Thursday, September 13, 2018

Sony 35mm f/2.8 Sonnar FE - 13 Sep 2018

I've been recently reading up on the new Sony a7iii Full-Frame camera when I came upon the Zeiss 35mm f/2.8 Sonnar FE ZA pancake lens. This lens is similar in size to my current Sigma 30mm f/2.8 DN lens that I'm using on my Sony Alpha a6300 APS-C camera for digiscoping.  At $800 the Zeiss/Sony 35mm f/2.8 Sonnar is expensive, especially for an f/2.8 lens. Reviews, however, have rated the lens as outstanding in quality and great as a compact travel lens.  I had the opportunity to pick up a brand new copy for only $200 so I decided to purchase and compare it with my Sigma 30/2.8 ($169).

Since I received the lens literally a day before we left for Newfoundland, I decided to use it exclusively on the Sony a6300 and give it a test run as both travel lens and digiscoping lens. On the crop-censored a6300 the 35mm gives an effective focal length of ~52mm. Images from the camera are the same as real life, and I found no evidence of distortion at the edges. The quality of images was impressive, especially when I generated panoramas from vertically-stitched image series. On the Sony a6300 the 35/2.8 Sonnar made for a great travel camera.

I then tried using it for digiscoping. On the Digidapter™the lens had the same profile as my Sigma 30, so I didn't have to make any adjustments to the mount. That said, after a week of digiscoping with it, I was frankly disappointed.  I found a Swamp Sparrow at Cape Spear Lighthouse and thought I had  great digiscoped images. They were a bit soft, even when I focus-peaked. Of the 2-dozen images I took only 1 was considered acceptable.

So, I thought I'd spend some time checking the setup and giving it more work. At Elliston, NL I had the opportunity to concentrate on a Great Black-backed Gull, and I was much more satisfied w/ the quality of images. Sharp, and little-to-no chromatic aberration in high-contrast white feathers.

Robin and I then drove to the Atlantic Puffin colony just a short distance away.  I spent some time in the mid-afternoon sun digiscoping puffins from about 150' away, and, once again, found myself disappointed in the quality of the images. I had some nice keepers. I had more losers; soft-focus birds with distinct CA that tells me that I was either front- or back-focusing on the birds.  I could possibly place some blame on time of day, wind, moving birds, and possible heat shimmer, but I did not feel good about the lens after this visit.

When I got home I decided I really needed to compare the Sony 35/2.8 with the Sigma 30/2.8 in a more controlled environment. This evening I set the scope up about 20' away from the thistle feeder and digiscoped some American Goldfinches with both lenses. To normalize results I not only digiscoped both lenses at 25X zoom on the scope (EFL~1125mm with the Sigma 30 vs. 1300mm with the Sony 35), but then shot the Sigma 30 at ~30-35X zoom (EFL ~1300mm).

Sony 35/2.8 @ 25X Zoom 
Sony 35/2.8 @ 25X Zoom
Sigma 30/2.8 @ 30X Zoom

Honestly, I could not see any difference in image quality between the 2 lenses under the same lighting conditions. All were taken at 1/800 sec at f/2.8 (Aperture-Priority) and ISO 3200. Feather detail is sharp in all instances and the amount of grain was similar in all. Images are all straight out of the camera.

Perhaps most telling, however, was during focus-peaking. When I focused the scope on the bird I then attached the Digidapter™ and camera setup, then used focus-peaking to get maximum sharpness of head feather detail. The balding male goldfinch really helped here. I found that focus-peaking with the Sigma 30 optimized just before infinity while the Sony 35 optimized right at infinity. This is kind of critical since I found at some moments I could not focus-peak w/ the Sony and get a super-sharp image unless I did some additional focusing w/ the scope! As a result, I ended up getting slightly softer captures more often than not.

The bottom line? When it comes to digiscoping with the Sony a6300 the Sigma 30/2.8 DN lens ($169) is every bit as good (and perhaps more reliable) as the Sony 35/2.8 Sonnar under the same conditions. I would expect the Sony to show better edge sharpness and less CA at the edges than the Sigma 30, but frankly, the Sigma 30 gives reliably sharper images, even when zooming the scope to 30-35X.

So, my advise would be to purchase the Sigma 30mm f/2.8 DN and save the extra $600 to buy something nice for your significant other. The Sony 35mm f/2.8 Sonnar is an excellent lens, and reliable as a travel lens and digiscoping lens, but in my case the extra $600 does not result in significantly better image quality. That said, if I do get my hands on a Sony a7iii the Sony 35/2.8 Sonnar may be a killer combo.

In the meantime, here is one of my resident Ruby-throated Hummingbirds that is still hanging around. I digiscoped this little beauty hand-holding the scope!

Sigma 30/2.8 1/1000 sec f/2.8 ISO 3200

Monday, August 27, 2018

Black-necked Stilts - 26 Aug 2018

Robin and I arrived a bit too late this morning to see the Peregrine Falcon, American White Pelican, and Red-necked Phalaropes that were at Howard's Marsh Metropark in NW Ohio. Still, we enjoyed a nice walk on this overcast, soupy, hot and humid Sunday morning.

Just next to the parking lot I found a relatively cooperative Horned Lark that allowed me time to set up and digiscope from 20' away.

I managed to see and get some nice images of the resident Black-necked Stilts (as many as 10 birds!) despite the poor lighting.

Saturday, August 18, 2018

More Hand-Held Digiscoping - 17 Aug 2018

I spent the afternoon running around the back yard w/ the Swarovski STX85 Spotting Scope and Sony a6300 and Digidapter™ to see how I could do digiscoping w/o a tripod. This setup, with the 30mm Sigma lens gives an effective focal length of 25x30x1.5=1125mm. Hand-held.

This Ruby-throated Hummingbird was being harassed by a male near the feeders, so I took the opportunity to photograph them with the rig. Shooting 10fps at 1/1000th of a second under ISO Auto helped overcome the lack of any stabilization.  I'm very happy with the results.

Sunday, August 12, 2018

Hand-Held Digiscoping - 11 Aug 2018

While on the Wildlife Drive at Blackwater National Wildlife Refuge (MD) last Sunday I was continually frustrated with the Osprey flying off as soon as I tried to get out of the car to digiscope them. So, on a lark, I decided to see if I could digiscope them from inside the car using the window as a prop. Despite engine vibration I was surprised at the quality of my digiscoped images without a tripod. Great Blue Herons and Eastern Kingbirds were welcomed subjects of my test.

This evening I decided to give hand-holding digiscoping a try. While sitting on the deck with my feet propped on the rails I took the Swarovski STX85, Sony a6300, Sigma 30/2.8 lens, and Digidapter™ and tried to hold it like a telephoto lens. To make focusing a bit easier I set the Sigma lens to infinity and then relied on the electronic viewfinder to gain critical focusing. The camera was set to Auto ISO at f/2.8 with a minimum shutter speed of 1/1000 sec. The camera was set to 10 fps.

I was impressed with the quality of my results. Despite over ¾ of my images slightly out of focus, I managed to capture razor-sharp images of the Chipmunks, Song Sparrows, Baltimore Orioles and Swallowtail butterflies at a distance of ~25 feet.

I will say that focus-peaking is out of the question while hand-holding. The magnification is too extreme to focus on my subject (eyes) so I have to trust my electronic viewfinder to get accurate focus. Holding the scope in my left hand I can support the tripod foot w/ the hand while focusing w/ the fingers and elbow braced against my chest. The Digidapter™ allows me to brace the camera / scope against my face, and 10 fps acts as my vibration reduction. Check out the feather detail on the House Finch at left.

This is going to be fun - I'll have to rig a harness if I decide to take it into the field. But, in the meantime it'll be a great rig for shooting from inside the car or at the hawk watch this fall!

House Wren Slo-Motion - 17 Jul 2018

I spent a bit of time this evening in the field behind the house trying to digiscope videos of a House Wren bringing food to almost fledged younger(s). I set the Sony a6300 to high-speed capture and waited for the parent(s) to come in. I managed 3 clips that I merged into a single video, while spending another 20 minutes or so waiting for a chattering parent to stop scolding me for being in the area.

Here's the video:

Monday, July 16, 2018

In Search Of... 08 Jul 2018

King Rails! Jan Palland photographed what appeared to be a pair of King Rails with 4 babies in the Long Pond Unit yesterday. I decided to go see if I could find them this evening. That meant having to hike through thistle and other sorts of pickery plants.

I would dip on the rails, but did have a chance to chase a Dickcissel through the Long Pond meadows next to the North Causeway. That included some bushwhacking and trudging through very soft mud. But I got a few pics, and even found a cooperative Bobolink on the way out.

Tuesday, July 3, 2018

Dickcissels - 28 Jun 2018

The antennae farm on Haggerman Rd. was loaded with Dickcissels and Bobolinks this evening. Lighting was great, and birds were cooperative.