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Pages: 1
Author Topic: Lytro Illum Test & Fail Shots


Machine198-
5
newbie
Posts: 7
Lytro Illum Test & Fail Shots
on: 2014/12/15 03:35

I made some test shots to check out the iso performance and refocus quality.
first picture is iso 100, second iso 3200. The quality is pretty worse i think, even at F16 it´s still not really sharp.
Ok, ISO3200 isn´t pretty fair. So have a look at the last one at ISO800.

The third picture is focussed at 1cm. Result is some image problems, don´t know how to name them.
(Focussing at 1cm or less is just possible at 30mm, so not the hole range of 30-250mm.)
The fourth picture shows a problem which comes pretty fast if the light source is a little brighter.
The last two pictures demonstrate some different artifacts which seem to come pretty random likely.

https://pictures.lytro.com/PeterPetersen/albums/171350



ArsMachina
newbie
Posts: 3
Re: Lytro Illum fail shots, ISO Test
on: 2014/12/16 19:26

Hi Peter,

thanks a lot for your test shoots!
I am currently thinking about buying an Illum and looked at many pictured during the last days.
I realized, that there was no single picture that was really as sharp as I am used to with other cameras.
This is the reason why I registered here to find out what is happening.
Perhaps the objective is not capable of a better sharpness in general and at f/2.0 ?

Best wishes ArsMachina


mike eng
newbie
Posts: 10
Re: Lytro Illum fail shots, ISO Test
on: 2014/12/17 22:26

The resolution is limited by the number of microlenses, not by sensor pixels. I guess there are about 10x10 pixels under each microlens, that means only 1/100th of the pixel count is used for x-y spatial resolution.

Also, these F/2 lenses are probably cheaply made. The ability to extract light rays also enable them to use low cost lenses and correct aberrations in software. It is an important advantage of light field imaging.

Both will get better with time.


ArsMachina
newbie
Posts: 3
Re: Lytro Illum fail shots, ISO Test
on: 2014/12/17 23:17

Hello Mike,

the number of microlenses is probably the reason for the poor resolution and sharpness - I did not have this in mind.

About the cheap F/2 lens and the software correction I already heard in the interview with the founder.
For me it is hard to understand why the quality of the lens does not matter the image quality at all.

Best Wishes AM


mike eng
newbie
Posts: 10
Re: Lytro Illum fail shots, ISO Test
on: 2014/12/18 02:07

I think the quality of aberration correction would have to be related to how accurate the rays are sensed. Aberration is caused by rays from different part of the lens not intersecting at the intended focal point. Now that they have all the rays, they can do some correction in their direction of propagation to force them to intersect at the right spot. But any error in a ray's direction would lead to an increase in the spot size. Over all, this could lead to drastic decrease in the cost and weight of imaging optics.

Maybe you can compare Illum with a Nikon D1 to see which has a sharper image.


Machine198-
5
newbie
Posts: 7
Re: Lytro Illum fail shots, ISO Test
on: 2014/12/19 00:45

Some more detailed test shots from the center of the card (f1 f4 f16). There you can see quite good why it doesnt come along that sharp.
It´s really not that detailed and with a longer focal length it gets more and more antialiasing. But i think, you actually shouldn´t look too close on sharpness and things like that at this stage. anyway, i think this is interesting. like the early beginnings of compact cameras. enjoy.
Image 30mm ISO100
Image 30mm ISO800
Image 30mm ISO3200
Image 250mm ISO100
Image 250mm ISO800
Image 250mm ISO3200
Image 30mm ISO100
Image 30mm ISO800
Image 30mm ISO3200
Image 250mm ISO100
Image 250mm ISO800
Image 250mm ISO3200

I´m done with uploading pictures manually! right here. What is that!?



Machine198-
5
newbie
Posts: 7
Re: Lytro Illum Test & Fail Shots
on: 2014/12/19 01:29

Image Lytro 30mm vs. Mark III 85mm


mike eng
newbie
Posts: 10
Re: Lytro Illum Test & Fail Shots
on: 2014/12/20 18:46

Side-by-side comparison is very helpful, thanks! For us non-Canon users, what is the sensor pixel count on Mark III? The left hand side column on the resolution chart is for F2 and not F1, right?
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