Revisited Milky Way Nightscape + MFT capability considerations

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Interceptor121 Veteran Member • Posts: 7,961
Revisited Milky Way Nightscape + MFT capability considerations
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Once home I have reprocessed the shots already shared here on my desktop and realised I had omitted some steps in my process so here are some updated files

Shots with GH5M2 PL12mm

This is a previous shot with the GH6 + PL15mm now that DxO is available

The shots are processed in Siril an astrophotography program on mac using standard techniques for deep space.

I then take the results in photoshop for blending as I do not use a one stop shop program like sequator as this only runs on PC

While deep space photography can certainly be done with small sensor and there a number of specialised cameras with MFT sensors nightscapes are actually more challenging

Frankly shooting a single exposure on MFT is very challenging and with all the noise reduction software you want you will go very high in ISO the DR will be low, the stars will clip and your image will look monochrome. You can try editing adding colors, dehaze etc but at the end it will not look as good as blending the shots.

In this field are the various fisheye lenses, the laowa 7.5 and any ultrawide lens

Then you move into stacking. I have maintained a table since a few years of the best lenses for Milky Way photography (the best for single shot being the PL12mm and other lenses 15-17mm good for mosaics or composites with more detail of the Milky Way)

Here MFT has two key issues.

1. When the sensor gets hot you get many pixel defects (hot pixels, glow etc)

2. The lens physical aperture is tiny due to the crop factor

The two issues above are of particular relevance as the 2 is mitigated by having longer exposure times while the first is impacted by exposure times.

In particular thermal noise goes linear with exposure however the benefit of stacking increases with the number of shots and the total exposure

What matters the most is that thermal noise depends more strongly on temperature than exposure time so if you can take your picture below 10C there will not be many pixel defects

I do not use dark frames as those are taken care by a raw editor however if you worked with raw files or dng you would need to take them and those will cure your hot and defective pixels as long as you take them in the same conditions otherwise they normally add noise.

A special mention are PDAF pixels, those show up with the process I use when the image is stressed so if you ever considered using an Olympus camera with PDAF pre OM-1 (there should not be a problem there) you need to take a whole set of flat, bias, dark frames in addition to your exposures otherwise you may end up with posterization issues and other nasty problem. I recommend not using a camera with PDAF and using one with nothing on your sensor. Please note the PDAF issue show up in any situation and are aggravated by thermal effects.

Finally when you do operate in a hot climate and you are taking your Milky Way shots in Thailand or similar there will be a disadvantage and you just need to make sure you don't end up with sensor glow that is hard to fix even with dark frames and destroys your image.

So other than the fact I need to spend more time imaging on the field to get the same result of a full frame camera (in effect 4 as much from 5' to 20') the results are pretty much the same for the Milky Way

Once you work with blending you know that you can take your foreground at twilight (my favourite is the nautical twilight) and this is not actually an issue for the format as the exposures will be short and if you want you can use LENR there are no visible issue once you crunch your exposure with a noise reduction program

So in short if you are prepare to do the work the challenges can be overcome but if you are expecting to snap away and get it looking great with a single shot you are going to face challenges. Obviously quality standards are personal and some people may say what I get is good enough

Finally my consideration is that the GH5M2 is the best camera for this job at present as it retains colors at high ISO this is important if you don't have a tracker an shoot at ISO 2000/2500. The OM-1 looks promising but I have not put my hands on one yet

 Interceptor121's gear list:Interceptor121's gear list
Sony a1 Panasonic Lumix DC-GH5 II Panasonic Lumix DC-GH6 Panasonic Leica DG Macro-Elmarit 45mm F2.8 ASPH OIS Canon EF 8-15mm f/4L Fisheye USM +19 more
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