Prev. Page      Main Page      Next Page      Page Bottom

Pentax K5 Long Expos in Low Light

Search. ?q= bing duckgo ecosia google qwant yahoo

K5: Revolutionary imx071 'Exmor' sensor inside

FPN shows mainly in Shadow areas of Canon Eos: 5d-III 6d-II 7d-II... included
Fixed Pattern Noise / EOS Shadows
Eos 5D Bias-Map Fixed Pattern Noise, FPN - Click Image, Ctrl+ to Enlarge

The way the sensor's designed leads to high Pixel Response Non Uniformity.
Power Supply corrupts sensor Analog Signal before ADC: Electronic Noise?
Even a 30 sec. Mid Exposure at ISO 100 in Low Light is a Banding disaster:
Canon Eos DSLRs are mostly Unusable at Low-ISO setting in Low-Light
Lifting Shadows was very touchy in PP with almost all these Canon DSLR. In
AstroPhotography, we used to Subtract a Bias-Map (offset frame) from each
Raw file. So, it was more of a pain to deal with the Amp-Glow at bottom-right.

High Conversion Noise, Signal Corrupted fore ADC: Canon Eos (x)xD...2019

High Convers° Noise, Signal Corrupted before ADC
FPN unseen by Dxo method is back here - Clic Image, Ctrl+ Enlarges

Pentax K5 Revolutionary imx071 Exmor, see this 5 min. ZWO Dark-Frame
imx071 Dark Frame 5min from ZWO
imx071 Dark-Frame 1000x less Noise, 0 Amp-Glow - Click Image Enlarges

The way the sensor is designed cancels 99% Pixel Response Non Uniformity
Nothing really can Corrupt sensor Digital Signal output = close to Zero Noise.
Long Exposures in Low Light at ISO 80 protecting High Lights are a pleasure
The frame is totally free of Amp-Glow even on a 300 seconds Long Exposure.
--The howto both images are from and made is written in their IPTC infos.

Exmor sensor ; from Pixel to Output: ~Zero Conversion Noise added

No Conversion Noise from Pixel to Output
Click Image, Ctrl+ to Enlarge

Dark Current levels have been Divided by Millions since 1st 1990 CCDs Astro:
1991 Sbig CCD-ST4 AstroCam's Dark Current compared to Pentax K5's

Pixel Response non Uniformity Levels have been Reduced a lot. Tartan Fabric,
Fixed Pattern Noise and Banding were totally absent since the Pentax K5 Sony
imx071 "Exmor" sensor. An analog Correlated double Sampling circuit before
Analog to Digital Converter, plus a Digital CdS After the ADC lowers the PRnU
levels to never seen levels
. Astro Pics from Exmor Sensor w/o any other Frame
that 3,4 Flat-Fields and only a few SubFrames are far better than what I got w/...

Exmor sensor ADConverter + Digital CdS Timing Chart
Exmor ADConverter + CdS Timing Chart
Click Image, Ctrl+ to Enlarge

... my Eos 20d-5d w/ Bias-Maps, Dark-Frames, Dark+Flat-Fields, Sub-Frames:
Canon Eos-20d and Eos-5d Astro-Photography, Tests ISO-100 vs 1600
Sometimes more than 100 frames total and the Results were just acceptable w/
Huge Amp-Glow ruining each SubFrame. Pentax K5 is the very First CMos ILC
that totally gets rid of any Amp-Glow, even after 25 min. Exposures (I tested) :
www.DPReview.com/Galleries/Tags/Pentax-K5-Astro-photo-ISO-80

How to get fine AstroPhotographies from P-K-5

Stacking is very efficient to Maximize the SNR of low Light Raw files that include
an imperative " Only Random Noise inside the Raw files " Condition.

RAW Smoothing Destroys the ' Random Noise Only ' Condition by introducing
Artifacts and by Erasing many Faintest True Stars from the Raw files. Astro Pics
Pentax Q10 w/ 4 min. exposures and w/o Raw-NR beats Samsy NX mini
require True RAW. Avoiding any Raw Smoothing or Star Eating. The Smoothing
of K5's RAW files begins at ISO 2000. Who will use the Pentax K-5 at ISO 2000
knowing that it doesn't have any Analog Amplification after ISO 80. It's far easier
to get very hight SNR stacking a handful of ISO 80 Long Exposures than with 60
ISO-1k6 30sec. Expos. Am I still the only one using his PK-5 at its best ISO 80 ?

Of course, you may keep shooting Astro-Photography at Hight ISO settings.
But, for the K5(II(s)), when shooting at ISO-80 instead of ISO-12800 :
Constant Light Value =160x more photons from 12800 to 80
+ ISO 80 DR Value 14,1 = ~twice ISO 12k8 DR-#...
... it's ~17929 vs only ~155 Luminance Values (Print).
+ ISO 80 SNR Value is ~2 times~ ISO 12k8 Value...
... this means ~42 dB instead of only ~21,3 dB ! (Print).
- ISO 12k8 Raw file Size is about ~twice ISO 80 Raw Size...
... this Huge Difference in File Size is due to NOISEs included !
- ISO 12k8 makes you Stack Much More Sub-Frames to get rid of Noises.
- ISO 12k8 implies to Subtract Bias-Maps, Dark-Frames to Clean Sub-Frames
Pentax K-5 Astro-Photography at ISO-80

Bad habit to shoot at Hight ISO-Setting in Low-Light began w/ Eos DSLRs :
100% unable to get Raw files w/o Banding, FPN, Tartan Fabric at ISO 100-400.
Eos 20d, 5D, etc's Optimum Setting is ISO-1600. ISO-800 in Warm-Summer.

-2010-11 Pentax K-5, Sony imx071 Exmor Revolution Docs still reachable.
Eos 5D Mk2 v Pentax K-5, both Pushed 9 Stops
-Dideos' thread about Sony imx071 Exmor CMos lift up to Top by Pentax K-5.
La Techno. Sony mise en Valeur par le Pentax K-5
-PK5 ISO 80 PEFs so Clean you only Stack few ones, even after 16min. Expos.
Pentax K-5's incredible Results + Astro-Photography

Pentax K-5s are still Not Obsolete at all versus Pentax K-3s

~~~~~ tbc... ~~~~~

Best APSC DSLRs (w/ 4/3, 1" stills Crop Mode)

For Astro-, Bird-Photography, there are not so many APSC ILCs available with
a Crop Mode down to 4:3 or 1" for stills. Now that they all get Fully Addressable
CIS, CMos Image Sensor, RoI, Region of Interest, is a 100% CostLess Option.
Very useful for Astro-Photos of Deep Sky Small Objects or Bird photography.

Let's examine 2 pairs of APSC DSLRs through P2P.net, a Used vs a New one.

Astro Low-Light Long-Expo APSC Cams
Click Image, Ctrl+ Enlarges

Used APSc cameras. Pentax K5(II(s)) better Eos 60d in every characteristic,
except for the Read Noise where the 60d's slightly better. Canon DSLRs were
at Top of Conversion Noise. Eos-60d: 8.5 vs PK-5: 0.6. Red Layer especially
suffers from that Huge Conversion Noise level. A Stock Pentax K5 with UHCS
filter shows at least equivalent Red Performance than an Expensive Eos 60dA.
The proof is here : dpreview.com/challenges/Entry.aspx?ID=1195990
dpreview.com/galleries/7467909648/photos/4208343/pentax-k5-rosette
Note the 52mm secondary mirror of my 200/1000 SkyWatcher is far too small.
At least a ~70mm 2nd Mirror, to light ~24mm Circle in 28mm Diagonal CMos.
Pentax K-5 is Weather Sealed, its specified min.operating Temperat°C is -10.
K-5 also has a very low Dark Current level so that you can Expose until 30 min.
ISO 80 by 12-25°C Ambient Temperature and get so Clean Raw files that any
Bias Map, Dark Frame's useless. In most cases, you only need 3-8 Raw files :
www.DPReview.com/Galleries/Tags/ISO-80
17 min. Exposure through an UHCS filter to darken M-51. Then Pushed 6 Ev :
www.cloudynights.com/gallery/sizes/32054-pk5lv-5-6/large/
Not a bit of Banding, nor any Fixed Pattern Noise. Not even only 1 Hot-Pixel !
Pentax K5 is IsoLess, far Better results are achieved stacking ISO 80 subs to
get a High SNR image you can Push, than a lot of ISO 1600 subs as you have
to with Noisy Canon DSLR near Base-ISO. 1st Exception in last Eos R5 +R6.
Image-Quality Bonus is huge from ISO 1600 up to 80 : A look at DxO Curves.
SuperBonus : 20x more photons from 15 to 300sec.

imx071 exmor sensor in the PK-5 is so fine that chinese camera makers did
not hesitate launching their Asi071, Qhy168C, etc. at Top Price of $3000€ = 3
times, 3x the Price I bought my Pentax K-5 New in Mars 2011. Models are still
available ~1/2 2/3 that price, see how low is their imx071's Dark Current level:
ZwoAstro.com/Asi071mc-Pro~Cool
Replace 'Cool' by 'Pro'. Add '+Manual' in Browser's Search-bar for more infos:

= 1st "Exmor" CMos sensor. Still in the Race after ~15 years on the market.

The 1st CMos sensor w/o any Amp-Glow.

Dxo 4 DSLRs APSc
Click Image, Ctrl+ to Enlarge

New APSc Camera: to buy an APSc camera for Long Exposure in Low Light
or Astro-Photo today, I would certainly choose a Nikon D7500 over the Canon
Eos 80d. Pentax K3-I, II, III are Not at the IQ level of the K-5. The later do Need
Strong Raw Smoothing to follow Modern Dual-Gain BSIs. Proof, the K-3 Mono
w/ imx571 doesn't need that strong Raw NR to gain 2+ Ev DR. The Eos 80d is
now closer to the Pentax K5, but 6 years later, the Nikon D7500 beats them all
in all characteristics. Except the K5 for Close DR and Long Exposure Noise :
www.brendandaveyphotography.com/more/Long-Exposure-Sensor-Tests
Pentax K5 is still the Long Exposure King, far less Noisy than either the D500
and the D7500 which share very Similar sensors, if not exactly the same. Eos
80d is roughly in between both for long exposures, but way more Noisy than
both the Nikon and the Pentax for Exposures of 30 seconds or shorter.

DxoMark 4 APSc DSLRs
Click Image, Ctrl+ to Enlarge

DxoMark don't allow comparing more than 3 camera. But it wasn't that difficult
to add the Canon Eos 60d over the screen shots of the 3 other DSLR. Canon
Eos 80d, Pentax K5, Nikon D7500, here sorted by their IQ Performance rate.

~~~~~ tbc... ~~~~~

Pentax K5 v 24Mpx High End 24x36 FF DSLRs

Let's compare the Pentax K5 APSc to 4 FF 24x36 High-End 24 Mpx DSLRs
Sony-Alpha-900-vs-Pentax-K5-vs-Canon-Eos-5D-Mark-III-Perfs-Compared

Pentax K5 vs 24 MPx High-End 24x36 Full-Frames
Click Image, Ctrl+ to Enlarge

Nikon-D3X-vs-Sony-Alpha-850-vs-Pentax-K5-Perfs-Compared
The Pentax K5 beats all these Flagships in almost every criteria measured by
DxoMark. Except the Nikon D3x's better of 1 bit Color-Depth in Portrait Mode.
But, it was launched at ~$8800 - more than 8x the price I paid for my K-5 New
PENTAX, me revoila : mon K-5 arrive juste !
The better ISO score of 24x36 is logical, it's because their 2,33x sensor Area.
All other things kept equal Dxo-ISO score is function of sensor's 2 dimensions
Low-Light Photography + Sensor Sensitivity Comparison Tools for Astronomy
The 24x36s are far from reaching ISO 2707 ; The Sonys are only 1,2x the K-5.
Dynamic Range Ability to show Noiseless Details from the Deepest Shadows.
Here the K-5 shines: 2,4 Ev better than the 2012 Eos 5dIII, 1,8 Ev better than
the Sony Alpha-900, 1st DSLR to implement an OnSensor ADC, an Analog to
Digital Converter prevents aSaP the Signal to be ruined by Conversion-Noise
External ADC, Weak Filtering PSU, Weak Shielding, ruin the Dynamic Range

Comments from DxoMark, plus their Review for the Pentax K-5
DxOMark Review, Comparisons of the Pentax K5
the Best APSC in all tested fields

Wide Open Lens Systems -- Closed to Pentax

2010. Sales of Samsung NX cameras took off quickly. Everyone noticed the
Fine Colors they got. A few months later, was the turn of Sony-Nex. Adapters
Makers, Sellers, were popping up everywhere
. Brands' Lens Systems always
closed, opened quickly. 2012 was Fujifilm X moment. Ricoh released its k-01,
their 1st and Last APSc MirrorLess. Then you could use almost Every Lens on
a ML camera: Samsy NX, Sony E, Fuji X. Except Ricoh that was 100% wrong
keeping its big K Mount, thus depriving itself of using all other lenses available
new or used, on its cameras. This was a Big Mistake - would have been Much
Better to provide the K Adapter at a low price to the K users
. Especially since
the k-01 didn't shine by any decisive advantage: as Big as a K-5 and crippled
by a Slow hesitating AF in Low light. Worse, No EVF available and 12 bit only
RAWs. 4 years later, you could always buy a k-01 New for less than a Quarter
of its launch price...
Open Lens Systems v Closed K
2013 Diagram of K-01 Fiasco - Click to Enlarge

DSLRs being the only "Easy to Sell Pentax", Ricoh kept on with them. Despite
Manufacturing a DSLR costs ~from 30 up to 90%~ more than an EVIL camera,
depending on AF + Framing Precision, AF and Fps Speed, etc. Thus the idea
to put Old CMos (K1, II), Basic ones (K3, II, III) in their DSLR to lower their Cost.
Crippling them with Strong Raw-NR to improve their SNR, DR. Mistakes often
lead to each other...
Few DSLRs in an EVIL-Mass-Market prevent Pentax from Earning money !

~~~~~ tbc... ~~~~~

Pentax K5s are still Not Obsolete vs K3, K3-II

Despite having 50% More pixels (Print) +being 5 years younger, the K3,II show
slightly lower performance than the D7k ~5 years ago. The 2015 D7200 has an
overall Score 7 points better than the K3II. The D7200 and the D7500 are 1 - 2
steps upward from the K3 in Image Quality, especially for the DR and ISO rating.

DxoMark Print-Mode comparison from 2010: D7k, K5 - to 2015: D7200, K3II

ND7k-PK5s-ND7500-PK3s
Better Scores expected from Higher pixel counts - Click to Enlarge

Ricoh will kill Pentax if Not Investing in EVIL cameras

Building DSLRs cost much more $ than EVIL cameras and Ricoh is Saving on
Sensor's Cost to Lower this $$ Annoying Penalty
. With a Better Sensor, the K3
could easily have reached a score of 84 as D5200,5600 did
. Please. Note that
these belonged to Nikon's affordable class $700,850€, but they sell in sufficient
number to Lower their sensor's cost. This is no longer the case for Pentax since
the K3s. Their last Best-sellers were the K5s. The K7 was a slight regression in
Image Quality vs the K200D which had the 10MPx last CCD from Nikon D200 :
Last CCD from Nikon D200 vs First 1" BSI CMos from Samsy NX-mini
For Long Exposures: the K3 had by far the Noisiest Sensor, compared to the
K1 and, to the K5 which values are between ~0.26 and ~0.71 these of the K3.
Pushed +5 Ev, the 5 min. Long Exposure of the Pentax K3 is Bright Light-Pink.
Take a look at B.Davey's Long-Exposure-Sensor-Tests in this §

~~~~~ tbc... ~~~~~

K3-M proves K3-III +imx571 don't need Raw-NR

The K3-III Mono w/ an imx571 let us see the big step-up from the K3-III Bayer:

Mono: Dual Gain boosts DR, thus No Need for Destructive 2 Steps Raw-NR.
No interest to cripple a basic CMos w/ Raw-NR, too low Mono Sales Volume
Plus we do know its Dark Current level is very low vs unknown in K3 III Bayer.
But as the later 'Basic' is just a Cost-Killer to lower the High Cost of a SLR...

Its Quantum Efficiency is TOP at 91% with the lack of any Bayer Mosaic.
Drawbacks are the Fixed LCD + the fact Pentax won't earn $1 with it:
Pentax K3-Mono DSLR is Cheaper than an Asian Astro-Camera
an Astro-Cam is Sensor, USB I/F, Voltage regulators and, euh...
Fujifilm: Op, Net-Margin ~10%, ~8% -vs- Ricoh: ~3%, ~2%
Ricoh Margins' way too low to survive the Techno. roller.

Pentax K5s, K3s Base ISO Noise in DN
Click Image, Ctrl+ to Enlarge

Bayer: 2 Stages Raw NR starting at ISO-160 as on a Q-Q10 boosts the DR,
but it kills one part of Stacking Bonus which is based on Random Noise only.
High DR Numbers'll never get the Stacking Efficiency of same CMos w/o NR:
Pentax Q10 Raw-NR kills Stacking Efficiency -vs- Samsung NX mini is 5/5
Even by Multiplying the subs, the gain tends to a limit, a Glass Ceiling effect.

Don't know if ISO-100 is really it. Not ISO-75 as it is more and more the case
No idea of its Dark Current level, can be very high, See K3, II chapter Above.
Dont't know its Quantum Efficiency, could be just a bit better than on the K-5.
For $2k, better buy a Pentax EVIL, but, w/ the true imx571 inside
+ Bonus: thus Ricoh could be able to correct their previous k-01 mistakes.
Else I'll keep my Pentax K5 + its Top IQ at ISO-80.

~~~~~ tbc... ~~~~~
  © Dima Lootvoet 2010-2024

Prev. Page      Menu Page      Page Next      Top of Page