Measuring the field of vision on a wide angle lens

Hi,

I'm currently in the process of upgrading my wide angle lens, Other than taking a photo from above and then a wide angle photo from the floor and measuring it in that way, could anyone advise me the best way to measure the quoted angle to check the manufacturers claims?

Cheers

Woody

to measure the quoted angle to check the manufacturers claims

You don't believe the focal lengths are correct? Why not?

You don't believe the focal lengths are correct? Why not?

Dyron's claims are notoriously optomistic...

You don't believe the focal lengths are correct? Why not?

Its not the focal length I'm enquiring about, its the angle as, to me, it makes more sense, maybe you can familiarise me with a link to the 2 so I can get an idea if ever the foacl length is quoted, all I think I know is the smaller the focal length the greater the angle?

I am curious prior to my investment thats all Jeremy, Dyron quoted on request 160 deg when zoomed into their 180 deg wide angle port to eliminate all vignetting

I have 100 deg at the mo and Tim uses 130 deg and, as you can see, is somewhat pessimistic to their claims!

Its not the focal length I'm enquiring about, its the angle as, to me, it makes more sense, maybe you can familiarise me with a link to the 2 so I can get an idea if ever the foacl length is quoted, all I think I know is the smaller the focal length the greater the angle?

 

I am curious prior to my investment thats all Jeremy, Dyron quoted on request 160 deg when zoomed into their 180 deg wide angle port to eliminate all vignetting

I have 100 deg at the mo and Tim uses 130 deg and, as you can see, is somewhat pessimistic to their claims!

Cute puppy! I am not entirely sure as to what you need. Below is a link to Bob Adkins's calculator for FoV:

http://www.bobatkins.com/photography/techn...ld_of_view.html

I have been trying to figure out what Canon means by a 1/1.7 sensor (e.g. G11 & S90). I "back calculated" the sensor size based on a focal lenght multiplier of 4.590 and the ratio of the sides 1:1.3 for their PS models.

Bob

Camera h w dia F factor Area mm2 %FF ratio

35 mm 24 36 43.3 1.00 864 100.0% 1.5

D300 15.8 23.6 28.4 1.52 373 43.2% 1.5

D700 23.9 36 43.2 1.00 860 99.6% 1.5

EOS 7D 14.9 22.3 26.8 1.61 332 38.5% 1.5

1D M III 18.7 28.1 33.8 1.28 525 60.8% 1.5

1Ds M III 24.0 36.0 43.3 1.00 864 100.0% 1.5

DP2 13.8 24.2 27.9 1.55 334 38.7% 1.8

E-P1 13 17.3 21.6 2.00 225 26.0% 1.3

GH1 13 17.3 21.6 2.00 225 26.0% 1.3

GF1 13 17.3 21.6 2.00 225 26.0% 1.3

G11 5.752077 7.4777 9.4 4.59 43 5.0% 1.3

S90 5.752077 7.4777 9.4 4.59 43 5.0% 1.3

Tim uses 130 deg and, as you can see, is somewhat pessimistic to their claims!

I don't think tim is questioning any specs from Inon - he mentioned Dyron ... a different beast altogether!

Which adapter are you thinking about? I have heard lots of people are disappointed with Dyron's performance claims, but never heard anyone question the specs on the Inon adapters.

Cute puppy!

Puggle?

Here's mine ...

Cute puppy!

Thanks

some serious stuff

:confused:

Thanks I'll have a read of that site, cheers

I don't think tim is questioning any specs from Inon - he mentioned Dyron ... a different beast altogether!

 

Which adapter are you thinking about? I have heard lots of people are disappointed with Dyron's performance claims, but never heard anyone question the specs on the Inon adapters.

Tim owns an Inon and gets 130 degrees with his dome unit, he also seems interested in buying the Dyron DY.WA180 like me

 

Puggle?

 

Here's mine ...

Yep! aw! Hows olds yours? mines 18 months now and still as cute as ever!

Yep! aw! Hows olds yours? mines 18 months now and still as cute as ever!

Now 6 months ... that was at 8 or 9 weeks. Great little dogs!

W/R/T to your original question, my hunch is that you'll get the FOV that they claim, but the real question will be what do the corners look like?

You may want to call the folks at Reef Photo ... I think they have tested a fair amount of the available adapters for these cameras as they are so popular underwater.

If you can get to 160 degree FOV with the Dyron adapter I bet the corners are miserable ... or we would have heard ... I just don't think something like that would remain a 'secret' for very long.

Hi Jeremy, the guy (forgot his name sorry, he's on here somewhere!?) at reef photo tested the one for the G10.

I asked Dyron on :cough:Sc'b'board:cough: and they seem confident there is nothing miserable about the corners, in fact they were very defensive. Its not an adapter its a dome port to replace the ikelite port