Hi,
I used to regard Lloyd Chambers "diglloyd" site as an excellent source of information. I don't subscribe any longer, but I have every reason to believe that it is still an excellent source.
So why I don't subscribe any longer? The answer is in part cost versus value. Lloyd's web sites have a lot of very good information, but once you have read them they just serve as reference. Lloyd still creates a lot of new content, but it is spread over a large number of sites. I would gladly pay 50$ a year for the whole set but not 250$, because I don't think there is enough new info.
But, there is another part - which I feel is worth discussing - and that is about openness, discussions and writer responsibility.
I have some background in the scientific community, having some unfinished postgrad studies in neutron physics and after that working a few years in commercial research. Science is much about sharing observations, publishing findings and having them challenged by a knowledgeable community.
I find the restrictions put up by "Diglloyd" a bit to restrictive. Obviously, "Diglloyd" sets the conditions, but I feel that not having full disclosure and no open discussion diminishes the value of information.
So, what do I mean with full disclosure? To begin with access to the raw files, with reasonable restrictions. I got a set of Leica S2 raw files from Lloyd and he was kind enough to let me write down my observations after reviewing my article. I was fine with that.
Not really a disclosure question, but I feel that there needs to be a discussion. If you draw conclusions they may be incomplete or even possibly entirely wrong.
Let's look at some of the more disturbing things Diglloyd wrote about.
1) Lloyd has found that tolerances were an issue on many camera systems. That finding is probably a bit uncomfortable, but probably quite true. The cause we often don't see those effects is that we are not used to critical viewing of image detail.
2) Another issue Lloyd often found that it is difficult to achieve critical focus. Autofocus is not accurate enough and manual focus is also difficult. This is also probably quiet true. Contrast Detect AF is often dead accurate and magnified live view can achieve perfect focus, at least in theory.
So, Lloyd indicated that quite a few camera systems could not deliver on AF (or MF) accuracy, that included some Nikons and Canons, the Sony Alpha 900, Leica S2, Pentax 645D, Leica M9 and M240 and few others. On the Leica S2 he indicated that of five series of shots two were usable.
These findings are not pleasant, but may be quite true, unfortunately. But there is more to discuss
Leica S reactionDiglloyd also has a blog, which he uses to inform about his commercial writing. This posting is worth reading:
http://diglloyd.com/blog/2010/20101221_2-LeicaS2Focusing.htmlAt that time I was subscribing to the Leica pages, mostly because I was subscribing to DAP before Leica was spun of as a separate "site". So I had access to the full article.
A couple of years later Diglloyd published another posting on his blog:
http://diglloyd.com/blog/2015/20150728_2330-LeicaS-autofocusError.html evoking strong reactions from the Leica community. Being aware of Diglloyd's former findings I posted some support for his view. The problem is that he posted a link demonstrating the issue on his pay site:
http://diglloyd.com/blog/2015/20150728_2330-LeicaS-autofocusError.htmlI sort of considered subscribing to check the information, but I have a marginal interest in the Leica system, and Lloyd's conditions would not allow me to share substantial information, anyway. I felt uneasy about the issue.
The Sony A7r, shutter shock issueDiglloyd was the first to discuss the Sony A7r shutter shock issue. That was unpleasant news for Sony folks and it has been confirmed by many other testers. Lloyd suggested some measures to mitigate the problem.
I really felt this was good information from Diglloyd. The vibration was caused by the opening and closure of the first shutter curtain.
There was no way to fix the issue in firmware. My opinion was at the time that the A7r was premature. The A7 had electronic first shutter curtain, but the A7r did not.
Yes, Diglloyd did a good job on this, although I wish he was not asking for a firmware fix, that probably not was possible. Some bright engineer measured the vibration using a voice coil and an oscilloscope, clearly demonstrating that opening the first shutter curtain was the cause of vibrations.
Now we get on to the Sony raw compression issueAs soon as the Sony A7r arrived Diglloyd discovered the "orange peel" artefact. He early on decided that the cause was Sony's raw compression. So he started a crusade against Sony's raw compression.
Now, Sony's raw compression is twofold. The first part is using a tone curve. Nikon uses the same technology and it is explained here:
http://www.openphotographyforums.com/forums/showthread.php?t=5499This compression is lossy, in the sense that a bitwise copy of the original cannot be built from the compressed image. On the other hand the information that is lost is essentially noise.
In addition Sony has a "delta encoding" based on 16 pixel segments. This delta encoding is mostly OK, but can cause artefacts on steep lumination gradients:
Jim Kasson has a long series of articles on the issue, this one gives some insights:
http://blog.kasson.com/?p=4854The someone mentioned on the first line happens to be me…
The issue is really that in all probability the Sony raw compression scheme cannot cause the "orange peel artefacts". So what is causing those orange peel artefacts? The way to find out is to analyse the raw files, use different tools and different raw converters. I asked and got access to some of the raw files where Lloyd has found the problem, under his quite restrictive terms. I did my homework and could identify the problem and asked Lloyd for permission to share my findings. He was not very positive to that…
So what were my findings? Sorry, I cannot share. Diglloyd's conditions…
That takes us to another question, writer responsibility…I feel that if you publish on the Internet you have some responsibility. For me, the proper way is sharing all information, including raw files and also being open to discussion. Things are seldom white or black, true or false. Real world is a continuum...
Interestingly, sites like DPReview and Imaging Resource fulfil reasonable requirements, not to mention a lot of serious bloggers.
Best regards
Erik