[batscanner2]

Hi all--I am new to Pentax, just bought a K-1 mII last week for astrophotography. (I have been shooting night sky pix for 3 years with a Canon 6D.) I am finding the BOC on the K-1 to be very misleading when trying to judge exposure in the field. Below is a comparison visual that shows the BOC of one of the very first images I took; the RAW shot as it looked when I opened it (yikes!); and the final edit. I nearly cried when I opened that RAW image and the shot looked almost totally black, as you can see. I was able to dig out the detail in Photoshop (bottom shot below is the final edit), but it was a lot of stretching to get any detail at all, and this isn't great for final image quality.


I have looked at using the Outdoor View Setting to dim down the BOC images, but am wondering if there is a different option that would give me a more realistic preview that doesn't require dimming down the entire screen.


Also of note: I am shooting RAW+JPEG, and the JPEG, when opened in Photoshop, more closely resembles the BOC image. But these RAW images are ridiculously dark.


Hoping someone has had this experience and can help me find a way to get BOC that actually resemble the RAW files.

Attached Images

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[UncleVanya]

On my KP the “outdoor view” option boosts brightness. I haven’t yet done any Astro but my plans this year include it. I would have suggested setting the screen in red light mode and transferring images to your phone to view - except your jpg and raw files are far different from each other. What was the actual exposure and what lens was used?

You can simply leave the screen in normal mode and turn down the brightness all the way down - that might be closer.

[batscanner2]

On my KP the “outdoor view” option boosts brightness. I haven’t yet done any Astro but my plans this year include it. I would have suggested setting the screen in red light mode and transferring images to your phone to view - except your jpg and raw files are far different from each other. What was the actual exposure and what lens was used?

You can simply leave the screen in normal mode and turn down the brightness all the way down - that might be closer.

Hi UncleVanya--This shot was 40 seconds at ISO 3200, f 2.8, with an Irix 15mm lens. From the tinkering around I've done with "outdoor view" it seems like it can boost or reduce brightness, depending on which arrow I click. How would I turn the brightness down, as you suggest? The only way I can find to do it is to use "outdoor view." I have so much to figure out with this new camera!

[othar]

I would never trust brightness of LV (especially at night).
LV is a tool for focusing and composing the image in my opinion (for that a brighter image can be an advantage).
I always take an initial image to check my exposure (I also take a look on the histogram)

[batscanner2]

I would never trust brightness of LV (especially at night).
LV is a tool for focusing and composing the image in my opinion (for that a brighter image can be an advantage).
I always take an initial image to check my exposure (I also take a look on the histogram)

I agree, and the image above isn't LV; it is an actual image that I took to test the exposure, as you suggest. The problem is that what I see in image review (after the image is taken) does not give me any sort of true indication of the exposure on the actual RAW file. The JPEG that I record at the same time as the RAW file is a fairly close match to the image review I see BOC after taking the shot, but the RAW file is way, way darker. So even if I take a bunch of shots at various settings to settle on a good exposure (which I did), the actual RAW file doesn't look a thing like my test images.

[UncleVanya]

Hi UncleVanya--This shot was 40 seconds at ISO 3200, f 2.8, with an Irix 15mm lens. From the tinkering around I've done with "outdoor view" it seems like it can boost or reduce brightness, depending on which arrow I click. How would I turn the brightness down, as you suggest? The only way I can find to do it is to use "outdoor view." I have so much to figure out with this new camera!

On the KP (I don’t have a K1) there’s an LCD settings menu item that lets you adjust brightness contrast etc. you can also tune the jpgs so they more closely match the raw.

[othar]

When the camera jpg is really closer to the final edit than to the Raw file, exposure wise, that's a little weird, otherwise I would have agreed that the display setting is too bright.
What are your processing settings for the jpg (bright, natural,...)?

[RichardJ]

What software are you using to open the RAW file? It sounds like the software isn't handling the PEF or DNG (depending which format you are using) file very well and its default presentation of the file is too dark. You might find different software does a better job of giving you a starting point in processing the RAW file.

I use DxO Photolabs to process my RAW files and find it does a good job for me.

The RAW file is unprocessed sensor data, but it contains a JPEG preview showing an example of how that raw sensor data could be processed into an image. When you view the RAW file on the camera display, it's that JPEG preview that you are seeing. When you open the raw file on your computer, the software you are using will make decisions about how to generate an image from the unprocessed sensor data. But all the information captured by the camera is still in that raw file, so you can further process the file in your software until it is presented as you wish.

Some software will use the JPEG preview embedded within the raw file as its starting point. Other software will generate its own image file from the raw data and show you that. So you do find that different software applications can do a better or worse job handling raw files.

[AstroDave]

I was able to dig out the detail in Photoshop (bottom shot below is the final edit), but it was a lot of stretching to get any detail at all, and this isn't great for final image quality.

Think of it the other way round: the displayed jpeg has been stretched (without your permission/knowledge/input - unless you've picked one of the custom images modes) to get it to show on your camera screen (i.e. it's already been rather highly processed!). When dealing with the PEF, you have to supply your own choice of stretching. As others have noted, how much of this you have to do depends on your PP software.

I just looked at some old astro pixs from my K1 for which I have both jpeg and PEF files, with DxO PhotoLab, and with the default DxO processing of the PEFs, the images on my PC display are nearly identical for both versions.

Your data ARE there in the PEFs - they just may not show up as bright as you expect until you do some processing. As to noise in that final processing - do a close comparison with the equivalent (unprocessed) jpeg, and I suspect you will find the noise pretty much indistinguishable, and perhaps actually better in the PEF-derived version (again depending on your software and how/if it does noise reduction).

[batscanner2]

When the camera jpg is really closer to the final edit than to the Raw file, exposure wise, that's a little weird, otherwise I would have agreed that the display setting is too bright.
What are your processing settings for the jpg (bright, natural,...)?

I don't process the JPEGs, just use them to preview the RAW files so I know what each shot is showing. I use Photoshop.

---------- Post added 07-05-21 at 04:19 PM ----------

Think of it the other way round: the displayed jpeg has been stretched (without your permission/knowledge/input - unless you've picked one of the custom images modes) to get it to show on your camera screen (i.e. it's already been rather highly processed!). When dealing with the PEF, you have to supply your own choice of stretching. As others have noted, how much of this you have to do depends on your PP software.

I just looked at some old astro pixs from my K1 for which I have both jpeg and PEF files, with DxO PhotoLab, and with the default DxO processing of the PEFs, the images on my PC display are nearly identical for both versions.

Your data ARE there in the PEFs - they just may not show up as bright as you expect until you do some processing. As to noise in that final processing - do a close comparison with the equivalent (unprocessed) jpeg, and I suspect you will find the noise pretty much indistinguishable, and perhaps actually better in the PEF-derived version (again depending on your software and how/if it does noise reduction).

Think of it the other way round: the displayed jpeg has been stretched (without your permission/knowledge/input - unless you've picked one of the custom images modes) to get it to show on your camera screen (i.e. it's already been rather highly processed!). When dealing with the PEF, you have to supply your own choice of stretching. As others have noted, how much of this you have to do depends on your PP software.I just looked at some old astro pixs from my K1 for which I have both jpeg and PEF files, with DxO PhotoLab, and with the default DxO processing of the PEFs, the images on my PC display are nearly identical for both versions.Your data ARE there in the PEFs - they just may not show up as bright as you expect until you do some processing. As to noise in that final processing - do a close comparison with the equivalent (unprocessed) jpeg, and I suspect you will find the noise pretty much indistinguishable, and perhaps actually better in the PEF-derived version (again depending on your software and how/if it does noise reduction).

====

I am processing the RAW files in Photoshop. Also saving the files in-camera as DNG. Maybe I should switch to PEF? I will try that tonight.

[DWS1]

I am processing the RAW files in Photoshop. Also saving the files in-camera as DNG. Maybe I should switch to PEF? I will try that tonight.

Don't think it will make any difference. I would stick with .dng. It's very universal across several platforms. I think there is a setting somewhere in Photoshop or Camera Raw to display the embedded jpeg in the raw file as a starting point. I know Lightroom does this.

[UncleVanya]

I would second the DXO option.

[JimJohnson]

As I understand it, DNG is a 'wrapper' created by Adobe for the multiple RAW formats. As such, the original RAW image is embedded within the DNG along with instructions on how the processing software is supposed to read the embedded data. Out of a Pentax body, PEF and DNG should be identical. However, if you edit a DNG file, the nature of the edits are also embedded within the file without touching the original embedded RAW image data. In other words, a DNG file can theoretically keep growing in size.

Adobe has a downloadable DNG converter (free download). Feed this utility a PEF file and you have a DNG file with the PEF data embedded. Based on this, you should in theory be able to extract and recreate the original manufacturer specific RAW file, however so far as I know there is no utility to accomplish this extraction. Read more here: Adobe Digital Negative Converter (there are also detailed discussions on Adobe's web site)

For the record I save DNG files from my Pentax bodies simply because I haven't yet found a downside.

[AstroDave]

Maybe I should switch to PEF?

Probably not - the general consensus is that a Pentax DNG contains all the information that would be in a PEF - and, a DNG will be a lot more edible by some post-processing software. I have switched to DNG when I am saving RAW files.

[SelrahCharleS]

I don't process the JPEGs, just use them to preview the RAW files so I know what each shot is showing. I use Photoshop.

---------- Post added 07-05-21 at 04:19 PM ----------




====

I am processing the RAW files in Photoshop. Also saving the files in-camera as DNG. Maybe I should switch to PEF? I will try that tonight.

I have had a raw converter give very different initial settings between a PEF and a DNG, although in that case it was the PEF that had issues with looking wrong at the start. It's worth a shot switching the raw format in camera to see what happens, although typically I stick with DNG.