MONOCHROME R+G+G+B with ASI071 MC-PRO

sikkim

Hello,

I would like to know how I should configure the ASICAP software, to obtain photographs in Monochrome, obtaining an image that is the result of PIXELS R + G + G + B.

I had thought of setting the camera in mono mode, and also activate the BIN2 box, do you think I can get an image whose result is the sum of the RGGB Pixels ?

Regards,

Xavier

chad

Hi Xavier

We are confused with your words.

Mono means it a gray value. Why is there an RGGB?

Bin is another thing, it means you can get one pixel from 2/3/4 same pixels.

Thanks

Chad

sikkim

Hi Chad,

Sorry for my bad expressions in english.

I explain you again, please be patient :

One color camera have groups of 4 pixels encapsulated with color Matrix Bayer: 1 red + 2 green + 1 Blue.

My ASI 071 MC-Pro, have 4944 pix x 3284 pix , and the matrix Bayer is R-G-G-B format.

When the camera work in a color mode, each pixel read the light filtered in his capsule : red, blue or green, and the file generated of your photo is one color picture, with 4944 pix x 3284 pix , total 16.236.000 pix., but in realy the photo have : 8.118.000 green pix + 4.059.000 red pix + 4.059.000 blue pix, and the picture is one composition of all theys.

When the camera are working in color mode and you select BIN-2 ( 2 x 2 ) , normally you sum 4 pixels, with the same color : 2 red + 2 red , 2 Blue+ 2 blue and 4 green + 4 green , the image result in this case is 2.472 pix x 1.642 pix. In this case you have one total of 4.059.024 pix, or : 2.029.512 green + 1.014.756 red + 1.014.756 blue.

It's god for get a more sensibility in the picture, normally you need less time to make a picture, or you can detected a very low signal object in deep space.

BUT, if you select Mono Bin in full resolution: 4944 pix x 3284 pix, the information captured is exactly the same in color , but the file generate is in gray scale , this is a small trap by software, because the pixel read the light through the capsulated color and the result of the read is not monochrome really. Is a conversion by algorithm of software.

But, if you select Mono Bin and BIN-2 , and the software ASI_CAP could be ADD the signals of pixels: 4 xRed + 8xGreen + 4xBlue, the result is very aproximative a real monochrome capture , because you ADD 4 diferents pixels colors to obtain 1 monochrome pixels in the picture.

The result is the same 2.472 pix x 1.642 pix. but more real .

For that , I ask you: if the ASICAP software work like the first or the second way , because Im very interested really in the second possibility .

Best regards,

Xavier

chad

Hi Xavier,

I think you misunderstand the monobin.

For mono bin, it means when you only select it, it does not perform the operation. If you also select Bin2, it will perform the bin2 in mono mode, ignore the color.

So for you mothod 2, it has no difference with select mono bin and bin4.

thanks

Chad

sikkim

Hi Chad,

I don't understain you exactly , I writte under your mail , please anwser me:

Hi Xavier,

I think you misunderstand the monobin.

Its very possible , I have not a manual to learn how work this camera in this mode mono bin . Please explain me

For mono bin, it means when you only select it, it does not perform the operation.

what operation ?

If you also select Bin2, it will perform the bin2 in mono mode, ignore the color.

I don't understain exactly what you want said with " ignore the color ". when you select BIN2 whats pixels sum to obtain 4.059.024 pix ?, pixels with the same color , or diferent color ? for obtain a monochrome image ?

So for you method 2, it has no difference with select mono bin and bin4.

Probably

thanks

Thanks

For further clarification:

Option 1

Probably, the simplest way to convert a color image into a monochroma and maintain the maximal resolution of the camera, is to eliminate from the original file the information of the pixel of color to which each of the pixels belongs: R / G / B, and in this way deceive the system, creating a grayscale image, but this way is a little unreal, because the intensity of the light captured by a red pixel, or a green one, or a blue one, is completely different. And for only separation of 4.75 microns, which is the size of the pixel, it results that the created image is quite false when creating irregularity in the intensity of light captured by each pixel due to the color of its encapsulation.

Option 2

Another very different system would be that, for the creation of a monochrome image, the software would collect the information of the 4 color pixels and sum them, obtaining a virtual pixel of monochromatic value, therefore the native resolution of the camera would be reduced to 1/4 part, that is, in the case of the ASI071, it would pass from 16 Mpx to 4 Mpx, but without doubt the monochromatic image obtained would be much more real, as we all know that the white light is the sum of all the colors, and So what better way to obtain a "whites" / grays scale, than sum the colors of each Bayer matrix R + G + G + B?

That's why my question is to know what system ASICAP uses to create a monochromatic file starting from a color file at maximum resolution.

And the same question when you select BIN2 in MONO mode.

Use option-1 or option-2, or use another method, and in that case which method?

chad

Hi Xavier,

I reviewed our communication, then I realized that maybe we both understood each other wrong.

I think you problem is that:

1, When I select the MonoBin in Max resolution, What did the ASICap do?

2, When I select the MonoBin and Bin2, What did the ASICap do?

3, Is there any way to get maximum resolution in mono mode using a color camera?

Am I right?

When you select the MonoBin in Max resolution, we do nothing except set a flag to true.

If this flag is true, when you select the Bin2, So, given the vertical and the horizontal, it's actually 4 pixles, the calculation will use 4 pixels to get a new value. These 4 pixles have different color, they are adjacent in physical. So now the new value should not represent any color, this is why the image is mono.

If this flag is false, when you select the Bin2, the calculation also will use 4 pixels to get a new value, but these 4 pxiels have same color, they are not adjacent in physical, they are just four pixels of the same color that are nearest to each other. And this new value will have a color.

For a color camera, you can select the disable debayer to get a mono image at max resolution, but you will see the Moire Pattern when you zoom the image. If you want to reach the goal like a mono camera, Sorry, there is no good way.

Thanks

Chad

sikkim

Hello Chad,

Thank you for your patience.

You have clarified my doubts.

In my case I always use the camera in color format, but I'm doing some photometry tests with exoplanets, and I needed to do it with a monochrome camera, but in order not to buy another camera I wanted to know how best to use this ASI 074, and I see that it is just as I wanted its operation: Mono BIN-2.

I will continue with the tests.

Thank you ,

Xavier

sikkim

Hi Chad,

Attached you have 3 files: 1 x Dark, 1 x Flat and 1 x Light, all three images are captured by ASI-071MC-PRO in Mono bin and BIN-2.

But, Darks, and Flat in Raw mode ON, and Light in Raw mode OFF.

If I open the file "Light" . I see a Gray scale picture, but if I make a big zoom I can see it is a color file, but I do not understand why, if it has been captured with selected Mono Bin and BIN-2.

Please can you explain me how is the relation between the funtions : Mono Bin and the RAW ?

Thank you for your help,

chad

That's because your white balance is not right.

Please set both the white balance(WB) R and B at 50, then it will be the mono.

White balance is used to modify the color channel to make the resulting of color image more consistent with the visual pattern of the human eye. But for a mono image, the WB-R and WB-B should be same, if they are not same, you will get this kind of image.

Thanks

Chad

sikkim

Hi Chad,

Thanks for your replay,

But , I want explain you that: the Dark, Flat and Light have been captured with the same configuration: White Balance and Mono Bin + BIN-2.

The only difference between the Light and the Darks/Flat is the RAW mode, active in Darks & Flats but un-active in the Light capture.

For that, I don't understain why the captures Darks and Flats are saved in monochrome file, but the Light capture in color file.

Please can you clear what do this funtion:

1- RAW mode .

2- And also Hardware Bin mode .

Thanks ,

Xavier

chad

Hi Xavier,

I am confused with your words, what the mean of "raw mode"?

We did not find this mode in the application.

Thanks

Chad

sikkim

Hi Chad,

My expression: " RAW mode ", is your: " RAW Data " , in the Capture Option ,

Wich you can see in the files attached, the files captured : Darks and Flats are saved in monochrome file, but the Light capture in color file.

By that my expression: " Raw mode " , because is a different mode to save the file.

Thanks ,

Xavier

chad

Hi Xavier，

For the raw mode, it means the original data which you get from the camera.

It just means the light intensity of each pixel, no other means at all. Usually, it use the gray-scale to represent. At now, you will get a mono image.

For a color camera, different pixel means different color, this step of matching values to colors is called debayer。

After debayer, we knows.

For hardware bin, it just indicates whether the bin operation is executed by the sensor or by our SDK.

Thanks

Chad