Again, Miro... All these things you tell me can be applied even better to
yourself...
Perhaps you should start offering yourself advice instead.
" Miro" <miro01@no-spam> wrote in message
news:3ef70bc1$0$26638$afc38c87@no-spam
>
> "Ubiquitous" <ubiquitous@no-spam> wrote in message
> news:3ef6f152$0$31507$5a62ac22@no-spam
> > Some of the things you argue for defy logic and reasoning. No amount of
> > 'experience' can explain blatant logically incorrect statements.
> >
> > I have plenty to offer other than analysis of you. However, this
> particular
> > part of the thread is all about you.
>
> Get a life. Or lease one.
>
>
"Eric Hocking" <ehocking@no-spam> wrote in message
news:bdctv1$1hp$1@no-spam
> " Miro" <miro01@no-spam> wrote in message
> news:3ef4846e$0$26633$afc38c87@no-spam
> > "Danny Smith" <smithbcd@no-spam> wrote in message
> > news:3ef43b3a.168662033@no-spam
> > > Of course! I'm so glad you posted this, I just realised I don't need
> > > any of my current zooms!
> > >
> > > You genius, Miro, you've revolutionised photography forever. No
> > > longer will anyone need anything more than a single prime lens!!!
> >
> > So you can actually tell me the difference between a 15mm and a 17mm
lens
>
> Be happy to. If we're talking about these lenses: Canon 17-40 f4 and the
> Sigma 15-30 f3.5-4.5, the former has a diagonal field of view of 74deg and
> the latter 110.5deg. Perhaps a fairer comparison would be the Sigma 17-35
> f/2.8-4 which has has a 103.7deg diagonal fov.
>
You mean to say that the Sigma 17mm has a FOV 103.7 degrees and the Canon
17mm has a FOV of 74 degrees.
Am I reading that correctly ?
And that 7 degrees of arc, 103 degrees versus 110 degrees produces
measurably large changes in composition at a distance of 2 feet (600mm) ?
This I must see ?
I think you should stick to what is possible.
>
> The Sigma 17mm gives an horizontal 38in fov - 11ins better than the Canon.
>
> Again the above is back of the envelope calcs - anyone feel free to
correct
> them, but it's good enough for government work in my book.
>
One minute you quote diagonal then you quote horizontal ....... lay off the
shiraz hey.
" Miro" <miro01@no-spam> wrote in message
news:3efa0551$0$26638$afc38c87@no-spam
> "Eric Hocking" <ehocking@no-spam> wrote in message
> news:bdctv1$1hp$1@no-spam
> > " Miro" <miro01@no-spam> wrote in message
> > news:3ef4846e$0$26633$afc38c87@no-spam
> > > "Danny Smith" <smithbcd@no-spam> wrote in message
> > > news:3ef43b3a.168662033@no-spam
> > > > Of course! I'm so glad you posted this, I just realised I don't
need
> > > > any of my current zooms!
> > > >
> > > > You genius, Miro, you've revolutionised photography forever. No
> > > > longer will anyone need anything more than a single prime lens!!!
> > >
> > > So you can actually tell me the difference between a 15mm and a 17mm
> lens
> >
> > Be happy to. If we're talking about these lenses: Canon 17-40 f4 and
the
> > Sigma 15-30 f3.5-4.5, the former has a diagonal field of view of 74deg
and
> > the latter 110.5deg. Perhaps a fairer comparison would be the Sigma
17-35
> > f/2.8-4 which has has a 103.7deg diagonal fov.
>
> You mean to say that the Sigma 17mm has a FOV 103.7 degrees and the Canon
> 17mm has a FOV of 74 degrees.
>
> Am I reading that correctly ?
Yes, unless I, of course did not. Source:
http://www.sigma-photo.com/html/lenschart.htm
http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_l
enses/ef%2017-40mm_specs.html
>
> And that 7 degrees of arc, 103 degrees versus 110 degrees produces
and 74deg for the Canon, who actually quote the horizontal fov as 84deg
> measurably large changes in composition at a distance of 2 feet (600mm) ?
My simple trig calcs were based on a 3ft separation from the focal point and
the wall.
> This I must see ?
>
> I think you should stick to what is possible.
As I invited in my other post - feel free to correct my simple trig calcs,
it is entirely possible that I hav misapplied the notion of angle of fov to
calculate the linear fov coverage 3ft away from the focal point. But I'd
hazard that my errors are +/- 1in well within a suitable "rule of thumb"
reckoning for this discussion.
What do you calculate as the physical dimensions captured/viewable by these
lenses at 3ft from the photographer?
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
REPLACE ".com" with ".co.uk" to reply
http//www.twofromoz.freeserve.co.uk
"Eric Hocking" <ehocking@no-spam> wrote in message
news:bdd4bv$7b2$1@no-spam
> " Miro" <miro01@no-spam> wrote in message
> news:3efa05aa$0$26639$afc38c87@no-spam
> > > The Sigma 17mm gives an horizontal 38in fov - 11ins better than the
> Canon.
> > >
> > > Again the above is back of the envelope calcs - anyone feel free to
> > correct
> > > them, but it's good enough for government work in my book.
> >
> > One minute you quote diagonal then you quote horizontal ....... lay off
> the
> > shiraz hey.
>
> It's called simple trigonometry - do the math for yourself.
Oh, and you should know me by now, Miro. I'm an engineer and like dicking
with numbers.
P.S. Why the ad hominem? I responded in what I felt was quite a reasonable
manner to your request "So you can actually tell me the difference between a
15mm and a 17mm lens"
P.P.S. The last person on usenet to call me a drunk was a kook that invaded
sci.skeptic a few years back. Not the sort of company you want to keep
shirley?
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
REPLACE ".com" with ".co.uk" to reply
http//www.twofromoz.freeserve.co.uk
"Eric Hocking" <ehocking@no-spam> wrote in message
news:bdctv1$1hp$1@no-spam
<snip>
> Well, in that 4x4ft box the original poster was talking about, my back of
a
> cigarette packet calculations gives the Canon 17mm an horizontal fov of
27in
> and the Sigma 15mm an horizontal fov of 43in at a distance of 3ft (I'm
> allowing 1ft for a "fathead" and the camera). So, it would appear that in
> the situation described, the Sigma will capture 16in more of the scene in
> the horizontal - that's potentially the difference only capturing a son
and
> daughter and chopping out another son/daughter from the photo.
>
> The Sigma 17mm gives an horizontal 38in fov - 11ins better than the Canon.
>
> Again the above is back of the envelope calcs - anyone feel free to
correct
> them, but it's good enough for government work in my book.
Let me be the first to correct. The above is based on 1/2 of the chord, so
I believe the dimensions of the view are closer to:
Canon 17mm: 54x36in
Sigma 15mm: 86x57in
Sigma 17mm: 76x51in
So perhaps the measurement is only signficant in this case in the *vertical*
And then again, my maths could *still* be wrong!
>
> --
> Eric Hocking
> "A closed mouth gathers no feet"
> "Ignorance is a renewable resource" P.J.O'Rourke
> REPLACE ".com" with ".co.uk" to reply
> http//www.twofromoz.freeserve.co.uk
In article <3ef4f849$0$59953$c30e37c6@no-spam>, "Gavin
says...
>
>
>" Miro" <miro01@no-spam> wrote in message
>news:3ef4846e$0$26633$afc38c87@no-spam
>
>> So you can actually tell me the difference between a 15mm and a 17mm lens
>> and know the two situations where 15mm would work 17mm wouldnt.
>
>I've got a 17mm lens (plus the 1.5x crop factor though) and theres been
>plenty of situations I've wanted extra wideness in indoor shots but had my
>back to a wall.
>
>Miro strikes again!
>
I tend to have problems with cliffs outdoors, or things being in the way (trees
typically have that habit).
> P.S. Why the ad hominem? I responded in what I felt was quite a
reasonable
> manner to your request "So you can actually tell me the difference between
a
> 15mm and a 17mm lens"
Well time and space bends in your hands. Two 17mm lenses have alternate
angles of view.
Maybe sigma quotes diagonal and Canon quotes horizontal angles. Im afraid
this is where engineering is no substitute for common sense.
I will stick with the kook. At least his calculations are plausible.
Bruce Murphy <pack-news@no-spam> wrote in message news:<m2d6h1snnl.fsf@no-spam>...
> "Eric Hocking" <ehocking@no-spam> writes:
> > " Miro" <miro01@no-spam> wrote in message
> > news:3ef4846e$0$26633$afc38c87@no-spam
<snip>
> > > So you can actually tell me the difference between a 15mm and a 17mm lens
> >
> > Be happy to. If we're talking about these lenses: Canon 17-40 f4 and the
> > Sigma 15-30 f3.5-4.5, the former has a diagonal field of view of 74deg and
> > the latter 110.5deg. Perhaps a fairer comparison would be the Sigma 17-35
> > f/2.8-4 which has has a 103.7deg diagonal fov.
>
> By what mechanism do you believe these (presumably all rectilinear) lenses
> have different fields of view at 17mm?
The spec sheets supplied by the manufacturers.
http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_lenses/ef%2017-40mm_specs.html
and
http://www.sigma-photo.com/html/lenschart.htm
It is entirely probable that I am misinterpreting or misapplying the
information in an attempt to determine what the linear dimensions of
the "view" is at a distance of 3ft from the focal point. As I said,
they were back of the cigarette packet figgerin's using very basic
trigonometry and an even more basic understanding of the terminology.
Out of curiosity's sake I'd be interested in the methodology that I
should apply.
--
Eric Hocking
>
> Out of curiosity's sake I'd be interested in the methodology that I
> should apply.
>
If we are talking about a 10D then let's start with the focal length
multiplier.
Then maybe the actual diagonal OR horizontal angle of view for that focal
length. And we know that doesnt vary.
Then I suppose we can look at the angle of arc for 17mm and 15mm lenses.
After all that is done we can all go back to ignoring this.
" Miro" <miro01@no-spam> wrote in message news:<3efac2f8$0$26638$afc38c87@no-spam>...
> > P.S. Why the ad hominem? I responded in what I felt was quite a
> reasonable
> > manner to your request "So you can actually tell me the difference between
> a
> > 15mm and a 17mm lens"
>
> Well time and space bends in your hands. Two 17mm lenses have alternate
> angles of view.
You *did* read the spec sheets then?
> Maybe sigma quotes diagonal and Canon quotes horizontal angles. Im afraid
> this is where engineering is no substitute for common sense.
Sigma quotes diagonal, and Canon both. You *did* read the spec
sheets, before you made this comment, didn't you.
> I will stick with the kook. At least his calculations are plausible.
I'm always ready to be enlightened and had already admitted that the
calc'ns could be in error. So how *does* one determine physical area
covered by angle of view from these numbers?
--
Eric Hocking
ehocking@no-spam (Eric Hocking) writes:
> Bruce Murphy <pack-news@no-spam> wrote in message news:<m2d6h1snnl.fsf@no-spam>...
> > "Eric Hocking" <ehocking@no-spam> writes:
> > > " Miro" <miro01@no-spam> wrote in message
> > > news:3ef4846e$0$26633$afc38c87@no-spam
> <snip>
> > > > So you can actually tell me the difference between a 15mm and a 17mm lens
> > >
> > > Be happy to. If we're talking about these lenses: Canon 17-40 f4 and the
> > > Sigma 15-30 f3.5-4.5, the former has a diagonal field of view of 74deg and
> > > the latter 110.5deg. Perhaps a fairer comparison would be the Sigma 17-35
> > > f/2.8-4 which has has a 103.7deg diagonal fov.
> >
> > By what mechanism do you believe these (presumably all rectilinear) lenses
> > have different fields of view at 17mm?
>
> The spec sheets supplied by the manufacturers.
> http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_lenses/ef%2017-40mm_specs.html
> and
> http://www.sigma-photo.com/html/lenschart.htm
Elementary trigometry combined with the magnification law shows us that
the figure on the Sigma website is correct, the Canon one is wrong. Or,
more accurately, mislabelled.
The fields of view for the Canon lens are given for a reduced sensor ala
the D30 et al, whereas the numbers /next/ to them are the dimensions of
a 35mm film frame.
You can check this by looking at the page
http://www.maxwell.com.au/photo/nikon/nikkor/zoom/afs_1735_spec.html
Which, becuase Nikon are a much better manufacturer than nasty old
Canon, give the fields of view for both the 35mm frame and for the
reduced sensor size on a D1 series camera.
You might find the numbers are the wide end somewhat familiar.
>
> It is entirely probable that I am misinterpreting or misapplying the
> information in an attempt to determine what the linear dimensions of
> the "view" is at a distance of 3ft from the focal point. As I said,
> they were back of the cigarette packet figgerin's using very basic
> trigonometry and an even more basic understanding of the terminology.
Naivete that manufacturers bother to check their website seems to be about
all you're guilty of in this instance, and a misconception over what
cauuses field of view :)
> Out of curiosity's sake I'd be interested in the methodology that I
> should apply.
Read the above, and then see how you feel about it.
B>
"Eric Hocking" <ehocking@no-spam> wrote in message
news:1e644e4e.0306260744.62db98aa@no-spam
> " Miro" <miro01@no-spam> wrote in message
news:<3efac385$0$26637$afc38c87@no-spam>...
> > By the way, not all people who enjoy wine are drunks. I simply think one
> > should attempt these calculations before a large meal.
>
> I'd be interested to see how I *should* have calculated this - there
> was certainly enough handwaving in my posts to indicate that they were
> done on-the-fly with the most cursory overview of the concept.
Think about it Eric, 7 degrees of arc and maybe 2 or 3 feet in it. Even I
think that is bordering on not being different.
Maybe the lesson from all this is that focal length determines angle of view
by definition. Just what is the focal length is the question.
"Eric Hocking" <ehocking@no-spam> wrote in message
news:1e644e4e.0306260741.754c69c4@no-spam
> " Miro" <miro01@no-spam> wrote in message
news:<3efac2f8$0$26638$afc38c87@no-spam>...
> > > P.S. Why the ad hominem? I responded in what I felt was quite a
> > reasonable
> > > manner to your request "So you can actually tell me the difference
between
> > a
> > > 15mm and a 17mm lens"
> >
> > Well time and space bends in your hands. Two 17mm lenses have alternate
> > angles of view.
>
> You *did* read the spec sheets then?
>
> > Maybe sigma quotes diagonal and Canon quotes horizontal angles. Im
afraid
> > this is where engineering is no substitute for common sense.
>
> Sigma quotes diagonal, and Canon both. You *did* read the spec
> sheets, before you made this comment, didn't you.
>
> > I will stick with the kook. At least his calculations are plausible.
>
> I'm always ready to be enlightened and had already admitted that the
> calc'ns could be in error. So how *does* one determine physical area
> covered by angle of view from these numbers?
>
> --
> Eric Hocking
I must agree with Miro that common sense must prevail and that possibly
Canon have misquoted or we are misunderstanding something.
The horizontal field of view (by very simple trigonometry) of
84° - 34° (36mm) "canon"
cannot *ever *be greater than the diagonal FOV of
74° - 29° (43.2mm) "canon"
in a rectangle (no matter how much it is distorted by the optics).
What are those lengths given in mm for?
I, too, studied engineering but my recollection of studying optics etc fails
me. But by simple trigonometry as you quote, the diagonal should be the
longest line (is that the 43.2mm as opposed to 36mm bit..dunno).
The angle from a given point in the centre should be greater in the
direction of the longest line from that point to the extremities of that
line.
I am not an expert in neither photography nor optics, but without sitting
down to work out the angles using *simple* trig as you did, a 17mm lens is a
about ~17mm lens it doesn't matter who has made it. I think canon has
misquoted as there should not be a 29°+ difference in the FOV.
As Miro said, I think its only common sense, but I stand to be corrected
also, as I really do not know the numbers of photography and optics.
BillP
> Let me be the first to correct. The above is based on 1/2 of the chord,
so
> I believe the dimensions of the view are closer to:
>
> Canon 17mm: 54x36in
> Sigma 15mm: 86x57in
> Sigma 17mm: 76x51in
>
> So perhaps the measurement is only signficant in this case in the
*vertical*
>
> And then again, my maths could *still* be wrong!
>
Your math my be correct, but your input data is more than likely wrong on
the canon 17-40 lens. It should probably be about 104degrees and not
74degrees. I'm not gonna do the math, but you could try it again.
The difference between the two sigmas sounds correct but the canon is (I am
99% sure ) is incorrect.
BillP
> As Miro said, I think its only common sense, but I stand to be corrected
> also, as I really do not know the numbers of photography and optics.
>
> BillP
>
>
Now that you have agreed with me you are an outcast. Now quickly disagree
with me before anyone thinks you are in a Miro consipiracy.
http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_lenses/ef%2017-40mm_specs.html
The spec sheet on this canon web site are WRONG... it is a trying error.
A clear case of don't believe everything that you read.... use your
common sense.
The 17-40 Diagonal angle of view quoted is using a 1.6x conversion for a
DSLR body with a 1.6 x crop.
(17 mm x 1.6= 27.2mm) if you look at the spec sheets (I have a canon
EOS system manual in front of me now) you will see that a 28 mm lens has
a diagonal angle of view of 75 Degrees diagonal... hence the misquote in
the above web site.
And then the site quotes the correct horizontal angel of view for a 17
mm lens based on a full frame SLR (84 degrees)
Clearly the hypotenuse of a right angle triangle (diagonal distance
across the screen through the middle) MUST be longer that any of the two
subtending side (horizontal and vertical).. this is year 7 maths (or for
Miro... MATH) A^2= B^2 + C^2 where a is the hypotenuse b and c are the
subtending sides.
This is a clear case of someone at canon's web page office stuffing up
and not realising it yet.
Basically a 17 mm lens has the same 35 mm FOV as any other 17 mm lens...
regardless of brand.
Brenton
PS Of course.. this ridiculous argument can continue... bit at least get
the facts right.
Eric...
You are asking too much of this group to actually be able to 'prove' one of
the lurkers therories - and that's all most of them are. Every so often
someone will toss in a grain of logical evidence like Brenton did a few
replies back but on the whole... It's all just good fun!
JT
"Eric Hocking" <ehocking@no-spam> wrote in message >
> Out of curiosity's sake I'd be interested in the methodology that I
> should apply.
>
> --
> Eric Hocking
How do you get 4 kids and a fat headed photographer into a 4ft square area?
JT
"Eric Hocking" <ehocking@no-spam> wrote in message
news:bdddgv$5so$1@no-spam
> "Eric Hocking" <ehocking@no-spam> wrote in message
> news:bdctv1$1hp$1@no-spam
> <snip>
> > Well, in that 4x4ft box the original poster was talking about, my back
of
> > a cigarette packet calculations gives the Canon 17mm an horizontal fov
of 27in
> > and the Sigma 15mm an horizontal fov of 43in at a distance of 3ft (I'm
> > allowing 1ft for a "fathead" and the camera). So, it would appear that
in
> > the situation described, the Sigma will capture 16in more of the scene
in
> > the horizontal - that's potentially the difference only capturing a son
> > and daughter and chopping out another son/daughter from the photo.
> >
"Auspics" <just@no-spam> wrote in message
news:rrbLa.550$l83.8075@no-spam
> How do you get 4 kids and a fat headed photographer into a 4ft square
area?
> JT
Give a 400mm lens to Eric and he will make it a fisheye. It's all in the
math.
> Now that you have agreed with me you are an outcast. Now quickly disagree
> with me before anyone thinks you are in a Miro consipiracy.
>
>
Ok. I disagree with you Miro.
I am not an outcast!!!
Phew, that was close. Thanks.
BillP
Brenton <neuschulz@no-spam> wrote in message news:<3EFD076B.7C1F5B62@no-spam>...
> http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_lenses/ef%2017-40mm_specs.html
>
> The spec sheet on this canon web site are WRONG... it is a trying error.
:) was that delifferate? ^^^^^^
> A clear case of don't believe everything that you read.... use your
> common sense.
>
> The 17-40 Diagonal angle of view quoted is using a 1.6x conversion for a
> DSLR body with a 1.6 x crop.
>
> (17 mm x 1.6= 27.2mm) if you look at the spec sheets (I have a canon
> EOS system manual in front of me now) you will see that a 28 mm lens has
> a diagonal angle of view of 75 Degrees diagonal... hence the misquote in
> the above web site.
>
> And then the site quotes the correct horizontal angel of view for a 17
> mm lens based on a full frame SLR (84 degrees)
>
> Clearly the hypotenuse of a right angle triangle (diagonal distance
> across the screen through the middle) MUST be longer that any of the two
> subtending side (horizontal and vertical).. this is year 7 maths (or for
> Miro... MATH) A^2= B^2 + C^2 where a is the hypotenuse b and c are the
> subtending sides.
Have to admit that I could not reconcile the horizontal angle of view
with the quoted diagonal one quoted on the Canon site so only worked
with the quoted diagonal angles.
> This is a clear case of someone at canon's web page office stuffing up
> and not realising it yet.
> Basically a 17 mm lens has the same 35 mm FOV as any other 17 mm lens...
> regardless of brand.
The quoted data had me quite thrown - that's why I attempted the math.
Jeez what's the world coming to when you can't believe everything you
read on a webpage?!
> Brenton
>
> PS Of course.. this ridiculous argument can continue... bit at least get
> the facts right.
Hey - this is usenet, fact have absolutely no precedence over opinion,
you should know that!
--
Eric Hocking
Andrew Mc <andrew@no-spam> wrote in message news:<bdfste02crt@no-spam>...
> In article <1e644e4e.0306260323.37a69b19@no-spam>,
> ehocking@no-spam says...
> >Bruce Murphy <pack-news@no-spam> wrote in message
> >news:<m2d6h1snnl.fsf@no-spam>...
> >> "Eric Hocking" <ehocking@no-spam> writes:
> >> > " Miro" <miro01@no-spam> wrote in message
> >> > news:3ef4846e$0$26633$afc38c87@no-spam
> <snip>
> >> > > So you can actually tell me the difference between a 15mm and a 17mm lens
> >> >
> >> > Be happy to. If we're talking about these lenses: Canon 17-40 f4 and the
> >> > Sigma 15-30 f3.5-4.5, the former has a diagonal field of view of 74deg and
> >> > the latter 110.5deg. Perhaps a fairer comparison would be the Sigma 17-35
> >> > f/2.8-4 which has has a 103.7deg diagonal fov.
> >>
> >> By what mechanism do you believe these (presumably all rectilinear) lenses
> >> have different fields of view at 17mm?
> >
> >The spec sheets supplied by the manufacturers.
> >http://www.canon.com.au/products/cameras_lenses_accessories/ultrawide_zoom_lenses/ef%2017-40mm_specs.html
> >and
> >http://www.sigma-photo.com/html/lenschart.htm
>
> Try here:
> http://www.usa.canon.com/html/eflenses/lenses/ef_17-40_4l/ef_17-40_4lspec.html
That makes much more sense - thanks. I wonder where the Aussie site
cut/paste their numbers from!?
--
Eric Hocking
" Miro" <miro01@no-spam> wrote in message news:<3efb850c$0$26639$afc38c87@no-spam>...
> "Eric Hocking" <ehocking@no-spam> wrote in message
> news:1e644e4e.0306260744.62db98aa@no-spam
> > " Miro" <miro01@no-spam> wrote in message
> news:<3efac385$0$26637$afc38c87@no-spam>...
> > > By the way, not all people who enjoy wine are drunks. I simply think one
> > > should attempt these calculations before a large meal.
> >
> > I'd be interested to see how I *should* have calculated this - there
> > was certainly enough handwaving in my posts to indicate that they were
> > done on-the-fly with the most cursory overview of the concept.
>
> Think about it Eric, 7 degrees of arc and maybe 2 or 3 feet in it. Even I
> think that is bordering on not being different.
Nice misquote there Miro, since we were talking about the difference
between 110deg and 74deg. Sure, the Canon data is misrepresented on
their webpage - but is it necessary to misquote my posts to win your
point?
> Maybe the lesson from all this is that focal length determines angle of view
> by definition. Just what is the focal length is the question.
No, the lesson here is not to believe everything you read on the
inter/usenet and look *very* hard at the source. Fortunately others
here participate in the spirit of usenet and I've learnt more than
something regarding photography.
--
Eric Hocking
"BillP" <abigb53@no-spam> wrote in message
news:3efc5768$0$9666$afc38c87@no-spam
> > Let me be the first to correct. The above is based on 1/2 of the chord,
> so
> > I believe the dimensions of the view are closer to:
> >
> > Canon 17mm: 54x36in
> > Sigma 15mm: 86x57in
> > Sigma 17mm: 76x51in
> >
> > So perhaps the measurement is only signficant in this case in the
> *vertical*
> >
> > And then again, my maths could *still* be wrong!
>
> Your math my be correct, but your input data is more than likely wrong on
> the canon 17-40 lens. It should probably be about 104degrees and not
> 74degrees. I'm not gonna do the math, but you could try it again.
>
> The difference between the two sigmas sounds correct but the canon is (I
am
> 99% sure ) is incorrect.
Yep, shown up by the true specs from the US Canon site.
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
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"Auspics" <just@no-spam> wrote in message
news:gnbLa.546$l83.8047@no-spam
> "Eric Hocking" <ehocking@no-spam> wrote in message >
> > Out of curiosity's sake I'd be interested in the methodology that I
> > should apply.
> Eric...
> You are asking too much of this group to actually be able to 'prove' one
of
> the lurkers therories - and that's all most of them are. Every so often
> someone will toss in a grain of logical evidence like Brenton did a few
> replies back but on the whole... It's all just good fun!
Old hand at this usenet thing. Read everything in context, follow the leads
and decide who gives information more reliably than others. Basically
usenet is the equivalent of the 19th hole in golf.
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
REPLACE ".com" with ".co.uk" to reply
http//www.twofromoz.freeserve.co.uk
> >
> > Think about it Eric, 7 degrees of arc and maybe 2 or 3 feet in it. Even
I
> > think that is bordering on not being different.
>
> Nice misquote there Miro, since we were talking about the difference
> between 110deg and 74deg. Sure, the Canon data is misrepresented on
> their webpage - but is it necessary to misquote my posts to win your
> point?
>
Dont give up your day job ..... snoring.
> Old hand at this usenet thing. Read everything in context, follow the
leads
> and decide who gives information more reliably than others. Basically
> usenet is the equivalent of the 19th hole in golf.
>
> --
> Eric Hocking
I thought it more like the water trap.
" Miro" <miro01@no-spam> writes:
> >
> > Evasion noted....
> >
> > --
> > Eric Hocking
>
> When you can hold a candle to a first year photo student then I will be glad
> to reveal the details. So long as you make an ass of optics in public dont
> expect me to waste my time on you.
Come on Miro, surely you can handle a little competition?
B>
> Come on Miro, surely you can handle a little competition?
>
> B>
:-P
" Miro" <miro01@no-spam> wrote in message
news:3f017301$0$26633$afc38c87@no-spam
> > Evasion noted....
>
> When you can hold a candle to a first year photo student then I will be
glad
> to reveal the details.
My shots are on my webpage for anyone to critique, but to quote someone on
this group who's opinion you obviously rate quite highly:
"The best way to ruin a hobby is to make it a contest."
> So long as you make an ass of optics in public dont
> expect me to waste my time on you.
Difference being that I can admit when I've made an error in a post and
moreover, take note of it and not keep repeating that error.
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
REPLACE ".com" with ".co.uk" to reply
http//www.twofromoz.freeserve.co.uk
>
> Difference being that I can admit when I've made an error in a post and
> moreover, take note of it and not keep repeating that error.
> --
That wasnt the thing ........ it was the flywheel effect of having to grind
your lunacy to a halt before you would spin the other way.
I dont expect you would comprehend what it is that I do let alone expect me
to bother taking the time to explain it.
"Eric Hocking" <ehocking@no-spam> wrote in message
news:bdstlv$8vo$1@no-spam
> " Miro" <miro01@no-spam> wrote in message
> news:3f00b23f$0$26633$afc38c87@no-spam
> > > Old hand at this usenet thing. Read everything in context, follow the
> > leads
> > > and decide who gives information more reliably than others. Basically
> > > usenet is the equivalent of the 19th hole in golf.
> >
> > I thought it more like the water trap.
>
> I guess that's the difference between us.
>
> I approach aus.photo as somewhere that people with a common interest get
> together to swap war stories, experiences, ask information and have the
> occasional stoush.
>
> Whereas you appear to think it's a frustrating contest where you spend
most
> of your time trying to get out of the hole you've dropped yourself into,
or
> replacing the ball and driving off in a totally different direction.
>
Oh its Guru Eric with the photographic-microdot bindi of enlightenment. We
worship your wisdom.
Miro wrote:
> > I approach aus.photo as somewhere that people with a common interest get
> > together to swap war stories, experiences, ask information and have the
> > occasional stoush.
> >
> > Whereas you appear to think it's a frustrating contest where you spend
> most
> > of your time trying to get out of the hole you've dropped yourself into,
> or
> > replacing the ball and driving off in a totally different direction.
> >
>
> Oh its Guru Eric with the photographic-microdot bindi of enlightenment. We
> worship your wisdom.
Gotta say, Eric makes a hell of a lot more sense than you do Miro.
>
> Gotta say, Eric makes a hell of a lot more sense than you do Miro.
>
>
Birds of a feather ..........
" Miro" <miro01@no-spam> wrote in message
news:3f02144d$0$26637$afc38c87@no-spam
>
> >
> > Difference being that I can admit when I've made an error in a post and
> > moreover, take note of it and not keep repeating that error.
>
> That wasnt the thing ........ it was the flywheel effect of having to
grind
> your lunacy to a halt before you would spin the other way.
>
> I dont expect you would comprehend what it is that I do let alone expect
me
> to bother taking the time to explain it.
Talk about taking a drop and driving off in a different direction. Miro
your non sequiturs are getting more obscure by the day. Since when was your
occupation a subject in this thread and how does it relate to any of the
text you left in that last post?
--
Eric Hocking
"A closed mouth gathers no feet"
"Ignorance is a renewable resource" P.J.O'Rourke
REPLACE ".com" with ".co.uk" to reply
http//www.twofromoz.freeserve.co.uk