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Desperately seeking optics to augment a camera viewfinder.

 
 
Peter Jason
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      05-10-2007
I have a digital SLR and the viewfinder with
the manual focusing is pretty poor;
especially in dim light.

I need some form of optical system to hang
off the viewfinder to enlarge the viewfinder
field and so make the manual focusing easier.

I already have one of the propriety
right-angle magnifiers which improve the
situation, but this is not enough.

I need more magnification, and so can someone
help me with some advice about adapting a
small monocular or microscope or small
telescope to do the job.

I don't have to see the whole field, just
the part I want to focus.

Please help.


 
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Shawn Hirn
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Posts: n/a
 
      05-10-2007
In article <f209i4$2lc6$(E-Mail Removed)>,
"Peter Jason" <(E-Mail Removed)> wrote:

> I have a digital SLR and the viewfinder with
> the manual focusing is pretty poor;
> especially in dim light.
>
> I need some form of optical system to hang
> off the viewfinder to enlarge the viewfinder
> field and so make the manual focusing easier.
>
> I already have one of the propriety
> right-angle magnifiers which improve the
> situation, but this is not enough.
>
> I need more magnification, and so can someone
> help me with some advice about adapting a
> small monocular or microscope or small
> telescope to do the job.
>
> I don't have to see the whole field, just
> the part I want to focus.
>
> Please help.


Which camera are you using?
 
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dj_nme
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Posts: n/a
 
      05-11-2007
Peter Jason wrote:
> I have a digital SLR and the viewfinder with
> the manual focusing is pretty poor;
> especially in dim light.
>
> I need some form of optical system to hang
> off the viewfinder to enlarge the viewfinder
> field and so make the manual focusing easier.
>
> I already have one of the propriety
> right-angle magnifiers which improve the
> situation, but this is not enough.


Maybe a split prism focusing screen like a Katzeye would be the way to go?
It replaces the frosted screen that is currently in your DSLR camera.
The focusing aide only helps for the central portion of the image, though.
 
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Peter Jason
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      05-11-2007

"Shawn Hirn" <(E-Mail Removed)> wrote in
message
news:(E-Mail Removed)...
> In article
> <f209i4$2lc6$(E-Mail Removed)>,
> "Peter Jason" <(E-Mail Removed)> wrote:
>
>> I have a digital SLR and the viewfinder
>> with
>> the manual focusing is pretty poor;
>> especially in dim light.
>>
>> I need some form of optical system to hang
>> off the viewfinder to enlarge the
>> viewfinder
>> field and so make the manual focusing
>> easier.
>>
>> I already have one of the propriety
>> right-angle magnifiers which improve the
>> situation, but this is not enough.
>>
>> I need more magnification, and so can
>> someone
>> help me with some advice about adapting a
>> small monocular or microscope or small
>> telescope to do the job.
>>
>> I don't have to see the whole field, just
>> the part I want to focus.
>>
>> Please help.

>
> Which camera are you using?


I'm using an Olympus E500 with a
"Varimagnifinder" right-angle viewfinder
accessory.
http://www.alanwood.net/photography/...ni-finder.html
This accessory helps a lot, but more
magnification is needed, especially in dim
light.


 
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Peter Jason
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Posts: n/a
 
      05-11-2007

"dj_nme" <(E-Mail Removed)> wrote in
message
news:4643c95a$0$9075$(E-Mail Removed)...
> Peter Jason wrote:
>> I have a digital SLR and the viewfinder
>> with the manual focusing is pretty poor;
>> especially in dim light.
>>
>> I need some form of optical system to hang
>> off the viewfinder to enlarge the
>> viewfinder field and so make the manual
>> focusing easier.
>>
>> I already have one of the propriety
>> right-angle magnifiers which improve the
>> situation, but this is not enough.

>
> Maybe a split prism focusing screen like a
> Katzeye would be the way to go?
> It replaces the frosted screen that is
> currently in your DSLR camera.
> The focusing aide only helps for the
> central portion of the image, though.


Thanx, I'll check this out.


 
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Salmon Egg
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Posts: n/a
 
      05-11-2007
On 5/10/07 4:23 PM, in article f209i4$2lc6$(E-Mail Removed), "Peter
Jason" <(E-Mail Removed)> wrote:

> I have a digital SLR and the viewfinder with
> the manual focusing is pretty poor;
> especially in dim light.
>
> I need some form of optical system to hang
> off the viewfinder to enlarge the viewfinder
> field and so make the manual focusing easier.
>
> I already have one of the propriety
> right-angle magnifiers which improve the
> situation, but this is not enough.
>
> I need more magnification, and so can someone
> help me with some advice about adapting a
> small monocular or microscope or small
> telescope to do the job.
>
> I don't have to see the whole field, just
> the part I want to focus.
>
> Please help.
>
>

I don't understand how you can be helped much with a passive system.
Conservation of brightness means that you will get a magnified image that is
going to be as dim or dimmer than the unmagnified image. I can understand
how a larger image might help a bit. What you really need, if you are
serious, is an image intensifier. That could also have built-in
magnification.

Bill
-- Fermez le Bush--about two years to go.


 
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Peter Jason
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Posts: n/a
 
      05-11-2007

"Salmon Egg" <(E-Mail Removed)> wrote
in message
news:C269284C.76D7B%(E-Mail Removed)...
> On 5/10/07 4:23 PM, in article
> f209i4$2lc6$(E-Mail Removed), "Peter
> Jason" <(E-Mail Removed)> wrote:
>
>> I have a digital SLR and the viewfinder
>> with
>> the manual focusing is pretty poor;
>> especially in dim light.
>>
>> I need some form of optical system to hang
>> off the viewfinder to enlarge the
>> viewfinder
>> field and so make the manual focusing
>> easier.
>>
>> I already have one of the propriety
>> right-angle magnifiers which improve the
>> situation, but this is not enough.
>>
>> I need more magnification, and so can
>> someone
>> help me with some advice about adapting a
>> small monocular or microscope or small
>> telescope to do the job.
>>
>> I don't have to see the whole field, just
>> the part I want to focus.
>>
>> Please help.
>>
>>

> I don't understand how you can be helped
> much with a passive system.
> Conservation of brightness means that you
> will get a magnified image that is
> going to be as dim or dimmer than the
> unmagnified image. I can understand
> how a larger image might help a bit. What
> you really need, if you are
> serious, is an image intensifier. That
> could also have built-in
> magnification.
>
> Bill
> -- Fermez le Bush--about two years to go.
>
>


I agree but there's always a lighted
cigarette end, or reflection from furniture
etc to assist. The auto-focus system is
difficult because the flash has to be
actuated for it to work, and sometimes it
hunts for about 10 seconds.


 
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Richard J Kinch
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Posts: n/a
 
      05-11-2007
Peter Jason writes:

> I need some form of optical system to hang
> off the viewfinder to enlarge the viewfinder
> field and so make the manual focusing easier.


I make an item like that:

http://www.truetex.com/canon_viewfinder_magnifier.htm

However I don't know if magnification is going to help as much as you hope
with focusing in low light.

The basic viewfinder problem in cameras like your Olympus E500 is the
compounding of beam-splitting (for the autofocuser) and prismatic-screen
focusing, which severely degrade brightness. That's one reason the the
viewfinder views are minifying instead of magnifying, to maintain some
brightness after all the losses.

If you can take the focusing screen out of your SLR, try doing so, and see
how much brighter the viewfinder view is.
 
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Mike Coon
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Posts: n/a
 
      05-11-2007
Peter Jason wrote:
> This accessory helps a lot, but more
> magnification is needed, especially in dim
> light.


But more magnification is only going to make it look dimmer. Conservation of
energy, and all that...

Mike.
--
If reply address = connectfee, add an r because it is free not fee.


 
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Wilba
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Posts: n/a
 
      05-12-2007
Peter Jason wrote:
>
>I have a digital SLR and the viewfinder with the manual focusing is pretty
>poor; especially in dim light.
>
> I need some form of optical system to hang off the viewfinder to enlarge
> the viewfinder field and so make the manual focusing easier.
>
> I already have one of the propriety right-angle magnifiers which improve
> the situation, but this is not enough.
>
> I need more magnification, and so can someone help me with some advice
> about adapting a small monocular or microscope or small telescope to do
> the job.
>
> I don't have to see the whole field, just the part I want to focus.
>
> Please help.


Shine a torch on the subject while you're focussing?


 
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