The S-Line’s Long-Awaited Wide Angle
Вячеслав Бахтыгозин
In early November, Panasonic announced that they would be releasing a 16-35mm f/4. Ever since Panasonic released the S1 and S1R, people have been asking about a wide angle lens, especially with the availability of a high-res mode in both cameras (96MP in the S1, 187MP in the S1R) making them a great camera for landscape shooters.
Currently, the only way to use wide angles on the S1 cameras is to either adapt, or use the Sigma 14-24mm f/2.8. The image quality of the Sigma is great, but having a bulbous front element prevents the easy use of filters, a downfall for photographers and videographers.
In taking photographs of starry skies or other celestial scenes at night, or of the seashore with a wide perspective, a large-diameter lens is a strong ally, since it allows the capture of a moving subject by adjusting shutter speed without relying on ISO sensitivity. With its full-frame 35mm coverage, 14mm focal length for an ultra-wide angle of view, F2 barrier-breaking F1.8, the SIGMA 14mm F1.8 DG HSM Art is the true high-speed ultra-wide-angle lens for which so many photographers have been waiting. Although some zoom lenses are available that can cover 14mm, the large diameter delivering F1.8 brightness is a singular advantage. Going beyond fast shutter speed, this lens can capture a swarm of fireflies with crystal clarity, a beautiful bokeh effect, and outstanding control of light streaking.
Ok -- so the first few trials that I put a lens through is distortion -- I don't use anything fancy, just my garage wall with horizontal siding and a window with some mullions to ensure no obvious vertical distortion, like pin cushioning, etc. The Tamron was initially fine in this regard at all lengths but I still re-tested it in the same light as the Nikon (of course, some 'distortion' at 24mm -- but that is expected at semi-wide angle). The most obvious difference in this test was that, since I usually stop a lens down by 1/3 stop because I prefer a slightly more contrasty image, the Tamron shows this as an ideal exposure while the Nikon showed it as under-exposed; setting the needle to 'perfect' exposure for the Nikon was much better. I put them both through the lens' ranges and most f-stops, then looked at the resulting images at 100% magnification. Truth be told, although there was a slight variation in tonality - I could not tell the difference between them -- although I would have to say it is possible that the Nikon might even be a hair softer at the focus point (but I would have to look at the images in a much more critical mindset -- which I never do because unless there is a glaring difference, once printed and ready to sell, it would be impossible to discern if it is a great image) -- to me if I can see fine-details, such as every blemish, mold spot, crack in the paint of my aging garage in fine detail -- the lens passes. I know the Tamron sees things that even the human eye at the same distance can not see (and many things on humans that you'd rather not know about :-) -- well, not just the Tamron; all of my images from the D810 no matter the lens, have this ability. So as long as it does this, I'm a happy camper. The Nikon did fine.
Roger comments in another article that the previous 24-70/2.8 from Canon was prone to requiring adjustment of the optics after mistreatment/impact so Nikon isn't unique in making fragile 24-70's. Canon was able to improve their 24-70 while retaining it as a relatively compact lens but it has no VR; Nikon's 24-70 VR has larger size and weight but as a result it has VR, and the main issues of image quality (corner softness, field curvature at wide angle settings) have been solved and at least according to Nikon it should have better resistance to impacts. (Note that I'm not saying the zoom problems with the 24-70 G version were due to impacts or abuse, but I consider it an inherent design weakness of the zoom mechanism.) The new version has much more even zoom feel and the sound from zooming is also more confidence inspiring, there is no rattle or grinding.
Other interesting features that cross both models are in-camera vibration reduction and a silent photography function that eliminates shake and noise caused by the shutter. In terms of lenses, the Z mount as a 55 mm inner diameter and a 16 mm flange focal range that allow for apertures up to f/0.95. Photographers can invest in one of three new lenses, a standard zoom (Nikkor Z 24-70mm f/4 S), a wide angle prime (Nikkor Z 35mm f/1.8 S), or a standard prime (Nikkor Z 50mm f/1.8 S). Nikkor F mount lenses can also be used with the system via the new Mount Adapter FTZ.
Getting to try the Atoll Ultra-Wide has been a delight. A wide angle lens is a must have for a photographer. It s a classic lens that allows you to stretch what you frame. There are so many fields where a wide angle comes in handy that it is hard to restrain to a single purpose.
The Atoll Ultra-Wide 2.8/17 Art Lens upgrades the game for wide angles, delivering impressively straighter lines. Corners are improved, and the remarkable close up to a 10 cm focal point, opens a new frontier of quirky close-ups.
An impressive work of Kolb et al has demonstrated a high-speed ultra-wide-field OCT retinal imaging up to 100 degrees viewing angle, showing great potential for peripheral retinal visualization to aid ophthalmic diagnosis [25]. Apart from ophthalmology, there is also an increasing need and vivid interest of wide-field OCT-based angiography in the fields, such as dermatology, neurology, oncology, cardiology and endoscopy. For example, the abnormal microcirculation of finger nail-fold area is a significant sign of serious illness, such as anemia, liver disease, thyroid disease and malnutrition, which is possible to appear at any location over a large area of finger nail-fold. However, due to the performances of most current OCT systems, i.e., relatively slow A-scan rate, short depth ranging distance, and poor penetration power, only a small portion of blood vessels in the dorsal nail-fold area and finger cuticle were demonstrated in previous works [26,27]. In addition, the volumetric imaging of cerebrovascular networks of the whole brain in mouse is critical to improve our fundamental understanding of the underlying mechanisms in neurological studies. However, most of current OCT systems requires open-skull cranial window or thinned-skull cranial window in a small region for OMAG imaging, which limits the assessment of the connection in the entire vascular system of mouse brain [28]. Although laser Doppler imaging (LDI) [29] and laser speckle imaging (LSI) [30] allows for in vivo evaluation of vascular abnormalities over a wide FOV, these methods are unable to provide detailed volumetric microvascular imaging. Photoacoustic microscopy (PAM) is also a powerful non-invasive imaging tool, which has been demonstrated for multi-scale vascular visualization to bridge the gap between microscopic and macroscopic imaging [31]. However, the contrast mechanisms is different between PAM and OCT, where PAM is mainly based on optical absorption of hemoglobin and melanin in blood vessel, while OMAG is an optical-scattering based imaging modality that provides both the structural morphology and vascular information of tissue in parallel. Moreover, considering the complexity and cost involved with PAM system, OMAG is a much more cost-effective and time-efficient imaging modality [32].
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