With the release of the D810A, Nikon has at long last entered the market for astronomical imaging, despite the company’s relatively tardy start in this area. At first glance, the only discernible distinction between the D810 and the D810A is the small, white letter ‘A’ that is located on the front of the shell of the D810A. The D810A is, in essence, a tweaked version of the immensely popular D810.
The D810A has several Astro-specific functions in addition to the standard D810, the most interesting and impressive of which is a modified infrared-cut filter. However, beyond its 36-megapixel resolution, which is the highest in the Nikon range, the D810A also has several other Astro-specific functions.
Nikon D810a Remote cable.
The D810A was simple to set up, and we only needed to reference the user guide once—to locate the option for front electronic curtain shutter control, which can be found in one of the custom menus. Other than that, we didn’t require the manual at all. In this mode, the effects of the mechanical vibration are no longer present.
The focal-plane shutter of a camera is made up of two curtains: the front curtain, which opens to begin each exposure, and the back curtain, which shuts to conclude the exposure. After the front curtain of a camera with an electronic front curtain shutter opens, the exposure begins to be electronically controlled, and it continues until the rear curtain is brought back.
By opening the mechanical shutter before the exposure begins, vibrations induced by the shutter may be eliminated, which in turn helps to reduce blur. Although a countdown timer would have been useful for us when taking photos with lengthy exposures, this is a rather minor criticism of the product overall.
Barnard’s Loop in Orion and a peek of the Wizard Nebula in Cepheus were captured using a single exposure that was five minutes long, set at f/2.8 and ISO 1000, and tracked using an Astrotrac mount. This resulted in the presentation of accurate star colors.
In order to conduct our evaluation of the deep sky, we paired the D810A with a Takahashi FSQ106. Our stacked photograph of the Heart and Soul Nebulae in Cassiopeia (comprised of 20 exposures at ISO 1000, each five minutes long) displayed outstanding clarity and superb color, despite the fact that the first quarter Moon was high in the sky.
It has been well worth the wait for Nikon to make their entrance into the market for astrophotography. The Nikon D810A is a remarkable camera that not only has a high resolution but also produces some really appealing shots and excels in Astro capabilities.
It would be absolutely ideal if Nikon were to incorporate both an articulated display screen as well as a timer countdown display for use during long exposures.
Nikon D810a Lighting
All single-lens reflex cameras feature a filter in front of the sensor that cuts down on the amount of red light that reaches it. This allows the camera to more accurately reproduce colors while shooting in natural light.
The transmission of the hydrogen-alpha spectral line at 656.28 nm, which is responsible for the red color in many emission nebulae, is unfortunately decreased as a result of this. This has a negative impact on astroimaging.
Getting the DSLR changed by entirely removing this filter is a typical solution, but doing so has a number of significant drawbacks: first, autofocusing is rendered inoperable, and second, the color balance of daylight photographs is shifted toward the red end of the spectrum.
The solution that Nikon came up with for this issue was to change the filter that is in front of the sensor on the D810A such that there is an increase of nearly four times in the amount of transmission that is allowed for the hydrogen-alpha area of the spectrum.
Using the D810A to take photos in broad daylight will still produce images with a small pink color cast; however, this issue is easily rectifiable in Lightroom or Photoshop by using a user-defined preset.
Nikon D810a Live View
A preview image that is equal to the one acquired at 30 seconds is presented when the long-exposure mode is used with shutter speeds that are longer than 30 seconds; live view photos may be enlarged up to 23 times.
When it came to framing photos and choosing a star to focus on, we discovered that this combination was really helpful.
Nikon D810a Aperture
When the electronic front curtain rather than the mechanical front curtain is enabled (a choice that may be made in the ‘Mup’ mode), exposure time is conducted electronically, which removes the potential for mechanical vibration caused by the mechanical front curtain.
When utilizing lenses or telescopes with a longer focal length, we discovered that this produced images with greater sharpness.
Nikon D810a Intervalometer
We found the intervalometer to be particularly helpful when it came to putting up time-lapse and star trail sequences because it enables the capture of up to 9,999 individual frames in a single series.
There is also an option called Timelapse, which, in the event that you do not own movie editing software, may automatically make a movie file for you.
Nikon D810a Manual Mode
In addition to the P/S/A/M settings, there is now also a manual mode for long exposures called M*. There are options for the shutter speed of four, five, eight, ten, fifteen, twenty, thirty, sixty, one hundred and twenty, two hundred and forty, three hundred and ninety, and bulb and time.
With this function, there is no longer a requirement to make use of an external timer remote.
Nikon D810a Sensor
If you want the greatest results, you should pair your full-frame sensor with optics of the highest possible quality. Lenses and telescopes that are able to provide an image circle of at least 44 millimeters would be ideal.
When the RAW data are stored as uncompressed 14-bit photos, the 36.3-megapixel sensor creates files that are 74.5 MB in size.
Nikon D810a Specs
| Type | Single-lens reflex digital camera |
|---|---|
| Lens mount | Nikon F mount (with AF coupling and AF contacts) |
| Effective angle of view | Nikon FX format |
| Effective pixels | |
| Effective pixels | 36.3 million |
| Image sensor | |
| Image sensor | 35.9 x 24.0 mm CMOS sensor |
| Total pixels | 37.09 million |
| Dust-reduction system | Image sensor cleaning, Image Dust Off reference data (requires Capture NX-D software) |
| Storage | |
| Image size (pixels) | FX format (36×24): 7360 x 4912 (L), 5520 x 3680 (M), 3680 x 2456 (S)1.2x (30×20): 6144 x 4080 (L), 4608 x 3056 (M), 3072 x 2040 (S)DX format (24×16): 4800 x 3200 (L), 3600 x 2400 (M), 2400 x 1600 (S)5:4 (30×24): 6144 x 4912 (L), 4608 x 3680 (M), 3072 x 2456 (S)FX-format photographs taken in movie live view: 6720 x 3776 (L), 5040 x 2832 (M), 3360 x 1888 (S)DX-format photographs taken in movie live view: 4800 x 2704 (L), 3600 x 2024 (M), 2400 x 1352 (S) Note: Photographs taken in movie live view have an aspect ratio of 16:9; A DX-based format is used for photographs taken using the DX (24×16) 1.5x image area; an FX-based format is used for all other photographs |
| File format | NEF (RAW): 12 or 14 bit, lossless compressed, compressed or uncompressed; small size available (12-bit uncompressed only)TIFF (RGB)JPEG: JPEG-Baseline compliant with fine (approx. 1:4), normal (approx. 1:8) or basic (approx. 1:16) compression (Size priority); Optimal quality compression availableNEF (RAW)+JPEG: Single photograph recorded in both NEF (RAW) and JPEG formats |
| Picture Control system | Can be selected from Standard, Neutral, Vivid, Monochrome, Portrait, Landscape, Flat; selected Picture Control can be modified; storage for custom Picture Controls |
| Storage media | SD (Secure Digital) and UHS-I compliant SDHC and SDXC memory cards; Type I CompactFlash memory cards (UDMA compliant) |
| Dual card slots | Either card can be used for primary or backup storage or for separate storage of NEF (RAW) and JPEG images; pictures can be copied between cards |
| File system | DCF 2.0, DPOF, Exif 2.3, PictBridge |
| Viewfinder | |
| Viewfinder | Eye-level pentaprism single-lens reflex viewfinder |
| Frame coverage | FX (36×24): Approx. 100% horizontal and 100% vertical1.2x (30×20): Approx. 97% horizontal and 97% verticalDX (24×16): Approx. 97% horizontal and 97% vertical5:4 (30×24): Approx. 97% horizontal and 100% vertical |
| Magnification | Approx. 0.7x (50 mm f/1.4 lens at infinity, -1.0 m-1) |
| Eyepoint | 17 mm (-1.0 m-1; from center surface of viewfinder eyepiece lens) |
| Diopter adjustment | -3 to +1 m-1 |
| Focusing screen | Type B BriteView Clear Matte Mark VIII screen with AF area brackets and framing grid |
| Reflex mirror | Quick return |
| Depth-of-field preview | Pressing Pv button stops lens aperture down to value selected by user (A, M and M* modes) or by camera (P and S modes) |
| Lens aperture | Instant return, electronically controlled |
| Lens | |
| Compatible lenses | Compatible with AF NIKKOR lenses, including type G, E, and D lenses (some restrictions apply to PC lenses), DX lenses (using DX (24×16) 1.5x image area), AI-P NIKKOR lenses, and non-CPU AI lenses (exposure modes A, M and M* only); IX-NIKKOR lenses, lenses for the F3AF, and non-AI lenses cannot be used: The electronic rangefinder can be used with lenses that have a maximum aperture of f/5.6 or faster (the electronic rangefinder supports the 11 focus points with lenses that have a maximum aperture of f/8 or faster) |
| Shutter | |
| Type | Electronically-controlled vertical-travel focal-plane mechanical shutter, electronic front-curtain shutter (in mirror up release mode) |
| Speed | 1/8000 to 30 s in steps of 1/3, 1/2 or 1 EV, bulb, time, X250 M* mode: 4, 5, 8, 10, 15, 20, 30, 60, 120, 180, 240, 300, 600 or 900 seconds shutter speed, and Bulb and Time settings are available |
| Flash sync speed | X=1/250 s; synchronizes with shutter at 1/320 s or slower (flash range drops at speeds between 1/250 and 1/320 s) |
| Release | |
| Release mode | S (single frame), CL (continuous low speed), CH (continuous high speed), Q (quiet shutter-release), QC (quite continuous shutter-release), Self-timer, MUP (mirror up) |
| Frame advance rate | With EN-EL15 batteries (FX/5:4) CL: Approx. 1 to 5 fps, CH: Approx. 5 fps, QC: Approx. 3 fps (DX/1.2x) CL: Approx. 1 to 6 fps, CH: Approx. 6 fps, QC: Approx. 3 fpsOther power sources (FX/5:4) CL: Approx. 1 to 5 fps, CH: Approx. 5 fps, QC: Approx. 3 fps (1.2x) CL: Approx. 1 to 6 fps, CH: Approx. 6 fps, QC: Approx. 3 fps (DX) CL: Approx. 1 to 6 fps, CH: Approx. 7 fps, QC: Approx. 3 fps |
| Self-timer | 2 s, 5 s, 10 s, 20 s; 1 to 9 exposures at intervals of 0.5, 1, 2 or 3 s |
| Exposure | |
| Metering | TTL exposure metering using 91K-pixel RGB sensor |
| Metering method | Matrix: 3D color matrix metering III (type G, E and D lenses); color matrix metering III (other CPU lenses); color matrix metering available with non-CPU lenses if user provides lens dataCenter-weighted: Weight of approx. 75% given to 12-mm circle in center of frame; diameter of circle can be changed to 8, 15 or 20 mm, or weighting can be based on average of entire frame (non-CPU lenses use 12-mm circle)Spot: Meters 4-mm circle (about 1.5% of frame) centered on selected focus point (on center focus point when non-CPU lens is used)Highlight-weighted: Available with type G, E and D lenses (equivalent to center-weighted when other lenses are used) |
| Range (ISO 100, f/1.4 lens, 20°C/68°F) | Matrix, center-weighted, or highlight-weighted metering: 0 to 20 EVSpot metering: 2 to 20 EV |
| Exposure meter coupling | Combined CPU and AI |
| Mode | Programed auto with flexible program (P); shutter-priority auto (S); aperture-priority auto (A); manual (M); Long-exposure manual (M*) mode |
| Exposure compensation | -5 to +5 EV in increments of 1/3, 1/2 or 1 EV |
| Exposure bracketing | 2 to 9 frames in steps of 1/3, 1/2, 2/3 or 1 EV; 2 to 5 frames in steps of 2 or 3 EV |
| Exposure lock | Luminosity locked at detected value with AE-L/AF-L button |
| ISO sensitivity (Recommended Exposure Index) | ISO 200 to 12800 in steps of 1/3, 1/2 or 1 EV; can also be set to approx. 0.3, 0.5, 0.7 or 1 EV (ISO 100 equivalent) below ISO 200 or to approx. 0.3, 0.5, 0.7, 1 or 2 EV (ISO 51200 equivalent) above ISO 12800; auto ISO sensitivity control available |
| Active D-Lighting | Can be selected from auto, extra high, high, normal, low or off |
| ADL bracketing | 2 frames using selected value for one frame or 3 to 5 frames using preset values for all frames |
| Focus | |
| Autofocus | Nikon Advanced Multi-CAM 3500FX autofocus sensor module with TTL phase detection, fine-tuning, 51 focus points (including 15 cross-type sensors; f/8 supported by 11 sensors), and AF-assist illuminator (range approx. 0.5 to 3 m/1 ft 8 in. to 9 ft 10 in.) |
| Detection range | -2 to +19 EV (ISO 100 equivalent, 20°C/68°F) |
| Lens servo | Autofocus (AF): Single-servo AF (AF-S); continuous-servo AF (AF-C); predictive focus tracking automatically activated according to subject statusManual focus (M): Electronic rangefinder can be used |
| Focus point | Can be selected from 51 or 11 focus points |
| AF-area mode | Single-point AF, 9-, 21- or 51-point dynamic-area AF, 3D-tracking, group-area AF, auto-area AF |
| Focus lock | Focus can be locked by pressing shutter-release button halfway (single-servo AF) or by pressing AE-L/AF-L button |
| Flash | |
| Built-in flash | Manual pop-up with button release and a guide number of approx. 12/39, 12/39 with manual flash (m/ft, ISO 100, 20°C/68°F) |
| Flash control | TTL: i-TTL flash control using 91K-pixel RGB sensor is available with built-in flash; i-TTL balanced fill-flash for digital SLR is used with matrix, center-weighted, and highlight-weighted metering, standard i-TTL flash for digital SLR with spot meteringg |
| Flash mode | Front-curtain sync, slow sync, rear-curtain sync, red-eye reduction, red-eye reduction with slow sync, slow rear-curtain sync, off; auto FP high-speed sync supported |
| Flash compensation | -3 to +1 EV in increments of 1/3, 1/2 or 1 EV |
| Flash bracketing | 2 to 9 frames in steps of 1/3, 1/2, 2/3 or 1 EV; 2 to 5 frames in steps of 2 or 3 EV |
| Flash-ready indicator | Lights when built-in flash or optional flash unit is fully charged; blinks after flash is fired at full output |
| Accessory shoe | ISO 518 hot-shoe with sync and data contacts and safety lock |
| Nikon Creative Lighting System (CLS) | Nikon CLS supported; commander mode option available |
| Sync terminal | ISO 519 sync terminal with locking thread |
| White balance | |
| White balance | Auto (2 types), incandescent, fluorescent (7 types), direct sunlight, flash, cloudy, shade, preset manual (up to 6 values can be stored, spot white balance measurement available during live view), choose color temperature (2500 K to 10000 K); all with fine-tuning |
| White balance bracketing | 2 to 9 frames in steps of 1, 2 or 3 |
| Live View | |
| Live view mode | Live view photography (still images), movie live view (movies) |
| Lens servo | Autofocus (AF): Single-servo AF (AF-S); full-time servo AF (AF-F)Manual focus (M) |
| AF-area mode | Face-priority AF, wide-area AF, normal-area AF, subject-tracking AF |
| Autofocus | Contrast-detect AF anywhere in frame (camera selects focus point automatically when face-priority AF or subject-tracking AF is selected) |
| Movie | |
| Metering | TTL exposure metering using main image sensor |
| Metering method | Matrix, center-weighted, or highlight-weighted |
| Frame size (pixels) and frame rate | 1920 x 1080; 60p (progressive), 50p, 30p, 25p, 24p1280 x 720; 60p, 50pActual frame rates for 60p, 50p, 30p, 25p, and 24p are 59.94, 50, 29.97, 25, and 23.976 fps respectively; all options support both high and normal image quality |
| File format | MOV |
| Video compression | H.264/MPEG-4 Advanced Video Coding |
| Audio recording format | Linear PCM |
| Audio recording device | Built-in or external stereo microphone; sensitivity adjustable |
| ISO sensitivity | Exposure modes P, S and A: Auto ISO sensitivity control (ISO 200 to Hi 2) with　selectable upper limitExposure mode M: Auto ISO sensitivity control (ISO 200 to Hi 2) available　with selectable upper limit; manual selection (ISO 200 to 12800 in steps of　1/3, 1/2, or 1 EV); can also be set to approx. 0.3, 0.5, 0.7, 1, or 2 EV (ISO　51200 equivalent) above ISO 12800 |
| Other movie options | Index marking, time-lapse photography |
| Monitor | |
| Monitor | 8-cm/3.2-in., approx. 1229 k-dot (VGA; 640 x RGBW x 480 = 1,228,800 dots) TFT monitor with 170 ° viewing angle, approx. 100% frame coverage, and brightness adjustment |
| Playback | |
| Playback | Full-frame and thumbnail (4, 9 or 72 images) playback with playback zoom, movie playback, photo and/or movie slide shows, histogram display, highlights, photo information, location data display, auto image rotation |
| Interface | |
| USB | SuperSpeed USB (USB 3.0 Micro-B connector); connection to built-in USB port is recommended |
| HDMI output | Type C HDMI connector |
| Audio input | Stereo mini-pin jack (3.5-mm diameter; plug-in power supported) |
| Audio output | Stereo mini-pin jack (3.5-mm diameter) |
| Ten-pin remote terminal | Can be used to connect optional remote control, optional WR-R10 (requires WR-A10 Adapter) or WR-1 Wireless Remote Controller (M* mode not supported), GP-1/GP-1A GPS Unit, or GPS device compliant with NMEA0183 version 2.01 or 3.01 (requires optional MC-35 GPS Adapter Cord and cable with D-sub 9-pin connector) |
| Supported languages (may differ by country or area) | |
| Supported languages | Arabic, Bengali, Bulgarian, Chinese (Simplified and Traditional), Czech, Danish, Dutch, English, Finnish, French, German, Greek, Hindi, Hungarian, Indonesian, Italian, Japanese, Korean, Marathi, Norwegian, Persian, Polish, Portuguese (Portugal and Brazil), Romanian, Russian, Serbian, Spanish, Swedish, Tamil, Telugu, Thai, Turkish, Ukrainian, Vietnamese |
| Power source | |
| Battery | One EN-EL15 Rechargeable Li-ion Battery |
| Battery pack | Optional MB-D12 Multi-Power Battery Pack with one EN-EL15/EN-EL18a*/EN-EL18* Rechargeable Li-ion Battery or eight R6/AA-size alkaline, Ni-MH or lithium batteries * Available separately; Requires optional BL-5 Battery Chamber Cover |
| AC adapter | EH-5b AC Adapter; requires EP-5B Power Connector (available separately) |
| Tripod socket | |
| Tripod socket | 1/4 in. (ISO 1222) |
| Dimensions / weight | |
| Dimensions (W x H x D) | Approx. 146 x 123 x 81.5 mm/5.8 x 4.9 x 3.3 in. |
| Weight | Approx. 980 g/2 lb 2.6 oz with battery and SD memory card but without body cap; approx. 880 g/1 lb 15.1 oz (camera body only) |
| Operating environment | |
| Temperature | 0 to 40°C/32 to 104°F |
| Humidity | 85% or less (no condensation) |
