All Forum Comments
Comment by ChrisA posted on Have You Converted Anyone? at 05/04/2012 - 23:44
Another Derby Lad - I have converted 2 Nikon users to Pentax in Derby and got one to join this site..... Derby on the rise.
As in, what exactly didn't they like about their Nikon gear, and what it was about Pentax that encouraged them to change.
It is, after all, quite a big deal, changing systems.
Comment by ChrisA posted on Have You Converted Anyone? at 05/04/2012 - 23:00
Did all my tests on a tripod. Why would anyone test their lenses handheld. It doesn't make sense as you're introducing obvious and significant veriables.
Comment by ChrisA posted on Sensor sweet spot at 04/04/2012 - 07:55
Don't use flash on newborns! Within the first 8 weeks of birth flash can in fact damage a baby's eyes...
This assertion has been around for years, but I think it's been fairly comprehensively debunked.
I mean, obviously don't go firing the thing into the poor kid's eyes from two inches away. But you wouldn't do that to yourself, either.
I think this one is a bit of an urban myth.
A couple of articles on the subject (but DYOR)...
http://www.sublime-light.com/index.php/2007/09/17/will-flash-damage-babies-sensi...
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http://photo.stackexchange.com/questions/16411/is-camera-flash-actually-harmful-...
Seriously, don't you think that if it was a real risk, we'd be inundated with health warnings from a) the nanny state and b) all the flashgun makers desperate to avoid lawsuits?
Comment by ChrisA posted on Tips for pictures of new born babies at 03/04/2012 - 20:37
Clearly, diffraction isn't going to be contributing significantly to any erosion in image quality from F5.6, say, to F11 or more.
Depth of field, and indeed lack of aberrations, are both going to be improved with a smaller hole in the middle, and both these effects would lead one to expect that IQ would improve, not deteriorate, down to moderate apertures.
Therefore, it seems likely to me that those reporting the best sharpness with lenses only slightly stopped down, are probably getting the benefit of the first stop or so of improvement that you get when the lens is no longer wide open, coupled with the least amount of camera shake, that you get with wide apertures and hence short exposures.
Feel free to shoot me down in flames with actual evidence, such as MTF charts, or where the images concerned have had shake rigorously eliminated as a contribution to lack of sharpness, but till then, my money would be on just a little camera shake being the main contributory factor as the lens gets stopped down.
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Edit: note to self: read earlier posts more thoroughly. Ken's comment is the sort of evidence I mean. What about non-DA glass? Do the charts suggest the same sort of thing?
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Further edit: Ok, supposing it's true, even for DA lenses, why is it true?
Comment by ChrisA posted on Sensor sweet spot at 03/04/2012 - 19:52
This is because there are two groups of viewers.
One consists of the parents, to whom the child in question is obviously and unarguably the most beautiful baby of any species that has ever appeared on planet Earth.
The other group consists of everyone else, who are mostly too polite to tell the truth.
Comment by ChrisA posted on Tips for pictures of new born babies at 03/04/2012 - 19:38
Another doom and gloom story. Will they ever end?
I know we're not supposed to admit that there are any silly questions on the forum, but if anyone were to belie the legend, 'twould be you.
Comment by ChrisA posted on Pentax lenses price increasing by 15-90%? at 03/04/2012 - 19:29
The shot of the Bristol and Fokker has got good detail, but it suffers from the impersonal feel you get when the cockpits are entirely out of view. Tricky to light well when they're overhead so that's worked well.
I like the Vampire very much, though. Lovely with the sunlight on it, and perfectly exposed for the aeroplane, not the sky behind.
Comment by ChrisA posted on DA 55-300 at the RNZAF 75th at 03/04/2012 - 10:33
You could also try image stacking, see following for an example :-
https://www.pentaxuser.com/forum/topic/focus-stacking-27255.
You will need a program such as CombineZP and, of course, a stable tripod
regards
Bernard
Comment by ChrisA posted on getting all over sharpness? at 02/04/2012 - 21:10
Thank''s for the positive comments fella's, and just for you Chris.
Comment by ChrisA posted on Open & Closed at 02/04/2012 - 14:41


It's a big deal if you have a big system.
Many people have just a body and one or two lenses.
She's very keen on the whole manual focus, manual exposure thing. Access to lots of good cheap lenses, with the added benefit of SR, makes her a prime candidate for switching to Pentax.