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Red Dot Sights. (1 Viewer)

The red dot sight is just a sight without magnification. It is not very accurate but it puts the target in the line of sight. No correction is needed - you adjust it for your average shooting distance and you're in business.
 
The red dot sight is just a sight without magnification. It is not very accurate but it puts the target in the line of sight. No correction is needed - you adjust it for your average shooting distance and you're in business.
___________

But if you're sighting through the red dot, how can the camera track focus? The focus point of the camera may not be on target if there is a parallax problem, it seems to me.
 
The sight is used once to point the camera in the right direction. Then you don't use the sight anymore. You should see the bird in the viewfinder or the LCD and then you work normally.

When using large magnifications, say 40X or more, it is often difficult to find the bird without a sight. Often, the bird will move before you find it. With the red dot sight, it is much easier because you point immediately in the right direction. Even if the sight is not adjusted right on target, it is much easier to find it.

Once you have found the bird, you compose, focus, adjust for light and take the shot.

If you can manage to try one, you will quickly understand.
 
The red dot sight is just a sight without magnification. It is not very accurate but it puts the target in the line of sight. No correction is needed - you adjust it for your average shooting distance and you're in business.

___________

But if you're sighting through the red dot, how can the camera track focus? The focus point of the camera may not be on target if there is a parallax problem, it seems to me.

It must be remembered that the Red Dot Sight was initially designed for use with (mainly) Air Rifles and Pistols. Although the parallax problem is still there, it is perceived as not being much of problem.
It is still quite a problem to set up for digiscoping use, but the secret is getting some sort of a compromise to suit the average shooting (i.e. photographic) distance. The vertical axis always remains the same, with the horizontal axis changing, dependant on distance between telescope lens and subject, therefore this vertical axis is the initial alignment aid.

Roger
 
Once you have found the bird, you compose, focus, adjust for light and take the shot.

If you can manage to try one, you will quickly understand.[/QUOTE]

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Thanks for the explanation, Jules. Now I understand.

Dennis
 
It must be remembered that the Red Dot Sight was initially designed for use with (mainly) Air Rifles and Pistols. Although the parallax problem is still there, it is perceived as not being much of problem.
Roger
What I omitted to mention, was, that the resultant parallax angle (when a Red Dot Sight is mounted on Air Rifles/Guns) is very narrow compared to that when used with a Telescope/Camera combination, due to the Red Dot Sight line of sight position relative to the Air Rifle/gun bore.

Roger
 
I use a Simmons 42mm red dot on my scope,, once it is aligned it is quick and easy to place on the object and have it centered in the camera,, I find the field of view to be very good and do not notice any parallax issues,, if there is any it has to be extremely small as I also use the scope for some astronomy and when aligning on a star the image is dead center in the scopes eyepiece,,

I have attached a photo of one of my digascoping arrangements,, I also use a Nikon P5000 as well as the Oly E3 to shoot afocal through several of my TeleVue eyepieces,,

Derry
 

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