Some digiscoping experiments with a dslr (1 Viewer)

[theMusicMan]

As per my newly modified sig, you'll see I'm now in possession of a Skywatcher Evostarr-80 ED. :king:
(I opted for the version with the eyepieces and finderscope included as I quite fancy having a go at sky watching myself!)

I just have to wait for my t-mount to turn up now.......

Weath.

Nice scope Weath - and you're going to use that for photographing birds? Very good price I must say when compared to spotting scopes et al.

 

[Weath]

Nice scope Weath - and you're going to use that for photographing birds? Very good price I must say when compared to spotting scopes et al.

Birds will be it’s primary function and I agree it’s a great price to pay, especially having seem some of the shots captured on this thread, when compared to spotting scopes/the next step up with 500, 600, 800mm lenses – which I really cannot justify being just a humble hobbyist.

Still no sign of the t-mount :-C

Weath.

 

[Weath]

The t-mount has arrived.

I appear to have some teething problems though.....the scope won't focus on anything when the 30D is mounted directly onto it.

i.e. camera -> tmount -> scope

When I say anything, I mean any object, at any distance - 5-10-20-30-40m etc ... away. I can't even see buildings in the next village 1.5km away ????

I notice from previous posts that Jules had a similar issue when trying the scope out in a shop, but this was put down to the travel of the focuser on the scope.

I've just checked how far the focuser travels and it's spot on 3" (silver part) which seems to be the same as Paul stated it should be back then.

When fitting: camera -> tmount -> star diagonal -> scope
Everything is wonderful (although upside down at certain angles)

Am I missing something fundamental here ????

Weath.

 

[phaser]

picture of your setup?

 

[Derry]

Weath, remove the diagonal and insert the T mount in place of it,, should work then,,


Derry

 

[phaser]

he says it wont work with only the t-mount.

Try to place the scope and something to put the camera on so you can line up the camera and scope. Then adjust the distance between them and se how much is needed to get focus.

 

[Weath]

picture of your setup?

Pic1 shows the 30d connected to the scope with just the tmount
Pic2 shows the 30d connected to the tmount, then the diagonal.

Setup 2 focuses
Setup 1 doesn't

[For completeness - the tmount is the True-2 type purchased from here http://www.cncsupplyinc.com]

 

[jpwone]

I have the same tmount, scope, camera.

With the tmount and the diagonal I get a focus range of approxiamately 5 meters to 10 meters.

With the tmount directly to the ED80 (no diagonal) focus is not possible. You need a minimum of 50mm of extension between the scope and tmount to get a usable focus range.

My set up is:-

30D --> 13mm EOS extension --> True2 adapter --> 50mm extension --> ED80

it will work without the 13mm extension. I have this in for two reasons. Firstly it gives me a slightly closer minimum focus distance. Secondly, I have fitted an AF confirm chip to the adapter and have put the 13mm extension in to avoid disturbing the contacts on the chip whenever I remove the adapter from the camera.

I'll take this opportunity to thank Paul Corfield for his assistance when I was choosing the bits and hard work in sharing his results with us all.

Hope this helps

 

[Derry]

yes,, you will need an extension tube to replace the distance of the diagonal if you can focus with it installed,,

my T mount is longer at 3 inches (76mm) and allows focusing from about 20m on out,, my focuser rack may provide a longer distance also,,

Derry


4/3 adapter--T mount--extension tube
OM T adapter

 

[Weath]

Try to place the scope and something to put the camera on so you can line up the camera and scope. Then adjust the distance between them and se how much is needed to get focus.

It's too dark here now to try anything meaningful.

2 additional pics to show the breakdown of the setup.

Pic3 - Camera with t-mount
Pic4 - Where the camera & mount attaches on the scope

Weath.

 

[Weath]

With the tmount and the diagonal I get a focus range of approxiamately 5 meters to 10 meters.

Yep, that sounds about right.

With the tmount directly to the ED80 (no diagonal) focus is not possible. You need a minimum of 50mm of extension between the scope and tmount to get a usable focus range.

That's put my mind at ease!

Hope this helps

Immensely!

Thanks a lot John (and everybody else) :t:

Look's like I'm not quite there yet....extension tube(s) will be ordered tomorrow.

Weath.

 

[Derry]

depending on how close you want to try and focus, you might consider two extension tubes, a two inch and a three inch, offering more flexability,,

Derry

 

[JGobeil]

The t-mount has arrived.

I appear to have some teething problems though.....the scope won't focus on anything when the 30D is mounted directly onto it.

i.e. camera -> tmount -> scope

When I say anything, I mean any object, at any distance - 5-10-20-30-40m etc ... away. I can't even see buildings in the next village 1.5km away ????

I notice from previous posts that Jules had a similar issue when trying the scope out in a shop, but this was put down to the travel of the focuser on the scope.

...

Weath.

Weath,

When trying the scope in the store, it would not focus on objects closer than about 30 meters but adding spacers fixed the problem. Paul suspected that the focuser was locked, but since I haven't returned to the store, I don't know.

As Derry said, since it works fine with the diagonal, there must be someting wrong in your procedure. I hope you can find the problem quickly.

Regards
Jules

 

[TenaCJed]

I have the same tmount, scope, camera.

With the tmount and the diagonal I get a focus range of approxiamately 5 meters to 10 meters.

With the tmount directly to the ED80 (no diagonal) focus is not possible. You need a minimum of 50mm of extension between the scope and tmount to get a usable focus range.

My set up is:-

30D --> 13mm EOS extension --> True2 adapter --> 50mm extension --> ED80

it will work without the 13mm extension. I have this in for two reasons. Firstly it gives me a slightly closer minimum focus distance. Secondly, I have fitted an AF confirm chip to the adapter and have put the 13mm extension in to avoid disturbing the contacts on the chip whenever I remove the adapter from the camera.

I'll take this opportunity to thank Paul Corfield for his assistance when I was choosing the bits and hard work in sharing his results with us all.

Hope this helps

Could you please elaborate more on the part that I put in bold and underlined?

Thank you.

 

[jpwone]

The AF confirm chip is fitted to the True2 adapter.

http://cgi.ebay.co.uk/AF-confirm-ch...30059QQcmdZViewItemQQ_trksidZp1713.m153.l1262

is a link to the item I purchased on ebay. Link also has fitting instructions. It works exactly as expected and gives AF confirm when manual AF is achieved. This will not work with an extender (1.4x or 2.0x) in place on a XXD camera body as the lens (ED80) is already at approximately f8 and adding an extender takes this to f11 (1.4x) or f16 (2.0x). It will work with a 1D body with the 1.4x extender as the 1D body has an extra stop of AF sensitivity. I have tested it on a 20D, 30D and 1DIIN and can confirm that all will confirm focus with the bare tube but only the 1D will confirm AF with a 1.4x extender fitted as well.

Fitting the chip was straight forward. I tacked it in place with a tiny spot of super glue to test it and despite being very careful about how I lined it up I was still about 1mm out of place. Tacking it in place saved the day as I was able to move it and then test again before fixing in place. The instructions recommend using epoxy for the final fixing. I used a medium viscosity super glue and this has worked very well.

Very pleased with it overall and it certainly makes it easier than relying on the view through the viewfinder for AF.

 

[TenaCJed]

John, Thanks for the info.

I am assuming that a barlow has the same affect as a TCon. So that really has me wondering, how dim is the viewfinder when you have a 2X barlow and a bunch of tubes. I believe I saw a couple of people using a 2X barlow and a 1.4X TCon. How difficult is it to manual focus?
Does anyone use any viewfinder magnification addons? I have seen some talk on another forum about using a NIKON eyepiece extender and making it work with the 40D viewfinder.

 

[jpwone]

TenaCJed

I have the Seagull viewfinder

http://cgi.ebay.co.uk/1x-2x-Seagull...photoQQcmdZViewItemQQ_trksidZp1713.m153.l1262

an equivalent (roughly) to the Canon right angle finder. In use (at 1x magnification) it is convenient to be able to swivel the viewfinder as it reduces the amount you have to physically move yourself each time you change the direction of view of the scope. The 2x functionality is slightly less useful as I find it difficult to use (I wear glasses) and the finder requires that you refocus it when you change from 1x to 2x (this is not absolutely necessary but I find I check it every time I change magnification as the focus adjuster on this particular brand is easy to move when you flip the mag switch). However, it is useful but in practise probably not a function you will use often. My experience has been that by the time I have changed to the 2x view, refocused the viewfinder, checked my focus, switched back to the 1x view, refocused the viewfinder and then adjusted composition the target has moved slightly or disappeared completely

You also need to be aware of where the eyepiece is pointing as stray light entering the eyepiece will give you incorrect camera metering. I shade the eyepiece with my hand if I am not looking through it to reduce this problem when I use it.

So, useful but not as usable as you would first imagine. Having said this, I certainly use it and would rather have it than not have it.

 

[TenaCJed]

Thank you again for the info. I think I will skip the auto confirm chip and go with a viewfinder magnifier. There seem to be some options in the 1.2X to 1.3X that still allow to see everything but the corners.

 

[JGobeil]

I also have a Seagull 90 degree viewfinder and magnifier. It can be handy at times but unfortunately it is of poor quality. When in the 2.5X position, it does not show a complete image of the viewfinder and yes the focus must be calibrated each time with an image at infinity. Also, the focus ring is quite loose and almost moves by itself - I found it necessary to tape it in place after adjusting the focus.. If I could do it again, I would not purchase it. However, as a 1X 90 degree adapter, it can be helpful.

 

[Paul Corfield]

Been away on holiday for 10 days so I've not had any internet access to keep up to speed on what's been happening on his thread.

Weath - yeah, you definitely need at least a 50mm extension tube to reach focus on the Skywatcher scope.

Spent my vacation with the family in a cottage on a farm just south of Birmingham and took stacks of photos. Found myself using the Kenko Pro 1.4X teleconverter virtually the whole time and it worked very nicely. Here's a selection of images, all taken with the Canon 450D - Skywatcher 80ED - Kenko Pro 300 1.4X teleconverter. All are at a range of 30m to 40m apart from the Buzzard which was fairly high overhead. The 12 million pixels on the 450D allows for a lot of cropping while keeping detail which is handy.

Paul.