The cat has left the bag

[Fine_Art]

These are bird shots with a telescope.
http://onsen-turi.com/kawasemi/

Sample






Is it sharp enough? This is 750mm f6 for under $3000  
Other quality APOs will have similar results. Note the borg is designed for astrophotography. Other "astrographs" will also have a flat field for a sensor.

[Isaac]

Wow.

[JonathanRimmel]

Now that is sharp!

[Alan Smallbone]

I use the Borg scopes for astrophotography they do make good optics. Their smaller 71mm objective (not focal length but objective diameter) is made by Canon for them. The 125mm objective that I use was made by Pentax, so they have good glass. The drawbacks for terrestrial photography are the slow focusing helical focuser and fixed aperture. Here is the web site for US and Europe for ordering and using them. Ted Ishikawa runs it and is very knowledgeable. They have adapters for most cameras.
http://www.hutech.com/


Here is an image I took with a cooled astrophotography camera with a full frame sensor, over 17 hours of exposure time over 3 nights to get it, using the Borg 125 at f3.9  488 mm focal length
http://apod.nasa.gov/apod/ap090211.html

Alan


edit: fixed typos

[telyt]

Good enough for web shots at least, but I see a lot of aliasing and no gradation.  I have to wonder how these photos were processed.

[Fine_Art]

If you follow the link to the manufacturer many of the shots are about 3600 pixels across. They still look sharp. Some have some noise from higher ISOs. Try looking at the exif.

I have no association with Borg or any other manufacturer. I was looking for a way to get good wildlife shots without spending $1000s for a piece of equipment. "Astrographs" are designed for astrophotography. A decent one must bring light to focus for an imaging chip ie flat field. Just like any other decent telescope they must be to the limits of light. Points are focussed to airy disks. The downside for terrestrial is manual focus with no aperture control. It is an optimized system. A zoom is a compromise system.

I got my 10" 1000fl f4 astrograph (with coma corrector/field flattener) delivered yesterday. I put my camera on with a T-ring. It works right out of the box. Its big. So what, i'm strong enough to move it easily. It was $599 plus $145.95 for the corrector.

Some people want money to be the barrier to entry or at least the fee for top results. It will never be. The real barrier is the lack of effort that most people put in.

[telyt]

Some people want money to be the barrier to entry or at least the fee for top results. It will never be. The real barrier is the lack of effort that most people put in.

Yup.  I recently attended a bird photography presentation by a well-known photographer who is supported by one of the Big Two DSLR makers.  What a joke.  His solution to most problems was to buy the longest, fastest lens the maker sells, or the fastest AF, fastest frame rate body the maker sells.  The problems that couldn't be solved with the latest camera & lens were solved with more flash.  Nothing about studying the birds and avoiding what alarms them (and nothing about several other subjects critical to top results IMHO).

I've seen some outstanding bird photos made with no more equipment than a simple film camera with 50mm lens and 2x extender.  Good field skills can often substitute for many mm of focal length, and knowing your subjects and anticipating their actions can often get better results than a fast frame rate.

[Johnny_Johnson]

Some people want money to be the barrier to entry or at least the fee for top results. It will never be. The real barrier is the lack of effort that most people put in.

I look forward to seeing some of your wildlife images made with this scope, in this thread preferably since I'm following it.

Cya,
Johnny

[fike]

These kind of setups tend to be okay for still subjects, but because of fussy manual focus they are very problematic for dealing with moving subjects.  You will get a few gems, but general wildlife photography with telescope setups isn't generally practical unless you are doing it from your living room looking at a bird feeder.

[epatsellis]

...
I got my 10" 1000fl f4 astrograph (with coma corrector/field flattener) delivered yesterday. I put my camera on with a T-ring. It works right out of the box. Its big. So what, i'm strong enough to move it easily. It was $599 plus $145.95 for the corrector.
...

Do you have source? I'd be very interested for occasional use.

erie

[Fine_Art]

Do you have source? I'd be very interested for occasional use.

erie

Sure
http://www.canadiantelescopes.com/Shop-By-Brand/Telescopes_8/Astro-Tech-10-f-4-imaging-OTA_2#.Ty7xr1xNJ8E

It shipped from Astronomics (US) so both websites are the same company.

Looks like they just put their price up. Maybe its selling well. Im also discussing it on Dyxum.com digiscoping thread.

Note until I get my fine collimator I cannot say one way or the other if it resolves down to 16MP on APS-C. I can say there is no vignetting so it seems well designed for a large (relative to eyeball) sensor. I can also say it resolves to fair focus at 7x live view right from the box. Its not up to 10x live view, i will see if adjustment corrects it.

[Alan Smallbone]

Sure
http://www.canadiantelescopes.com/Shop-By-Brand/Telescopes_8/Astro-Tech-10-f-4-imaging-OTA_2#.Ty7xr1xNJ8E

It shipped from Astronomics (US) so both websites are the same company.

Looks like they just put their price up. Maybe its selling well. Im also discussing it on Dyxum.com digiscoping thread.

Note until I get my fine collimator I cannot say one way or the other if it resolves down to 16MP on APS-C. I can say there is no vignetting so it seems well designed for a large (relative to eyeball) sensor. I can also say it resolves to fair focus at 7x live view right from the box. Its not up to 10x live view, i will see if adjustment corrects it.

The problem with a large catadioptic scope like you are using is that the bokeh will look funny because of the large diameter mirror in the center, but that is a matter of taste. The other thing you will find with moving a large scope like that, the RC optics can be knocked out of collimation and you will no longer get a flat field. I do not believe that that scope supports a full frame chip size, but they may have come out with a larger flattener for it. All things to take into consideration as it is not really portable but it will be fun to play with on terrestrial subjects.

Alan

[Fine_Art]

The problem with a large catadioptic scope like you are using is that the bokeh will look funny because of the large diameter mirror in the center, but that is a matter of taste. The other thing you will find with moving a large scope like that, the RC optics can be knocked out of collimation and you will no longer get a flat field. I do not believe that that scope supports a full frame chip size, but they may have come out with a larger flattener for it. All things to take into consideration as it is not really portable but it will be fun to play with on terrestrial subjects.

Alan

All good points Alan. My plan for the bokeh was to have none. The A55 shoots up to 10fps with no mirror flap so rotating the buttery smooth focuser while holding down the cable release with the other hand should give me good focus stacking.

I plan to make a dobsonian type mount for it in a collapsible truss structure. Most of the weight is in the back with a 37" moment arm. Rotating will be easy. I'm finding the inertial mass of it resists vibration.

The manual on the 8" says it has 10% light falloff in the corners on APS-C. I find none on the 10" (part of why I picked it). The writeup on Astronomics says the 10" was designed for FF 35mm. It makes sense that Astrophotographers would want to use the latest ultra ISO FF cameras.

Im not claiming this $750 system will be as good as the large Borg or a Televue. For a fraction of the thousands its worth it.

Testing the bokeh on an evergreen about 100ft away the doughnuts look tiny. A simple Gaussian blur might be ok. For valuable shots the focus stacking should do it.

[Fine_Art]

I just put a FF 35 mm on it.  There is no sign of vignetting.

[Alan Smallbone]

But what about edge sharpness, I had early reports that the even with the flattener it was flat only for aps-c but I have not tested it, so just what I have read. I would still worry about the collimation RC designs are quite sensitive to it. Hope it works out for you, looking forward to seeing some images, it will certainly attract some attention in the field.

Alan

[Fine_Art]

But what about edge sharpness, I had early reports that the even with the flattener it was flat only for aps-c but I have not tested it, so just what I have read. I would still worry about the collimation RC designs are quite sensitive to it. Hope it works out for you, looking forward to seeing some images, it will certainly attract some attention in the field.

Alan

It is a newtonian not their Ritchey-Chrétien.

In the parks it will be in a blind or under netting.