Spotting Scopes vs Astronomical Scopes

[jpspeeddemon]

i am in the market for a spotting scope. i live close to a store called Hands On Optics, their website is handsonoptics.com. they sell spotting scopes but are mostly into astronomical stuff. so i went there the other day and said i wanted to look at a Zeiss, Pentax, and Swaro. the owner asked me what i was goiing to use it fore and i told him long range shooting so mainly to spot trace and hopefully see some bullet holes at 500yds.
suprisingly to me he asked if it needed to be waterproof or extremmely durable or small to carry. i said i was just going to use it for range/target shooting so no.
he recommended that i should buy an astronomical scope saying because the huge objectives of even the lesser ones have much better resolution than the most expensive spotting scopes. he showed one to me, the Celesrton XLT 127, i looked through it but it was starting to get dark so i could not tell its performance accuratly,i was a dope for going right before the sun went down, do not know what i was thinking on that one).
anyways, the 127 had a 5inch objective which is huge and he said that i could get a 31x fixed eye peice all the way up to a 50-150x zoom or 300x fixed before resolution starts to suffer.
so i ask, what do you guys think?
When i went in i was pretty set on the Pentax 20-60x80mm ED scope for $1000, but the XLT 127 is $650 for the nice heavy stand and everything. i researched the 127 and its for serious ameteur astronomers.

 

[CatShooter]

The astronomical scopes offer a lot of sharpness, but are more susceptible to mirage, and are much more fragile.

The Pentax 20x60-80mm ED is available for a lot less than $1,000. I paid $750 for mine, and I see them on eBay for $800 all the time.


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[rstreich]

There's a lengthy thread here that talks about astronomical scopes. You can get good results for reasonable money.

They can be more susceptible to mirage, but then that would only be because they have greater resolution--the bigger the objective, the better the resolution. How much resolution you'll need depends on the size of the bullet holes that you want to see, Bear in mind, however, that atmospheric conditions can make it difficult, if not impossible, to resolve a bullet hole at 500 yards.

Personally, I'll stick with a spotting scope 'cause they're easier to transport.

 

[CPorter]

The most sure way to see bullet holes at 500 yards is a video camera transmitter/receiver rig. I have both a spotting scope and a Meade telescope. Mirage makes both of them fairly useless past 300 yards on a regular basis.




PC164C Super Low Light - High Res Monochrome Video Camera
Price $89.99

2-12 mm varifocal auto iris lens 59.95

AVX900T4 900 MHz High Power FM Wireless Audio/Video Transmitter
Price $74.99

AVX900R1 900 MHz FM Audio/Video Receiver Price $94.99

MON7TFT 7" TFT Monitor Kit Price $149.99

You will need a few other small pieces like batteries and a tripod for the camera but this is the general setup.

 

[Fred Bohl]

The thread that rstreich was referring to is here and as he says long but it does cover the topic and is probably worth the read time. You may also find this useful Bullet Hole Resolution Calculator.

CPorter is correct that for the most reliable 500 yard target spotting, a camera and receiver system is the answer. However these are not permitted in matches at this time. This is also a very expensive solution and a lot of gear to haul and setup. Also note that for a proper view of the target, some of the most expensive parts are in the field of fire,think about what gets hit besides the target particularly at a public range).

Another consideration is the visibility problems caused by air quality, wind and particularly mirage. While these tend to make use of any spotting scope difficult beyond 300 yards, the same atmospheric issues exist for the rifle scope and the effects are just as bad if not worse. For practice or load development my belief is that if you can't spot the shots your wasting barrel life to be shooting. In a match your stuck with the conditions but at least all competitors are in the same predicament.

 

[rstreich]

Thanks for catching that, Fred. Guess I wasn't paying attention to what was in my paste buffer. I fixed my link.

 

[djones]

CPorter writes: The most sure way to see bullet holes at 500 yards is a video camera transmitter/receiver rig.
_____________________________

Do you have pics of your setup in use and do any/all of the components run on battery power or do they require AC?

 

[Duey1267]

After reading several pages on this topic I decided to go with the Celestron C130MAK. After comparing it to a Leupold spotting scope i am very happy. The only down side is the size of the celestron it is considerably larger and heavier than the Leupold. It is something that you couldn't go hiking with, its huge But the clarity is something that you need to see to believe.

Just my $.02 worth

 

[Travelor]

Duey1267, I too bought the Celestron 130MAK. It came with the 36mm eyepiece for a magnification of 63x. We took it out to the 1000 yard range and before the match were able to see bullet holes in the number borads, but never in the targets.

For those that are contemplating one - the smaller 10x50 finder scope is upside down and backwards as it does not have the correcting lens and the crosshairs are terribly out of focus. For those that have one - is this normal? I see NO adjustments on the finder scope.

Have you changed eyepieces yet?

We are going to the 600 yard line today and will just have to see what happens with the 36mm eyepiece.

George

 

[Duey1267]

I have not shot past 600 yds with it yet and i am using the eye piece that camt with it. I was able to clearly see .22 cal holes at 600yds. My spoting scope worked fine i was ready for the mirror image and it was in focous for me. It did take me some time to get it aligned with the main image. If you have a problem with the image call the Celestron I hear that the CS is good.

Duey

 

[Travelor]

Well, shot 600 yards yesterday and used the Celestron. We were able to see 6mm bullet holes on the white part of the target but not the black. I think a better rear lens is in order to increase clarity and power is needed over the one supplied with this product.

George

 

[Fred Bohl]

I'm glad to hear still others having good results with the C130MAK.

Neither of you said how you were using the lens. For best possible image clarity and minimum distortion, it would be best use the rear cell with the flip mirror down,this does produce and image that is both reversed, left is right, and inverted, up is down). This requires an eyepiece holder on the rear cell. The ScopeTronix Visual Back STVB,$30 at scopetronic.com) or the combination of Meade - Rear Cell Adapter for ETX Telescopes [ME-07036],$25 at OPT) plus Meade - Eyepiece Holder for Schmidt-Cassegrain or Maksutov-Cassegrain Telescopes [ME-07182],$25 at OPT) will work fine. I only view through the rear cell using one of these and either a lens or digital imager.

A suggested range of lenses to provide a good match of magnification to range: 40mm 50x for 100 & 200 yards; 20mm 100x for 200 & 300 yards; 10mm 200x for 300 to 600 yards and 5mm for 600 to 1000 yards. The overlap is meant to provide a lower magnification in poor seeing conditions and higher magnification in the best seeing conditions and to provide options for limiting costs by limiting the number of lenses. For example you could delete the 5mm as that will be useful only on rare occasions.

While the above equipment will provide the needed resolution and magnification, you are limited by the atmospheric conditions,pollution, haze, fog and mirage). Also note that it is very important to have sufficient contrast between the bullet hole and the target surface.

In Travelor's case a bullet hole is essentially non-reflecting and the white areas are good reflectors so that there was adequate contrast. However, the same target black areas provided insufficient contrast to see bullet holes in the black. It would be better to change targets to get improved contrast such as the newer light blue on white of the 600 and 1000 yard IBS targets or a similar color contrast rather than any black.

 

[Travelor]

Mr. Bohl, not sure of the termnology, but I am using the lens and the 45 degree "elbow" that came with the Celestron and am using the rearmost lens opening to observe the bullet holes. I have not been inpressed with the lend that came with the Celestron as the focus is very very critical and not very clear.

At your suggestion, I ordered a 8-24mm Zoom Lanthanum LV Eyepiece - 1.25" [VX-3777] yesterday.

It will be interesting to see how this lens works out.

George

 

[Fred Bohl]

George,

The "elbow" you are referring to is actually an "erecting diagonal" and when used on the rear cell provides an erect,up is up) and normal,left is left) image that is easier to use for terrestrial viewing such as bird watching.

However, the "erecting diagonal" which uses a roof prism,like an SLR camera) not a mirror, the typical refractor spotting scopes use either a Schmidt prism,bent or folded types) or a lens set,straight tube type) to produce an erect image. All these systems degrade the image by introducing more elements and distortion potential but this is in comparison to and astronomic telescope that does not use any of these as it does not provide an erect image,they need the least possible distortion so they forgo this nicety).

If you could get either of the rear cell lens holders and use the lenses without the "erecting diagonal" you will probably see a definite improvement in image sharpness and apparent color quality. You will have to adapt to seeing the image as inverted and reversed but the improvement in image quality is worth the effort.

 

[CPorter]

Travelor,

Part of the reason for the critical focus issue is a low effective f-stop for more light gathering produces a narrow depth of field and it is further narrowed by high magnification. It's been a long time since fooling around with my 35mm but if you talk to the scope dealer he should be able to find a compromise.

djones - don't have pictures of the video rig but for the transmitter/receiver try here:

http://www.supercircuits.com/index.asp?PageAction=VIEWPROD&ProdID=3449

 

[ronemus]

I've revived this thread to announce that I've put together a system to link a video camera at the target to a display at the firing line using wireless technology. If you're interested, please see the full announcement in the Tools, Dies, Optics & Misc. forum for details.

Regards,
Alan