I took my first astrophoto around twenty years ago. With a Smena 5 camera and a 40mm f/5.6 lens – a camera not very well suited for astrophotography. Then, things got better. I had a Zenit and a Praktica, but I settled for an Olympus OM-1, probably the best 35mm film camera for astrophotography. My parents bought me a 50mm f/1.4 lens; I was hoping for an f/1.2, but it was too expensive for their budget. I used the OM-1 for many years and I fell in love with it and its range of lenses.
Some more years passed, and film cameras were surpassed in performance by digital technology. As, outside my astrophotography, I was shooting with a Canon SLR. it made sense for me to choose Canon DSLR as my main camera. Being a professional photographer, I used almost all top lenses out there, no matter the manufacturer. Of course, I was using the same lenses for my astrophotography. And then, I had a problem. My expensive lenses, which allowed enough detail to print wall sized advertising photos, were not exceptional for astrophotography.
What was wrong? When I was shooting wide open (and you need that in astrophotography from time to time), the stars in the corners of the frame were affected by several aberrations, the most annoying being coma (stars were looking like small comets not like points of light). It might seem strange to you, but it’s very tough to photograph points of light. It’s not easy at all to build an optical system able to render points as points across the whole frame. And, in astrophotography, we are basically taking photos of points.
I believe it was October 2015 when I got a press release from Zeiss about a new lens: Otus 28mm f/1.4. It was advertised as the best wide angle lens ever made, with constant resolution across the frame and great corner performance, even wide open. My reaction? Another one bites the dust…
In January, I went, together with my wife, in a one month long holiday in New Zealand. I was finally going to see the Southern stars. I don’t know if you’re familiar to the subject, but part of the stars visible from the Southern hemisphere are different than the ones seen from the North side of our planet. For an astronomer, seeing the Southern sky is like being reborn.
Before leaving, my friends at F64 (that’s the coolest photo equipment store in Romania and one of the largest, if not the largest, in Eastern Europe) offered me a Zeiss Otus 28mm f/1.4 to test under the stars. It’s full name is Zeiss Otus 28mm f/1,4 APO Distagon T* and it is a BEAST. It weighs around 1.4 kilos and is quite a large piece of metal and glass. It’s all metal (including the lens hood, which fits seamlessly to the body of the lens, like being made from the same piece of metal) and the optical system is built out of 16 elements in 13 groups. Focusing can only be done manually, but it is very accurate.
The weather was not exceptionally friendly at the other end of the world. Out of 30 days, we got rain for half the time and only three clear nights.
My first meeting with the Southern skies happened at Cathedral Cove, a very famous beach on the Coromandel peninsula. Even though most tourists go there during daytime, we chose to visit it at night. And for a good reason. Once it got dark enough to see a few stars, I put the camera on my tripod, focused and took a shot. Opened the image, zoomed to the max and I started checking the aspect of the stars. The centre of the frame was great; I was expecting that. Then, I started to move towards the corners. Nice stars, nice stars, more nice stars… And suddenly the image stopped moving. I was in the corner of the frame, and the stars still looked very, very well for a 1.4 wide angle lens. Yes, there is some aberration there but, compared to any other 1.4 lens, that is nothing. Here’s a 100% sample from one of the corners of the image. I did my best to bring a very bright star close to the corner of the image to better show all optical defects. If you look at the less brighter stars, they look quite exceptional. At f/2, all stars were perfect.
Vignetting is there and it is quite visible, but that’s normal for a 1.4 lens. And you can easily correct it in post-processing. Astrophotographers will use a special technique for correcting a vignette. You shoot an evenly lit white screen and then you subtract this image from the original one.
The 28mm Otus is not wide enough for landscape astrophotography. But we can stitch the individual frames into a panorama. I merged 33 vertical photos, shot on three rows, to get the photo you see below. For merging I used Hugin. Above the horizon, we can see the arch of the Milky Way and to the right, the two blue fuzzy patches are the Magellanic clouds, satellite galaxies of our Milky Way. They are only visible from the Southern hemisphere. If you look closely, in the ocean, you will notice some electric blue areas: bioluminescent plankton. I used a Canon EOS 5D Mark III. The exposure time was 13 seconds, the aperture 1.4 and I set the ISO at 3200.
When viewed from the Southern hemisphere, constellations common to both hemispheres will look strange for someone used to their Northern aspect. Orion, for example, will be upside down. Here’s another panorama, this time shot from three horizontal images shot one on top of the other.
After leaving Coromandel, we spent one night at StarDate 2016, a very nice kiwi star party, where I was invited to give a talk about my astrophotography in the Northern hemisphere. The sky was amazing and it totally blew me away. I really have no words to describe it.
This time, I switched to tracked shots. For that I used my trusty portable mount, my beloved Fornax 10 tracker. This way, i was able to use longer exposure times, without getting star trails. I framed in such a way that I have both Magellanic clouds in the frame together with part of the Milky Way. The Souther Cross fit perfectly together with the Coalsack obscure nebula (the dark cloud on the lower left side of the image) and the Carina nebula (the pinkish patch left of centre). I was totally amazed by the level of detail rendered by the Otus in the galactic clouds.
The photo is a stack of nine individual frames, 100 seconds each, shot at 1.4 and ISO 1600. Post-processing was done in PixInsight, a piece of software specially written for astrophotographers.
Here’s another shot of the Milky Way, an adjacent area of the one above. Only two frames. 90 seconds per frame, f/1.4 and ISO 1600.
Then, for the rest of our trip, the night sky was hidden by heavy clouds for most of the time. We saw a few stars from the Aoraki / Mount Cook National Park. We had a Full Moon that night, so the landscape looks almost as during daytime. Having so much light around, I was able to use an aperture of 5.6. I was not able to see any difference in sharpness between the centre and the corners of the image and the level of detail in the mountains is fantastic.
The 28mm Otus is not a lens that will suddenly transform you into a better photographer nor it will win photo contest for you; you can do that with any lens. Yeah, it’s insanely expensive, it’s heavy, bulky and it’s not even capable of autofocus. It’s a lens you buy if you really need the extra level of image quality that you get out of it. Astrophotographers are exceptionally demanding when it comes to the quality of optics and, yes, I can say that this lens is better than absolutely any other lens with a similar focal length ever made. Is it worth the price tag? It is, for me. But it’s up to you if it makes sense to invest that much in a lens. Is it the best wide angle available today? Definitely!
I’ve never been so enthusiastic when talking about a lens. But, when you find the lens you’ve been looking for all your career as an astrophotographer, you have a good reason to be ecstatic.