16bit / 8bit ?

[Davey-T]

Messing about with stuff yesterday and tried capturing in 16bit SERs , is there any noticable difference in the end image as displayed on screen ?

Seeing and sky was pretty abysmal here yesterday so both versions look crap.

Using Skyris274 and Lunt 60DS

Dave

[riklaunim]

Screen is 8-bit

If the noise is very low and the signal is very strong then you would be able to take advantage from more than 8-bit capture format.

[Ewan]

Dave if you can go for 16Bit mate, you wont really see it on screen but it does mean you can capture good proms & chromosphere in one capture.

I have been getting on great guns with my PG IMX174............NOT!

With the fast Sammy SSD I found going from 8Bit up to 16Bit dropped the frame rate by about 25 if that, with 16Bit you will be able to pull out subtle details in dark areas (so I have read anyway), not sure if this would include sunspots but Lunar would be a good example, also from what I read............I read a lot

I have now tried all combinations of AOI & 8Bit or 16Bit & to be honest anything above the DMK""618's max 60Fps is a bonus.

As you say yesterday was crap, hazy here so shooting through candy floss like clouds is not going to achieve much for me, just to get one capture from this electronic paper weight would be good.

Are you on about a camera you have already Dave I presume ?

[Davey-T]

7 hours ago, Ewan said:

Dave if you can go for 16Bit mate, you wont really see it on screen but it does mean you can capture good proms & chromosphere in one capture.

I have been getting on great guns with my PG IMX174............NOT!

With the fast Sammy SSD I found going from 8Bit up to 16Bit dropped the frame rate by about 25 if that, with 16Bit you will be able to pull out subtle details in dark areas (so I have read anyway), not sure if this would include sunspots but Lunar would be a good example, also from what I read............I read a lot

I have now tried all combinations of AOI & 8Bit or 16Bit & to be honest anything above the DMK""618's max 60Fps is a bonus.

As you say yesterday was crap, hazy here so shooting through candy floss like clouds is not going to achieve much for me, just to get one capture from this electronic paper weight would be good.

Are you on about a camera you have already Dave I presume ?

Yes, Skyris 274 mono USB3 that I bought to achieve full disc on the Lunt LS60DS which it does, the only draw back is that it is limited to 20fps, even an ROI runs at 20fps as all it does is crop the downloaded full image.

Dave

[Herra Kuulapaa]

18 hours ago, Ewan said:

Dave if you can go for 16Bit mate, you wont really see it on screen but it does mean you can capture good proms & chromosphere in one capture.

Does is actually affect the dynamic range?

I have been in impression it's only about the color depth and you'll get exactly same data with 12/16 bit, only with more fine shades if you go higher one. Well capacity (along with noise characteristics) are the variables that affect the dynamic range.

[Davey-T]

5 minutes ago, Herra Kuulapaa said:

Does is actually affect the dynamic range?

I have been in impression it's only about the color depth and you'll get exactly same data with 12/16 bit, only with more fine shades if you go higher one. Well capacity (along with noise characteristics) are the variables that affect the dynamic range.

To be honest I couldn't detect any noticeable difference when displayed on the screen but the weather was dire and not looking any better today.

Dave

[Ewan]

5 hours ago, Herra Kuulapaa said:

Does is actually affect the dynamic range?

I have been in impression it's only about the color depth and you'll get exactly same data with 12/16 bit, only with more fine shades if you go higher one. Well capacity (along with noise characteristics) are the variables that affect the dynamic range.

From what I have read 16Bit is better at the end of the day. I don't use colour cams either so I can't help there.

Why produce a product that can capture 16Bit & not use it if possible ? just don't make sense.

Seeing, write speed & general capture capabilities will make a difference yes BUT if your system can do it then why not use it.

Agreed Dave 20Fps is a little low mate & I know I could not suffer that at all.

These days all people want is more more more, I am the same if I am honest.

Dave I will put my hands up now to being a wally mate, as I have said I havn't had to chance to capture anything of use so 8Bit or otherwise as I am still working the correct settings out compared to the DMK618, on the way to work I was mulling the settings over & then realised the PG cameras use the Shutter option, I felt like a right door K nob, I must have fiddled with everything but didn't twig I need to change the Shutter (as the camera is Global Shutter) & not just Exp etc. How embarrassing is that.

Sunday is looking to be a scorcher all day here on the coast & will try my hardest to do some comparison Bit depth captures of only 10 seconds just to see if 16 is really worth doing. It's ok everyone adding there 2 pence worth (what forums are for) but all said & done you can't beat do numerous tests on your own gear. If the Max Frae Rate is 20 then I would use the camera on it's best settings at FPS shouldn't be an issue.

Dave when you said ' is there any noticeable difference in the end image as displayed on screen ?' you do mean ONLY the preview shown in real time don't you ?

When I switch my options from 8Bit to 16Bit I can see proms a lot easier than without it enabled Dave so for me it could be a viable option, let me know though if you do test it out all the way to processing an image & upload them both if you could, 1 8Bit & 1 16Bit maybe ?

All the best for Monday mate hope you get a chance for the transit.

[Davey-T]

Thanks for the input Ewan, yes 20 fps is a pain, didn't realise until after I'd bought it and read the small print, just thought ah USB3 = quick 

Been messing around again today but trying to do meaningful comparisons in the changing conditions is a bit pointless, I did a couple of vids without the focal reducer in the Technosky for the first time so will see how they look.

Just following the Sun down ATM to see if I'll be able to catch the end of the transit but looks like it's going to end behind my neighbours six foot chimney stack 

Dave

[Grotemobile]

I have tried using 8bit & 16 bit with my colour 185C  ZWO cam. I find I get better results using 8 bit. That is what I use on planetary imaging now.

[Ewan]

49 minutes ago, Davey-T said:

Thanks for the input Ewan, yes 20 fps is a pain, didn't realise until after I'd bought it and read the small print, just thought ah USB3 = quick 

Been messing around again today but trying to do meaningful comparisons in the changing conditions is a bit pointless, I did a couple of vids without the focal reducer in the Technosky for the first time so will see how they look.

Just following the Sun down ATM to see if I'll be able to catch the end of the transit but looks like it's going to end behind my neighbours six foot chimney stack 

Dave

Dave address please I will nip round with my breaker & reduce that stack to 6" for ya , I have the same thing mate but it's 3 massive GayLandEyes or whatever there called, a real pain & probably costs me 2.5Hrs of Sol catching, I guess you could say you are Sol Searching then  Dave? hehe sorry mate couldn't resist.

Dave if I wasn't keeping the DMK  as a backup cam I would have offered it to you for free, maybe get a new cmos once you got that tasty mount saved up for & sorted ?

I remember going from the CG5 to the AZ I have now, wow what a change, it will be worth the wait Dave i'll bet.

Now I know where I went wrong with the Shutter etc I am hoping, praying even I get it right Sunday.

Got home today early, saw the haze & thought 'no chance' just wasn't worth loosing more of the whispy stuff on me ed for a bad capture.

Ewan

 

 

[Davey-T]

Things keep cropping up and making a hole in my mount budget (about £7000.00) the Tecnosky 152mm, you know how much that cost, then about the same amount on the camper van clutch and a few other bits, and I hear that front mounted ERF whispering buy me, buy me 

Theoretically I don't need to buy the mount until the autumn but that's assuming it all works as advertised out of the box 

Looks like I'll miss the end unless I decamp and set up somewhere with a better horizon.

Dave

[Ewan]

 

 

2 hours ago, Davey-T said:

'and I hear that front mounted ERF whispering buy me, buy me '

 Haha it never ends does it.

[Herra Kuulapaa]

I think we're partly discussing two different things in this thread:

a ) ADC bit depth, which defines the color/grayscale shade amount in data. 

and

b ) dynamic range, which defines how many photons one pixel can record without saturation.

Higher bit level should and will record faint details better than low one, but it's not related to dynamic range, only how signal is digitized, right?

[Davey-T]

This is in relation to Solar imaging which is by it's nature a very bright target and some pixels will be saturated.

Presumably more grey levels will be possible but as my images never get any further than being displayed on computer screens will the end result be any "better" ?

Dave

[Herra Kuulapaa]

I believe they will be better, because you'll strech the data before publishing/viewing it and in that the higher source data bit depth comes very handy.

[Davey-T]

Don't actually do any stretching as such on solar data, just a bit of sharpening, does that count ?

Waiting for a nice clear blue sky then I will experiment.

Dave

[Drop Of Sun]

I don't have any example piccies to hand Dave but I did some tests a while back and my findings were, the main difference between 8 bit and 16 bit capture is that with 16 bits you can capture disc and proms in the same shot and stretch the proms and they should come out fine. With 8 bits the proms did not look very good stretched. The other way of course is if you do 8 bits, to do a separate shot for the proms with the disc overexposed then merge the disc and prom shots together in Photoshop.

Otherwise on disc detail, I couldn't really tell any difference. My ASI174 in 8 bit on disc showed little difference to my Grasshopper 3 in 16 bit.

I also found that 8 bit captures actually get greater bit depth when you stack them. They felt more like 10 or 12 bit images after stacking to a 16 bit images!

[Davey-T]

Thanks for the input Luke.

I think I was coming to the same conclusion that the close ups were not really better in 16bit but I'm still waiting for that elusive clear blue sky all day to test a few things

Dave

[Drop Of Sun]

I usually did 16-bit with the Grasshopper on disc as well as I figured, can't do any harm and who konws, maybe there is some improvement.  With the ASI174 I did 8 bit, as I could get a faster frame rate and that sometimes paid off I felt, like if there were 15 second gaps!!