First, let me setup the discussion here.

The reason I'm getting into digiscoping is a little unique. I am a competitive shooter and have been for decades, most of my adult life in fact. I participate in rifle competitions to 1000 yards, in an NRA discipline called F-Class; in F-TR to be exact, where TR stands for Target Rifle.

I shoot at the state, national and world level. I'™m a past Texas state champion at 1000 yards and I have been shooting nationally for 7 years now and shot at the World's in '13 in New Mexico. The World'Âs is every 4 years and the venue goes to different countries. This year, it's in Canada and in 4 years hence it will be in South Africa.

A few years back, I formed a team here in Texas to take part in team competitions at various venues; our stated goal is to win the world cup in 2017, in Canada. The format of team shooting is simple; four shooters and a wind coach. The shooters shoot one at a time and they aim where the wind coach tells them to aim and they shoot when the wind coach tells them to. I'™ve been wind coaching the team since we began a few years back and we've won repeated state matches and other regional competitions and medaled in the last two national competitions; silver and bronze.

Long range shooters are obsessed with optics; riflescopes primarily and spotting scopes also. As the wind coach, my focus is on the conditions; how to detect, quantify and correct for them and anticipate when it's time to break the shot. I'™ve developed a bit of a knack at it, we even broke the existing national record in '™15 only to learn that another team somewhere else had bested us by a point. Bummer. I have fantastic shooters on the team.

I'Âm trying to figure a way to record or document my observations through the spotting scope and without the scope to educate other shooters in what is really a black art. The spotting scope allows me to monitor what we shooters refer to as 'œmirage,' but is really an atmospheric disturbance that long range photographers are familiar with. Reading the mirage tells me a lot about what's going on downrange, especially where I focus my spotting scope.
Anyway, enough of the setup, let'™s talk equipment here. My spotting scope is a Kowa TSN-82SV with an 82mm objective lens, for which I have two eyepieces. The TE-17HD, which is a 27x LER (long eye relief) design, and a TE9Z 21-63X zoom eyepiece. In competition, I use the 27X LER exclusively because I wear glasses and it makes it easy to get a good picture once in position on the rifle. (My riflescope is a March-X 5-50X56, which I usually run at 40X.)
The camera is a plain old Nikon D5200 with a series of lenses, including the 35mm prime lens. This is the one I have been using when digiscoping.
I attach the Nikon using the digiscoping adapters from Kowa. I leave the TSN-LS2 sleeve on the Kowa all the time as it does not get in the way. When I'™m ready to install the camera on the Kowa, I screw the TSN-DA1 camera adapter on the sleeve, install the TSN-AR adapter ring on the 35mm prime lens and then screw the other side of the adapter onto the TSN-DA1 camera adapter. It starts getting heavy.
When I first attempted to use this with the 27X LER eyepiece, I could not focus it on the objecting. I think there may be something to do with the distance between the camera objective lens and the eyepiece lens. The camera adapter allows you to change that distance, but did not find it quickly enough that day. Instead, I replaced the LER eyepiece with the zoom eyepiece and tada, I had focus.
I took some pictures of the target line at various magnifications for the eyepiece and then put everything away.
Here are some examples of the target line at 1000 yards.

So here are some questions. I'™m wondering about the relationship between the size of the image compared to the black in the pictures. The higher the magnification, the bigger the image.
I'™m wondering about the relationship between the LER and the objective as I would like to use that eyepiece when I'™m in competition. My thinking is that the camera objective lens should be located about where the eye (eye relief) should be and for the LER, it'™s 32mm and for the zoom it's 16mm.

I will be playing more with this, but I'™m trying to get some main rules or guidelines here, or postulate some, because I want to make it simple and repeatable and I want to be able to record the mirage flow and other things for documentation.

I have other lenses from 18mm to 300mm, but the 35mm is so nice and light.

The first picture is at 20X. Each target is 6 feet wide and 6 feet high. The aiming black is 44inches in diameter and the smallest ring, the X-ring is 5 inches in diameter.
The next picture is at 40X, what I usually set my riflescope at.
The last one is at 60X.

Because I'm not doing it for astronomical purposes.

Kind of what I figured since I'm getting responses. I'll write up details and come back to post in a bit.

I'm set up to take pictures with my Nikon DSLR through my spotting scope and I would like to discuss some concepts. I realize this is very esoteric, but I was hoping some people here could discuss it with me. Where should I post an OP on that subject?

Correct, well, all except from inside a manhole. I'm not eve sure there was one there. Need to check other pictures.

Bob, very nice picture.

Yeah the fisheye look is different, it's not the kind of lens that you can use everywhere.

When I took the picture, the ground under the tower was just dirt and full access. This was in summer of 2000, a very innocent age.

The fisheye picture was taken with my first digital camera, a Nikon Coolpix 990. The fisheye lens attached to the front off the lens.

Answer to question #2:

Yeah, I'd hate to be hit by one of those peppercorns, or even pepper flakes.

Ok, next question. What year was it taken?

The picture, I mean.

I will add that this was done freehand, standing. In retrospect, I wish I would have noticed that I was not perfectly centered underneath, but that was difficult and it's a busy place.

Then again, having it a tad off-center gives it a bit of character.

Gosh, you guys are good. And quick on the uptake. Yes, it's indeed the Eiffel Tower.

This is a picture I took with a fisheye lens some years back.

My first post here and I'm enjoying the site.