Field of View 'Converter' for small sensor DSLRS?

Archived from groups: rec.photo.digital (More info?)

Folks,

Does anyone know if there are any devices (or if it is even practical)
to make a field of view 'converter' device which may fit between
lens and body to compensate for the reduced field of view
due to non full-frame sensors?
It is very frustrating to have wide-angle lenses which are no longer
wide angle due to the small sensor size in 99% of digital SLRS.
I don't want to buy another lens....especially one which I cannot
use on my film body (e.g. EF-S series).
I would guess if it was practical to make an optical device which
would 'squeeze' the normal field of view of let's say a 24mm (or any)
lens onto the smaller sensor someone would be offering it.

Any comments?

W

Archived from groups: rec.photo.digital (More info?)

<winhag@yahoo.com> wrote in message
news:1121642679.464343.8640@z14g2000cwz.googlegroups.com...
> Folks,
>
> Does anyone know if there are any devices (or if it is even practical)
> to make a field of view 'converter' device which may fit between
> lens and body to compensate for the reduced field of view
> due to non full-frame sensors?
> It is very frustrating to have wide-angle lenses which are no longer
> wide angle due to the small sensor size in 99% of digital SLRS.
> I don't want to buy another lens....especially one which I cannot
> use on my film body (e.g. EF-S series).
> I would guess if it was practical to make an optical device which
> would 'squeeze' the normal field of view of let's say a 24mm (or any)
> lens onto the smaller sensor someone would be offering it.
>
> Any comments?

This one works:
http://www.bhphotovideo.com/bnh/co [...] ype=search

Archived from groups: rec.photo.digital (More info?)

On 17 Jul 2005 16:24:39 -0700, "winhag@yahoo.com" <winhag@yahoo.com>
wrote:

>Folks,
>
>Does anyone know if there are any devices (or if it is even practical)
>to make a field of view 'converter' device which may fit between
>lens and body to compensate for the reduced field of view
>due to non full-frame sensors?
>It is very frustrating to have wide-angle lenses which are no longer
>wide angle due to the small sensor size in 99% of digital SLRS.
>I don't want to buy another lens....especially one which I cannot
>use on my film body (e.g. EF-S series).
>I would guess if it was practical to make an optical device which
>would 'squeeze' the normal field of view of let's say a 24mm (or any)
>lens onto the smaller sensor someone would be offering it.
>
>Any comments?
>
>W

I don't know of any "wide angle" converters.
I do think, though, that you are laboring under a misconception: you
do not need to buy EF-S lenses. Standard EF lenses will work fine.

And you are far from the only one who would like such a device.

--
Bill Funk
replace "g" with "a"
funktionality.blogspot.com

Archived from groups: rec.photo.digital (More info?)

>>Folks,
>>
>>Does anyone know if there are any devices (or if it is even practical)
>>to make a field of view 'converter' device which may fit between
>>lens and body to compensate for the reduced field of view
>>due to non full-frame sensors?
>>It is very frustrating to have wide-angle lenses which are no longer
>>wide angle due to the small sensor size in 99% of digital SLRS.
>>I don't want to buy another lens....especially one which I cannot
>>use on my film body (e.g. EF-S series).
>>I would guess if it was practical to make an optical device which
>>would 'squeeze' the normal field of view of let's say a 24mm (or any)
>>lens onto the smaller sensor someone would be offering it.
>>
Why not make one so I can get the same 35mm "FOV" with my Hasselblad. I put
a lens on and it doesn't match. It's know as learn your equipment.

Archived from groups: rec.photo.digital (More info?)

Folks,

Thanks. It appears this is indeed possible. For the others who did not
understand my point.
My point was that I have already invested in lenses with particular
FOVs which I desire. I do
not want to invest in other lenses (EF or EF-s) just to compensate for
the smaller sensor.

W

Archived from groups: rec.photo.digital (More info?)

<<I do think, though, that you are laboring under a misconception: you
do not need to buy EF-S lenses. Standard EF lenses will work fine. >>

This is NOT the point! What is the point is that if I want a 24mm lens
(35mm format-equivalent) field of view, I need to buy a 16mm lens. So
he wants a means of getting a wider field of view with the same lens on
the smaller DSLR format, rather than buying a whole new lense. Plus a
fast 16mm lens is a whole lot more expensive than an equally fast 24mm
lens, making the re-investment all that much more painful to endure.

--Wilt

Archived from groups: rec.photo.digital (More info?)

On 18 Jul 2005 07:38:13 -0700, "winhag@yahoo.com" <winhag@yahoo.com>
wrote:

>Folks,
>
>Thanks. It appears this is indeed possible. For the others who did not
>understand my point.
>My point was that I have already invested in lenses with particular
>FOVs which I desire. I do
>not want to invest in other lenses (EF or EF-s) just to compensate for
>the smaller sensor.
>
>W

In that case, maybe a little more investigation would have revealed
the .6x factor,and the problem could have been avoided.

BTW, we can't read minds here, so when you say you don't want to buy
an EF-S lens, some of us will think that you mean what you write. I
know, it's a radical thing to do, but there it is.

--
Bill Funk
replace "g" with "a"
funktionality.blogspot.com

Archived from groups: rec.photo.digital (More info?)

In message <c79md15pq2qnhpnh7q1jff0nt2hj7um4ov@4ax.com>,
Bill Funk <BigBill@there.com> wrote:


>I don't know of any "wide angle" converters.
>I do think, though, that you are laboring under a misconception: you
>do not need to buy EF-S lenses. Standard EF lenses will work fine.

>And you are far from the only one who would like such a device.

Theoretically, such a device could deliver an image that is nearly as
high in resolution as full-frame, as most super-wide lenses are not
particularly sharp and are quite oversampled with a full frame, with
fine grain or pixel pitch. The MTF could theoretically improve with
such a device.
--

<>>< ><<> ><<> <>>< ><<> <>>< <>>< ><<>
John P Sheehy <JPS@no.komm>
><<> <>>< <>>< ><<> <>>< ><<> ><<> <>><

Archived from groups: rec.photo.digital (More info?)

On 18 Jul 2005 00:12:55 -0400, Michael Meissner <mrmnews@the-meissners.org>
wrote:

>"winhag@yahoo.com" <winhag@yahoo.com> writes:
>
>> Folks,
>>
>> Does anyone know if there are any devices (or if it is even practical)
>> to make a field of view 'converter' device which may fit between
>> lens and body to compensate for the reduced field of view
>> due to non full-frame sensors?
>> It is very frustrating to have wide-angle lenses which are no longer
>> wide angle due to the small sensor size in 99% of digital SLRS.
>> I don't want to buy another lens....especially one which I cannot
>> use on my film body (e.g. EF-S series).
>> I would guess if it was practical to make an optical device which
>> would 'squeeze' the normal field of view of let's say a 24mm (or any)
>> lens onto the smaller sensor someone would be offering it.
>
>Kodak has a patent on such a device, but they never have made a product out of
>it. I remember reading from a lens maker who made one of his own, and then
>discovered the patent......

There was a "negative" lens made to fit on to the filter ring of camcorder
lenses. You set the camcorder on "macro" and screwed on the lens.
It effectively increased the field of view. I have a negative lens that
I purchased from Edmund Scientific that does somewhat the same,
but is just a single element and not very well corrected. I did an
internet search for "minus lenses", but only came up with eyeglass
lenses. Apparently there are no longer any minus lenses made for
cameras. Decades ago they were made, but are now "out of print".
The idea back then was that you mounted your camera lens on a
bellows (with an slr on the other end) and used a minus lens to make
a longer focal length lens. Then there is a focal length reducer made
for the SCT astronomical telescopes sold by Meade and Celestron.
These can reduce the focal length from F10 to F6.3. I don't think that
they will work with cameras however. Perhaps the best idea would be
to buy a shorter focal length lens if you have a camera that takes them.

Jerome Bigge
Photographer and Astronomer
Author of the "Warlady" & "Wartime" series.
Download at "http://members.tripod.com/~jbigge"