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View Full Version : So how good is the EM1 MKII sensor for low noise?


birdboy
27th December 2016, 04:17 PM
Believe it or not this is from a single frame uncropped saved as tiff in OV3 and processed in Star Tools.

300mm f4 40sec exposure ISO400 NR on:

http://e-group.uk.net/gallery/data/500/PC260443_tiff_b.jpg (http://e-group.uk.net/gallery/showphoto.php/photo/91496)

pdk42
27th December 2016, 04:52 PM
That's very impressive for a single frame!

Bikie John
27th December 2016, 04:52 PM
It looks good but not having experience of that kind of work I'm hard pushed to say how good. Is that amost incredible?

John

Otto
27th December 2016, 05:17 PM
Looks impressive, certainly - what are we looking at?

birdboy
27th December 2016, 05:30 PM
It looks good but not having experience of that kind of work I'm hard pushed to say how good. Is that amost incredible?

John
I have seen 30 min astrophotograpy challenges which look amazing but the EM1 MKII seems to me to be a game changer for astrophotography. When I have used the EM1 (mkI) with the 300mm prime lens it takes some finding of the target because what would appear on the back of the screen was a faint blob that you think is your target. I would have to take a picture and look at it in OV3 to confirm if that was my intended target. With the EM1 MKII and LV boost on2 you see almost what you see here, thats a wow for me, and it works so much quicker than the MKI.

birdboy
27th December 2016, 05:32 PM
Looks impressive, certainly - what are we looking at?

This is M42 Orion nebula which is in the milky way. It is sort of visible by the naked eye as a white blob.

birdboy
27th December 2016, 05:44 PM
That's very impressive for a single frame!

Strickly speaking it might not be a single frame although it came out of the camera as a single frame 10368 x 7776 pixel dimensions:eek:

It was a high res shot so 8 x 40 secs = 320 secs. Still a short exposure time for astrophotography. The processing allowed me to reduce the size (bin data) and consequently noise as well. There is a process called dithering where you take a number of frames at slightly different positions and stack them in astro software. The EM1 MKII seems to me to do the same thing in camera, the benefits in noise reduction are very clear to me. The file sizes on the other hand are causing problems for my stacking programs and my 4GB memory pc.

Bikie John
27th December 2016, 05:57 PM
Thanks John, it does indeed sound very impressive and not just because of the low noise. Although, to play devil's advocate a bit, I think your smart use of the high-res mode has tilted the balance even further in its favour.

So far I have held off the Mark II and sunk the pocket money into a 12-100 instead. Having seen all the tales of lock-ups I am glad I did, as I really don't want to repeat the teething troubles of the Mark I. But all the reports of fast focus for action, image quality etc. are making it harder and harder to resist. Will you all please stop it :)

John

birdboy
27th December 2016, 06:04 PM
I bit the bullet in buying the MKII for two reasons; one was the feature of using the high res mode below 8 secs as in the EM5 MKII and the CAF and pro capture feature. I am sorry to say John but both these features are exceeding my expectations.

Phill D
27th December 2016, 07:42 PM
That's very interesting and a cracking shot John. I was musing about the use of the high res mode for astro images myself only yesterday and was thinking of asking the question to see if you all thought it would work. You've so brilliantly answered the question before I asked it!!!. Is ESP one of the new EM1 mk2 modes ;)

OM USer
29th December 2016, 06:05 PM
Hard to believe that was only a 40 second exposure such is the clarity. Good use of the high res mode. What are you using as a tracking mechanism?

birdboy
29th December 2016, 06:31 PM
What are you using as a tracking mechanism?

I am using the Star Adventurer with guiding although only on the RA axis. Been trying to push exposure time to 60 secs but get star trials when 1:1 with the 10368 x 7776 image.

wornish
30th December 2016, 11:27 AM
What is different in the EM1mk2 Hi Res shot mode compared to the same mode in EM5mk2 ?

IainMacD
30th December 2016, 12:19 PM
Larger (MP), more advanced sensor for a start.

birdboy
30th December 2016, 04:14 PM
What is different in the EM1mk2 Hi Res shot mode compared to the same mode in EM5mk2 ?

I have not tested the high res shot for astrophotography because of the restriction of the slowest shutter speed being 8 seconds, but having now used the EM1 MKII I now realise that it may be worth giving it a try. I started testing the EM1 MKII at 60sec exposure on the 300mm f4 pro lens but this leads to too much star trailing. I can get away with about 40secs with guiding, but it is a bit hit and miss.

My instinct so far is that the sony sensor in the EM1 MKII is far better than the one in the EM5 MKII for astrophotography.