Nikon D600 monochrome images

[Coco]

Stunning images.. very nice indeed..

Keep hold of that TS65Q scope, ive tried 2 and they were both rubbish, tried all the mods and they both were appalling..

[Herra Kuulapaa]

Keep hold of that TS65Q scope, ive tried 2 and they were both rubbish, tried all the mods and they both were appalling..

I've heard there has been some issues with the TS65Q. My lenses were too tight and that resulted pinching. I loosened the packs and now it seems to work fine.

What kind of issues you had with yours?

[Herra Kuulapaa]

I've been wondering about the pixel size effect between full frame DSLRs. Now I got the Nikon D800am (astromono) version done and was able to make a comparison between the cameras. You know that the D600 has 6µm pixels while the D800 has 4.9µm ones. In theory D600 should gather more light per pixel and thus give a better SNR. So I did a brief comparison in web friendly size. I can provide more pixel level data later.

Both sets are dithered and taken with same scope, ISO and exposure. True dark current mode was used to ensure true unaltered raw data. No bias, flat, dark correction applied. Both have identical amount of frames, stacking method, sigma rejection and post processing. Images are stacks of 6x660s exposures with ISO500. Histograms are stretched identical with the applied curves and details enhancement. I left them pretty flat looking by purpose to make comparison easier.

D600am:

D800am:

Larger versions:

http://www.kuulapaa.com/D800/D600_2000.jpg

http://www.kuulapaa.com/D800/D800_2000.jpg

What do you think? (not about the picture itself, but the difference)

I'm having an issue though: Pretty limited imaging time nowadays for all the cameras, especially for the D600am, so I'm looking for a partner, who could help me image more southern objects that are hidden from my 60 degrees North location. Please contact me if you interested in such or the D600am overall.

[davew]

To be honest Herra, I can't really see much difference. I would take that as a positive.

Have you had any problems with the shutter lubricant on the 600 ?

Dave.

[Herra Kuulapaa]

Hi Dave,

They're practically identical, but then, it might be my scope too. I think there should be at least some visual difference with higher quality optics.

No issues with lubricant spots. The shutter has been replaced by Nikon so it could be also that.

I took some Cederblad 214 exposures with D800am last night, but the temperature drop was too much (+5 -> -4C) and I can see that the focus wasn't spot on anymore with the second half of the series. There should be some recoverable exposures to make a second comparison with D600am though.

[davew]

Hi Herra,

Up to a certain point you'd be quite correct thinking the scope would have a greater effect on the final image than the resolution of the chips. I hadn't really thought of that in this case but it's quite obvious. The noise seems to hold up well on both too. Under normal conditions with affordable scopes I'd have the 600 because - 

I think all the laptops I have access to would much prefer the size of the 600 chip rather than the 800 Stacking a large quantity of the 800 subs would take one of my laptops a week !

Good to know the shutter is behaving.

Re focus point and cool down. When trying out stuff I normally use DSS as I'm going along and it gives me a free and simple way to check focus. I Register each sub once they've downloaded ( Can be done in the background I think ) and use the FWHM figures it produces as a monitor. I now know which scopes have to be re focused regularly. I do know an auto focuser works but we don't all have them on every scope Just a thought for you to try.

Dave.

[Herra Kuulapaa]

Thanks

I usually let the scope stabilize (cool down) at least 2 hours outside before focusing first time.

Last night I was too lazy and just threw gear out in hurry, which I normally never do, but last night I did and I paid the price of two lost hours for it

[Herra Kuulapaa]

Same processing with TS65Q on Ced214 brings identical results with D600am and D800am when downsized to web. Naturally D800 image is larger, but there is no meaningful detail difference.

Here's the D800am version. Processing is different to D600am so they are not directly comparable:

10x900s Ha

[Herra Kuulapaa]

It was a clear night, in December!

NGC1893, Flaming star and hydrogen mist, lots of it.

8x900s with D600am and TS65Q

[Herra Kuulapaa]

Wide field Fat Horselover

8x900s with TS65Q

[MartinFransson]

Oh, come on! You're making me drool here! [emoji4] Care to monoconvert a Canon for me?

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