your camera's dynamic range

I need a sunny day to do this exercise and as there are none of these around at the moment, I will leave this to one side and carry on with some of the other exercises.

I have also being doing some research on photographers whilst I am waiting for the weather to improve and whilst reading 'Professional Photographer' magazine I cam across an article on the photographer Rankin, my thoughts on this article and some of his work are under Photographers I am interested in.

I have been reading The Digital SLR Handbook in particular the article on Dynamic range, and I noticed that it explains how to check your cameras dynamic range using a grey card as this is something I do have I will attempt to use this to check the range of my camera, having read this article I can now understand a bit more how to measure the dynamic range of my camera and I think this way will be more effective for me to look at.

Well the weather is still against me its got worse if anything I had a very small window to try and take the photographs I required for this exercise and although I am not completely happy with them its got to the stage that I am concerned I will start to lose the momentum if I don't get back into it very soon.

The first photograph measured  F10 1/400's  with the brightest spot measuring between 245 and 249 on the three channels. The shadows were a bit more difficult and I could only get them to measure between 16 and 33 I would have liked to have got this a bit closer to five. I measured the shadow at the top of the door as it was the closest I could get to what I wanted.

The second photograph I spot metered the white at F16 1/1000's and the highest measurement I could get this time was all three channels measuring 225.

The third photograph had no shadow detail left as the sun had gone in and I had lost the small window again, I then tried to do the other exercise I mention on here but again I couldn't get the two extremes correct. I guess I will have to try again if we ever get any decent weather.!

 

Well the weather has improved a little bit and I have managed to have another go at this exercise I can't say I am still completely happy with results as it makes my cameras dynamic range about 8 but having done this exercise in the past on a sunny day using the grey card method I know my camera's range is 10.

Here is my second attempt  below;-

This first photograph was average metered to F10 1/400's there was a tiny amount of highlight clipping to the white board but so small an amount it was negligible.

The second photograph was done by spot metering this measured F16 1/1000's with the white measuring R250 G 251 B 252

I had used my zoom on this to concentrate just on the white area.

The third photograph was again spot metered to F6.3 1/100's in the shadow area again I used my zoom lens to concentrate just on the shadow area, this photograph I am not really happy with as I think I should have kept the door closed a bit further as it is difficult to see too much shadow area.

Overall I am still not completely please with this exercise but as I understand the principles I feel I need to move on with the other exercises rather than keep hoping that the good old British weather is going to help me out.

 

Your tolerance for noise

The idea of this exercise is to check out the range of iso on my camera and also to look at the amount of noise and how it affects a photograph as the iso gets higher.

I use a nikon D300s and the range of iso on that camera is between 200 and 3200 but with the option to go three 1/3 ev stops either way in special conditions.  I decided to include these as well in the exercise and picked an aperture of F5.6 and began taking the photographs, as this exercise needed to be indoors and I had no white walls I finally settled on using my backdrop with a small red chair and teddy bear on it. This way I had some sharpness in the form of the chair to look at plus the white backdrop and also I thought it might be interesting to see how the 'fur' of the teddy bear reacted to the higher iso.

Above is the range of my camera, the one photograph came out very dark the only thing I can think of is that the sky clouded over slightly more for a second.
Having looked closer at the photographs I could see that there was no noise until the iso got to about 800 from there it started to get progressively worse, and by the time it reached the highest iso on my camera the effect was so bad it would render the photograph useless, not only could you see the deterioration in the white background but also in the chair and  it was very evident   in the fur of the teddy bear where there was some much noise the detail was lost.

these two photographs show there is no noise present in the lowest iso which is probably about iso 75 at a guess.

the three photographs above are the highest iso in my camera's range, I have included the photograph of the bear as I think the noise is clearer in this photograph than the one above.

ISO is also the third way of adjusting the amount of light that is let in, after the aperture and shutter speed, sometimes using a high iso and getting noise can add to the image, for example a band photograph might like the slightly 'gritty appearance'.

Interestingly I brought the April edition of Practical Photography and in it was an article on iso and grain they also had three photographs of coloured pencils at various iso settings which gave me another example to look at, they also go onto say that sometimes noise can be used as an effect for example on some black and white work.

So what have I learned from the exercise? I have learnt that you can adjust the iso and it can be a useful tool to use, sometimes to a great effect but I have also learnt that there is very often a trade off when using a very high iso, I think the motto is don't be afraid to alter the iso when the need is there but use it wisely.

Highlight clipping.

Highlight clipping is where an area of the photograph is in danger of having no detail retained in it, snow would be a good example of where highlight clipping could occur and also a bright day with detail lost in the sky., you can check for highlight clipping on the back of most camera and it normally shows up by flashing, by checking on this when you take the photographs it gives you the opportunity to alter your exposure if needed.

For this exercise I need to take a total of five photographs one where the highlight clipping just appears, then the next one one f stop lighter then the next three decreasing the exposure by one f stop at a time, the first challenge at the moment will be to find somewhere where I can produce a contrasty image with the weather as it is at the moment this may well have to be indoors possibly a still life but lit so I can 'control' the exposure and therefore the highlight clipping.

Well I have taken the photographs I went for something simple in fact it was the light coming through a tiny window in my house.


This was the metered shot but as you can see there is only a very small amount of highlight clipping to the photograph, burning out areas and showing no detail to the light areas at all.

the second one was taken at one f stop lighter this time the is a much larger area of highlight clipping and a much larger burnt out area with no detail, there is a slight colour cast and less definition to the flowers

the third shot is taken at one f stop darker than the original this time there are no clipped highlights and no areas that have lost detail around the flowers.

The fourth shot was taken at two stops darker than the original  the photograph is really getting dark now but detail is visible in the window that is missing in the first couple of photographs.

the fifth shot was taken at three stops darker than the original far More detail is visible in the window area, but the colour saturation is wrong on the  rest of the photograph.

It is difficult to talk about loss of saturation as the window is clear or frosted rather than a light colour I would like to re do this exercise with my black and white cat as I feel that it will be easier to examine the effects of highlight clipping in the mean time I will process the raw files of the other photographs and see what happens to them.

Below is the photograph with the recovery tool used however I don't think the effect can be seen too clearly on this photograph so #I have also taken the photograph taken a t one f stop lighter and used the recovery tool on this to a better effect.

i have taken the recovery slider about two thirds of the way along the scale and it is possible to see that some of the detail in the glass is now visible for example there is a leaf pattern in the glass which can now be seen.

Sensor Linear Capture

 For this exercise we need to take any JPEG or TIFF photograph open it in photoshop elements convert it to 16bit and then make a curve, this is a bit of a problem for me I have photoshop elements 11 but I can neither open the photograph in 16 bit ( although I am wondering if it is already showing in that) or find the curves control, I was under the impression that this was still missing from elements, so the only thing i can really do with this exercise at the moment is read through everything and try to make sense of it that way, I do confess I would much rather work it out step by step but I am unable to do this at the present time.

I always shoot in raw and jpeg and now have always know that raw files need to be 'processed' what I didn't realise was the work that happens 'behind the scenes in the camera' to help capture the detail that will be needed later,
I have since found out that I can do this exercise the notes are slightly round in the folder and I can't convert to 16 bit, but I do have a kind of curves and having located this I set to work with the image of a boat taken back in the summer.

The first one is the original JPEG and the second one has been darkend then lighten again to try to recreate the original picture, I found this interesting but quite challenging to do it may be because I don't have the proper curves facility or it maybe because I haven't had a lot of practice with it, you can see the noise in the darker shadow area of the boat, but  there is not too much on this image.

Editing

for this exercise I need a set of at least 50 shots all covering the same theme or location, I chose a country park not too far from where I live, the day I chose was one of the coldest days so far this year some snow had fallen and more was forecast.

Wrapping up well I set off and found the chosen location then set about walking along the path taking photographs as I went, I didn't realise quite how cold it was until I got home and uploaded my photographs and saw the amount of camera shake, I was unable to use a tripod and I don't have a mono pod so I guess this result was pretty inevitable.

From the technical edit as I said I put a lot of shots in this folder, I then went through the rest of the shots and started to pick out the ones I liked, a selection of which are below.

From these I needed to select the first selects this took me a bit longer as I needed to decide why I like them.

The first one I like as it shows a birds foot prints something I tried very hard to find as a nice clear shot  .

Photographs two and three are both of different paths but as both show the path disappearing I hope it makes the viewer wonder where the path leads.

Photograph four is of an old wreck on the mud flaps, its quite hard to see these once work horses left to rot and there are plenty of them along the shore line and out in the mud flaps.

Photograph five I just liked the arrangement of large rocks with the grasses behind them.

the final three photographs I picked out from the rest of the selects as they showed off the mud flaps and the patterns that are formed by the water running along them, and also the one shows an inlet.

Overall I picked these photographs as showing a slight arty side to some which is something I would like to develop as I go through the courses, I did take some shots which I deliberately blurred but these I have kept back for another time and my own use at the moment.

The next step means taking a break and then looking at the photographs again with a fresh eye to see if I still agree with my selection.

Well I have taken a break and having left it a few hours I have looked the shots back over  and have picked my final two shots.

My first choice is the one I have called 'wrecked', it was an extremely cold day as I have previously said and this shot just shows what the weather was like. I have done some small adjustments in elements I adjusted the clarity increased the contrast, hue and saturation in levels and did a small amount of burning to the sky to try and bring out some detail, but it really was a featureless sky that day.

The second one I have called 'mud' I liked the way the water have formed patterns in the mud flaps I also liked the gritty look to the mud and the fact it was almost colour less apart from the small patch of green two thirds of the way up on the right hand side.

One of the books I found to be very useful was Design Principles 01 details are in my reading list, I liked the photograph by Jeremy Webb of Hemsby Sand Norfolk and the simplicity of the sand there was no real colour to it but texture and light it was the inspiration behind my mud photograph.

Exercise Histograms

Having completed the first two exercises and looked at the histogram exercise I have decided to have a break from it until after Christmas as with everything else going on and it being a tricky subject to get my head around completely might not be able to put the amount of time into it as I would like, although having said that I have read through the exercise and if the opportunity crops up I will take the shots but I won't be going out especially to take them.

Well Christmas is over I have had a rather large birthday and its time to get back to work, I have had many attempts at this exercise  and although I am still not completely happy with the images I do understand the importance of a correctly exposed histogram,

The first one is the low contrast one I thought this would be fairly easy to do all I needed was a scene with little tonal change that was my first mistake, I took many photographs checked the histogram on the back of the camera and deleted them, finally starting t o get a bit despondent I decided to photograph fence panels not exactly exciting I know but it was the results I was mostly interested in.
below is the histogram taken from the metered reading

This was quite strange in that the histogram on the back of the camera showed all three colours together where the red is on this histogram but the colours are correct in relation to the actual colour of the fence.

Photograph two is + 1 stop and the histogram looks much more like the one on the back of the camera but the colour is wrong, detailing is also lost.

Photograph three is - 1 stop and this time the colour is much darker the histogram is much closer together and more detail is shown.

On all three photographs there was no clipped highlights.

Average contrast

The metered shows there is more of the photograph in shadow but there are no clipped highlights on the photograph and no shadow highlights either.

The next shot is one stop lighter this time there is quite a bit of clipped highlights and a small amount of shadow clipping. How ever the histogram looks more evenly spread but the image is not true to the day.

The final image is 1 stop darker there is plenty of shadow clipping and the histogram is mainly to the shadow side, I quite like this shot, although I would have liked slightly more detail to it maybe it would be worth dialling in 1/3 stop from the metered one.

Finally the high contrast shot.
I was surprised how difficult this was to shoot, but trying to get the right conditions in the winter when its been really gloomy and hardly any sun was interesting to say the least. I finally decided to try and set something up in side.

I used a white glass and a black beaded arrangement hoping that because of the contrast in the two colours ie both ends of the histogram I might get something useful from it, the first one shows no clipped highlights at all although you can see that the main part of the histogram was to the right hand side. Pattern is reasonable clear and fairly like the original work.

Photograph two which is one stop lighter, this time you can see the clipped highlights area although I would have expected to see this slightly larger, the detail of the glass has almost disappeared.

Photograph three taken one stop darker and this is the most like the original set up, the glass can be seen clearly there are no clipped highlights, probably the best of the three shoots.

I am glad to finish this exercise not because I didn't understand it or don't appreciate the importance of a correctly exposed histogram but more because of frustration with weather conditions and not getting a bright day which would have helped with the high contrast photographs and when we did get a bright day I was in my day job.

Part one Workflow Exercises one and two

As these two exercises can be combined with others in this section I have decided to write about them both together.

For both exercises I need to plan and then put into practise a work flow that works for me.
My starting point is to read the section on work flow in 'the digital SLR handbook by MICHAEL FREEMAN' further details open this book are written about in the page on reading materials.

I have taken the photographs for the second exercise first although I still intend to document the exercises in order I just happened to be going on a day trip to London and it seemed too good an opportunity not to make use of.

Well its time to start the first exercise and here is my work flow, it will be interesting to see how I might need to adjust this as I go along.

Exercise one
This needs to be a portrait session and limited in time.
work flow pattern

• Find a location
• Check camera, are the batteries charged is there room on the memory cards, are the lenses cleaned and does the flash gun have batteries. finally make sure there is space on the hard drive or you have enough disks/ memory sticks to house the new photographs.
• Camera settings, I always shoot in raw and jpeg, but will i need a tripod and remote trigger, think about the shutter speed and white balance likely to be needed.
• Take the shots, check the poses and lighting looks ok, time this section to about 10 to 15 minutes
• Upload to computer
• Delete any really bad ones (out of focus, too dark bright etc)
• Give the ones left a number
• process these ones
• final selection process choose the best two to print use on website etc.
• Save on external hard drive and a disk labelled with correct title and date.
• Print photographs or complete upload.

So far as location was concerned I decided to use my home studio and bribed my mum to pose for me, I told her it would only be a 10 to 15 minute shoot and she was more than happy to help me out.
I had already metered the room and set the camera up with the correct settings in this case it was F11 shutter speed 125/s iso 100 and white balance set to flash.
I proceeded to take 30 photographs opting to take close up facial photographs and then just about from waist up.
The photographs were then uploaded to the computer and I checked through them showing my mum at the same time as she was interested in the whole process. There was a few photographs that I knew straight away I didn't like so I deleted those and finally settled on the ones I wanted to label then work on before making my final selection.

Mum 1

 

Mum 2

Mum 3

Mum 4

Mum 5

 

Mum 6

From the six above I finally decided on Mum 2 and 3 as the ones I would use, I should add here that I am sure my mum won't mind me revealing her age to be nearly 73 as I don't think she looks anywhere near to that, these are the best photographs I have taken of her so far and she was couldn't quite believe herself how good she looked.
The final two

In terms of how the work flow went overall I thought it went well, I have never had to rate photographs before and it took me a while to work out how to do that but once I had worked it out it was really quite straightforward, the next thing I want to try to work out is how to embed photographs with the information I know who to print them as a contact sheet with the information underneath but I don't know any other way at the moment so I guess its back to the reading books for me.

 

for the second part of the exercise I needed to do a less structured shoot, My husband was given tickets to the London eye as a birthday present and we finally decided to go (it only took from Feb to Nov for us to go), and the day we chose could not have been better for the actual trip however it was very bright making conditions for photographing more challenging.

I decided to follow the work flow pattern I had used before but with the added step of reviewing my photographs 'on locatation' and deleting some of them as I went.

I took about 80 to 90 photographs during the course of the day but on uploading them to the computer I choose about six or seven that I really liked. I noticed when viewing them on the computer screen that I could see reflections of people In the pods on the eye and have made a mental note that the next time I am doing anything like this I need to pack a polarising filter.

Below are my favourite four photographs

The settings used for photograph one was 18mm focal length, iso 200 f10 shutter speed 1/400's white balance was direct sunlight.

The settings used for photograph two was the same as for photograph one

The settings used for photograph three was the same as for photograph one

 The settings used for photograph four was 200mm focal length, iso 200 shutter speed 1/320's f11

again with a white balance of direct sunlight.

The post production I used was the same for all four photographs I opened them in raw checked the exposure and made any small adjustments to clipped areas and adjusted the clarity, I then opened them in elements and cleaned the dust spots from the photographs (my sensor had dust on it but has now been cleaned) then adjusted levels flattened the image then used the unsharp mask, before renaming the photographs and resizing them to use in my blog, the only other process I did was on the second photograph I cropped it as I felt there was a bit too much sky in it.

My overall thoughts on using a work flow rather than just taking photographs and then down loading them in a hap hazard way are that its less time consuming overall to be organised its easier to find the photographs looking back for them and by developing a routine you don't miss any thing out.