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Old Aug 21, 2009, 5:21 PM   #1
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Default Newbie with Digiscoping question.

Im a new DSLR owner (Rebel XSi) and have also been in the market for a telescope. I just stumbled across the world of digiscoping. I live in a highrise building facing the lake and would love a telescope/spotting scope strong enough to zoom in on passing boats, planes, wildlife. And while Im at it, snap a photo on my DSLR if I can. Im not too concerned with photo quality as I know I wont get the best photos considering my budget (under $400).

I currently have a 250mm Canon lens. With regards to scopes, Im considering at least 80-100mm lenses. What does this translate to in terms of DSLR mm's ?

The scope will sit on a tripod in my living room most of the time, and ill bring it outdoors on occasion so size isnt the most important factor.

Can anyone recommend a strong/decent scope for under $400 ?

Ive checked some bird and digiscoping forums, but just thought Id get an opinion from someone in the same boat.

Thanks !

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Old Aug 21, 2009, 5:42 PM   #2
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I currently have a 250mm Canon lens. With regards to scopes, Im considering at least 80-100mm lenses. What does this translate to in terms of DSLR mm's ?
...
Millimeters (mm) is simply a unit of measure (1/1000 of a Meter). You have to specify, or know from context, what you are measuring.

Photographic terminology shorthand and telescope terminology shorthand are different. There can be no comparison of "mm" between the two. You must use the full, untruncated terms to communicate successfully.

In photographic slang, when you refer to a lens as being N number of mm you are referring to the lens' focal length. "250mm lens" really means "a lens with a 250mm focal length". There are other camera lens attributes that can be measured in mm, but they are used less frequently and are thus always used in the full untruncated form (e.g. "52mm filter size", ...).

In telescope slang, focal length is less commonly discussed. The "biggy" with telescopes is the diameter of the objective, its aperture. This is specified as its actual diameter (mm, in, or meters) rather than as a ratio of its diameter to the focal length (f/stop in camera jargon or "focal ratio" in telescope jargon).

The 80-100mm specification you are seeing in the spec's for scopes is the objective diameter. For astronomical use, the physical size of the aperture is what's most important; the f/stop is of little concern for most such use. For terrestrial use, f/stop can be important, but only when using the scope without an eyepiece.

For digiscoping, 80-100mm objectives are good. To get an idea of the image size that will result you multiply the focal length of the camera lens you will be using behind the eyepiece by the magnifying power of the scope. If you have a 10x scope and a 55mm lens on the camera the resulting package would give the same field of view of a 550mm lens mounted directly on the camera, assuming there is no vignetting.
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Old Aug 21, 2009, 6:37 PM   #3
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Thanks for the input. Im now working on narrowing down my brand/model selections. Any recommendations ?

Should I try to stay above or below a certain f# with regards to the scope lens ?

Also, do larger objective diameters allow for more light ?

Last edited by RebelXSi; Aug 21, 2009 at 6:42 PM.
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Old Aug 22, 2009, 4:59 PM   #4
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Millimeters (mm) is simply a unit of measure (1/1000 of a Meter). You have to specify, or know from context, what you are measuring.

Photographic terminology shorthand and telescope terminology shorthand are different. There can be no comparison of "mm" between the two. You must use the full, untruncated terms to communicate successfully.

In photographic slang, when you refer to a lens as being N number of mm you are referring to the lens' focal length. "250mm lens" really means "a lens with a 250mm focal length". There are other camera lens attributes that can be measured in mm, but they are used less frequently and are thus always used in the full untruncated form (e.g. "52mm filter size", ...).

In telescope slang, focal length is less commonly discussed. The "biggy" with telescopes is the diameter of the objective, its aperture. This is specified as its actual diameter (mm, in, or meters) rather than as a ratio of its diameter to the focal length (f/stop in camera jargon or "focal ratio" in telescope jargon).

The 80-100mm specification you are seeing in the spec's for scopes is the objective diameter. For astronomical use, the physical size of the aperture is what's most important; the f/stop is of little concern for most such use. For terrestrial use, f/stop can be important, but only when using the scope without an eyepiece.

For digiscoping, 80-100mm objectives are good. To get an idea of the image size that will result you multiply the focal length of the camera lens you will be using behind the eyepiece by the magnifying power of the scope. If you have a 10x scope and a 55mm lens on the camera the resulting package would give the same field of view of a 550mm lens mounted directly on the camera, assuming there is no vignetting.
Many telescopes are available with camera adapters. With an SLR, this would be the best way to go. In other words, these adapters, plus a cheap t-adapter, allow you to use a scope with the same ease as using a lens. In my case, my Swarovski, (which unfortunately is a heck of a lot more money than your budget) depending on which of the two adapters I'm using, allows me to use it as either an 800mm or 1100 mm lens. Respectively they are f10 and f13.

The adapter screws into the Scope, and the T-adapter is actually a specific camera mount.

The Swarovski, Zeiss, Leica, and other high end spoting scopes are built tough, and that explains most of the cost. However, look to the brand name Meade. You'll find something in your price range there, and the optical quality will be just as good. Just don't bang it around...

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Old Aug 23, 2009, 12:17 PM   #5
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If you are wanting to photograph moving targets, I suggest that you stay away from scopes with angled eyepieces. A straight scope is easier to align on the target when time is an issue. I suggest you look at Bushnell, which has a number of reasonably priced models. List prices on scopes and binoculars are inflated, and they can usually be found at about half the price. For example, 60mm Bushnell Spacemasters have been a favorite for years - the straight models have a peep sight which makes for speedy target aquisition - they list around $600, but can be found for $300 from reliable sellers like B&H for $300, and have a lifetime guarantee. I once sent an older one in with a damaged prism, and they replaced it with a new one! The Bushnell Discoverer (which has an internal zoom, so no fixed focal length eyepiece is available) even is supplied with a camera adapter, and costs even less. They even have an Imageview model with a built in digital camera - I have no idea how good it is - that is even less expensive yet. There are specialty spotting scope web stores that have a selection of models from a variety of manufacturers that you can compare (or visit optical shops like Scope City); there are even reviews you can find on the internet. People can certainly give you good advice based on their own experiences, but everyone's preferences are different, so any one person's advice might not suit your particular requirements, so do your research and you should be able to find something satisfactory.
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Old Aug 25, 2009, 1:45 PM   #6
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Looking over the Bushnell products on B&H, unlike the Meade, the Bushness adapter even though it connects directly to the camera, uses the zoom eye-piece of the Scope. Does this mean that your camera is getting it's image from the small hole of the zoom eye-piece?

If so, I suspect there will be serious viewing limitations.

On the Meade, you remove the Scopes eye piece, and the camera screws directly to the tube assembly.

If I am mistaken, please correct me.

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Old Aug 25, 2009, 4:36 PM   #7
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Using the 15X magnification of a zoom lens would have the same exit pupil size as a single magnification 15X eyepiece. The Bushnell Discoverer (which is supplied with a tube adapter for which you would have to purchase an inexpensive camera specific T-adapter) does not have a removable eyepiece. The Spacemasters (I don's know about the newest version - you would have to inquire) have always had screw out eyepieces, but they no longer offer the slower selling single magnification oculars, which probably can be found used on ebay, nor the tube adapter, which would have to be found on the used market as well. I do not believe any spotting scope can be used without an eyepiece, unless there is a specific adapter with built-in optics for it. P&S digiscoping has become so popular, that the market for slr digital photography has moved to the higher end scopes, where adapters are still offered. Your options in your budget range for suitable new scopes are limited.
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Old Aug 25, 2009, 5:27 PM   #8
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Using the 15X magnification of a zoom lens would have the same exit pupil size as a single magnification 15X eyepiece. The Bushnell Discoverer (which is supplied with a tube adapter for which you would have to purchase an inexpensive camera specific T-adapter) does not have a removable eyepiece. The Spacemasters (I don's know about the newest version - you would have to inquire) have always had screw out eyepieces, but they no longer offer the slower selling single magnification oculars, which probably can be found used on ebay, nor the tube adapter, which would have to be found on the used market as well. I do not believe any spotting scope can be used without an eyepiece, unless there is a specific adapter with built-in optics for it. P&S digiscoping has become so popular, that the market for slr digital photography has moved to the higher end scopes, where adapters are still offered. Your options in your budget range for suitable new scopes are limited.
I think we're cross communicating here. A true camera adapter is *not* an eyepiece. It is, in the case of my Swarovski, a complete replacement to focus all the light of the scope properly onto the film/sensor. Or in the case of the Meade, to allow the light from the Meade assemby to focus onto the film/sensor. In both cases, you cannot use the 'Scope in the normal manner with your own eyes and these adapters.

Perhaps, it's not as important as I believe it to be. Can you post an example shot from your Bushnell?

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Old Aug 25, 2009, 5:57 PM   #9
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I think we're cross communicating here. A true camera adapter is *not* an eyepiece. It is, in the case of my Swarovski, a complete replacement to focus all the light of the scope properly onto the film/sensor. Or in the case of the Meade, to allow the light from the Meade assemby to focus onto the film/sensor. In both cases, you cannot use the 'Scope in the normal manner with your own eyes and these adapters.

Perhaps, it's not as important as I believe it to be. Can you post an example shot from your Bushnell?

Dave
I don't think I ever said an adapter was a substitute for an eyepiece. In the case of the Meade adapter, if it is the one on B&H, I believe it is for an astronomical telescope, not a spotting scope. Sorry, I have not done any photos through the scopes in years, as I have the necessary telephoto lenses for what I do, and which I think do a better job. If I have time in the next few days, I will dig things out and take some for you - I am somewhat curious myself to see if digital cameras will do a better job than the older film ones, with the ability to postprocess the images. I swapped my older Spacemaster zoom lens for a newer one with a higher eyepoint, and it is too wide for the tube, but I think I have a nonzoom lens that I kept for that purpose - that is provided you can tell me why in the world you would be looking for a cheaper alternative if you have a top drawer scope like a Swarovski. . . .
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Old Aug 25, 2009, 8:23 PM   #10
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I don't think I ever said an adapter was a substitute for an eyepiece. In the case of the Meade adapter, if it is the one on B&H, I believe it is for an astronomical telescope, not a spotting scope. Sorry, I have not done any photos through the scopes in years, as I have the necessary telephoto lenses for what I do, and which I think do a better job. If I have time in the next few days, I will dig things out and take some for you - I am somewhat curious myself to see if digital cameras will do a better job than the older film ones, with the ability to postprocess the images. I swapped my older Spacemaster zoom lens for a newer one with a higher eyepoint, and it is too wide for the tube, but I think I have a nonzoom lens that I kept for that purpose - that is provided you can tell me why in the world you would be looking for a cheaper alternative if you have a top drawer scope like a Swarovski. . . .
Lin Evans, who used to post here, and for all I know still does, used an ETX Meade for digiscoping. I forget which model, but he raved over the optics.

Of course he, like I, prefered one of the higher end spotting Scopes, (Swarovski, Leica, Zeiss, etc) but he stated that optically the Meade could hold it's own.

As I get older and poorer, I'd like to know which one of the cheaper spotting scopes is best - Because while I am one of the few people who shoots with these gadgets handheld, that would certainly not occur with the Meade...

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