Photoclub Alpha

My review of the Alpha 550 has caused controversy because of the blue sky noise. I might as well say that over the last week, I’ve used the 550 in a wide range of conditions – some very bad conditions included – and its failure to match ISO 100 finesse would not worry me at all. The performance at higher ISO settings is so much improved it’s worth putting up with the minimum of ISO 200, and a touch more noise than the best ISO 100 results from the Sony CCD sensors.

Even so, something was clearly happening during the period of sunnier weather used for my earlier A550 tests. I used Auto ISO initially, because I had not realised how readily the camera will select settings right up to 1600. Auto ISO has thrown up some surprises. Here’s something to consider:

Please note that although ‘process’ symbols are shown with these Adobe Bridge/ACR images, the defaults were restored and then each picture was set back to defaults. They are all shown relative to each other in density, the image preview built by ACR. There is no question of DRO or any other tonal setting interfering with the apparent exposure – DRO does not affect the .ARW file, ACR discards any DRO generated embedded preview in my setup prefs, and DRO was not being used anyway.

It has already been noted by other reviewers that the A550 has considerably more headroom without clipping, even compared to the A350 which was already a top-ranking camera for dynamic range. This is what I meant when I compared its default images to Canon with Highlight Tone Preservation switched on, or KM/Sony older models using the Hi200 setting. This can mean that the A550 is really ISO 100 at its lowest on-sensor gain setting, but the exposure system is programmed to underexpose by a stop and the post-processing (BIONZ) is set up to boost the gain.

Why would Sony do this? Perhaps they read the many posts referring to the Alpha 900 and 700 ISO settings. The on-sensor gain controls the main ISO steps, but a rather cleaner post-process gain adds the 1/3rd step intervals. Experienced Alpha 900 users set ISO 320 manually because the sensor is at its optimum at roughly ISO 160 (DxO tests bear this out). The standard ISO 200 setting can produce more noise than ISO 320 because two different digital stages are used to produce the gain.

In search of superior high ISOs, they may have realised that the early gain stage (on the chip assembly) is inferior to the later BIONZ processor, and you can indeed get better high ISO by underexposing a lower ISO setting, then processing it with clipped blacks. That’s a Nikon technique, which has served them well. It’s also a technique used by experienced DSLR owners.

Now consider the four shots above. They are all taken at ‘ISO 200′ but the camera was set to auto ISO. Other shots in the same set show ISO 250, 500 etc confirming the auto ISO was in operation. They are taken in the afternoon in Scotland, so it is fairly near to the end of the day for sunshine by 14:49hrs, around an hour away. But the two locations at 50 minutes apart, 14:00hrs and 14:49hrs, should not have the extreme variation in exposure shown here.

Just what is going on for an exposure of 1/400th at f/11 to look correct at ISO 200, with the dark sandstone buildings of Jedburgh at the end of October? 1/400th at f/11 is the ISO 200 exposure for full sunshine in midsummer (aka f/16 light). You hardly ever find f/16 light in Britain unless you are on the beach, surrounded by pale concrete, in a field of golden corn or out on a lake.

50 minutes later, exposures range from 1/60th at f/11 to 1/100th at f/11 – that is, more or less, from two to three stops more. In fact these exposures are in line with what I would expect, it’s the 1/400th at f/11 which is the odd one out. I have no evidence to suggest that my CZ 16-80mm has an aperture which fails to stop down consistently.

Now look at some sky samples:

Here is an in-camera JPEG version which shows less noise – the in-camera process is equal to using much stronger NR in raw conversion than I would normally choose for ISO 200:

Now for the same processed from raw – notice that despite the noise, it is slightly more detailed or sharper:

This is a reprocessed second version of the original noisy sky instance. Here, I have used Adobe Camera Raw 5.6r1 defaults, which include some basic sharpening and also 25 on the chroma NR scale. No exposure adjustment is made at all. This view, by the way, looks more or less due north and it is not a case of a brighter sky underexposed; also, the stone and the chimney pots look normally exposed.

This is the 1/100th at f/11 shot, processed exactly the same way. It’s interesting in that I expected to see much lower noise, but in fact it’s much the same. The sky density is similar as well. The view is slightly more towards the east. While my Alpha 380, 200, 100 and even 700 shots are capable of showing blue sky noise at ISO 100 and as much as this as 200 it’s not as obtrusive.

Finally, this is the 1/60th exposure – perhaps more what would be expected at ISO 100 in this light with f/11. Here, I have set -1 EV exposure reduction in Adobe Camera Raw to get much the same final sky tone density. The noise is lower.

Checking other images I’ve taken since, I am now suspicious about the Auto ISO function in the Alpha 550, and whether it reports the gain applied to each shot accurately. It’s hard to reconcile the same ISO 200 setting shown in EXIF with the range of exposures encountered, and the actual exposure of the raw file. Yet ISO 250 was also selected for this shot taken a few minutes before the chimney shot:

This is also included in the main report (click image to view full size on pBase). If I darken the sky as much as the other examples, I get noise similar to the 1/60th ISO 200 clip, or better.

Since making these tests, I’ve started using the Alpha 550 only on fixed ISO settings, with some misgivings as intermediate gain like ISO 250 or 320 might possibly be yielding better results. I just feel something is happening in the BIONZ stage, perhaps involving analysis of the Auto ISO images and compensation for deviations from the reported EXIF Auto ISO setting. This is just a hunch. Fixed settings seem to be equal to the worst case from Auto ISO. Here’s a textbook example, 1/125th at f/16 for a blue sky on November 3rd, facing due north, at 14:19hrs, ISO 200 fixed setting, ACR 5.6 defaults as above:

The answer seems to be to overexpose your manual ISO 200 shots by not simply one stop, but as much as two stops when shooting raw. At least if Adobe Camera Raw is used, recovery of normal tones (not burned out highlights) will fully restore the exposure from 1 or 2 stops over depending on the subject.

Here is an overexposed image, taken at 1/80th at f/10, ISO 200, in mid-day sunshine:

Below is what the sky looks like in a normally exposed image (1/250th at f/10), processed using Adobe Camera Raw defaults (including sharpening at 25/1/25/0 and NR at 0/25), looks like:

And here, finally, is what an adjusted ACR process from the overexposed image looks like with sharpening turned off, NR set to 25/50, exposure and brightness determined by the simple process of using Auto (which can be set as a default in ACR if you want to consistently make generous – over – exposures ‘to the right’):

This is much more how I expect to see a sky looking from the base ISO of a 2009 DSLR release, viewed at 100 per cent. From this stage, different types of sharpening can be applied to suit resized versions for different purposes.

Results with other raw converters, as more become available for the Alpha 550, may be finer in noise structure than ACR or may offer less scope for overexposing – ACR is well known for its ability to recover highlights. I do not intend to go much further into this with tests of converters, but I hope I have shown how the ‘true ISO’ of the A550 is difficult to pin down especially in Auto ISO mode, and how it is possible to benefit from the great high ISO performance of the camera (just use it!) and at the same time secure good low ISO results for travel and landscape shots where a clean blue sky is important.

It’s important to note that in-camera JPEGs will not necessarily show similar noise levels. If they do it’s not so easy to fix without using NR software. I prefer to shoot raw for many reasons.

So, why not be very happy with the Alpha 550 as a choice? Here are two pictures. You can view the full size Alpha image, and the Nikon D3S image resized to match 14 megapixels, by clicking on the smaller size here. Of course the Nikon image is better, though 1/250th at f/5.6 and ISO 400 is more of a step away from 1/250th at f/9 and ISO 200, and I’m not sure the light was SO different on the two occasions:

- DK

According to Sony UK, the Alpha 5oo and 550 were shipped to UK dealers starting at the beginning of this week (October 19th) – though calls to WarehouseExpress, and to our local Edinburgh Sony ACE dealer, produced no knowledge of the new cameras. WE said that they expected the camera ‘hopefully within the next month’ and Edinburgh Sony Centre Shandwick Place said ‘we will have it in stock on October 29th’.

Paul Genge of Sony UK confirmed that deliveries had in fact been made by October 22nd to selected dealers and that ‘both cameras have been available since the beginning of the week’.

However, a Google search showed no for sale items except Hong Kong based grey market shippers. WarehouseExpress still showed a pre-order status for the Alpha 550 and its kits. We have been trying to obtain one for the past two weeks, as review samples were not available. The initial report in Photoworld magazine has been completed with the help of our Photoclubalpha subscribers round the world who already have the camera, and will appear in the edition printed next week.

UPDATE: Monday October 26th – WarehouseExpress had bodies, 18-55mm and twin lens kits all in stock this morning.

- DK

I don’t have an Alpha 500 or 550 here yet, even though Photoclubalpha has been second in the Google search results for ‘Sony Alpha 550′ for some time and remains so as I write (the New York Times is first). That’s not bad for a Wordpress blog website which does NOT employ the services of the dozen or so ’search engine optimisation’ experts who contact us each week! Hopefully we’ll have a review camera very soon, preferably the 550.

In the meantime, a few samples have been posted on various sites which show the raw conversion engine of the camera/s (not necessarily the JPEG compression stage, as always seems to be assumed) has been radically revised. Sony call this ‘enhanced BIONZ’ and I think there’s a clue to how it has been enhanced in the relationship of Sony Europe and DxO Labs, the French company which specialises in in-camera process analysis and development.

SONY has a stand at Focus on Imaging in the UK after an absence of three years for the Alpha brand from this major annual photo fair, said to the be largest national show in Europe with the exception of photokina. On Stand L28 – right next to the Canon exhibit – the UK’s technical sales executive Paul Genge has lined up a nonstop programme of speakers and demonstrations.

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 Alpha 900 – and indeed the Alpha 700 with new firmware v4 – offer a three-bracket sequence at a 2 stop interval to enable HDR blending, usually from static tripod-mounted views. At the Edinburgh Alpha 900 launch, I braced myself firmly against an open window, leaning out over the street, and tried an example hand held.

Sony has released – without announcement – a new firmware version for the Alpha 700 which includes an OFF function for high ISO. This is presumed to be in advance of tomorrow’s press conference, where the Alpha 900 will be revealed. Journalists could be expected to ask questions about the NR, and the lack of firmware upgrades to the Alpha 700, and they have acted just in time for this launch and photokina to remedy the situation. Article with image samples and download links:

There seems to be a lot of speculation about the Alpha 900 or Pro, and uncertainty about the timing of introduction. The August 14th date is not the 900, it’s two Cybershot models. The Alpha 900 will, as far as we are aware, be shown to the press on September 9th/10th worldwide.

The Sony DSLR A200 is now on sale, following the end of Alpha 100 production. Although it is without any doubt the Alpha 100 replacement mentioned by Sony executives in October 2007, when they first revealed that the 100 was no longer being made, it is not an exact equivalent and represents a mixture of upgraded performance and simplified specification. Because it has gone in two directions at the same time, the A200 poses a problem for A100 owners.

AT THE Consumer Electronics Show, Las Vegas, Sony has announced introduction of the new Alpha DSLR-A200 camera which has been the subject of some strange speculation but was known beforehand to be a replacement for the Alpha 100. This is the first time a DSLR has been launched to the world at this show, and Sony’s decision to do so sends a major signal out as to where they see themselves and the Alpha system in the marketplace. It is highly competitive in price and we have just ordered our body for £369 including VAT (£314 + VAT) plus £13 express shipping from www.sonystyle.co.uk. This is exactly the same price as we paid for our last Alpha 100 in summer 2006.

THE ALPHA 700 cameras tried in Italy by press representatives, including Paul Olsen of Dinside Data in Norway who sent us the raw and JPEG files for the image used here, may or may not have been pre-production samples. Some cameras which were felt to be poor had over 1,000 exposures recorded before the event. Olsen’s camera appears to have been new, recording frame counts in the 40s during his shoot, and may be a final production sample rather than one of the much-used demo bodies.

IT IS very difficult to find a good JPEG from the Alpha 700 pre-production model tests shot in Italy, because too few cameras were available for too short a time – and many of the journalists present were not photographers. But we have found one image you will love.

I know that many of you expect a full detailed report about new Alpha 700 (writes Damir Tiljak). Unfortunately we had limited time to spent with new camera, which left us with just a few impressions. Good news is that most of impressions are positive. Although Sony rates this camera as their ‘advanced amateur’ model, I am sure it will be suitable for semi-professional or even professional use in fields like wedding photography.

THE PROBLEM of darkened extreme corners with the 16-80mm CZ Sony lens definitely exists. They are there in many of my shots, with or without SSS anti-shake enabled, significant softly darkened corners. Everyone is saying this must be due to filters, and at least one of Forum regulars has emailed Zeiss about this issue (and got a reply almost admitting that the lens falls short of ideal design). But is it?

A review by David Kilpatrick from Photoworld Spring 2007 with additional updates

MY SONY Carl Zeiss 16-80mm “superzoom” arrived from Warehouseexpress – the best price I could find and one of the very best dealers in terms of service – packed rather minimally for a £465 purchase.