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Hi Paul.Quote:
Originally Posted by Paul
Actually was the same image as edited on the mac with no changes on the laptop which gave me the closest prints so far.
BTW have you used the datacolor spyderprint for printer profiles as wex photographic have it on offer at the moment so thinking of buying one...
So if image wasn't altered then its your printing software set up.
No never used datacolour so not sure how good it is.
Ps. Do not attempt profile laptop screen ;)
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We use Spyder and like it, and did when we did most of our work on a laptop (dell precision with very high res screen) had good results ... It's better to profile than not, but as long as you know it may not be as good as proper dedicated monitors.
Get a good monitor like an EIZO or a NEC Spectraview these show a good colour range not like cheapo monitors and even the glass in macs isnt that great these days. Use a decent spectrophotometer like an i1 if doing many profiles an automated is even better, The camera use a 50mm prime and get a polarising filter.
I do this a lot for a local artist using a nIkon d7200 , dont try and capture larger than around 20 x 30 inch as the lens wont handle it and youll get weird bending of the edges of your images, it was explained to me by a pro photographer but went right over my head as its wasnt about colour.
Polarising filters shift colours like crazy. Two soft boxes either side, take light reading, set up tripod, spirit level and shoot. They were my first studio jobs when I was training.
The way round this is to treat the image as a panorama, capture sections with a 30% overlap and process in Photoshop, always use the camera in portrait orientation as the sides of the image will be less likely to be affected by lens distortion (think oblong in a circle). I use a Nikon 105 macro which has almost zero edge distortion. Continuous lighting is required to maintain consistent exposure and of course use a tripod. If your lens has noticeable distortion, and you need to use both two or more rows of images for a large picture, then crop top and bottom of each frame but not the sides. Allow additional overlap. I also use a Spectraview + i1, £1200 about 5 years ago but once calibrated it makes wysiwyg a reality.Quote:
Originally Posted by mags1892
Well I have heard some myths in my time as a professional photographer but this latest group of suggestions forces me to speak out.
You do not need to treat your image as a panorama - that is a bad idea and will lead to all sorts of issues if there is the slightest difference between adjacent slices. Also, you need to use a lens in excess of the 'standard' focal length of the camera. Ideally this should be a 'prime' lens - one of a fixed focal length. If this were full frame 35mm (or digital equivalent) then I would suggest 80mm to 135mm as being the sort of lens to use.
There are a number of issues to contend with when copying. First is lighting and the lighting must be even. This is the simplest thing to achieve using nothing more than a wooden ruler. Subject must be absolutely parallel to the camera so, lets say for now both are absolutely vertical (use a level). Camera must be absolutely central to the subject so spend good time ensuring this is so and place an X in the centre of the artboard to help both camera alignment and, later, artwork placement. The least error will lead to keystone distortion where one edge appears longer than its opposite.
The lights (2) should be set at 45º to the copy board far enough away to ensure full coverage of the artwork and even for A4 I would expect them to be at least 1 metre distant to ensure evenness of illumination. They should also be absolutely level with the centre of the artwork (and thus the camera). I will assume you are using continuous lighting - naked lamps, and not flash for now. Even if your artwork is massive you can always double up the lamps placing one higher than the other (as if on a single stand). What I am saying is this setup can be adapted to suit almost anything.
Now the ruler - place the ruler VERTICALLY in the centre of the copyboard but perpendicular to it - not laying flat. It will cast two vertical shadows - one each side of the ruler. Do not use a shiny ruler but other than that almost anything can be substituted that is similar in nature - a piece of card for instance. The object is to see both shadows at the same time. Shadows should be identical in tone and width. Any difficulties assessing this - use a sheet of white paper on the copyboard.
If the left shadow is darker then the left lamp is weaker (yes, yes, - or the right lamp stronger). Move the appropriate lamp nearer/further to adjust. When both shadows appear identical in tone the light output is matched - taking care of the fact output from lamps changes with age. Now check the shadow widths. Any difference means one lamp is not at the same angle as the other so swing the lamp forward/backward to achieve same widths. Whilst in the centre, move the ruler so the top end of it falls on the centre x of the artboard - the shadow will show you if your lamps are matching height because the double shadow should appear as a single horizontal line across the top of the ruler. If one side tilts up or down then the opposite lamp needs height adjustment.
Now move your ruler to the left side of the artboard. If one shadow becomes significantly darker than the other your lamps are too close. Move them away from the copyboard and repeat stage 1 with the ruler central before again checking at the edges. Perfectionists will say it will never be possible to get matching shadows at the edges and this is correct but you can get reasonably close and that is what we require. Significant differences will mean you get noticeably brighter illumination towards the edges and this will lead to uneven results possibly burning out edge details.
Spend a bit of time doing this - it is worth the effort.
So, having done this you should have camera square and central to artwork, lighting even and matched.
Your choice of lens is important - prime lenses are non-zoom lenses so they tend to introduce less image distortion since they are specifically designed to do a single job. If you must use a zoom then try to keep it away from the 'wide angle' end of its range. The wider the angle, the greater the barrel distortion for a start.
I think that is about it - exposure is critical too, but as with most photography there is a difficult way of doing it based on myths and mirrors or there is a simple way.
Before you all shout at me - I have been doing this work professionally for over 40 years
I omitted to say the ruler should also be moved to the right side after checking the left - just to ensure evenness of illumination across the full width of the copyboard.
Also, polarising filter comment: PL filters do not shift colours, they are the equivalent of an ND filter, plain grey, so the only have the effect of introducing density and reducing the amount of light entering the camera. The purpose of a polarising filter is to counter the effect of light being reflected from non-metallic surfaces and light that is already partially polarised such as skies. It does not have a place in copying under normal day to day circumstances and it is only when you get onto such things as schlieren photography that they are used to any extent.
Even when using glass in front of your artwork to hold it flat (yes, this is very common practise) you will not need a filter on your lens and you will not get any reflections providing you follow the basics above.
We all have our opinions which I respect. I am guessing you have never tried this but faced with capturing image detail from a large image it is worth a try.
I have used the panorama method on several occasions with excellent results, CC stitching has advanced a lot over the years and if the source images are captured properly there should be no sign of errors. The 105 is an excellent portrait lens and perfect for this application. My method involved sliding the artwork along a wall mounted shelf with the camera fixed. Markers were placed to show the center of each shot to ensure the correct overlap was achieved. For the second and subsequent rows the shelf was raised keeping the picture square. Lighting via two large softboxes. Another advantage of my method is that you end up with a much higher resolution image after stitching as each segment contributes say 50% of its capture size to be added to the overall size. Very useful if you want to print large format.
I like your method of setting the illumination and would not have thought of that.
No offence, but using rulers to check shadows sounds very 40 years ago. I used a very precise Minolta IVF digital light meter to check even illumination across the painting. Polarisers are probably the most extreme of camera filters; manipulating light, of course your contrast, saturation and colours will be affected. Just like polarising filters, ND filters are far from neutral either. It took me a lot of research to find filters will the least amount of colour casts. I haven't read this in any detail, but this guy spent a lot of hours trying to find an ND filter that doesn't shift in colour, nothing is just grey or neutral in photography. Anyway, polarisers are not used on the camera for copy work becuase they are used at an angle to remove reflections. It is polarised filters on lights and who is going to bother with all that unless you are working for the British Museum?Quote:
Originally Posted by Brixhamboy
http://www.ryanewalters.com/Blog/blo...17295579746489
http://www.tiffen.com/camera_filters.htm