Velocity Reviews > Tele-converter (1.7x) math

# Tele-converter (1.7x) math

eNo
Guest
Posts: n/a

 06-09-2004
So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
(multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
range of 65mm-323mm, but that sounds too good to be true. Can someone set me
straight on my math?

--
ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
eNo
"If you can't go fast, go long."
ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º

David Sommers
Guest
Posts: n/a

 06-09-2004
It multiplies, so you are getting 65mm to 323mm. It should be obvious from
your shots taken with it in place.

Bye.

"eNo" <(E-Mail Removed)> wrote in message
news:uXtxc.1597\$(E-Mail Removed)...
> So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
> 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> (multiplicative)? I'm thinking "x" means the latter, for an equivalent

zoom
> range of 65mm-323mm, but that sounds too good to be true. Can someone set

me
> straight on my math?
>
> --
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> eNo
> "If you can't go fast, go long."
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
>
>

Bay Area Dave
Guest
Posts: n/a

 06-09-2004
sounds correct!

dave

eNo wrote:

> So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
> 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> (multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
> range of 65mm-323mm, but that sounds too good to be true. Can someone set me
> straight on my math?
>

eas
Guest
Posts: n/a

 06-09-2004
it's still a "5x" zoom..... the range has just changed- i.e.the maximum
focal length is 5 times the minimum... right?

eNo wrote:
> So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
> 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> (multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
> range of 65mm-323mm, but that sounds too good to be true. Can someone set me
> straight on my math?
>

Gene Palmiter
Guest
Posts: n/a

 06-09-2004
No......its not done like that. The 5x means that your short wide angle
times 5 equals your long or telephoto. Now forget that for the next step
because its not related. Your wide is 38x1.7 and your tele is 190x1.7....and

"eNo" <(E-Mail Removed)> wrote in message
news:uXtxc.1597\$(E-Mail Removed)...
> So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
> 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> (multiplicative)? I'm thinking "x" means the latter, for an equivalent

zoom
> range of 65mm-323mm, but that sounds too good to be true. Can someone set

me
> straight on my math?
>
> --
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> eNo
> "If you can't go fast, go long."
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
>
>

DiVenZ
Guest
Posts: n/a

 06-09-2004

"Gene Palmiter" <(E-Mail Removed)> schreef in bericht
news:Owuxc.19897\$(E-Mail Removed)...
> No......its not done like that. The 5x means that your short wide angle
> times 5 equals your long or telephoto. Now forget that for the next step
> because its not related. Your wide is 38x1.7 and your tele is

190x1.7....and

But he cannot use the wide side anymore because of the "big black circle"
arround his picture.
I think it starts at 100x1.7 til 190x1.7 (so thats about 2x)
Regards
Div

>
>
> "eNo" <(E-Mail Removed)> wrote in message
> news:uXtxc.1597\$(E-Mail Removed)...
> > So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add

a
> > 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> > (multiplicative)? I'm thinking "x" means the latter, for an equivalent

> zoom
> > range of 65mm-323mm, but that sounds too good to be true. Can someone

set
> me
> > straight on my math?
> >
> > --
> > ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> > eNo
> > "If you can't go fast, go long."
> > ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> >
> >

>
>

DiVenZ
Guest
Posts: n/a

 06-09-2004

"DiVenZ" <(E-Mail Removed)> schreef in bericht
news:40c6c9bf\$0\$92963\$(E-Mail Removed) et...
>
> "Gene Palmiter" <(E-Mail Removed)> schreef in bericht
> news:Owuxc.19897\$(E-Mail Removed)...
> > No......its not done like that. The 5x means that your short wide angle
> > times 5 equals your long or telephoto. Now forget that for the next step
> > because its not related. Your wide is 38x1.7 and your tele is

> 190x1.7....and
> > still 5x your wide.

>
> But he cannot use the wide side anymore because of the "big black circle"
> arround his picture.
> I think it starts at 100x1.7 til 190x1.7 (so thats about 2x)
> Regards
> Div

PS to eNo
If this about the 717 and the Sony Converter I can show you some samples.

>
> >
> >
> > "eNo" <(E-Mail Removed)> wrote in message
> > news:uXtxc.1597\$(E-Mail Removed)...
> > > So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I

> a
> > > 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> > > (multiplicative)? I'm thinking "x" means the latter, for an equivalent

> > zoom
> > > range of 65mm-323mm, but that sounds too good to be true. Can someone

> set
> > me
> > > straight on my math?
> > >
> > > --
> > > ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> > > eNo
> > > "If you can't go fast, go long."
> > > ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> > >
> > >

> >
> >

>
>

Don Stauffer
Guest
Posts: n/a

 06-09-2004
There are two ways of looking at it.

If you are talking about the range with the teleconverter attached, it
goes to a 5X zoom from 65-323. However, if you consider the whole range
you have available (removing or adding the converter when needed), then
you do have a range of 38 - 323.

eNo wrote:
>
> So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
> 1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
> (multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
> range of 65mm-323mm, but that sounds too good to be true. Can someone set me
> straight on my math?
>
> --
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º
> eNo
> "If you can't go fast, go long."
> ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø,,,,ø¤º°`°º¤ø¤º °`°º¤ø,,,,ø¤º

--
Don Stauffer in Minnesota
http://www.velocityreviews.com/forums/(E-Mail Removed)
webpage- http://www.usfamily.net/web/stauffer

TheNewsGuy
Guest
Posts: n/a

 06-09-2004
On Wed, 09 Jun 2004 01:43:54 GMT, "eNo" <(E-Mail Removed)> wrote:

>So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
>1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
>(multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
>range of 65mm-323mm, but that sounds too good to be true. Can someone set me
>straight on my math?

I think you have to read the manufacturer's recommendations - from
what I understand the manufacturer matches the optics of the
teleconverter to LONG focal lengths of the camera's lens. So shots
taken at the wide angle setting of 38mm would not be of good quality,
even if the camera could mechanically zoom back far enough with the
teleconverter attached anyway.

The logic of the optics design is that you already have a 65mm setting
in your original lens - it is the 191mm to 323mm that you want to add.

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Guest
Posts: n/a

 06-11-2004
On Wed, 09 Jun 2004 01:43:54 GMT, "eNo" <(E-Mail Removed)> wrote:

>So... I have a camera with a 5x, 38mm-190mm equivalent lens. Now, I add a
>1.7x. Do I have an effective 6.7x (additive) or 5*1.7x=8.5x
>(multiplicative)? I'm thinking "x" means the latter, for an equivalent zoom
>range of 65mm-323mm, but that sounds too good to be true. Can someone set me
>straight on my math?

Neither.

You still have a 5X zoom. The difference is with the 1.7X in place
you have a 64.6 to 323 equivelant. The focal length is multiplied by
1.7.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)