Milky Way - 32mm f/1.4 - (PIC).

The Milky Way with the EOS M6 + EF-M 32mm f/1.4 STM lens - last week.,
I'm not sure what to think of this.  Last week I took two JPEG pictures of the Milky Way with the new EF-M 32mm f/1.4 STM lens just seconds apart.  One shot used Auto WB and the other used Tungsten WB.  Both were unappealing so I aligned them together and then edited and blended the two to allow more of the Tungsten color to bleed into the warmer tones of the Auto WB shot.
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The color spectrum of the Milky Way is viewed differently by our eyes compared to the infra Red, Ultra Violet and Gamma Spectrum etc ... so there's really no hard rules involved here. Purists like Auto WB although the human eye mostly perceives the Milky Way to be a blue-grey color even though the natural colors is warmer with red and orange hues and a slight teal glow coming from the core. 
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Hence I ended up with something that leans heavily towards what the traditionalists like. But the colors are interesting and I had hoped to generate more teal-colored hues around the Galactic Core... and this edit seemed to do the job.  I haven't seen anyone else blend two different WB shots of the Milky Way before and I did it out of frustration while editing.  This lens was so bright that the glow of the Milky Way all but washed out the image.  I didn't expect that.  It's possible that the recently set sun and soon-to-be rising moon threw too much light into the sky. I would like to re-shoot again but with a different orientation and using a smaller aperture. I missed out on aligning with Antares - which has tendrils of dust/gas streaming out towards that bright star and the colorful ones that escort it ... hopefully next time.  The number of stars this lens captured was unexpected. 
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I just wish the clouds hadn't covered the sky and the moon hadn't risen because I was only just setting up when the conditions were ruined for me.  I'd have liked to have experimented more with this lens and the Milky Way.  Right now our drought in Sydney has broken and the skies are filled with rain-clouds... so it might be a while until I try again.

Nice image.

In the astro forum most purist actually seem to favour a Daylight WB setting to avoid the blueness. It is a personal taste thing though.

I am quite surprised by the roundness of most stars. I was expecting to see more elongation at 15 seconds on a 32mm lens on APS-C. In FF equivalent terms this would be Rule of (32 x 1.6 x 15) = 768. Most modern sensors tend to start generating star elongation (trailing) around 200-300. The old Rule of 500 is usually successful only on old film cameras or old low-res digital. I know that I start seeing it at anything over 20 seconds (and even at 20 seconds in places) on my 6D ii + 14mm f2.4, which is 280, so a long way from 768.

Colin

Andy01 wrote:

Nice image.

In the astro forum most purist actually seem to favour a Daylight WB setting to avoid the blueness. It is a personal taste thing though.

Hi Colin,

Yeah, if NASA followed the Purists their artists and photographic retouch unit would have nothing to do. Most of the planet images we see (including those of the surface of Mars and the planets themselves, even the Milky Way) are "false color images". Sometimes they're entirely created and other times they show false color spectrum (including many of the recent Pluto images). The Milky Way has a very different look when we see it through different wavelengths.The human eye generally only sees a limited number of colors from distant objects like this.  I'm not too worried about what the folks on the astro forum think about this because I've seen them go off at people for shooting with Tungsten in the past - and I think that the effect can be flattering in many ways.

I am quite surprised by the roundness of most stars. I was expecting to see more elongation at 15 seconds on a 32mm lens on APS-C. In FF equivalent terms this would be Rule of (32 x 1.6 x 15) = 768. Most modern sensors tend to start generating star elongation (trailing) around 200-300. The old Rule of 500 is usually successful only on old film cameras or old low-res digital. I know that I start seeing it at anything over 20 seconds (and even at 20 seconds in places) on my 6D ii + 14mm f2.4, which is 280, so a long way from 768.

The lack of Coma was VERY surprising to me with this lens. The same applies with the EF 50mm f/1.2L USM lens as well but I really did expect to see noticeable Coma with the 32mm lens.  And the 50mmL lens has a lot more PF/CA visible (it's possibly corrected more on the 32mm).  It much stronger/worse with the EF 24mm f/1.4L USM II lens and Canon had managed to correct it somewhat with lens optics curvature and optical coatings that corrected both the falloff and reduced coma.  But it's still there.  Even Sigma couldn't eliminate it from their own similar lenses.
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The lack of obvious elongation (star-streaks) was great to see although this shot has just the tiniest amount because it use data from a 15 second shot.  They say that the rule of 600 applies to APS-C so that ought to offer about 18 seconds of exposure before streaking with a 32mm lens (I guess 20 seconds would apply).  I've usually applied the 500 rule which gives me 15.6 seconds with this lens.
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Like you, I've noticed that 20 seconds with the 22mm and 24mm lenses is the safe zone. I'd love to purchase an effective EQ tracking mount sometime soon but I might not use it enough to warrant buying one.

According to my calculations, of the 32mm on the M5's 24MP sensor:

A) Time for a star (at celestial equator) to cross from one pixel to the next: 1.59 seconds

B) Rule of 200 (for high res sensors) Max exposure of 3.91 seconds for no star trailing.

- A) So, if a star is say, 8 pixels in diameter on the sensor (based on brightness and bleed, all stars are actually points) a 15 second exposure would result in an 8 x 15 pixel oval. Pretty unnoticeable without pixel peeping. certainly masked by posting a jpeg to the internet.

- B) a 4 second exposure results in round stars under 4-1 zoom in my testing. You are doing more like the "rule of 600" at 15 seconds, which most people find acceptable, especially at web resolutions. I don't usually, but that is my opinion, not a rule or anything.
I noticed a tiny bit of corner coma at 1.4, seems mostly gone at 2.8. Acceptable at 1.4, and waaaaaaaaaaay better than my Rokinon 24mm at any aperture.

All that said, I'll still use my tracking mount when I can, but this does open up the possibility of getting useful shots when I don't have it.

I'd love to purchase an effective EQ tracking mount sometime soon but I might not use it enough to warrant buying one.

Consider building a hinge (barn door) tracker for a really cheap tracker. At these short focal lengths, it would probably give you decent results without spending very much money at all

https://garyseronik.com/build-a-hinge-tracker-for-astrophotography/

Finally looking at my tests from last night and I have to correct myself. No noticeable difference in coma between 1.4 and 2.8 and 4. Significant difference in vignetting. But that is (somewhat) easily corrected for. Once Adobe gets lens profiles it should be totally solved.

FYI, My manual lens corrections (so far, I need to do some serious testing yet) are:

Distortion +19

Defringe

purple 6, 30/70

green 2 40/60

vignetting (at f/1.4) +46 and midpoint 9

vignetting (at f/2.8) +21 and midpoint 9
I can see minor trailing at 8 seconds, none at 4 seconds

If I have clear skies on my trip to Ireland (HAHAHAHAHA!) I'll stack 9 four second exposures at ISO 800 and f/1.4.  Being as it's Ireland in October, I don't see any point in bringing my tracker, the odds are not good

Thank you Marco for the 32mm/f1,4 pictures,,, i think i must have this lense now 🙂

lovely!