Photography Chat - 2014-04-23

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1:50 AM

For years I would spend my summers up at a camp on a mountain with no AC and no computers . It wasnt till I got old enough with a career that I had to give it up. Even met my wife there. Loved it, miss it tons.

2 hours later…

3:50 AM

@AJHenderson Huh, I'm looking at it on computer screen, and now I see how I've once again gone burnt-eyes while setting up the photo :(

13

Q: How to avoid visual "burnout" during post-processing?

Sometimes I keep on adjusting a photo for longer than is healthy. What follows is that I go somewhat blind to tones and colors. Then, I get oversaturated and dark images. I am new to RAW processing, and owned a digital system camera for less than three months, so I'm still learning a lot as I go...

post-processing color-correction

Due to the harsh light the shadows were very very dark to begin with. So I pulled more light into those shadows, and went too far with it.

Anonymous

-1

A: what is the nikon equivalent to canon lens L series EF 24-105 f4?

I think you should consider the 6D! The kit w/24-105mm can be found near $2k!

Anonymous

flagga

6:20 AM

Guys, in a facebook group I'm in they cursed the task of photographing black tableware. So, I took a shot and I don't think it went too badly.

Could be better of course, but considering the fact that I just put the things on a table and took a few shots, a quick-n-dirty job, I think I'm satisfied with this:

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Michael Nielsen

7:17 AM

@AJHenderson as kid when my father took me camping/canoeing, I brought my walkman and death metal casette tapes, and heard it almost non stop :)

@EsaPaulasto maybe you havent been subjected to 4000+ pollen. and its not like everyone gets it. it is like rolling a dice. Ive lived in Davis, CA 4 times which is known for giving people allergy because you can showel pollen off the streets like snow. and all your clothes are yellow from it. I didnt get it there, but back home in DK we had another attack of thousands of pollen and that attack did me in . a lot of danes got allergy that year.

4 hours later…

11:32 AM

possibly interesting to you guys: mashable.com/2014/04/22/lytro-illum

@EsaPaulasto ah, the classic Scandinavian open-faced sandwich. Because who cares if the food falls off everywhere? :P

2 hours later…

1:03 PM

@ElendilTheTall Actually, we don't dance around the house with a sandwich in hand.

@EsaPaulasto you could, if you just put another damn piece of bread on top

is the bread even buttered?

And, what more, we get to see the stuff on top of the sandwich. Nobody's going to hide anything extra in between.

Buttered? Why would I ever eat UN-buttered bread?

I'm not entirely sure if that's as much of an issue as you think

@EsaPaulasto for the same reason you wouldn't put another piece of bread on top - the stoic tight-fisted dreariness of the Northern European ;)

Well, if you can't afford butter on your bread, I'm sorry, I didn't know.

;)

user image

^^^ that's the theory.

user image

^^ reality.

Those "proper sandwiches" are the cheapest and most industrialised form of food there is available in a Finnish grocery shop.

@ElendilTheTall There's a solution for every problem:

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@EsaPaulasto maybe for you

1:17 PM

Ehh, right. Don't get the idea that I'm somehow trying to convert you!

back later.. now afk

1 hour later…

2:25 PM

bhphotovideo.com/c/product/1040177-REG/…

sooo pretty

3:17 PM

@ElendilTheTall someone linked that yesterday, I forget who

@rfusca Elendil, I guess it was rfusca, here

@EsaPaulasto they have those at my office, made with a different label on it, but the exact same type of package

3 hours later…

5:59 PM

@AJHenderson btw, it looks like that translates to about 4 MP

6:27 PM

That's for the new model?

So that would mean the old model is only 1MP? Wow, that's kind of nuts.

6:41 PM

@MattS. well most of their pixels are used for getting the depth resolution. As I understand it, they use microlenses to direct light to different photosites depending on direction

so that's actually only using 10 photosites per pixel, which isn't really all that many

What's a normal photosite per pixel?

6:58 PM

1

each photosite is normally either red, green or blue and there is one per pixel. Color information is derived from neighboring pixels

@MattS. not sure about the old model, but reports are that the new one comes out to 4MP

ah okay, so it could be that it's a 10 MP camera, but they're storing 10 different variations of light in the same image. So it's really 10 images at 1 MP each?

I don't think thats quite the way it works

I don't know, it all sounds like buzzwords to me.

lol. Its really very interesting technology

I think eventually it will be 'the future'. Its just quite a ways off yet

7:09 PM

I was looking at the new model being 40 megaray. Which is 4 MP. And the old one is 11 megaray, which then would be a tad over 1 MP

@MattS. But the sensor size is different - so that may matter for this technology

Other sites say the resolution may be as high as 5MP for the new one

Ya, it looks like the original Lytro camera is about 1MP

7:41 PM

From the viewer's point of view (literally) it seems the trick is that you either make a photo a video, or you use their special viewing software in order to be able to switch focus as you wish.

I think it only works with their software. So technically the second is right.

For example my photo of black tableware, where the cup is in focus and the apple on the plate is out-of-focus blur. If that was an illum-photo then you could point at the apple to bring it in focus, if you so wish.

@MattS. not exactly

they store information about what angle the light is hitting the main "pixel" by passing it through a specialized microlens that directs it to one or more of the subpixels

which are each a standard photosite

@MattS. The video would work, only you don't have control over where the focus is. You just watch the photo changing focus, without control. A bit lame, but it's for lazy people ;)

but the information from those photosites allows determinations to be made about what light was coming from what angle

that can then be used to piece together the entire light-field

7:47 PM

So they're essentially taking a literal snapshot of the environment.

Capturing not only the light, but the angles and brightness too.

yes, that's what a lightfield is

hard to wrap your head around unless you are familiar with either optics or raytracing though

because you can't really see a lightfield

ah I gotcha

So I imagine is takes a relatively large sensor to do something like that. Hence why the actual image resolution isn't that much.

but if you know the direction of each light component, then focus becomes largely irrelevant depending on the level of angular accuracy you have

right

it's actually a 40mp sensor

however many megarays it is is the number of actual photosites on the sensor or atleast the number of rays they can measure

it might actually be a higher number of mp

I don't know the exact translation from rays to photosites

but I am fairly certain it is a traditional CMOS sensor under their microlensing from what I read about it when the original lytro came out

Light-field camera

A light-field camera, also called a plenoptic camera, is a camera that uses a microlens array to capture 4D light field information about a scene. Such light field information can be used to improve the solution of computer graphics and computer vision-related problems, and to make digital plenoptic pictures that can be refocused after they are taken. Technology The first light-field camera was proposed by Gabriel Lippmann in 1908, which used integral photography as the underlying technology. In 1992, Adelson and Wang proposed the design of a plenoptic camera that can be used to signif...

@EsaPaulasto Sounds like a recipe for motion sickness. :p

you can also selectively choose the DoF you want in their software to output a finished flat image if you want

and more usefully, in theory anyway, you should be able to get a rough depth map

depthmaps are hugely useful for effects work

7:53 PM

Did they make up the word plenoptic?

How many is a plen?

I don't think they made up that word

I've never even seen it used in their material

I think it may be the more traditional term for the device

the concept isn't new

Okay, I finally found a definition. The only results I was getting was for Lytro before.

"Of or related to light travelling in every direction in a given space."

yeah, Lytro are the main ones in the space since their founder is the one who came up with the processing algorithms

but they are not the only ones by any means

okay, so one microlens can capture one direction or point of light. So if it has 11 microlenses, it can capture 11 directions/points of light.

it can capture 11 directions of light, but they may all only resolve to 1 point depending on the angle

and the focal point

8:01 PM

right

it's kind of like when a beam of light hits a prism, depending on the direction of the light, it ends up at a different point

and if a pixel on the left has a light beam coming in in the proper direction and a pixel on the right has just the right direction, then if you set the focal distance back a bit, you could end up with those two rays combining in to one pixel in the middle of the sensor

basically, you end up simulating the direction of the rays and then move the sensor back and forth through it

and see what resolves

Right, so to get a better image, it would need to be able to capture more light rays. Which means more microlenses

yeah

well, sort of

more microlenses means more angular resolution

but less spatial

because you need two things, a microlens to divide the light based on angle at the plain the microlenses sit at, but you also need a photosite to detect what angle it came at

err, I'm sorry

I think I got that backwards

more microlenses increases spatial resolution but decreases angular unless you similarly increase photosites

because the precision of your angle measurement is limited to how many samples you can take of the result of each microlens

raytracing is actually probably a good primer for this kind of stuff, but it is still really complicated and pushes the boundaries of my personal understanding of it

raytracing is basically the same principal in reverse

where the screen acts as a plane which and the eye works as a focal point and the lightfield is calculated in reverse based on how it applies to the viewer

ie, each pixel on the screen is formed by starting a ray from the virtual viewers perspective, sent through that pixel on the virtual screen and then bounces around until all the ray splits hit a light source

and the sum of those rays produces the color value of that pixel

Yeah, it's been forever since I've done any 3d graphics stuff.

Michael Nielsen

talking about lytro?

8:15 PM

Yeah, related thing to think about is that color is illusion made up in our head. In the "real" world nothing is "red" or "purple" or anything, there is no color as we think in the real world. There is only light, rays of light reflecting off surfaces all around.

Michael Nielsen

its just a spectrum of wavelengths. and most people interpret certain spectrums in certain ways. others (like me) interpret it differently.

@EsaPaulasto Solipsism?

Solipsism (; ) is the philosophical idea that only one's own mind is sure to exist. As an epistemological position, solipsism holds, that knowledge of anything outside one's own mind is unsure; the external world and other minds cannot be known, and might not exist outside the mind. As a metaphysical position, solipsism goes further to the conclusion that the world and other minds do not exist. Varieties There are varying degrees of solipsism that parallel the varying degrees of serious skepticism. Metaphysical solipsism Metaphysical solipsism is the "strongest" variety of solipsism....

or Nihilism?

No not Nihilism..

Nothing is real.

Michael Nielsen

Hedonism is thje best ism

Matrix! ;)

I saw Dark City before I saw the Matrix, and it ruined it for me.

Dark City is much better in my opinion. Same story, just told better.

Out of curiosity, I looked up colorblind photographers, to see what their photographs look like.

facebook.com/KilianSchoenbergerPhotography

Not fully colorblind (red/green), but still pretty cool.

I'm more curious if a fully colorblind person would have a better sense of contrast in photos.

8:37 PM

user image

(c) Jörg Kahlhöfer - supposedly...

trippy. I like it.

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Apr '1423

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