format (like what is called Large Format) a "normal lens" (like the 50mm) is a 180mm lens and (my f5.6) lens yeilds 32mm at "wide open".

Perhaps a Full Frame with a 50mm @ f1.8 (using a 1.4 lens so as to not get too much corner darkness) would do it. However when one is using even 100ISO full sunlight will require super short shutters (or a ND filter) if you're using f1.8 ... Then there is the highlight clipping to deal with...

I still keep my 4x5 camera and some chemistry around for just this sort of specalised thing (and its cheaper than a Sony A7).