Newbie setup question

[aclockworkgnome]

Hi All,

I've been trying to come up with an ideal setup for medium range photography of larger birds (hawks, eagles, herons, egrets).

The William Optics ZenithStar 70 seems like an especially cost effective option. Unfortunately, I'm a bit concerned about the shorter focal length (only 430mm). As I already have a 300mm f/5.6 lens to go with my Nikon D80, more reach would better justify the expense.

With that in mind, could I use a GSO 2x Barlow and a WO 0.8x field reducer/flattener designed for a scope with ~860mm focal length?

The math yields...

430mm @ f/6.2

with 2x Barlow becomes...

860mm @ f/12.4

with 0.8x reducer/flattener becomes ...

688mm @ ~f/10

It seems like an ideal compromise in my mind as an outside observer, but I invite the opinion of the members of this forum.

Thanks for reading,

a_clockwork_gnome

[Paul Corfield]

I doubt you would need a field flattener/reducer. Did you have a reason for that? I wouldn't worry about trying to keep the f ratio down if that was the reason as the 2" GSO 2X barlow lets through a lot of light compared to a 2X teleconverter. If I was at say 1/200 sec with a 2X converter then I'd expect to be at around 1/250sec or more with the GSO barlow. If I stack my GSO with my Kenko 1.4X teleconverter I'm working at around f20 which is still easy even on a cloudy day. You should be able to push that scope to around 1200mm without too much hassle. I had the old Zenithstar 80 for a while which was 480mm focal length but I quickly moved up to a 600mm scope to get more reach. What sort of range are you going to be working at?

Paul.

[aclockworkgnome]

First of all, thank you for the quick response.

I suppose I was relying on the reducer to make the setup more practical for bird photography.

However, eliminating that, could I get a 2" photo adapter with a t-ring connection, attach the barlow to the end, then ultimately to the telescope?

My range will be approximately 15 - 30m.

Not sure if this forum allows embedding photos, but I'll try. Here are some sample shots taken at my favorite birding spot:

http://lh4.ggpht.com/_rMfvTF5cRhs/R8H7VzVH0MI/AAAAAAAACoo/OR8YLNjFEyo/s800/DSC_8665.jpg

http://lh6.ggpht.com/_rMfvTF5cRhs/R69WfzVHz4I/AAAAAAAAClA/7EjlnYgW9fI/s800/DSC_8440.jpg

http://lh3.ggpht.com/_rMfvTF5cRhs/R69WkDVHz7I/AAAAAAAAClY/0L584gvw8cI/s800/DSC_8509.jpg

My ultimate desire is for image quality rather than extreme reach, so a setup which produces consistent results at between 700-900mm would be sufficient.

Thanks,

a_clockwork_gnome

[Paul Corfield]

Yes, that's a set up some of us use here and I've attached a photo below showing the GSO barlow and how it attaches to the 2" scope adapter.

The focal reducer doesn't really have much use for photography and unless designed for a specific scope they can introduce more problems than they fix.

Paul.

[bluedubius]

Nice photos. Love Florida, always something around to photograph. Not sure about your budget, but a quick look at the opticsplanet website shows that you could actually get a Celestron 80ed refractor (600mm, f7.5) scope for less ($440 plus free shipping) than the 70mm Zenithstar. Maybe you can find the WO scope cheaper somewhere else. I use the Celestron and it's a good scope for the price. I'm no expert, but here is a link to a set of photos taken with the celestron 80ed and a several different cameras and accessories: http://www.flickr.com/photos/ricksphotos0501/sets/72157610220585793/. Just FYI.

Rick

[aclockworkgnome]

Paul,

Which barlow do you consider superior, the Celestron Ultima 2x 2" or the GSO 2x 2"?

Thanks for the replies; I am feeling more confident about the setup now.

Rick: WOnline (WO's own online shop) have the 70mm Zenithstar for $379 Nice pictures!

a_clockwork_gnome

[RJM]

My ultimate desire is for image quality rather than extreme reach, so a setup which produces consistent results at between 700-900mm would be sufficient.

Consistently sharp focus manually on a live animal with the D80 will not be easy and gets increasingly more difficult with distance. Getting spectacular flight shots will next to impossible.

If this is the focal length you expect to work and can afford US$1000 I highly recommend going with a AF camera lens like the Sigma 150-500 DG OS HSM + 1.4x TC. A small piece of Scotch tape over an electrical contact on the TC will still let the lens autofocus. Instead of 1:10 keepers, you will have 9:10. You will even be able to handhold in most scenarios because of lens' 3-4 stops of image stabilization.

cheers,
Rick

[Paul Corfield]

Paul,

Which barlow do you consider superior, the Celestron Ultima 2x 2" or the GSO 2x 2"?

Thanks for the replies; I am feeling more confident about the setup now.

Rick: WOnline (WO's own online shop) have the 70mm Zenithstar for $379 Nice pictures!

a_clockwork_gnome

The GSO is superior, nice and bright and very sharp. The Celestron is quite hard to mount although rated at 2X will give around 3X or more which is too much for most stuff. I disagree with what Rick says about focusing and flight shots. With the ranges you are working at focusing will be easy and flight shots are easy too once you've had some practice, especially with a small scope like the WO. If I go out specifically for flight shots I will nail pretty much every one I go for. Just comes down to ability but it's not that hard and all the more rewarding. If your ratio was only 1:10 keepers Rick it's no wonder you recently bought a lens. I think if I was to use my scope at its native 600m I would probably get 10:10 keepers. Most days I'm at around 1800mm and when I go to 600mm it seems like nothing at all.

Paul.

[Fritzz]

Consistently sharp focus manually on a live animal with the D80 will not be easy and gets increasingly more difficult with distance. Getting spectacular flight shots will next to impossible.

If this is the focal length you expect to work and can afford US$1000 I highly recommend going with a AF camera lens like the Sigma 150-500 DG OS HSM + 1.4x TC. A small piece of Scotch tape over an electrical contact on the TC will still let the lens autofocus. Instead of 1:10 keepers, you will have 9:10. You will even be able to handhold in most scenarios because of lens' 3-4 stops of image stabilization.

cheers,
Rick

Well I think flight shots with a telescope are still possible. I post one of my first attempts of flying geese taken with a Skywatcher 80 ED Kenko 1.5 tc. I only cropped it and did some noise reduction with unsharp masking. My camera is a Sony Alpha 700.

[Paul Corfield]

Here's some of mine from last year. The 2 insect ones were at around 10m range. All the bird ones are in the 150m - 200m range. With the Cormorant I literally had just a few seconds to set the tripod, find the bird, focus and set the shutter speed and take one photo before the opportunity had passed. That sort of shot comes with practice. While I'm aiming the scope at the bird I'm focusing and setting the shutter speed all at the same time and with practice it can all be done very quickly. The 2 insect ones were pretty hard but in the end I think it's all the more rewarding than just pointing a lens to get instant results.

Paul.

[RJM]

Of course great flight pics are possible with a manual focus lens or telescope. As is drawing four aces in poker too. Distance is the key. The further the distance, the easier it gets as the scope is focused at or near infinity where depth of field is greatest and field of view is maximized. Get in close under 40m and the task is exponentially more difficult. The FOV is only ~1m at 800mm!

Which brings me to another point about working close-in with a telescope...a fixed focal length really limits your ability to frame large birds like egrets and herons. Having a good zoom range of a camera lens allows so much more creative flexibility. I submit the below as an example taken from ~25m. Neither I nor the heron moved during this series. Not cropped, only resized for upload. Focal length in the title.

cheers,
Rick

[erniehatt]

Of course great flight pics are possible with a manual focus lens or telescope. As is drawing four aces in poker too. Distance is the key. The further the distance, the easier it gets as the scope is focused at or near infinity where depth of field is greatest and field of view is maximized. Get in close under 40m and the task is exponentially more difficult. The FOV is only ~1m at 800mm!

Which brings me to another point about working close-in with a telescope...a fixed focal length really limits your ability to frame large birds like egrets and herons. Having a good zoom range of a camera lens allows so much more creative flexibility. I submit the below as an example taken from ~25m. Neither I nor the heron moved during this series. Not cropped, only resized for upload. Focal length in the title.

cheers,
Rick

This is the lazy mans way of doing things, no sense of adventure, no DIY ability, and to much money. Most people using scopes generally already have the equipment from doing astronomy, and others do not have a spare 1000+ bucks. Ernie

[aclockworkgnome]

This is the lazy mans way of doing things, no sense of adventure, no DIY ability, and to much money. Most people using scopes generally already have the equipment from doing astronomy, and others do not have a spare 1000+ bucks. Ernie

I have to agree, though I am not so critical of the traditional approach.

But, since I am querying a digiscoping forum, it's likely that I'm already unsatisfied with the traditional approach and am looking for worthwhile alternatives.

Thanks to everyone for replying and I'll get back with results once I've made a decision.

Bart

[aclockworkgnome]

Just a brief update:

I've ordered the WO ZenithStar 70 refractor with a 2" prime focus adapter.

The prime focus adapter is a bit of custom machining purchased from here http://cncsupplyinc.com/true2_nikon.htm

Should have everything by the end of this week.

Thanks everyone for your suggestions

Bart