Photoclub Alpha

Continuing to make profiles when time permits, here is a reasonably detailed profile for the Sony DT 16-80mm f/3.5-4.5 ZA Carl Zeiss zoom (2007) created using the Sony Alpha 550 14.2 megapixel camera using Manual Focus Check Live View at 14X to set the lens focus and ensure the chart is positioned to use 100% of the frame.

http://www.photoclubalpha.com/DSLR-A550 (DT 16-80mm F3.5-4.5 ZA) – RAW.lcp

Right click to download this 56Kb file which should be placed in the Lens Profiles/1.0/Sony folder of the directory on your computer which holds Adobe Lens Profiles.

This profile has been created at full aperture and f/8-f/11 depending on focal length, at 16mm, 24mm, 35mm, 50mm and 80mm focal lengths and involved 90 raw captures.

It is possible in ACR/Lightroom to use profiles which are not created on your own camera type. This profile can be applied to any APS-C Sony or Minolta camera using the 16-80mm lens; because the A550 is currently the highest resolution body, the CA data gathered is more accurate than would be possible using a lower resolution body but may need a saved adjustment in defaults. Individual lenses differ slightly and may also need adjustments.

I have checked the operation of the profile on files from A100, A700, A200, A380, A350 and A550 and it’s very effective in removing CA. Illumination is much improved at 80mm (notably). You may prefer to turn the geometric correction down to zero (off) when the angle of view matters more than perfect straight lines – and also, where people are in the shot near the edges at 16mm. The distortion of the lens is optimised to lessen ‘stretched faces’ at the ends and corners of the shot, applying the profile removes this slight barrel distortion and does not improve groups. It’s most useful for horizons, rooms, seascapes, and subjects where a good straight rendering is critical.

It has been suggest I should add a donation button for these profiles. By all means see our subscription page, there’s a downloadable PDF of the latest Photoworld magazine for $3. I could easily have zipped profiles and sold them in the same manner, but that is not why photoclubalpha is here; Adobe provide the software to do this free (OK, I know what the rest of their stuff cost me…) and profiles should be made public domain by creators.

- David Kilpatrick

Although it’s far from a perfect lens, this small 1999 Minolta RS optic is my favourite for general travel and everyday use on the Alpha 900. It is a convenient size and weight, performs well when stopped down a little, and has exactly the range and minimum focus I need.

Mouseover image to see effect of this profile used on a shot taken at 70mm focal length.

The profile created for ACR6/LR3 is at four focal lengths – 24, 35, 55, 85 – and two apertures, wide open and f/9. The chart distance ranges from about 120cm to about 4m.

To download:

http://www.photoclubalpha.com/DSLR-A900 (24-85mm F3.5-4.5) – RAW.lcp

Right click and save. Correction of CA and distortion is pretty good, and this profile identifies itself correctly as a Minolta lens. It should be placed in the Sony directory of Adobe Application Support>Camera Raw>Lens Profiles.

- David Kilpatrick

I have made a simple (f/2.8 and f/8 chart set) Adobe Lens Profile for the 16mm f/2.8 NEX E-series pancake lens. It seems to work well for closer distances, because that’s how it had to be made; CA is reasonably well corrected, vignetting is eliminated, and distortion of closer lines – maybe if you are looking through a door frame, etc – is very accurate. The profile was created using NEX-5 and 16mm.

You can get this profile here:

http://www.photoclubalpha.com/Sony NEX-5 (Sony E 16mm F2.8) – RAW.lcp

Right click to download/save the target file, and install this in:

Library>Application Support>Adobe>Camera Raw>Lens Profiles>Sony

Uncorrected 16mm shot

Using Adobe Camera Raw 6.2 RC with the profile active at default settings

JPEG profile added (17/08/10)

I have now added a JPEG profile from the same set of images as the raw – this is lucky, I didn’t think people would need a JPEG profile but happened to have the camera set to RAW+JPEG when the test shots were made, and this has been requested for those using HDR or other JPEG-only modes.

http://www.photoclubalpha.com/NEX-5 16mm JPEG.lcp

Above: HDR three-shot with 16mm, straight JPEG

HDR shot opened in Camera Raw without adjustments, but with the Profile enabled

Using the profiles

A full Adobe Profile is undertaken at several focus distances, apertures and zoom settings (or for prime lenses, just at a range of distances and apertures). The largest chart I can print is A2+ using the Epson 3800, and with a 24mm equivalent lens, this means having the camera surprisingly close to the target. The profile is therefore only 100% correct for subjects at 115cm from the camera, which corresponds to the 4X minimum focus distance suggested by Adobe.

I have found from using the 16mm that its optimum aperture for central sharpness is probably f/5.6, and that chromatic aberration and vignetting do not improve at stops smaller than f/8. There is a slight improvement in detail sharpness in the extreme corners at f/11 and f/16, but this is due to extra depth of field helping to cover a curved focus field. I therefore made test sets at f/2.8 and f/8 for this profile.

The geometric distortion is most visible with closer subjects such as the subject above (The Slave Girl, a bronze c. 1870 by John Bell, at Cragside House in Northumberland). This is a hand-held exposure of 1/4 at f/8, and is perfectly sharp despite the lack of stabilisation; every word of the interpretation can be read at 100%. I have found most shots are perfectly sharp with the 16mm given reasonable care, as you would take with a Leica, to breathe correctly and make a shake-free exposure. This is not the case with SLRs where the mirror action nearly always causes shake.

For more distant subjects, the 100% default setting of the ACR/LR Lens Correction panel can be reduced and where there are few straight lens removed entirely to secure the maximum field of view. Similarly, the vignetting correction can be reduced or removed entirely as the natural darkening towards the corners with this lens is attractive.

Although this profile is named to match perfectly the naming convention used by Adobe for the 18-55mm, I find that ACR 6.2 can not be relied on to use it for Auto as a default (if you work with more than one lens, Adobe Lens Correction soon proves unpredictable in this anyway). If you select Auto, then select Sony, the lens profile will be selected but the Auto button changes to Custom. If you then save new Lens Correction Defaults, or Camera Raw Defaults, ACR will attempt to force this profile on the 18-55mm and the reverse will also happen. So it’s necessary to check which profile is selected. Using ‘Previous Conversion’ for shots taken on the same lens is a quick way to get there.

The additional Manual Controls can be used on top of the profile (the second tab of the interface). The most useful are the geometric distortion (camera angle) corrections. The Chromatic Aberration/Colour Fringe controls can be fine tuned as the correction for CA while very effective relates only to the tested focus distance. CA may change with focus but my particular lens doesn’t seem to suffer from this. All that is necessary is to enable Defringe All edges as a default, and this will remove any hint of colour remaining. As a tip, setting Colour Noise Reduction to a high value can help remove CA and purple fringes in many shots processed through ACR/LR. The colour NR detects 1-2 pixel fringes just the same way it detects individual pixels, and neutralises much as it does noise.

- David Kilpatrick

Tamron’s 18-250mm lens – later adopted by Sony – was so good that it really takes some effort to beat it. Sigma has put that effort in, but the cost is a very much larger and heavier lens. If all you got was some better performance, it might not be all that exciting. But you get potentially superior anti-shake through its built-in OS, and faster focusing with HSM, the Sigma equivalent of SSM.

Sony’s new Alpha 850 will be identical to the Alpha 900 in size, handling and external design – including the omission of onboard flash. The camera, expected to be launched before September, uses the same 24.6 megapixel CMOS sensor as the Alpha 900 but has – it is rumoured – only a single BIONZ processor, and a very slightly modified viewfinder. It is shipped without the Remote Commander (this becomes an optional extra) indicating that minimum retail price is Sony’s aim.

This is a screen grab from Fotobrenner.de in Germany who have the body only offered for €1999.00 and the kit with SAM 28-75mm f/2.8 new lens for €2699.00. As listed that makes the body about 10% more expensive than the current street price of the Alpha 900 – indicating either that the A850 prices are RRP and will rapidly fall, or that the A900 is about to get a price hike. They offer the A900 for €2499.00 and that would – pro rata – make the UK street price for the A850 about £1599. Please note: though the 28-75mm picture is authentic, the body shown has the AF switch set to C – just like the Sony shots of the A900 issued to dealers. Maybe they would do this for all packshots for some reason, maybe it was chance – more likely. It would be unlikely to happen again for the 850 shot so I reckon this is shopped.

SIGMA redesigned their 70-200mm not long ago to change the EX version to DG, introducing new coatings which greatly improved microcontrast and eliminated digital camera sensor reflections. In 2008, this was further upgraded to the Macro II model with HSM sonic motor focusing, a new optical design capable of focusing down to 1 metre distance. In 2009 this became available, along with matched HSM-compatible 2X and 1.4X converters, for the Sony Alpha mount.

The new Alpha 230, 330 and 380 models are radical ergonomic redesigns of the existing 200, 300 and 350 series. There is a 15% reduction in size (volumetric) and weight, an update to the styling, and a completely revised user interface with graphic representation of setting adjustments – with a built-in ‘handbook’ to accompany the modes and options. They also have mini-HDMI image output, compatible with Bravia TVs and with interactive software inside the camera to allow the Bravia’s own remote control to change, orient and zoom into images (Bravia Sync). Twin card storage is MS ProHG Duo/SD and only one card is usable at a time, with a hardware switch to change slots. A smaller battery type (shared with the HX1 Cyber Shot) is used. A new self-timer drive mode grabs a quick burst of 3 or 5 frames, cutting the chances of spoiled portraits and groups shots when someone blinks at the wrong moment.

The new flashgun HVL-F20AM operates as a wireless flash controller for the full-frame α900. “While Sony’s flagship DSLR does not have its own integrated flash, the HVL-F20AM can be used as an inexpensive trigger for wireless remote flash heads” according to Sony UK.

Tamron’s new ultra wide angle zoom for APS-C/DX is getting a bit of a blasting from reviewers. Now, when I see this happen, I get curious. Lens testing is often badly designed for such zooms, involving test chart targets at distances which are extremely close and result in very bad figures caused mainly by a strong curvature of field (dished, ‘cap’ shape relative to the camera) when gets worse in effect the closer you focus.

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 Japanese camera and photo product manufacturing association CIPA has issued a press release PDF, containing a table of predicted figures, relating to 2009-2011 projections. Here we reproduce the text and the table (as a JPEG).