petrochemist

Joined: 27th February 2010

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petrochemist
I like no 2, a great high contrast shot, but I don't understand why you'd take an IR picture then try & get the colours to look normal.
The effect you've ended up with in no 1 makes me think HDR.

Neither shot particularly looks like IR, mainly because they contain little that shows classic IR effects.
IR causes green plants show very pale, but ripe corn has not shown this so much, the high cloud contrast is a IR effect but is often seen via polarisers or red filters (in B&W shots)
Perhaps the ultra sharp images also detract from the IR feel I'm used to, my IR shots are usually somewhat soft.

Comment by petrochemist posted on Two IR shots - two treatments at 29/07/2011 - 20:32

petrochemist
My e-bay special version arrived today.
I'm disappointed to find that in lens stabilization doesn't work, but as a Pentax owner I always knew body stabilization is better!
(But having beer in my Caniam might spoil that...)

I guess even without IS it works out as £3.50 well spent.

Comment by petrochemist posted on Finally a decent use for CaNikon lenses at 28/07/2011 - 22:21

petrochemist
Stunning shot.
Just how close did you get?

Comment by petrochemist posted on Damsel .. in no distress at 24/07/2011 - 09:54

petrochemist
dougf8 wrote:
reso wrote:
how do you rate this lens good or bad advice please
If its the one on ebay, it's rubbish.
Does that mean your watching it Doug?
Mine's not bad but is lacking the filter.

Comment by petrochemist posted on cosina 100 macro AF at 23/07/2011 - 00:57

petrochemist
bretti_kivi wrote:
We get to renew every 10 years, too - and the complete roadblock for alcohol testing? I've run into those at least 4-5 times now.

Bret
I've run into one over 10 years ago in France, where the policemen insisted on testing my passenger (who fortunatly passed). I don't think he reallised the driver's seat was on the right of the car!

Comment by petrochemist posted on Another pointless thread at 22/07/2011 - 14:19

petrochemist
Frogherder wrote:

#8 has a percentage pass of 0.061% to 0.61% in the visible spectrum
it has a percentage pass of 0.0003% @313nm and 0.025% @365nm in the UV
it has a perentage pass of 0.43% between 780-1400nm in the infra red

If we ignore all but the visible light (can we?) then a #8 equates to between 9-1/2 and 12-1/2 stops

Unless you have a specially modified camera IR & UV response is very much less than visible. So the variations with non-vissual light are not significant.

Comment by petrochemist posted on Welding Mask Glass at 22/07/2011 - 14:04

petrochemist
Algernon wrote:
Just grind the edges smooth with silicone carbide paper or a stone?
I used a diamond knife sharpener on the one of mine that had sharp edges, plastic splines would probably have been easier it was slower work than I expected.

Comment by petrochemist posted on Welding Mask Glass at 22/07/2011 - 13:53

petrochemist
philstaff wrote:
Is there any chance of members posting more of the trial photos this is an interesting apprroach and as said worth the few pounds just to give things a whirl.
Regards Ian
Two of the few I've done, on a bright day back in February:

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Comment Image



According to my records these were with a shade 8 (My weakest). The filter was just slipped into a Cokin mount without any further light proofing. I must get round to trying them out again!!!

Comment by petrochemist posted on Welding Mask Glass at 21/07/2011 - 23:07

petrochemist
Frogherder wrote:

Is ND16 the same as 16 stop (I doubt it - so what is it equivalent to?)
Do DLSR's suffer the equivalent of Reciprocity failure? or was this a red herring designed to keep me out of the clique?
ND16 reduces the light 16 fold. This is 4 stops (each stop halving the light).

DSLRs show increased problems from hot pixels in long exposures, but do not show reciprocity failure, which causes problems in long film exposures.

Comment by petrochemist posted on Welding Mask Glass at 20/07/2011 - 21:29

petrochemist
I have to admit I rarely post comments to others photos, it's got to really impress me before I take the effort to add a sentence or two.

I find 'Wow' type comments do help encourage me, and generally feel that the better shots get slightly longer comments, reducing the dilution factor of 'over-use'. I have noticed recently an increase in comments consisting of only smileys, which seem to be a quick way of saying things like 'I like this' - though they don't work so well in the 'My photos' forum (They get confusing in Recent Activity, my preferred way of browsing new posts)

Personally I also find the number of Views a useful gauge of the standard of my photos.

I've rarely posted photos in the forums, as the Gallery is much easier to use. This certainly doesn't mean I'm not after critique - perhaps just that I'm lazy.

Comment by petrochemist posted on Photo Critique at 20/07/2011 - 21:22

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