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**interested_observer** · 11-17-2014, 11:01 PM

Good article. He ran into the 645Z's inability to disable high ISO noise reduction (over 30 seconds)

Astrophotography-Next-Steps

DSims · 11-18-2014, 01:59 AM

I guess Ricoh needs to fix this in their next firmware update - It actually sounds like a genuinely easy change to make (if it doesn't trigger all kinds of testing).

LensBeginner · 11-18-2014, 07:52 AM

Very interesting...
I'm against all forms of pre-RAW NR, be it high-ISO or long exposure... I'd like to be able to exploit the full power of innovative algorithms and faster computers when they appear on the market, rather than being tied to the processing power and denoising algorithms of the camera...

Victor Wolansky · 11-18-2014, 04:55 PM

The only thing is I'm not sure you would be able to denoise the same as the camera does, it supposedly taking a blank exposure of the same time which produces a file with the same pattern noise as the photo that was just taken and then uses that to reduce the noise. That kind of quality of noise reduction might be very difficult to do without that noise pattern.

boinger · 11-18-2014, 08:45 PM

The problem is for example when shooting start trails, long exposures would leave gaps in your star trails. If I am trying to stack lets say 20 of 1 minute exposures. I would have gaps in the stars.

Victor Wolansky · 11-18-2014, 08:46 PM

totally get it, for now you probably have to make those 29 seconds or less :-) hope they fix it.

LensBeginner · 11-19-2014, 02:09 AM

Originally posted by Victor Wolansky

The only thing is I'm not sure you would be able to denoise the same as the camera does, it supposedly taking a blank exposure of the same time which produces a file with the same pattern noise as the photo that was just taken and then uses that to reduce the noise. That kind of quality of noise reduction might be very difficult to do without that noise pattern.

Yeah, then please I'd like to have the blank saved as a separate image so that I can feed it to a my software of choice...

---------- Post added 11-19-14 at 10:10 AM ----------

Originally posted by boinger

The problem is for example when shooting start trails, long exposures would leave gaps in your star trails. If I am trying to stack lets say 20 of 1 minute exposures. I would have gaps in the stars.

It also depends on which was the interval between the exposures, and the Fov of the lens you used...

Victor Wolansky · 11-19-2014, 11:25 AM

oh, I have not seen a single camera on the market that gives you the option to save that separately, then you should have a software that understand how to use it :-)

**Ed Hurst** · 11-19-2014, 02:05 PM

For the record, I do a lot of star trail photography with the 645Z and, although it's true that the dark frame functionality cannot be turned off, if you set it to 'Auto' I have found that there is usually an exposure setting (combination of ISO and exposure length) that avoids the dark frames being fired. In this respect, the behaviour is much more suitable than the 645D was (presumably because the sensor is inherently less noisy, so they have been able to set the algorithms about when the dark frame fires less stringently). The algorithm seems to be about exposure length, ISO and temperature; since temperature varies, I suggest experimenting. Unless it's much hotter than I have experienced (and I live in Australia, where it's quite warm at times) you will find it's workable.

Good luck!

---------- Post added 11-20-14 at 08:12 AM ----------

Some examples shot with the 645Z:
https://www.flickr.com/photos/16063951@N00/15120439737/in/set-72157632566383126/lightbox/
https://www.flickr.com/photos/16063951@N00/14793972756/in/set-72157632566383126/lightbox/
https://www.flickr.com/photos/16063951@N00/15212134730/in/set-72157632566383126/lightbox/
https://www.flickr.com/photos/16063951@N00/15376286626/in/set-72157632566383126/lightbox/
https://www.flickr.com/photos/16063951@N00/15581598395/in/set-72157632566383126/lightbox/
https://www.flickr.com/photos/16063951@N00/14814203911/in/set-72157632566383126/lightbox/

Ed

LensBeginner · 11-19-2014, 05:25 PM

Originally posted by Victor Wolansky

oh, I have not seen a single camera on the market that gives you the option to save that separately, then you should have a software that understand how to use it :-)

You can already shoot a second frame manually.
You can use Photoshop and layers...
I was saying I would like it to be done automatically (shooting and saving a separate file) just for convenience, but it's already possible (albeit manually).
All the more reason to give the option to turn it off.

**Ed Hurst** · 11-19-2014, 09:55 PM

Couldn't agree more! I have been complaining about that for years....

Victor Wolansky · 11-20-2014, 06:53 AM

They just released a new firmware with this option. You are lucky :-)

LensBeginner · 11-20-2014, 03:12 PM

Originally posted by Victor Wolansky

They just released a new firmware with this option. You are lucky :-)

so they actually listen to customers!
Well... at least if the product sells well!

11-17-2014, 11:01 PM	#1
interested_observer Loyal Site Supporter Join Date: Jun 2009 Location: Tumbleweed, Arizona Photos: Gallery \| Albums Posts: 5,707	645Z - Astrophotography - Michael Reichmann Good article. He ran into the 645Z's inability to disable high ISO noise reduction (over 30 seconds) Astrophotography-Next-Steps

11-19-2014, 05:25 PM	#10
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by Victor Wolansky oh, I have not seen a single camera on the market that gives you the option to save that separately, then you should have a software that understand how to use it :-) You can already shoot a second frame manually. You can use Photoshop and layers... I was saying I would like it to be done automatically (shooting and saving a separate file) just for convenience, but it's already possible (albeit manually). All the more reason to give the option to turn it off. Last edited by LensBeginner; 11-19-2014 at 11:50 PM.

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11-18-2014, 01:59 AM	#2
DSims Veteran Member Join Date: Sep 2009 Location: Southern California Photos: Gallery \| Albums Posts: 3,236	I guess Ricoh needs to fix this in their next firmware update - It actually sounds like a genuinely easy change to make (if it doesn't trigger all kinds of testing).

11-18-2014, 07:52 AM	#3
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Very interesting... I'm against all forms of pre-RAW NR, be it high-ISO or long exposure... I'd like to be able to exploit the full power of innovative algorithms and faster computers when they appear on the market, rather than being tied to the processing power and denoising algorithms of the camera...

11-18-2014, 04:55 PM	#4
Victor Wolansky Inactive Account Join Date: Oct 2014 Posts: 91	The only thing is I'm not sure you would be able to denoise the same as the camera does, it supposedly taking a blank exposure of the same time which produces a file with the same pattern noise as the photo that was just taken and then uses that to reduce the noise. That kind of quality of noise reduction might be very difficult to do without that noise pattern.

11-18-2014, 08:45 PM	#5
boinger Inactive Account Join Date: Nov 2014 Posts: 17	The problem is for example when shooting start trails, long exposures would leave gaps in your star trails. If I am trying to stack lets say 20 of 1 minute exposures. I would have gaps in the stars.

11-18-2014, 08:46 PM	#6
Victor Wolansky Inactive Account Join Date: Oct 2014 Posts: 91	totally get it, for now you probably have to make those 29 seconds or less :-) hope they fix it.

11-19-2014, 02:09 AM	#7
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by Victor Wolansky The only thing is I'm not sure you would be able to denoise the same as the camera does, it supposedly taking a blank exposure of the same time which produces a file with the same pattern noise as the photo that was just taken and then uses that to reduce the noise. That kind of quality of noise reduction might be very difficult to do without that noise pattern. Yeah, then please I'd like to have the blank saved as a separate image so that I can feed it to a my software of choice... ---------- Post added 11-19-14 at 10:10 AM ---------- Originally posted by boinger The problem is for example when shooting start trails, long exposures would leave gaps in your star trails. If I am trying to stack lets say 20 of 1 minute exposures. I would have gaps in the stars. It also depends on which was the interval between the exposures, and the Fov of the lens you used...

11-19-2014, 11:25 AM	#8
Victor Wolansky Inactive Account Join Date: Oct 2014 Posts: 91	oh, I have not seen a single camera on the market that gives you the option to save that separately, then you should have a software that understand how to use it :-)

11-19-2014, 02:05 PM	#9
Ed Hurst Site Supporter Join Date: May 2010 Location: Sydney Posts: 1,657	For the record, I do a lot of star trail photography with the 645Z and, although it's true that the dark frame functionality cannot be turned off, if you set it to 'Auto' I have found that there is usually an exposure setting (combination of ISO and exposure length) that avoids the dark frames being fired. In this respect, the behaviour is much more suitable than the 645D was (presumably because the sensor is inherently less noisy, so they have been able to set the algorithms about when the dark frame fires less stringently). The algorithm seems to be about exposure length, ISO and temperature; since temperature varies, I suggest experimenting. Unless it's much hotter than I have experienced (and I live in Australia, where it's quite warm at times) you will find it's workable. Good luck! ---------- Post added 11-20-14 at 08:12 AM ---------- Some examples shot with the 645Z: https://www.flickr.com/photos/16063951@N00/15120439737/in/set-72157632566383126/lightbox/ https://www.flickr.com/photos/16063951@N00/14793972756/in/set-72157632566383126/lightbox/ https://www.flickr.com/photos/16063951@N00/15212134730/in/set-72157632566383126/lightbox/ https://www.flickr.com/photos/16063951@N00/15376286626/in/set-72157632566383126/lightbox/ https://www.flickr.com/photos/16063951@N00/15581598395/in/set-72157632566383126/lightbox/ https://www.flickr.com/photos/16063951@N00/14814203911/in/set-72157632566383126/lightbox/ Ed

11-19-2014, 09:55 PM	#11
Ed Hurst Site Supporter Join Date: May 2010 Location: Sydney Posts: 1,657	Couldn't agree more! I have been complaining about that for years....

11-20-2014, 06:53 AM	#12
Victor Wolansky Inactive Account Join Date: Oct 2014 Posts: 91	They just released a new firmware with this option. You are lucky :-)

11-20-2014, 03:12 PM	#13
LensBeginner Veteran Member Join Date: Sep 2014 Photos: Albums Posts: 4,696	Originally posted by Victor Wolansky They just released a new firmware with this option. You are lucky :-) so they actually listen to customers! Well... at least if the product sells well!

645Z - Astrophotography - Michael Reichmann

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