Tagged: crop

10th November 2016 – Ann Cook and Carnivals

Anne Cook made a welcome return to Reflex with another illuminating talk that was, let’s face it, fun.  We can’t always locate the terms guest speaker and fun in the same sentence and whether we learn anything apart from the hardness of chairs that children are subjected to in modern day education (chairs, damn it, the cold hard floor was what we  got, etc etc) is not necessarily a topic we need to travel to club to speculate on.  The feedback from members was particularly effusive which is always a good sign.

 

Ann showed, amongst many other fine examples some images taken at carnival, which is particularly apposite to this time of year as we are coming to the end of the Somerset season. The last one on the Somerset circuit is at Wells this coming Friday (18th November 19:00 get there early). Having attended the Burnham-On-Sea round this year I can definitely affirm that it is something well worth making the time and effort, if you can get there.

 

So we are going to look at taking photo’s of street processions at night. The most obvious thing is that we are talking of photographing very high contrast scenes, that are moving, admittedly slowly, that  can look distinctly two dimensional as brilliant point of light swim through a sea of black, which generally require high ISO’s to get reasonable shutter speeds and some interesting metering challenges.

 

There will be the large floats, some a part of a two three or four articulated trailers, but there will also be smaller floats, hand carts and individuals decked out in lights, there will be groups and there will be all sorts of other wheeled and ambulatory traffic. Variety is not short at these affairs and the lights are the main attraction.

 

The basic answers to these conundrums is to crop tight, centre weight or spot meter and expose to the right.

 

Cropping tight means we are likely to even out the overall exposure in a reasonable amount of the frames we capture. We will still get areas of high contrast and some of them will still have totally blown out areas of white and areas of inky blackness, but there are a significant number where we can limit the dynamic range some. This can put more emphasis on the mid-tones but whether  that is a good or a bad thing is a matter of taste and of colour.

 

Metering these days is a lot smarter than it was five years ago. Leaving our camera on matrix / evaluative (basically our cameras approximation of the whole frame)  isn’t necessarily a disaster, modern algorithms are pretty good at drawing conclusions that prove to be reasonably “accurate” (they are accurate but that has to be measured against our expectations) but  we are talking an average balanced somewhere between the highest and the lowest value.  Most cameras have the opportunity to switch between two other modes that increasingly ignore larger parts of the scene.

 

This gives us more  information about a smaller part of the scene that we have judged to be more important. How do we know that? Well we’ve pointed our camera at it and taken notice of what effect this has had on our suggested exposure triangle settings. This is either  because the scales in our view finder for shutter/aperture or under or over exposure are indicating a problem or the scene in our EVF is too dark or too light. What the camera has done is taken all the zones programmed into it and set these against where we are focused to give the reading a final weighting. There are other considerations but these change form manufacturer to manufacturer and can incur consideration such as colour, highlights and so on – Nikon use a comparison data base of shots of similar light/shade characteristics. This is common to Evaluative and centre weighted modes.

 

More so than fancy names for “Taking-the-whole-frame-into-consideration”, centre weighted does what it says on the tin. It takes the information in the centre of the frame into account either severely downgrading or completely ignoring the information on the outside of the frame.  It doesn’t, by and large take notice of the focal point, instead just giving it a general, centre balanced reading. By restricting the area taken into consideration, prominence is given to the area more likely to include the crux of the image.  Good when the boarders contain light that is in strong contrast to the main subject and might otherwise have undue influence on the final decision.

 

Spot takes the central are only, around 2% of the frame, around the focus point. Everything else is ignored. Photographing wildlife or Super-moons (or just the plain old ordinary moon which in the carnival context is a lot more apposite) benefit from this. Taking the moon in particular, the difference is a blown out image using the evaluative or centre weighted options because the light reflected from the moon is many, many times stronger than that which might be bouncing around the rest of the atmosphere. The argument in the wildlife example stems from a similar situation, say in the question of a bird in flight where it will be darker than the sky it is set in, or for the variations between fur and the cover it is in or breaking from.  A characters face in comparative dark to the lights of a float with, potentially, tens of light bulbs throwing a shadow, yields a similar situation. Our meter might read the scene but in ways only remotely related to the way we see it.

 

Exposing to the right in itself gives no clear clue as to what exactly it is we are talking about. It relates to the histogram (posh name for graph) that we find somewhere in our camera’s menus and which we can turn on so that it appears in our camera’s live view and or view finder (depending on make and model). Pretty much every camera has the facility including some, but certainly not all, compacts and is also referred to as ETTR, even in polite company. The way the histogram is set out the shadows are on the left and the highlights are to the right. We don’t want spikes at the extremes of the scale because that tells us we are producing images that are heavily under or over exposed. Fine, but only to a degree, if we are shooting high key or low key portraits or similar.

 

What we want, in an ideal world is for there to be a fairly even shaped curve in between the two extremes of the histogram. That gives us an image that is evenly exposed. Of course this depends on the lighting of the scene and in extremes we know that shadows are more recoverable than burnt out highlights (if it is truly burnt out there is no useable information there to recover). Therefore we expose deliberately for the highlights in the picture and recover the shadows in post using whatever editing programme we have access to.

 

Of course it is a matter of personal preference, some people are dead set against the idea of ETTR, personally I find it useful, especially when someone else is controlling the lighting. In the studio we have more options and it entirely depends upon the sort of image we want to craft. The argument evolves around the number of tones on show in the image. If we are shooting a 12 bit RAW image we have 4096 tones available across the range. Each f-stop in our range (remember our meters render an average for the scene) accounts for twice as many tones as the previous one as our f-number increases. The brightest part of the range in the image accounts for half of the available tones, the next stop about half of that again and so on. The whole calculation takes place within the dynamic range of the camera sensor and that again is dependent upon make and model.

 

What happens is that by exposing to the right stretches out the details to the left and the more that happens the less smooth the transition between the dark tones, and we risk compromising the quality of the picture. That is why we need to look at taking pictures of the carnival floats in the context of the other two considerations we talked about above because the more we operate towards the centre of the cameras dynamic abilities the more leeway we have to accommodate the extremes of light and dark.

 

Go and enjoy.

 

N E X T   M E E T I N G

Kev Spiers and Rich Price on their return to Iceland.

28th January 2016 – An evening with Steve Hallam.

Last meeting was the territory of club member and treasurer Steve Hallam, talking through some of his digital history. Steve is an Olympus fan and has been for over ten years. Micro four thirds, the name come from the diameter of the sensor in inches, is the invention of Olympus and as Steve pointed out, the first system to be designed exclusively for digital from scratch. The first Olympus Steve owned had a 5 MP sensor , which when compacts these days can pack 20 Mega Pixels, sounds restrictive. In reality most people would be largely untroubled by 5MP sensors, the key being the quality of rendition not the size. More Mega Pixels give you more room to crop and still get a reasonable image. The ability to resolve reasonably accurate colours and the capacity to restrict noise at higher ISO’s are generally bigger factors in most peoples’ photography . The bigger numbers in terms of Mega Pixels are something driven more by perceived marketing needs (bigger must be better) than actual customer requirements.

 

For so long full frame, as Steve pointed out a tag rather than a technical term of any enlightening feature. The 35mm (actually 36 mm but that is a spurious accuracy) was of course the film size in most SLR’s and has carried over to the digital age as the most common “professional” size. I will come back to the need for the inverted comma’s shortly. In the film age, especially from the late 60’s onwards, 35mm was pretty much everywhere. Unless you were doing advertising or studio work then the frame size went up to 6 x 4.5, 4 x 5, 10 x 8 and so on. Hasselblads used 120 roll film (6 x 7 cm). Just like the Box Brownie. Only there was a bit of difference price wise. Also, it has to be said, there is a slight difference in quality too.

 

The reason for the inverted commas around professional above is that there is no such thing as a camera by which one becomes a professional by being in possession of. There is plenty to be said for the idea of a larger sensor – and some people bang on endlessly about it – but, as been said before in this blog, unless it is predicated on an actual photographic need then there is no reason why a professional has to shoot with a 35mm sensor. Damien Lovegrove doesn’t, as he explained when he visited us back in July 2014, he uses APS-C (among other formats I am sure). Any argument based on the logic of sensor size would have that a 6 x 4.5 medium sensor format has to better than a 35mm and so on. The question always has to be “At what”?

 

Lugging a D800 across Antarctica to photograph polar bears in the wild may seem like hard work, it is, after all a sizeable chunk of Bakelite in its own right. Adding in the heavy duty lenses adds even more bulk and that’s before you realise the nearest wild polar bear is 12,500 miles to the north (it pays to do your research). You had better have a really, really good reason for packing it in the first place. Well that would be weather sealing, shock-proofing, reliability given that it’s 2,500 miles to the nearest camera shop to replace that broken lens (assuming both that you are going North and turning left(ish) and Punta Arenas has a camera shop, otherwise it’s 3,700 miles in a completely different direction to Auckland). You may require very large blow ups at a high dots per inch count, there are any number of reasons you need a full frame camera, but , logically, not one of them is because you are a professional. Steve pointed out the main advantage of the Micro 4/3rds format is the capacity to build smaller, lighter cameras.

 

Smaller lighter cameras with smaller sensors, yet we still think of lenses in 35mm equivalent terms and that does make things easier for comparison reasons, but allows for some confusion. When we talk of crop sensors we are talking about the size of sensors relative to 35mm and as most sensors are smaller than this then we are seeing a smaller image given the same focal length of lens.

 

A confusion creeps in with the idea of “magnification” which a lot of people assume to be a telephoto effect because a 100 mm lens on a 35mm camera shows the same as a 150 mm lens on an APS-C or a 200 mm lens on a micro 4/3rds and the logic goes (off at a tangent but it’s easy to see why) a 200 mm pulls in the image twice as much as a 100 mm lens. Well when you double the focal length on the same size sensor it does, the mistake is to not factor in the change in the size of the sensor. If an image is made with the same lens, but a smaller sensor, it shows a smaller area. Enlarge both your 35 mm and you crop sensor images to, say, 10 x 8 inch print and the degree of enlargement, the magnification if you will, will be greater for the smaller sensor than for a larger one. Hence you might get an inkling of why more Mega Pixels on this year’s sensor than last sounds attractive – you can make larger prints without a loss in quality. Well sort of, as, after a point, those extra pixels start to get in each other’s way.

 

So, our thanks to Steve for bringing up some interesting topics and for sharing his images with us. Much appreciated.

 

N E X T W E E K

NOT AT THE CLUB. Light trails, meet at the fountains on the centre. Bring cameras and tripods we are going to be taking some light trails. 7.30 commencement.

15th October 2015 – We can edit too

As we approach carnival season, Somerset style (see below)  and the photo opportunities that creates, we spent last meeting huddled around various laptops editing in a handful of different editing programmes following on from Marko Nurinem’s virtuoso display last week. So there was Lightroom (of course) but also GIMP, Smart Photo Editor, Picasa, and Photoscape with CS2 (free from Adobe and all quite legal here is how to get it) ACDSee getting honourable mentions from new member Gary.

 

Now, you long term readers of this blog will know that the world divides into two camps, the Get-it-right-in-the-cameraista’s and Ye-Accolytes-of-Photoshop. As an avowed Get-it-right-in-the-cameraista I sure do a lot of editing. The argument is that the more you get it right for you in the camera the less fiddling around you have to do in post-production. In my case it comes from a youth spent shooting expensive slide film on a shoestring budget. In these digital days, when the hardware is still expensive but the marginal cost of the next image is a fraction of a penny, what that is really about is expanding the chances of achieving the image you want to capture. The principle categories in photo editing programmes are those that alter the fundamentals of the image and those that layer effects on. Of course the real world contains a bit of both usually, but the fundamental approach will be one or the other.

 

If you are shooting in RAW the images can seem a little flat and dull – remember that what you see in the viewfinder is either a reflected image of the actual light falling on your subject or, in CSC’s and compacts, effectively a jpeg. Sometimes a little cropping or erasing extraneous details make for a more satisfying final product. Maybe a shadow could do with lightening or a sky darkening to get back some detail, or a blemish on the skin would be more flatteringly removed from the portrait. Smart Photo Editor is the proprietary, paid for (£19.95 ‘on sale’ and a bargain stand alone and £34.95 as a Photoshop Plug in) programme I use and also Gimp and Picasa, both free. Others use other combinations, some paid for some free.

 

Your ambition may not quite extend to the do everything Photoshop (yet at least) and I will venture two reasons pecuniary why you may not, one more obvious than the other, viz: (A) you don’t have the set up or space or need for it to make the most of it and (B) Zombies. The former is more obviously expensive than the latter, and I don’t want to get into an endless and ultimately fruitless kit pornography rant, so ’nuff said, but the latter can have quite an impact on the pocket. Let me explain.

 

Fortunate as most club members are to be living in a city that has an “Official” policy for handling of a Zombie outbreak, that isn’t quite what I mean – though there are worrying sightings. Zombies are those little items, small denominations, that walk out of your bank account every month without much thought. In isolation they are not a lot. Their attraction is their affordability, the trade is made worth it by the perceived quality/quantity you get in return – at the point of purchase. You get a lot of things with Adobe’s Creative Cloud for photography for £8.57 a month, no doubt. A more detailed and flexible programme there is yet to be brought to market, though the gap may be closing. It is, I suspect, a lot more than most amateur photographers need, but it’s always nice to have some extra wumph under the bonnet. If it wasn’t no sports cars or sports bikes would ever get sold. For a vocal minority bragging rights are always the primary concern.

 

That, though isn’t quite the point. Are you going to pay (and keep on paying) £102.84 straight out on something you might need? No? But might pay £8.57 a month on something that is more than you need, something you can expand in to. It’s there and it ticks over and you get used to it. But, when is it just one item? When it’s a couple, or three, it grows. £20.00 a month isn’t a lot to spend on a hobby, say on editing and storage. £240 a year is not an inconsiderable amount to waste. Certainly less than a divorce lawyer when the other half finds out how much you really spent on that camera body. That’s halfway to a very decent new lens or a goodly second hand one even on £20.00 a month. The zombies keep on walking and are easy to add to, easy to forget. The costs add up. On the other hand it keeps you up to date and Adobe get a steady revenue stream, pirate copies are fewer and far between. Easier if you are self employed and you can claim it against tax, of course.

 

Not that I am seeking to dissuade you. The reality is Adobe first, the others a long way behind when it comes to sales and it is a de facto industry standard, which in itself generates market share for Adobe. Our focus, though, was on a broader range of editing opportunities as well as Photoshop. We looked a little at the alternatives to Photoshop on the Ask Reflex evening, this evening was a chance to get closer to the subject. From a little tour round I would say that there is a great deal that you can do with a little practice, patience and occasional lateral thinking as members showed how they adapt what they have to get what they want.

 

There is another benefit to using editing software that may not be immediately apparent, at least at the time of shutter release and really is about getting your money’s worth. Through cropping your original image you can often find more than one image possibility from a given frame. (Don’t confuse image crop, cutting out bits of a bigger picture with sensor crop the physics of collecting the same amount of light on different sized sensors). You effectively recompose the photograph, albeit with less data in it. It might be that the light and shadow falling across a landscape actually yield two very different moods when you isolate each area and you now have three opportunities from one frame. I would say that, in work flow terms, cropping is the first thing that you do, because you have the essential character in view that you want to work with. The crop is basically a magnification of the connection that drew you to take that frame in the first place. There are frequent chances to re-crop a frame rarely do we crop so tight that there isn’t any wriggle room and even then, sometimes, going more extreme tells a different story. Of all the editing you can do this is perhaps the simplest and the one with the biggest potential, which is why I would suggest it’s the best place to start the editing.

 

SOMERSET CARNIVAL DATES

follow the link as it will show you the dates and also has descriptions of themes. Click on the individual carnival websites for start times etc. Below is a copy of Myk’s post on the club Facebook page:

“This year’s Someset Carnival season is almost here. If anyone would like to attend one of these events as a group, please see the dates and locations below.

We’ll be making announcements on club meetings so everyone will get to hear about it.

Monday 09/11/15 – Burnham on Sea
Friday 13/11/15 – Weston Super Mare
Monday 16/11/15 – Midsomer Norton
Wednesday 18/11/15 – Shepton Mallet
Friday 20/11/15 – Wells
Saturday 21/11/15 – Glastonbury

The preferred date/venue is Wells on 20/11 as they have market stalls, hot food/drinks and a fairground in the market square”.

 

NEXT MEETING

Reflex Open Competition Round 1.