Nikon’s Expeed 7 processor – used within the Nikon Zf, Z5 II, Z6 III, Z8, and Z9 – added quite a lot of capabilities to the Nikon Z lineup. Amongst its most notable traits is that the dealing with of RAW (.NEF) information on these cameras has a brand new possibility known as Excessive Effectivity* (HE*) compression. Nikon asserts that this codecs is “visually equivalent” to their conventional Lossless Compressed RAW information, but a lot smaller – and extra able to taking pictures lengthy bursts with out filling up the buffer.
On this article, I’ll study the importance of this declare, exploring the know-how behind HE* compression and the important function of IntoPIX and its TicoRAW software program.
This text’s idea originated from my hesitation about utilizing this format for space-saving. I doubted its effectiveness and felt compelled to confirm its picture high quality efficiency. Fortunately, I used to be capable of enlist Jason Polak’s experience for the scientific evaluation; he dealt with the file comparisons and authored the “Chroma and Luminance Variation” part of this text.
As a way to make a technical article like this yet another entertaining, I’ve sprinkled in some images of lovable mallard chicks doing their factor. Why mallard chicks, you ask? As a result of I had a pleasant Saturday morning snapping pics of them on the lake, and their sheer cuteness was simply too good to not share! Hopefully, their allure will make it easier to waddle by means of this technical stuff with a smile.
The RAW Dilemma: High quality vs. Measurement
Historically, Lossless Compressed RAW information have been the popular alternative for photographers resulting from their potential to seize most picture high quality, with out the dimensions of taking pictures uncompressed RAW. Nevertheless, even Lossless RAW is just not a very small file. Some cameras supply smaller RAW information with lossy compression, however this comes on the expense of picture high quality.
With the Z9 (after which all the following cameras utilizing the Expeed 7 processor), Nikon launched an progressive resolution with HE* compression, promising the very best of each worlds: smaller information with out compromising visible high quality.
Nikon’s Assertion: “Visually Similar”
Within the Nikon manuals and on its official web site, Nikon emphasizes that HE* compressed RAW information are “visually equivalent” to lossless RAW information. This assertion isn’t meant to be advertising hyperbole. Reasonably, it’s meant to point that – whereas the file is technically compressed – the information loss is so minimal and intelligently managed that it’s imperceptible to the human eye, even after intensive post-processing.
IntoPIX and TicoRAW: The Masters of Visually Lossless Compression
The important thing to this functionality lies in Nikon’s collaboration with IntoPIX, a Belgian firm based in 2006 specializing in high-performance video and picture compression applied sciences. Their flagship product, and the know-how behind Nikon Z9’s HE* compression, is TicoRAW, a RAW codec designed to protect most picture constancy, significantly in crucial areas resembling highlights, shadows, and fantastic particulars.
On their web site, IntoPIX states that their software program can:
- Cut back file sizes by as much as 16 instances in comparison with uncompressed RAW, whereas preserving visible high quality much like the unique.
- Present low latency, which is essential for high-speed picture acquisition resembling that of the Z9.
- Be energy-efficient, which is helpful for battery-powered gadgets.
- Keep the sensor’s full dynamic vary and shade depth, permitting for flexibility in post-production.
TicoRAW analyzes RAW knowledge and applies an clever compression algorithm that identifies and removes redundancies with out compromising data essential for human notion. At the least, that’s the idea.
Compatibility: Opening HE* Compressed NEF Recordsdata Throughout Software program
Whereas HE* compression affords vital benefits, it’s essential to contemplate compatibility with standard picture enhancing software program. Not all applications can natively open these compressed information, particularly on older working methods or with software program that hasn’t been up to date.
A major limitation that Nikon Z9 house owners encounter is the lack to natively open HE* compressed NEF information on a Mac utilizing default system functions or fast previews. This doesn’t imply the information are unusable, however that they require particular software program to open.
Luckily, the most important and hottest post-production software program have adopted assist for HE* NEF information, together with on Mac. These embrace:
- Adobe Lightroom Traditional / Lightroom
- Adobe Photoshop
- Seize One
- DxO PureRAW
- Affinity Picture 2
- Nikon NX Studio (Nikon’s proprietary software program)
Sensible Benefits of Smaller HE* Recordsdata
Capturing smaller information affords three vital advantages for photographers:
- Much less Storage Wanted for Journey Photographers: The decreased file dimension is helpful for journey photographers managing quite a few pictures. It means fewer reminiscence playing cards, much less exterior space for storing, and less complicated knowledge backups.
- Sooner Picture Switch Speeds: When transferring massive numbers of pictures, a smaller file dimension hastens the method.
- Increased Burst Charges and a Bigger Buffer: With HE* RAW information, it’s attainable to shoot nearer to the digicam’s most body price. The buffer additionally takes longer to fill, even with out requiring a top-of-the-line reminiscence card.
Nikon’s HE* information common 30-32 MB every, whereas .NEF lossless information common 50-54 MB, with some reaching 70 MB.
Discipline Testing: Absence of Seen Points
I’ve used the Nikon Z9 extensively in a variety of real-world situations, taking pictures 1000’s of pictures in each Lossless RAW and HE* RAW codecs. It’s essential to make clear that, previous to this text, I didn’t carry out pictures beneath equivalent laboratory situations for a pixel-by-pixel comparability. Nevertheless, I subjected the information to all kinds of ordinary post-production processes: I tuned the publicity and the distinction, recovered the shadows, pulled the highlights, and experimented with sharpening and noise discount each with Seize One and PureRAW.
What I discovered, after this extended and diverse use, was a full absence of seen points or limitations within the picture high quality of the HE* RAW information. I didn’t discover compression artifacts, shade banding, lack of element in crucial areas, or reductions in dynamic vary that would distinguish HE* file from a lossless file. This remained true even after post-processing.
Nevertheless, I wished to confirm past my discipline impressions and put some HE* information by means of a extra rigorous check. I’ll share these outcomes subsequent.
Lab-Type Exams and Findings
To conduct a meticulous comparability, I took some basic banknote pictures beneath managed situations to emphasise even the smallest nuances. The protocol concerned taking pictures indoors with the Nikon Z9 digicam mounted on a tripod and operated through a distant cable. I employed ISO settings of 64, 500, 3200, and 6400, taking seven completely different exposures at every ISO worth, starting from extraordinarily vibrant to extraordinarily darkish, for each Lossless compressed .NEF and HE* codecs. This resulted in a complete of 56 distinct information. (I used a Nikon Z 105mm f/2.8 S Macro lens, which is extremely sharp. I targeted with AF-S utilizing Pinpoint, and to keep away from any distinction, I didn’t refocus between the pictures.)
To examine for compression artifacts, I did a radical pixel-level inspection at 400% magnification, from which I generated these screenshots. I couldn’t discover any variations that had been significant. As an alternative of boring you with all 56 images, listed below are just a few pattern comparisons. In every pair of pictures, the primary picture is HE*, and the second is NEF Lossless compressed.
First, a comparability at ISO 3200:
Any variations in compression artifacts between these pictures are too small to be significant.
Subsequent is a pair taken at ISO 500, underexposed two stops, and recovered. Right here, I additionally see no main variations – solely just a little little bit of differing distinction within the eyebrow, and maybe within the letter “T” on the fitting, however not what I’d contemplate a significant compression artifact:
And at last, a comparability at ISO 64, the place the story is identical:
I conclude that beneath sensible discipline situations, any seen variations or compression artifacts are negligible, if not merely zero.
Chroma and Luminance Variation
One other side of compression is that it could actually trigger refined modifications in colours and luminance values.
For instance, a crop from a compressed JPEG will present a comparatively low quantity of shade and luminance variation, as a result of the JPEG makes use of a technique of changing some colours with related colours to scale back file sizes. Within the graph beneath, a better variance worth is a good factor, representing much less compression. (I examined at a number of shutter speeds merely to offer a higher variety of pattern images for the comparability.)
Check out the variations between a Lossless RAW file (dashed traces) and a JPEG file (common traces), and also you’ll see that the JPEG has a a lot decrease chroma variance – AKA, blockier colours. Specifically, the dashed line representing chroma variation is far decrease on the JPEG, an indication of excessive compression:
Though the luminance variation in pixels is general fairly related, it’s clear from the distinction in chroma variation that the lossless RAW is superior to a JPEG.
However, right here is the corresponding graph at ISO 64 evaluating Lossless RAW (dashed traces) to Nikon’s HE* format (common traces):
Right here, there isn’t a statistical distinction between both the luma or the chroma variation on the pixel stage. The dashed traces are successfully interchangeable with the non-dashed traces. In different phrases, Lossless Compressed and HE* are comparable in picture high quality.
The outcomes are literally related in any respect ISOs, however right here is the ISO 3200 comparability for reference:
There is a bit more variation right here, which is to be anticipated at ISO 3200. The random nature of noise implies that there shall be rather less correlation between any two images at a better ISO. Nevertheless, in line with statistical testing, this variation is throughout the anticipated bounds, so there isn’t a measurable distinction between them.
A barely completely different method of trying on the variation is to measure entropy reasonably than variance. Though I received’t go into technical particulars, virtually talking, entropy will be extra delicate to paint alternative compression than variance. That’s as a result of theoretically, a digicam firm might do shade alternative in such a method that hides modifications in variance, whereas that may be tougher to do for entropy. Right here is the normalized entropy measure for luma and chroma noise (the dashed traces representing Lossless Compressed information, and the common traces representing HE* information):
Once more, there’s no statistical distinction. What can we surmise from these computations? The HE*, whereas being a lossy algorithm, doesn’t appear to be making any vital modifications to colours on the pixel stage in comparison with the crude compression of the JPEG algorithm. Due to this fact, though there are certainly some very minor variations between lossy and HE* information, the variations in shade and luma variation are more likely to be so minimal as to be invisible to the attention in any sane use case.
Conclusion
Nikon’s HE* RAW compression, utilizing IntoPIX’s TicoRAW know-how, marks an underrated development in digital images. Nikon’s declare that the information are “visually equivalent” to lossless RAWs is supported by sensible use. Photographers have lengthy confronted the selection between most RAW high quality and smaller file sizes, and I consider that that is the very best steadiness now we have seen but. Even for one thing like panorama images, I see no sensible cause to shoot Lossless Compressed any extra, and positively not for one thing like motion or wildlife images. HE* is just a greater use of house on the cardboard, with none sensible picture high quality drawbacks.
I hope you discovered this text on Nikon’s HE* .NEF information useful. In case you have any questions or suggestions, please don’t hesitate to go away them within the feedback part beneath!