All posts by Jonathan Crowther

Large format digital imaging with LargeSense backs

Some new photographic products have obvious uses and markets, others, well, other that come along, can be a little more difficult to categorise.  I came across this recently, a company in the US making a large format digital camera back, which to me falls in to that latter definition;

http://largesense.com/

What they are doing is taking the concept of a type of photography with its roots in wet plate gelatin and bringing it bang up to date.  Imagine being able to use those fantastic old plate camera lenses, and to be able to control the perspective and plane of focus through the use of manual controls, combined withe the convenience of digital imaging.

Of course you may well be asking, why bother?  For me the key thing is pixel size, and the increase in the signal to noise ratio that goes along with that.   Add to that the fact that they are making monochrome cameras with no Bayer filter or microlenses, and this is getting very close to a digital emulsion layer.  The monochrome camera should be great for IR and even UV (depending on the cover glass they end up using for the sensor), making this a tool with huge potential.

So, taking all that into account, very much a purists camera.  However if the purist wants one, they will need to be well funded, as they are not cameras that will be made in huge numbers or be cheap to buy.

To be honest I find the concept amazing – to see someone push the boundaries of what can be developed like this gives me hope in the future of the art.  I wish LargeSense LLC all the success in the world, and I hope they continue to push at the edges of what is possible.

#LargeSense

New optical transmission measurement service

Need a rapid and cost effective measurement of the optical transmission properties of something?  Maybe a camera filter for a graph to provide data for a paper you’re writing, or do you want to know whether your product you’re interested in marketing which is supposed to block UV is actually doing so?  I now offer a light transmission measurement service.  Read more about it here, along with some examples of the type of things I can measure.  Contact me to find out more…..

Hasselblad Zeiss UV Sonnar 105mm – The Sonnar has landed

A very special lens has arrived in the lab, a Zeiss Hasselblad UV Sonnar 105mm f4.3.  Consisting of quartz and calcium fluoride lenses, this was one of the ones designed for space exploration work with NASA.  An amazing piece of history (manufacturing date shows this is one month younger than I am, so unfortunately it would have never made it to the moon), and now to be used for my UV imaging work.

Black 2.0 – optically neutral matt black paint

I recently found myself needing a black paint for a project I was working on that would be a) very absorbent of light, b ) as neutral as possible over a wide range of wavelengths, and c) be cheap and readily available. A chance conversation with a colleague put me on to Black 2.0, which is a paint developed by a UK artist Stuart Semple (http://stuartsemple….k-art-material/). This is supposedly extremely matt black, and there’s a fascinating story behind the development of it, which is highly typical of the art world and makes for a great read (put simply, it was developed to provide the wider art world a really black paint, after a UK company developed something called Vantablack which absorbs more than 99% of light, and then restricted who could buy it to scientists and one artist in the UK).

Anyway enough of the back story – just how black is Black 2.0? Given I have access to a nice UV Vis spectrometer I got hold of a sample of this material, painted it onto some white card, and compared the amount of light it reflected to a the black tile on a X-rite/Gretag Macbeth Colour Checker chart (old version, pre November 2014). And this is what it looks like;
Attached Image: Full range blacks only.jpg

I was very surprised to see Black 2.0 reflected less light than the X-rite/Gretag Macbeth Colour checker chart black (GM black in the graph).  So it’s blacker than a black photographic standard – the proverbial black cat in a coal cellar.  Needless to say I was very impressed with it, as it fitted my key requirements (neutral, low reflectivity, cheap and readily available), oh and smells of cherries too. All for the princely sum of £12 for 150ml, which they reckon is enough to cover about 1-1.5m2.

Check out this paint and Stuarts work at http://stuartsemple.com/art/

 

Arrival of Asahi Ultra Achromatic Takumar 85mm f4.5 lens

I am very excited to have recently acquired an Asahi Pentax Ultra Achromatic Takumar 85mm f4.5 lens.  A bit of a legend in the imaging world, this extremely rare lens was made in the late 1960s using Calcium fluoride and Quartz elements, and is chromatically corrected for imaging in UV, visible and IR regions. Look out for a more detailed review in my ‘Techniques’ section soon.