Wayne Shumaker wrote:
> I'm a sony convert so I feel OK to jump in...
I was hoping you would. I actually went all crazy with SONY purchases
in 2024 because of your and Moose's influence. My heart said "Olympus"
but my head reminded me that for once in my life I needed to embrace
at least ONE mainstream system along with the "artisan" system.
> I once was an engineer, designing over sampled A/D converters (switched
> capacitor analog circuits). The great thing about over sampled A/D is the
> anti-alias filter in front could be very simple. Image sampling is the same
> only in two dimensions. Hence the anti-alias filter on camera sensors.
Exactly! The oversampling technology I helped develop ended up as
cr@p, but the idea was correct.
> One thing most don't realize about filters is the transient response, which
> you alluded to. With a non-oversampled A/D, the anti-alias filter needs to be
> sharper. However, the shaper a filter is the more over shoot there is in the
> step response. If you restrict the step response of a low pass filter to no
> overshoot, it smooths out the frequency response with the ideal being
> a bessel filter. Not a very sharp filter frequency wise, but a very pleasant
> transient response.
And this is where oversampling has become a critical factor again. We
are using oversampling for audio plugins that simulate an analog
process within the digital realm. For example, if I throw a Pultec
style EQ as an insert on one of my channels, the path of the audio
goes into the plugin, get's processed, then returns to the channel.
This insert actually simulates a complete D/A and A/D process.
Depending on the plugin, I can turn oversampling on or off, and
depending on what my project’s sample rate is, and the type of audio
content, I do need to. My normal working sample rate is 96, so I
almost always leave it off, but if I’m using 48, I do have to turn it
on.
One of my plugin makers has made the oversampling setting
non-filtering. So overshoots can be brutal if not addressed by other
means. But what is so nice about it is the spacial accuracy and the
phase-coherence.
Speaking of, as we know, adjusting EQ is a phase thing. Well, there
are EQs that don’t change the phase. They sound different, and can get
really nasty sounding. They are to be used very selectively.
> I notice You are using an A9, which is 24mp. A7Rv is 62mp or about
> 1.6 times more linear sampling. Sony has to make sharp lenses if
> they are to match their cameras. My go to lenses are the 20-70/4 and
> the 70-200/2.8 II with sometimes adding the 1.4x. Everyone has
> there preferred system and it is a wonderful time for photography.
The 70-200/2.8 GM II is a crazy good lens. I really love it, but, but,
but… It was either that or the fleet of CDJ3000s, and the CDJ3000s won
out. The CDJ3000s earn me magnitudes more money than the cameras do.
Speaking of. One of the reasons the CDJ3000 decks cost so much is the
internal processing. The deck converts all files, regardless of sample
rate and bit depth to 96kHz and 32bit floating point. All speed and
pitch adjustments are made with the uprezzed digital audio. It also
applies some other secret sauce to simulate the effect that vinyl
playback does in the creation of overtones. I’ve never had a playback
device actually IMPROVE the sound before. It’s uncanny. These are the
decks that are used for the headliner acts at festivals and clubs
around the world, so the proof is in the pudding as to how good these
decks are. Even a low-rez MP3 sounds better on these decks.
Feature-wise, they are dumb as bricks, but there is no denying their
audio quality. (You can speed change without pitch shifting, in real
time, by about +/- 20% without hearing any artifacts, and +/- 50% with
mixed with something else to blend the artifacts. It’s absolutely
bonkers. Serato’s Pitch-n-Time is also extremely good, but this is
much gooder. I can do anything I want, pitch change or speed
change—even actively doing both without artifacts. (There are limits
to how good, but those limits are usually aesthetically limits for the
performance anyway. (Just because I can play a 80 BPM song at 140 BPM
doesn’t mean I should, although sometimes I do).
Continuing on with this topic that nobody else cares about…
The CDJ3000 has both analog outputs (standard stupid RCAs) and a
digital output. The newer mixers have both types of inputs. The DJM-A9
mixer I also got (everything is latest greatest) is a digital mixer.
Everything is done in the digital realm. With the CDJ3000 and DJM-A9
(or V10) combination, nothing hits analog until it eventually hits a
D/A, which can be in the mixer, or in some other downstream device. We
can go digital out of the DJM-A9 to the FoH system if we want, and in
a full Dante setup, it never hits analog until the amplifiers.
I mention this because there are people who prefer the sound of the
double-convert, by going out of the CDJ3000 with analog into the
DJM-A9 where it gets reconverted into 96/32 all over again. These
converters are good enough (this stuff is stupid pricy, and the
DJM-Euphonia, DJM-A9 and DJM-V10 have converters that are VERY good),
that any differences in sound quality are negligible at best. How good
is my DJM-A9 as a mixer? Good enough that I am currently using it as
my primary mixer and audio interface in my studio. (Yes, it is also an
audio interface for computers).
To further continue on with this nonsense, “summing” is one of those
things that is more black arts than science. We learned that back in
1993 when I was involved in DAW development. We had to apply a
dithering process to the summing algorithm to get it to sound right.
Just like in photography, if I overlay two images together I can get
aliasing artifacts. However, if I ever so slightly randomize the two
images (blur, low-pass filter, dither), the aliasing artifacts are
reduced or eliminated. Same thing with audio. The thing I IMMEDIATELY
noticed with my DJM-A9 mixer was that they got the summing algorithm
pretty much perfect. I threw a couple of tracks at it that were
intense with square and saw waves (typical D&B and bass-house using
REESE Bass sounds) and it was flawless. Stuff that will choke my
Computer/Controller system passed through the CDJ3000/DJMA9 combo with
ease. I know it’s not using hi/low pass filtering because the
phase-coherency is maintained.
Anyway, that’s why I’m eating Raman these days. Typical DJ in that my
equipment costs more than the vehicle it’s being carried to the gig
in. And I drive a BMW.
> When I go back to my A7iii images, 24mp, I rarely feel there is not
> enough resolution.
I really considered the R version of things. It’s not so much the
resolution gain for resolution sake that I notice. It’s the glassier,
more transparent look to the images at higher ISOs. But I’m not
printing much of anything these days, so with the downsizing for
digital display and consumption, it’s not anything I would really ever
see, and I address that in Lightroom anyway through other means. 24mp
is my comfort size and those files are already too large as it is.
DJ Schnozz
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