Astrophotography with EF-M Prime lenses (PIC)

Lens Comparisons with Canon EF-M lenses for shooting single-exposure Astro shots

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I literally just got home from testing my four EF-M Primes plus the 11-22mm lens with the Milky Way. It was not my intention to post another thread on the subject but I thought it might be useful for other members who have any or all of these lenses. I chose to do this since the sky is currently so clear in the mountains tonight. Unusually clear night skies with no moon. It seemed like the ideal chance to compare them for the following:
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* a suitable aperture for detail/clarity.
* an Ideal shutter speed for reducing star movement.
* Best ISO for exposure and subtle details.
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There may be room for further refinement by other members... but this was the best I could come up with under perfect skies and no light pollution whatsoever due to the altitude I was at. I didn't take as many shots as I would have liked because it was so cold I couldn't feel my fingers.
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The brightest 'star' in these shots was the planet Jupiter. When shooting at wider apertures, the 32mm. 28mm and 22mm lenses all produced a slight bowtie effect with the bright light... I couldn't remember this happening previously so I've since cleaned my lens and sensor of dust when I returned home. I had to set up a lens heater to stop ice building up on the lenses when they were on the camera. There's a chance the velcro element of the lens heater had a hair or strand of nylon that was in the way of the lens. I've had these lenses produce a similar effect with street lamps when shooting with wide apertures so who knows?
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Wider apertures were possible with both the 32mm and 22mm lenses but they resulted in more chromatic and optical aberrations. Even with f/2.2, the 22mm lens still produced Coma (quite visible in the lower left corner). The other two lenses (28mm + 11-22mm) were both shot at maximum apertures for their respective lenses because they needed every bit of light. The 11-22mm looks great on the LCD but when downloaded is fairly muddy and soft compared to the other lenses. The results of this lens were far better on the EOS M6 compared to the older EOS M (Mk1).
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Feel free to use the template above for your own initial settings. I used Tungsten White Balance - which is why these unedited images above exhibit a teal tone. I will later edit some of my images by adjusting the color tones and contrast. You can use a more neutral setting like 'AWB' if you wish to be more 'authentic'. Alternately you can alter your colors and WB during editing. But that's a whole other discussion.
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But the point of this brief post is just to give folks an idea of what to expect from their lenses and to offer a template for settings to use for taking their own prime lenses for what might be useful exposure settings.
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Regards,
Marco Nero.

Asla wrote:

Hi!

Thank you for photos and sharp, yet enjoyable story/tutorial. Few questions raise to me: what kind of temperatures there were? What kind of lens heater do you use? (I have not ever used heater of any kind, just try to keep my gear dry before photographing winter and then let slowly get to normal temperature in closed camera bag, when getting back inside)

I'm curious because never had a broblem you mention...

Nights are getting incresingly light here Finland, so no night photography anymore this spring here. But pleasure to watch others photos of night sky!

A s l a

I am curious about the temperature as well. I was shooting at night in Mt Cook (South Island, New Zealand) last September with my 6D ii and Samyang 14mm f2.4 XP when the temperature was about -1°C (felt like -3°C) and saw no ice formation on my lens (a BIG front element compared to a EFM 22mm). There was certainly ice all over the car the next morning (hotel carpark).

I am in Brisbane (Australia), and did not think it would be colder than that in the (presumably) Blue Mountains near Sydney, but I have limited experience of Sydney. I guess it would depend on how moist the air was as well ?

Nice photos Marco. Personally I prefer using a daylight WB to bring out the colours of the Milky Way more, but it certainly is a personal preference thing

Colin

I bought a Made-in-Japan anti-condensation lens warmer from Protage for use with my EF-M lenses.  I chose this one because of the narrow elasticized velcro heating strip which gives me access to the focus dial on most of my lenses while still heating the outer lens elements.  I happen to have a USB Power Supply for a telescope to run it on although any pocket-sized PowerBank with a USB connection (preferably above 1A) will probably do the job.
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If you're only taking 20 shots or so, it's not necessary.  But if you're doing long exposures and the temperature drops, you'll end up with dew and then usually frost.  As they glass and metal on your camera begin to chill, tiny ice crystals can (and do) form on your lens.  Warmer climates are unlikely to be a problem. 
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I find the Lens Warmers to be a little fiddly to put on.  Sometimes I wrap it around the lens hood but other times I'll put it around the lens body.  I bought mine for about AUD $45 and I deliberately paid more for one that came from Japan simply because a cheaper one from China might overheat and melt my lens gaskets or cause a fire.  I've not had a problem with the Protage model and it's enabled me to shoot while my whole car and tripod is covered in moisture and ice.  If dew is a serious issue as the camera is cooling down in the night air, I will tie a disposable plastic bag around the body of the camera to prevent dew from forming on the body and getting into any cracks around the buttons and seams.... but I have only done this once.
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EOS M + 11-22mm lens: Ice crystals on my 11-22mm at 7C in the days before I had a lens warmer.  The Milky Way looked horrible when the lens frosted up.

Using a Lens Heater on my lens.  The cable is plugged into a USB power port on the device with the red light (a Celestron LiFePo Lithium battery designed for powering telescopes).

M6 +32mm: Lens heater after putting it onto the NiSi Natural Night Filter .... and it's just starting to do its job here.  You can see how the frost is disappearing from the outside even before I got to take this picture.

noisephotographer wrote:

The other two lenses (28mm + 11-22mm) were both shot at maximum apertures for their respective lenses because they needed every bit of light.

It could make more sense to shoot at 22mm f/5.6 instead of 11mm f/4.

22mm f/5.6 captures twice as much light from distant objects than 11mm f/4. (22/11 x 4/5.6)² ≈ 2

A 22mm crop of the 11-22mm at 11mm f/4 is equivalent to 22mm f/8 on a 6 megapixel Aps-c camera. Though it wouldn't be as bad as one would expect because the low resolution (6 megapixels) gives a read noise advantage. Therefore it's possible that it could perform better at 11mm f/4 despite capturing less light per object.

Oh GOD!  I don't want to go out there again in the cold... but that observation you've made actually piqued my interest.  I will certainly try this soon if nobody else with the 11-22mm lens wants to give it a go.  I think this might have merit enough for an experiment.  Anyone want to give it a whirl?

Marco Nero wrote:

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 The results of this lens were far better on the EOS M6 compared to the older EOS M (Mk1).
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I have an original M and the 11-22mm, and have not been very impressed at all with the image quality out of the lens despite all the praise for it by users and testing sites. I have been wondering if a newer M would improve it. How much better are your results on the M6 rather than the M, and do you know why there would be a difference?

Marco Nero wrote:

noisephotographer wrote:

The other two lenses (28mm + 11-22mm) were both shot at maximum apertures for their respective lenses because they needed every bit of light.

It could make more sense to shoot at 22mm f/5.6 instead of 11mm f/4.

22mm f/5.6 captures twice as much light from distant objects than 11mm f/4. (22/11 x 4/5.6)² ≈ 2

A 22mm crop of the 11-22mm at 11mm f/4 is equivalent to 22mm f/8 on a 6 megapixel Aps-c camera. Though it wouldn't be as bad as one would expect because the low resolution (6 megapixels) gives a read noise advantage. Therefore it's possible that it could perform better at 11mm f/4 despite capturing less light per object.

Oh GOD! I don't want to go out there again in the cold... but that observation you've made actually piqued my interest. I will certainly try this soon if nobody else with the 11-22mm lens wants to give it a go. I think this might have merit enough for an experiment. Anyone want to give it a whirl?

That's why i used tracker to compensate the low signal from wide angle lens vs normal lens by exposing longer.But doing long exposures (3-8 mins range) introduce another problem: sensor heating! It will make the read noise more nasty even shooting at low iso, so even using tracker, I will still go for 22mm, doing mosaic instead of using long exposure with 11-22mm, waiting to try out the magnificient 32mm when I get the hold of it.

If you remember my shot last year using 11-22m, ISO 2000, 2 mins exposure x 4 shots, camera was so hot that the last shot was full of noise.

biggles266 wrote:

Marco Nero wrote:

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The results of this lens were far better on the EOS M6 compared to the older EOS M (Mk1).
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I have an original M and the 11-22mm, and have not been very impressed at all with the image quality out of the lens despite all the praise for it by users and testing sites. I have been wondering if a newer M would improve it. How much better are your results on the M6 rather than the M, and do you know why there would be a difference?

This lens on the EOS M should produce a wide view at 11mm with crisp details and quite a lot of contrast with strong shadow areas.  It's not really ideal in dimly lit scenarios due to the narrow aperture.  So I usually swap it out with the 22mm or 32mm lens for indoor shots at night.  But for daylight (or even long exposures of between 1 to 30 seconds on a tripod) it ought to produce appealing results in terms of landscapes and city-scapes at night.  There are people who use this as a walkabout lens and it does offer something many other lenses can't.  But if you like the shallow DOF that other lenses often offer, then this isn't going to do it for you.  Your images ought to be reasonable on the original EOSM.  I personally enjoyed using with with landscapes and in the city.  It tends to distort people when wide open (which is one of the appeals of a super-wide lens). I think that the M6 has more pixels on the sensor plus the advantage of DPAF (26MP compared to 19MP).  The image processor in the camera might be more capable as well since Digic 7 is likely to be more advanced (with newer processing algorithms) than Digic 5. Denser sensors with more photosites means less obvious optical aberrations and less noticeable antialiasing. 
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Something I noticed with using the 11-22mm lens is that I would get some bold magenta hues and soft, degraded images with long exposures of the night sky.  This would occur consistently on the right hand side of the image. But there was less destruction and more even color hues on the M6 ...even with higher ISOs.