Photoclub Alpha

SONY has released a new alogrithm for raw conversion (deBayer) which offers improve high ISO noise. IDC (Image Data Converter) is the program issued with all Sony DSLRs. Up to now, no maker has ever revised their ‘house’ converter to offer high ISO improvement as a specific feature. The new version can be downloaded free by existing users (download link is provided at end of story). We have direct download links now for Windows and Mac OSX versions.

SONY has shown itself to be lagging behind the competition as we reach the third bend on the second lap of the development of HD-video capable DSLRs. At PMA 2010, nothing ‘real’ was shown and the closest they came to further launches in the Alpha range was an advanced pre-production prototype of a 24mm f/2 Carl Zeiss T* ZA SSM.

But Sony may prove yet to be the tortoise – or perhaps to be Brer Rabbit. They could make the finishing line, the goal of a truly useful video DSLR, before Nikon/Canon/Pentax/OlySamPanny get there.

In an unusual move, probably designed to cut down the work of rejecting submissions which fail to make the grade, the on-line picture library Alamy has published lists of cameras (by make) which will NEVER produce a file acceptable to pass their Quality Control. It includes all the Sony Cyber-shots ever made as far as we can tell! They say: “Check your camera – do NOT submit any images from camera models featured on the list below. Camera models featured on this list do not produce files that are capable of passing Alamy’s QC standards.”

ACCORDING to specifications revealed on a German site, the new Sony Alpha 500 will have a 12.3 megapixel CMOS sensor capable of providing Live View to the rear 3 inch medium resolution screen – with Manual Focusing at 14X magnification. The in-prism based Quick AF Live View is retained, giving a choice between two entirely different systems of Live View, Sony’s innovative and easy solution scanning the focus screen, and a critically accurate alternative for tripod work. The camera may sell for just €50 more than the Alpha 380 – or break the £500 body only barrier in the UK right from the start.

Adobe’s Camera Raw Release Candidate 5.5, which introduces global corrections for all Bayer sensor cameras requiring a differential value treatment between the two Green channels, has a visible effect on the colour of Sony Alpha file conversions.

There is a white paper by Sony Semiconductor on the imaging processing which I think is in the HX1, http://www.sony.net/Products/SC-HP/cx_news/vol55/pdf/featuring55.pdf. I assume it is the IMX-032 CMOS sensor (http://www.sony.net/Products/SC-HP/cx_news/vol55/np_imx032cqr.html) mated to a CXD4109AGG image processing chip. There seem to be some interesting techniques employed, multi-plane synthesis to combine several frames for low light and HDR capture.

With the IMX-032, it is interesting to note that the on-board programmable gain amplifier has a gain value of up to 18dB or a factor of 8, so if base ISO is 80, then maximum “analogue” ISO is 640. If we compare the IMX-032 versus Sony’s first column ADC CMOS chip (IMX-017), the IMX-32 has an 11.8% better photo-electron efficiency per unit area (2300e per 1.75 micron square pixel compared to 4500e per 2.5 micron square pixel). Might be a sign that Sony is improving the process and design used to make their CMOS chips.

The backside illuminated chip is called the IMX-061, http://www.chipworks.com/uploadedFiles/Aliased_Pages/CMOS_ImageSensors_Spotlight/Chipworks%20-%20Sony%20IMX061%20EXR-0902-813.pdf
6MP and 1.75 micron pixels in ClearVID (45 degree) layout with a 1:6:1 RGB Bayer filter array, sacrificing colour resolution for spatial resolution.

The Nikon D90 chip is called the IMX-038 (not the IMX-021 as for the A700), so this suggests it has significant revisions compared to the IMX-021 (possibly linked to LiveView and HD Video?).

– Dr Daniel K. L. Oi

Here is an article which is mainly a test review of the Sigma 50mm f/1.4 EX DG HSM for Sony Alpha, and also Nikon, fit (both were tested). It also deals with the Alpha 900 and D3X, the two 24 megapixel full frame cameras used to test the lenses and two comparison 50mm f1.4s.

The custom white balance function on the Konica Minolta Dynax 5D could not be quicker to use; turn the left hand top dial to the custom symbol, press the button in the centre of the dial, press the shutter after aiming the camera at your white or grey target. Custom WB is now set until changed with a new reading, or returned to fixed or Auto WB.

Like Mike Johnston writing in The On-Line Photographer, I’m aware that any attempt to line up one or more cameras and show comparison images or make judgements is on to a loser from the start. And any webmaster who puts an external link in the first half dozen words of a new post is losing the plot too! But here, for what it’s worth, is the first line-up of results processed using the same software from A900 and D3X uncompressed raw files converted without sharpening or noise reduction.

The latest release of Adobe Lightroom, v2, handles all Sony Alpha and earlier KM digital camera raw formats including the Alpha 700, 200, 300 and 350. It is also updated, along with the final release of Adobe Camera Raw 4.5, to handle Nikon D700. Because Canon appears to have left their filetype identical to the A400, their new 1000D was recognised immediately by ACR even in 4.5 beta version.