Quote:
Originally Posted by wolfie
.........Soon all the oldies such as Don will be shooting IR
Harry
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Harry,
Well its all a matter of cost. I just could not afford the covenience that an IR converted camera would give. £35 for a 52mm Hoya R72 filter, although more than my for free film filter, still reasonably falls into the IR on the cheap bracket. Of course the advantage of being an oldie is that I am used to what is by todays standards, more primitive kit.
The next step is to get to fully understand the response of the 3 channels to infrared and get a FAR better understanding of photoshop to be able to play with the subleties of tints.
Keep posting pics here as I am sure I will learn a lot from them.
Andy,
Your link is does not work ...... sign in job so I expect it is a pay to view so I cannot see what you are pointing me at.
12-24 then to quote Bjørn Rørslett, and he is a guy who has done a lot of IR with mostly 'UNCONVERTED TO IR' Nikons, and a huge array of lenses, so who I am I to argue. " IR performance: This lens is frequently severely flawed by a dominant hot-spot. The tendency for hot spotting develops towards the shorter focal settings and is exacerbated when the lens is stopped down. You have to try with your own camera to see if the combination works satisfactorily, the chances are against it though. " By contrast from what I read in a previous link Diglloyd appears to be using converted cameras.
A significant difference here as converted cameras have the AA filter swapped out. At IR wavelengths some lenses suffer a 'hotspot' as a result of light bouncing back and forth between the AA filter the rear lens element. I cannot remember what I was playing around with, ( not IR but maybe flash experiments ), but I have come across this 'hot spot' effect before, and it does not show in normal use. So it is a lens specific phenomenon at certain wavelengths of light. Complexity of the lens design and coatings may well be the factors influencing this. So stunning visible light performance does not equal the same in the IR wavelengths, and equally a mediocre lens in normal light can redeem itself in IR. For example for normal light photography the ancient Sigma 24mm f2.8 I am using for IR cannot hold a candle to my Nikkor 28mm f2.8 AIs. In IR though the 28mm produces a 'hotspot', so in this case the Sigma wins, as it has no 'hotspot'.
For your interest I have a number of AIs lenses in 52mm filter thread that I can test when the sun finally comes out for long enough to conduct a series of consistent tests. - 24mm f2, 28mm f2.8 (tested-hotspot), 50mm f1.4, 55 f2.8 micro, 105mm f2.5, 105mm f2.8 Micro and 200mm f4,
I could have gone the Cokin route despite needing to tape the whole thing up to prevent visible light leak, to allow use of the 85mm, 180mm and Stevies 18-35 on adaptor rings but these lenses lack decent distance markings or in the case of the zoom an IR focus mark. So there is something to be said for old technology after all.
Don