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Forum: Pentax Full Frame 03-30-2019, 08:25 AM  
K-1 ISO internals
Posted By elicius
Replies: 32
Views: 3,543
A perfect ISO invariant camera does not exitst on the market yet. Though cameras and sensors have improve quite a bit so that the generated post sensor noise has become less, cupple that with an improvment in noise cancel algorithns you can get really great results just using iso 100.


Like GUB said you can do the test, but please don’t use a random RAW editor for that, a lot of raw editors like lightroom apply noise cancelling in background making the results look better then they actually are. I have tried it for myself and I can say that there is a difference.
Forum: Pentax Full Frame 03-23-2019, 08:02 AM  
K-1 ISO internals
Posted By elicius
Replies: 32
Views: 3,543
Well just wanted to give my butter on the subject.

Lets look at what the different steps are and why ISO on digital cameras do make sense and that some types do not. Here is a simplified way of object to data. And a quick overview of the factors that thereof influence the image quality in 3 Steps:
Object ---> Medium(usually air) ------------------------------> Lens -------------------> filter on sensor for IR/UV ---> micro lenses --->Bayer Filter-------------------------------------------> Sensor --------->
-------------|Dust, Humidity, Temperature differences… ---| Optical errors, etc. ---| Filters out unwanted light ----|------------------- | Lowers luminosity and sharpness for colour--- |



---> Amplifier on each pixel(Mostly CMOS) --------------------------> Amplifier after processor -------------------------- ----------------------------------> Analogue processing and conversion to digital signal converter--------->
-----|First Factor for A-ISO, k-1 ISO happens here I assume ----- | This is the K-1 mark II ISO improvements happen I assume -----------------| Creates NOISE!!!!!

|||||| This ISO Amplification makes sense since it is before new Noise gets generated |||||

-------------------------------------------------------------------------------------------------------------


--> Real RAW data ---> Magic Processing -------------------------------------------------------------------------------------------------- ----------------> RAW FILE -------------> Conversion to JPEG
-----------------------------| Here a lot of magic proprietary stuff and the ISO multiplication that can be done theoretically in post happens--|---------------------------- | Loss in DATA over and over in each save.


So why is the PENTAX almost ISO invariant, well digital cameras have improved a lot in these years and the Noise generated post sensor, has become relatively low. Also programs like photoshop apply noise filters in background that hides noise, that is why you will get similar results results shooting at iso 100. But ISO Analogue amplification still make a lot of sense as it avoids a lot of later noise.


I from experience in experiments outside of fotography know how important such early amplification of low signals can help with a lot better cleaner results.

Please also look at this article:
Is ISO Fake? | DSLRBodies | Thom Hogan
Forum: Film SLRs and Compact Film Cameras 03-13-2019, 03:36 AM  
Why did pentax give up completly on SLR?
Posted By elicius
Replies: 58
Views: 5,923
Yes

Well I guess you are right with that but competition still offers some Film SLRs so it must still be a little profitable.
Forum: Film SLRs and Compact Film Cameras 03-13-2019, 02:44 AM  
Why did pentax give up completly on SLR?
Posted By elicius
Replies: 58
Views: 5,923
Tell me if I am wrong but pentax got into the DSLR market quiet late. They had a great history of Film SLR cameras so why did they completely drop it?

They should have kept one SLR that gets maybe over time updated from time to time to work with their newer lenses…

As the brand pentax will exist for a century in november it would be a good surprise to release a modern updated commemorative Film SLR in a nice looking old style ;).
Forum: Pentax DSLR Discussion 09-22-2017, 06:15 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
I just saw that one of the huwai makes mobile phones has a monochrome sensor…

If they can get there hands on b/w sensors why could not a DSLR company…
Forum: Pentax DSLR Discussion 07-22-2017, 05:05 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
If I am right you get about 1/6 more coverage in square format out of the lens than in 2/3?

I get that asking for such a niche product as Mono is like asking for the impossible ^^ but I continue dreaming on.
Forum: Pentax DSLR Discussion 07-22-2017, 02:04 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
That would definitively bump up the price even more than just a small change in the production line.

If the producer of the chips accepted to produce the same sensor in monochrome, you would not need to do any extra hardware changes to the camera (or almost?). Now if you have to change it to another sensor then you have to start changing things in the hardware with greater costs, the sensor would also have greater cost because you need to open a completely new production line…

Also can someone tell me the advantages of a square sensor?
Forum: Pentax DSLR Discussion 07-20-2017, 03:05 PM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
I am the one who started this thread ^^ and having studied in a scientific field for a while I can say that a Monochrome DSLR camera that is not too expensive would come in handy quite often.

The production cost will always be higher since it will probably be a lower production quantity. Also the quality of Monochrome sensor need to be higher since defects are noticed more easily. But I do not know the production scale of pentax so I cannot judge the extra costs involved. I think pentax has had lower profit lately (don‘t quote me on that I am not sure but I think it was mentioned somewhere) so maybe filling some gaps in the market is not a bad Idea, this might just be too niche for that,

@victormeldrew
I do not think R&D is that great of a factor, the modifications would not be that great. mostly software side on removing a lot of things that are not so useful in Monochrome and maybe adding one or two nice extra features. The main cost is the interruption of line of production to make a lower scale production ot monochrome sensors and a special camera version. So the best way to do it would be to calculate what a good target price is, the calulate R&D cost and the number of sales needed for a break even point with a slightly lower product price and make a crowdfunding out of it.
Forum: Pentax DSLR Discussion 07-20-2017, 02:15 PM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
I am not but there is a reason why it is so common to use monochrome or why it used to be a lot in astrophotography.

But often Luminosity is more important than colour… Also it is quite common to take pictures with filters for specific wavelengths which works hell a lot better with a monochrome sensor.

There are also other types of sensor like RGBW which has a pixel without filter instead of a second green one, Sony and Kodak have done work on it but it does not seem to have caught on but I am not well enought informed on the advantages and disadvantages but maybe somebody can explain them ^^

Here a little extract on the benefits and disadvantages of monochrome in Astrophotography from an article on RGB Planetary Imaging with a Monochrome Camera:






QuoteQuote:

Benefits of Monochrome over One-Shot Colour:
  • Higher resolution

  • Ability to choose a filter with matched spectral characteristics according to what you want to image

  • Ability to re-focus between colour channels

  • Ability to change settings (fps, gain etc) between colour channels

Benefits of One-Shot Colour over Monochrome:

  • Lower cost (no need to buy filterwheel and filters)

  • Easier to use during capture (no need to capture 3 avi’s for a single image)

  • Faster processing (don’t need to process 3 avi’s for a single image)




Also getting the right colour in Astrophotography is a huge thing and with monochrome cameras and filters you may be able to get a lot closer to the ‘right’ colour.
Forum: Pentax DSLR Discussion 07-18-2017, 12:06 PM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
If the companies would make the firmware opensource the community would have already done this for their modified cameras ^^

Well that is a funny Idea but it is impossible for us to calculate the break even point for a specifique price per unit…

But big companies should lauch presale compaines similar to kickstarters if they are not sure if a project is sustainable but wanted by a community.
Forum: Pentax DSLR Discussion 07-18-2017, 09:56 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
Why that?
Forum: Pentax DSLR Discussion 07-18-2017, 05:51 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
If you use the raw files it should work.

Well does anyone know how to contact the production line?

I would be willing to pay such a premium since I am considering to by a leica one day, the main obstacle being objectives not being compatible.
Forum: Pentax DSLR Discussion 07-18-2017, 05:24 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
@D1N0 That would be an option but you lose the micro-lenses and will definitively damage the sensor
@Na Horuk Well you have to interpolate because the pixels only measure the incoming light of one color, imagine you would photography something very blue then every fourth pixel would be bright the rest dark. And since you have to interpolate you lose clearness in the picture. This can be solved with pixel shift but that has the disadvantage that it has to take 4 pictures instead of one.
Another advantage is that you have a higher light sensitivity since you measure all the light on every pixel and not just one color.
Forum: Pentax DSLR Discussion 07-18-2017, 03:11 AM  
Poll: Monochrome DSLR
Posted By elicius
Replies: 99
Views: 9,251
Hello Everyone,

I know that kind of camera would be a niche.

But a Monochrome camera (without bayer filter) would really fit a lot of the features and image of Pentax cameras such as the Astrotrace function just to name one.

I really love taking Monochrome pics and a pure monochrome camera would improve the image quality of such image by a lot. I know that leica has such a camera but it is not an SLR and I would like to stick with pentax.

What do you guys think?
Forum: General Photography 03-02-2015, 01:39 AM  
How to get the most out of pictures if the night sky?
Posted By elicius
Replies: 6
Views: 2,272
After a bit of more editing here is what i got. What do you think?

---------- Post added 03-02-15 at 09:57 AM ----------


[CC BY-SA 4.0]
Forum: Welcomes and Introductions 03-01-2015, 09:47 AM  
Gretings from Germany
Posted By elicius
Replies: 4
Views: 511
Hi, My name is Lukas..

Just bought my first Pentax and am very happy with it. (I wanted to buy a camera for a long time but the price tag is kind of scary ^^)

I hope I'll shot great pictures with it.
Forum: General Photography 03-01-2015, 09:32 AM  
How to get the most out of pictures if the night sky?
Posted By elicius
Replies: 6
Views: 2,272
Hi guys,

I took some pictures of the sky yesterday with my new pentax. I randomly caught Capella, Haedus, and a few Per stars.

Do you have any tips on how to get the most out of the picture?
Night-sky CC BY-SA 4.0

Also anyone knows what the red cloud at the bottom is? Is it just light pollution from the city?

Thanks
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