Search found 702 matches

by Bill Jurens
Fri Jan 24, 2020 7:06 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

P.S. I'm certainly glad to see that reasonable commentary and criticism seems to be the new order of the day in our discussions. This has become (again) a pleasant place to visit, and makes the moderator's job much, much, easier.

Bill Jurens
by Bill Jurens
Fri Jan 24, 2020 6:22 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

Photogrammetrically, all items in a photo tend to recede in a radial pattern away from the exact point at which the camera was pointed, which is -- at least in English terminology -- called the 'principal point'. Very long ago, we used to make maps using a device, appropriately defined as a 'radial ...
by Bill Jurens
Thu Jan 23, 2020 6:45 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

That's what I suggested earlier. The chances of having a photographer wandering about the weather decks and basically just getting in the way in a combat situation are pretty slim. That's why my guess was that the photo was exposed from inside the galley, looking through an open air port. The geomet...
by Bill Jurens
Thu Jan 23, 2020 5:00 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

My estimate is something in the vicinity of two meters assuming a 35mm camera ( or a "press camera") , held at eye level. If it were a twin-lens, or some of the Graflex press types, the camera would be held somewhat lower and the distance correspondingly greater. Perhaps three meters... Without more...
by Bill Jurens
Thu Jan 23, 2020 2:32 am
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

The angle between the camera and the muzzles can be determined -- if one has a sufficiently sharp image -- by measuring the ratios between the major and minor axes of the ellipse cast by the circular muzzles on the image plane. The ratio is related to the tangent of the angle. But the images I've se...
by Bill Jurens
Wed Jan 22, 2020 5:03 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

The photo geometry to estimate Bismarck's distance goes roughly as follows: The vertical offset of the muzzles, assuming they are horizontal and using drawings of the mount as a guide for the distance between the muzzles, allows one to construct a line angled downwards pointing at the camera. The he...
by Bill Jurens
Mon Jan 20, 2020 11:59 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

There is an unspoken and very subtle assertion being made when it is said that 'History is written by the winners.", the implication being that the history is therefore not to be trusted or is in some way inferior to history written by the 'losers', which is often assumed -- usually well after-the-f...
by Bill Jurens
Mon Jan 20, 2020 4:07 pm
Forum: Announcements, News and Updates
Topic: New Moderator
Replies: 28
Views: 5448

Re: New Moderator

As mentioned yesterday, I have taken the action of deleting significant portions of material posted by Mr. Virtuani in January as being inappropriate, offensive, and repetitive. Although these attacks were primarily pointed at myself, similar action would have been taken had any other participant to...
by Bill Jurens
Sun Jan 19, 2020 11:22 pm
Forum: Announcements, News and Updates
Topic: New Moderator
Replies: 28
Views: 5448

Re: New Moderator

I was unaware of Mr. Virtuani's parallel postings on this thread until very recently. The content and tone of the more recent postings by Mr. Virtuani speaks for itself. He has made his points and stated his positions. Repeatedly. Although I could respond, and have before, I honestly feel it pointle...
by Bill Jurens
Sun Jan 19, 2020 4:46 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

My own calculations and analysis, done via a method essentially identical to that used by Herr Nilsson, and using identical source material, would suggest that the photographer would be at or near the rail with the mount trained at only about 35 degrees off the centerline. I feel it unlikely that th...
by Bill Jurens
Sun Jan 19, 2020 7:34 am
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

My thanks to Northcape for what I consider an excellent response to my question. As they sometimes say 'I couldn't have said it better', but in this case, I'd have to admit that I probably couldn't have said it half as well. I think that even though the outcomes might be trivial in the overall conte...
by Bill Jurens
Sat Jan 18, 2020 9:25 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

To Wadinga.

One shouldn't offend in public and apologize in private. You are correct; reading your comments carefully, I do find it difficult to take serious offense -or perhaps any offense at all -- regarding the content.

I made a mistake in censuring you.

Bill Jurens.
by Bill Jurens
Sat Jan 18, 2020 12:44 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

One problem of course is that in reality we have no real idea of how much the photograph has been cropped or enlarged, etc., which renders scaling issues problematical. It's possible from perspective to obtain some idea, but only an approximate idea, of how far the camera was from the gun mounting. ...
by Bill Jurens
Thu Jan 16, 2020 7:25 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

Mr. Virtuani is cautioned. Although I can sympathize with your feelings that some individuals may be attacking you personally, you will have to trust in my judgement to determine at which point these sorts of comments, which I almost always find unnecessary and unproductive, cross the line into an a...
by Bill Jurens
Thu Jan 16, 2020 4:37 pm
Forum: Bismarck General Discussion
Topic: A correct attribution for the "Flash Effect" photo?
Replies: 200
Views: 5787

Re: A correct attribution for the "Flash Effect" photo?

The previous dozen posts have remained fairly reasonable in tone, but I can see that we are beginning to slip back into personal commentary again. I'd once again ask that participants stick to the issues at hand rather than alluding that the motivations of others are in some way driven by deliberate...