Write TIFF file only

[mpoelzl]

Hello!

I am trying to 'interface' Backyard Eos with my AllSkEye application to allow users to use DSLR cameras. Initially I will only look at reading image files from the target folder but hopefully I can extend it to include camera control via the API at some point.

A question I have at this point is whether it's possible to 'only' output a tiff file to the target folder and no raw or jpg files? This would save me the extra processing step to convert to tiff on my side.

Thanks,

Mike

[admin]

No, this is not possible. DSLR output their raw format only + JPG.  In order to create any other format like TIFF the DSLR raw file must first be downloaded on the PC and only then can it be converted into another format. I've always been careful to ensure that BYE/BYN does not delete files and this has saved me a few times in the past so for this reason the file downloaded from the camera will never be deleted by BYE/BYN.

Hope this makes sense.

Regards

[mpoelzl]

Thanks for the fast answer! I'm using dcraw to convert the raw files to tiffs before I load them into my app so it looks like we are doing the same thing 🙂and there is no time saving to be had. No worries, I'll just stick with what I have!

I did have one more question if you have the time to answer. I was wondering if (for astro images) it might be useful to use some of the colour balance data in the exif tags. Do you have any experience with that at all (sorry I'm not very knowledgeable when it comes to DSLR imaging)? 

Thanks again,

Mike

[astroman133]

The camera puts white balance information in the EXIF data for raw images. Here are EXIF tags that are related:

WhiteBalance                  : Daylight
WhiteBalanceRed               : 0
WhiteBalanceBlue              : 0
BlueBalance                   : 1.544922
RedBalance                    : 2.015625

[mpoelzl]

Thank you. So are these values just coefficients e.g. all red pixel are multiplied by 2.015625? Or is there a different way these would be applied to the raw data (I'm looking to apply before the debayer process).

Thanks,

Mike

[astroman133]

I would think that the Debayering software would support applying the White Balance settings as an option. While it is no longer an active product, ImagesPlus does this during Debayering with its "Bayer At Capture White Balance" setting.

[mpoelzl]

Thanks for the replies, I've managed to implement this in my app and it seems to work well.

I do have one more question with regards to the datetime the exposure was taken. Ideally I do not want to use camera datetime but a datetime created by the PC. For now I am using the datetime the file has been created which is ok but does include the download time which is not ideal. I noticed that the file name has a timestamp that seems to indicate exposure start. Is this timestamp available in the metadata anywhere? I don't seem to be able to find it and extracting it from the file name would be prone to break if it is changed...

LIGHT_Tv1125s_1600iso_f4_+24c_20200404-08h54m19s321ms.CR2

Thanks,

Mike

[admin]

Yes, the image timestamp is the start of the exposure, this is by design. 

[mpoelzl]

Thanks!

Sorry I wasn't entirely clear. I was hoping that this 'start of exposure' datetime would also be available in the meta data of the image file but I couldn't find it? 

[admin]

1 hour ago, mpoelzl said:

Thanks!

Sorry I wasn't entirely clear. I was hoping that this 'start of exposure' datetime would also be available in the meta data of the image file but I couldn't find it? 

If you enable EXIF WRITE in the advance settings it might be.

[astroman133]

I looked at a recent image, but the only start time that I found was put there by the camera as "DateTimeOriginal" and "CreateDate". The resolution of these times is 1 second and is only accurate as the camera's time.

I will create a post in the Suggestion Box Forum to add this time to the Backyard... metadata as well as to make the Exif Data dialog be re-sizeable or to present a horizontal scrollbar.

[mpoelzl]

Thanks, for me that would be a useful addition wich hopefully won't be much work to implement.