Comments for Blandford Forum Camera Club

Comment on Points Cups No.3 by Malcolm Bowditch

Malcolm Bowditch — Fri, 04 Dec 2009 16:12:04 +0000

Thank you Pam. We hope to see you back soon.

Comment on Points Cups No.3 by Pam Woodhouse

Pam Woodhouse — Thu, 03 Dec 2009 22:44:02 +0000

Thankyou Malcolm for such comprehensive reports which keep absentee members up to date. I have been unable to attend the club for a few weeks but feel that I have not missed out on what is/has happened. I hope to be back soon and also to be able to resume my photography efforts. Keep up the good work!!

Comment on The camera that changed the world by Malcolm Bowditch

Malcolm Bowditch — Thu, 26 Nov 2009 21:07:24 +0000

How right Marilyn is! We all do what the existing technologies - and our individual skills - allow us to do. I often strip colour from an image recorded in full colour both because I can and because it suits me. Fred’s example eliminated a mechanical stand, mine often remove colour. It’s not important; it’s the picture that counts. Unless you are recording something - like one being shot, as photographed by Robert Capa perhaps?

Comment on The camera that changed the world by Marilyn Peddle

Marilyn Peddle — Wed, 25 Nov 2009 21:08:10 +0000

Talking of digital jiggery-pokery, early on in his presentation Fred showed us a photo of a man on a bike and you could see a stand very faintly holding up the bike. The photographer had attempted to remove it in the darkroom, not too successfully. Nothing is new as we found out in John Burton’s and now Fred’s presentation, we are just using different tools! And why not?

Comment on Basic Photoshop Techniques by Marilyn Peddle

Marilyn Peddle — Tue, 17 Nov 2009 11:17:33 +0000

Thank you Keith, they have already proved useful to me. I was working on some photos for printing this weekend. I had the sharpening tutorial open and after following it I was pleased with the results.
I look forward to more!

Comment on Basic Photoshop Techniques by Malcolm Bowditch

Malcolm Bowditch — Thu, 12 Nov 2009 10:38:03 +0000

I really do think that this is a good idea. I, too, find it handy to have some decent, succinct hard copy to hand as an aide-memoire. Also, I’m not ashamed to adnit that I have learned things already!

Malcolm Bowditch

Comment on Points Cups No. 2 by Marilyn Peddle

Marilyn Peddle — Thu, 05 Nov 2009 18:40:22 +0000

I always enjoy Malcolm’s reports, they are very well observed and quite often amusing.

Comment on Points Cups No. 2 by Keith Chaloner

Keith Chaloner — Thu, 05 Nov 2009 10:48:59 +0000

And a cracking report!
I do hope as many members who turned up and enjoyed the meeting also read and enjoy Malcolm’s consummate reporting.

Comment on Getting (a bit) Teknical by Keith Chaloner

Keith Chaloner — Mon, 26 Oct 2009 10:40:08 +0000

Colin, yes I understand that the histograms I described showed a correctly exposed image, the point I was making was that in those circumstances, if only the luminance channel had been used to evaluate the exposure, the exposure would probably have been increased which would have increased the channels and the red channel would have been ‘blown out’.
I started this hare because I had learnt something I didn’t know before (and didn’t quite understand) and from now I will give more respect to the individual channel displays. And in those cases where one of them differs appreciably from the luminance (probably only in extreme circumstances) I will be guided by that information when adjusting exposure correction.
Regarding your explanation about how the histograms are generated, I think I have read somewhere also that the histograms are generated from the processed jpeg (that is apparently produced even when shooting only raw (maybe only with D3?)
I think I will switch off now and just worry about things to aim my camera at, while still remembering to keep half an eye on the channel info!
Keith

Comment on Getting (a bit) Teknical by Colin Cross

Colin Cross — Sun, 25 Oct 2009 22:16:42 +0000

“the red channel reaches a full 100% and would be blown out with any more exposure.”

That’s OK Keith, as long as the red channel is not clipped.

Going on to your other point, the luminence channel is based purely on exposure (in grey scale) and the camera works this out at the first pressure of the exposure button. If you take the second pressure to make the shot, that is what is captured.

The RGB colour histogram is only available post capture, as a result of your camera’s processing of the shot to turn into int a RAW file, or Jpeg.

Although there isn’t a direct relationship between the two histograms, one is pre-capture and the other is post processing, there will be nearly always be a similarity between the two. It is not the same data, interpreted in two different forms ….. that may be where the confusion lies.

Cerebral stuff this isn’t it?

Colin