Monday, July 14, 2014

Early July w/ the RX100 III - 14 Jul 2014

I am seriously loving this camera. Focus-peaking is necessary, but having the Hoodman Loupe on the LCD makes digiscoping much easier! I've posted a short blurb describing the setup on the Digidapter™and RX100 III.




















Friday, July 4, 2014

Dickcissels! - 30 Jun 2014

I took the Digidapter™, Zeiss 85T*Fl Diascope, 40X W Eyepiece and Sony Cybershot DSC-RX100 III down to the antennae farm in n. Monroe Co. late this afternoon to test out the rig on some (hopefully) cooperative Dickcissels along Haggerman Rd.  From my previous post I had mentioned that the 40X W eyepiece was a nice compliment to the 24-70mm zoom range of the RX100 III so I was confident that this outing would be much more successful than the last. It was.

While walking the fence-line I came upon several Savannah Sparrows that (I'm sure) had nests nearby. They were chattering and posturing on the fence top and so made good first targets.

I was hearing several Dickcissels calling from inside the fence but couldn't see any.  I then found one about 50 yds. up the road and headed in its direction.  A nice male singing from a tree branch next to the fence. Broken clouds alternated backgrounds between cyan blue to bright white, so it was an opportunity to see how the RX100 III handled CA.  Not bad at all. Focus-peaking allowed me to focus on the bird's face even though he was obscured by branches in front. The magnified view really helped in this case!


I was able to move around past the bird so that the sun was more behind my back. From about 30' away I was able to play w/ focus-peaking and continuous shooting (6 fps in RAW). I shot Aperture-priority at ISO 200 with the Zeiss lens wide open (f1.8 - 2.8). With white clouds behind the bird I had a chance to test chromatic aberration - only a touch along the edges of the photo. Well done!

I absolutely love these two portraits of the male. They look like pencil drawings. 


He then flew over to the fence, and the sun came back out, so I was able to get a few 'photographs'.




Another male appeared about 60' away, so I digiscoped him through the fence.





I just love these little sparrows! 

As we headed home we swung by Roberts Rd. and checked out the Osprey tower. One bird was perched in the late afternoon sun, so it was an opportunity to get some pics from about 150' away.





I'm excited w/ the possibilities from this camera. I want to play more with focus points and peaking, and possibly play w/ using the Hoodman Loupe on the LCD. Stay tuned!

Monday, June 30, 2014

Sony RX100 III vs Nikon 1 - 30 Jun 2014

I attempted to perform a controlled-lighting test to see how the Sony Cybershot DSC-RX100 III compared w/ the Nikon 1 V1 and V3 cameras.  In order to do this test some justice I switched out the Zeiss 20-75X Zoom Eyepiece on the 85T*Fl Diascope and used the 40X W Eyepiece in its place.  However, I needed a proper adapter to connect the RX100 III to the eyepiece.

A trip to the hardware store resulted in the purchase of a 1.5" long PVC coupler (2" internal diameter) that fits around the 40X eyepiece and acts as a spacer for the Digidapter inner ring.  I wrapped a layer of electrical tape 3X around the end of the tube, and this provided a perfect compression fit for the Digidapter ring that slides on the end. I then wrapped a few layers of electrical tape around the eyepiece where the rubber eyecup was removed so that the tapered eyepiece was more uniformly thick. A single layer of tape on the inside barrel of the PVC tubing now results in an inner sleeve that fits snugly around the eyepiece and supports the Digidapter platform perfectly! 45 cent investment!





With the Digidapter now customized for the 40X W eyepiece I was able to mount the RX100 III so that the lens of the camera at 50mm butts up against the eyepiece for a sharp focal point.  Note that the lens barrel extends at 24 - 50mm range, so the Digidapter needs to be slid back so as not to cause a lens error on the camera.  I make it a point to turn on the camera and zoom it to 50mm and leave it there. If I decide to zoom out to 30mm I just slide the Digidapter back a bit. The lens on the RX100 III gives a sharp vignette circle at all focal lengths when in contact w/ the scope eyepiece.  With an adapter ready to go I was able to test image resolution of the three cameras.

My assistant Beaker was placed under a fluorescent drafting lamp and the scope was set up about 25' away.  I set each camera up at ISO 200 and Aperture Priority, and used a 10 second self-timer to take the exposures.  I let the camera choose shutter speeds.  Note that in all cases the shutter speeds were the same for all three cameras! I took exposures at f1.8 (when possible), f2.8, f3.5, f5.6, f8 and f11 so that I could compare w/ the 10-30mm f/3.5-5.6 Nikon lens. All images were taken in RAW format (NEF for Nikon and AWR for Sony).


The above image was taken at 27mm equiv. for the V1 and V3 and 24mm equiv. for the RX100 III. The RX100 III produced a consistently cooler image than the V1 and V3, which gave warmer colors. I think the Sony produced a more realistic color. The V3 tended to give a slightly darker exposure (~-0.3 EV). In terms of sharpness all three appeared equal with similar noise and resolution.


At 50mm equiv. (middle zoom for all three cameras) results were similar.  Noise and resolution were very similar with only the slight color shift noted between the three cameras. As expected for RAW the images have a softness to them that sharpens easily in Photoshop.


At the highest magnifications for each camera the V1 and V3 provide 81 mm equiv. magnification while the Sony provides 70mm. Again, all three cameras produced very similar resolution and noise properties.  I didn't test any other ISO ranges. Check out the studio comparison tool at DPreview.com to view the RX100 III against similar Nikon and other brand cameras.  

I did compare the RX100 III at each Aperture to see if there was a resolution difference between f1.8 to f11.  In general most spotting scopes give an equivalent aperture of around f8 so adjusting camera apertures between f1.8 - f8 really does nothing to improve depth of field or resolution.  I found this to be true in this case, as well.  The only difference between exposures was a faster shutter speed.  When  you get to f11 you'll find that the cameras slow down, and tend to overexpose the image - this was more evident w/ the Nikon V1 and V3 relative to the Sony. Bottom line: shoot at the widest aperture possible to get the fastest shutter speed. You won't be sacrificing resolution or depth of field. The only observable differences are due to focus accuracy.


At this point I feel very comfortable that the Sony RX100 III will prove to be a very capable digiscoping camera for my Zeiss 85T*Fl and 40X W eyepiece.  With my Digidapter™ modification I have a very stable rig that will give me an effective focal length (EFL) of 960 - 2800 mm for digiscoping.  The 21Mpx images that this camera will provide should give me a push of resolution over the Nikon 1 V1 camera (10 Mpx) with no added noise.
 
Some nits about the Sony RX100 III: The EVF is very nice, but smaller than the EVF of the V3, which I liked very much. The AWR (RAW) files produced by the Sony will not be read by the Nikon Transfer Software (expected) but will not be visible in NikonView either, so reviewing images is difficult.  The Sony software requires that files be 'imported' into their viewer, ie., if you copy the files using Finder (on the Mac) to the Desktop, the software won't allow you to select that folder for viewing. Plus, in order to Delete photos, you have to go to the drop-down menu to select Delete, then verify, then wait while the camera deletes the file. I found it easier to grab a bunch of files and copy them into Adobe Raw and preview the images using their zoom tool - at least you can Delete images on the fly.  Even though I have the latest Adobe Raw Converter software, the files from the V3 and RX100 III cannot be viewed as icons in Finder, so that's an additional limitation. But I'll get used to it.  

Now to see if I can improve my keeper rate with this rig.



Sunday, June 29, 2014

Field Test: Sony DSC-RX100 III - 28 Jun 2014

I took the Sony Cybershot DSC-RX100 III to Pt. Mouillee SGA this morning to give it the first real field test. My impressions are based on its use with the Zeiss 85T*FL Diascope with 20-75X Zoom Eyepiece and Digidapter™digiscoping adapter.  Most images were taken with the scope at 20X and distances that exceeded 30' (most cases 40 - 150').  Skies were generally clear, but humidity was high with little to no wind.

Overall I was not thrilled with the results of this outing.  My first two dozen images of a Song Sparrow 50' away in early morning light were all throwaways. Of the approximately 1000 images I was able to capture with 1.5 batteries (all shot RAW using Speed-Priority Continuous) I had less than 10% keeper rate. A fully-charged battery lasted about 3 hours, but I got about 800 photos despite a rating of only 320 images per charge.

With the 24-70mm lens on the 20X eyepiece vignetting was present until about 50mm. As I mentioned in the previous post the 20-75X eyepiece has issues with color cast (yellow) that is the result of chromatic aberration (CA) that is present mainly along the outside edges of the eyepiece but presented itself greatly in all of the images.  The longer the distance the worse the problem got.  Generally images came out w/ a greenish tinge (blue sensor + yellow cast = green?).  If focusing was not spot-on, the birds had a yellow edge on one side and a blue edge on the other.  This was really evident w/ the majority of avocet and grebe photos.





I was shooting ISO 100 and Aperture-Priority, so that didn't help, either.  Auto-ISO would've gotten me faster shutter speeds, but I was interested in image quality, not quantity.  Using the DMF 'focus-peaking' helped (I think) in most cases, but I still ended up w/ a lot of out-of-focus images.  I will need to compare image captures using the Autofocus mode versus manually adjusting (w/o DMF) or fine-focusing using the EVF versus using a Hoodman Loupe on the LCD display.




When I was able to get close to my subjects (American Avocet, Savannah Sparrows, dragonflies) I was generally happy w/ the images.  Long-distant shots of the Black-bellied Plover, Wilson's Phalarope were generally more degraded in terms of image quality.  If I zoomed the eyepiece I could get a few better-quality images.   When I did get keeper images, I was impressed with the noise quality - very little noise reduction was required.  Exposures generally required little adjusting, but I had to generally add red channel, reduce blue channel, increase tint, desaturate yellow and desaturate blue or cyan in order to recover images.




All of this I'm going to blame more on the eyepiece and shooting conditions than the camera at this point. The reason I say this is that the camera performed wonderfully on the 40X W Zeiss Eyepiece, which has NO issues with CA and is optically excellent.  I spent this afternoon shooting my friend and model Beaker (of Muppet fame) and found resolution, color and exposures impressively captured, with edge-to-edge sharpness and no evidence of CA when shot at distances of 20-30'. I plan to post a comparison of images taken this evening, using controlled lighting, using the Sony RX100 III vs. Nikon V1 vs. Nikon V3 cameras.