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GSO 2x (1 Viewer)
- Thread starter Musoman
- Start date
Paul Corfield
Well-known member
Are they with the barlow baffled as the contrast seems ok in them?
The Yellowhammer is a Yellow Wagtail but some similarities in the head markings. I photographed a Yellowhammer last night, see attached to compare differences.
On the whole though all your images are all sharp and the first and last Barn Owl ones are ok for the range too. Was the Barn Owl in the same place as the last one you photographed? If it hunted there regularly then it would be a nice place to visit and get set up for some close range shots.
Paul.
The Yellowhammer is a Yellow Wagtail but some similarities in the head markings. I photographed a Yellowhammer last night, see attached to compare differences.
On the whole though all your images are all sharp and the first and last Barn Owl ones are ok for the range too. Was the Barn Owl in the same place as the last one you photographed? If it hunted there regularly then it would be a nice place to visit and get set up for some close range shots.
Paul.
Attachments
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Musoman
PETE - Nikon/Sony Shooter
No, the Barlow wasnt baffled at that point.
Thanks for pointing out the Wagtail ..i consulted my Bible on that one and it looked nothing like the Wagtail and everything like the Yellowhammer, but the Bible isnt a book of photos, its a book of artist sketches. Alright in an emergancy but sometimes get it wrong
The Barn Owl wasnt at the same spot as last time. I went to that other bird hide first for around 2 hours, and it was dead, so i moved onto the next hide and all the shots above apart from the Gull were at this 2nd hide.
I'd love to get closer to that Owl but its not possible
Better make up that baffle i think, and flock the scope tube, and see if i can remedy that contrast prob.
Thanks for pointing out the Wagtail ..i consulted my Bible on that one and it looked nothing like the Wagtail and everything like the Yellowhammer, but the Bible isnt a book of photos, its a book of artist sketches. Alright in an emergancy but sometimes get it wrong
The Barn Owl wasnt at the same spot as last time. I went to that other bird hide first for around 2 hours, and it was dead, so i moved onto the next hide and all the shots above apart from the Gull were at this 2nd hide.
I'd love to get closer to that Owl but its not possible
Better make up that baffle i think, and flock the scope tube, and see if i can remedy that contrast prob.
mooreorless
Well-known member
Hi Guys, As always thanks for your posts. When you say you baffled the barlow you are just stopping it down right? Most times to 50% full glass.
Musoman I can see why you are not happy with the results and want to try to get "closer" to that Barn Owl.Beautiful bird.
Regards,Steve
Musoman I can see why you are not happy with the results and want to try to get "closer" to that Barn Owl.Beautiful bird.
Regards,Steve
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Paul Corfield
Well-known member
It depends on the barlow. With my little Antares 1.5X barlow all I did was stick flock paper to all the shiny black paint and that did the trick. I didn't need to cover any of the glass. With my GSO the glass diameter is so big that I can afford to cover a lot of it up without vignetting the image so I just cover up as much of it as I can. The more I cover it the better the contrast gets. Every barlow I've tried suffers from some degree, they just seem susceptible to any stray light no matter how small an amount. I guess because they are meant to be used in the black of night that the need for reducing stray light isn't an issue and the manufacturers don't actively try to reduce it. Might be better on the really expensive ones but certainly not on the mid priced ones.
Paul.
Musoman
PETE - Nikon/Sony Shooter
Hi Guys, As always thanks for your posts. When you say you baffled the barlow you are just stopping it down right? Most times to 50% full glass.
Musoman I can see why you are not happy with the results and want to try to get "closer" to that Barn Owl.Beautiful bird.
Regards,Steve
I wondered too Steve, whether thats whats happening when covering the barlow up with a baffle.
I know you can stop down by using the 80ED Scope hood, and attaching the large end cap, but remove the small centre cap. I'm sure Paul said this was the equivalent of stopping down. I know the scope starts with an Ap of f7.5, but how stopped down this would end up. i dont know. Paul will likely know though.
As you say, this is probably whats happening when baffling the barlow, but i dont know for sure.
As for the Owls, I dont see enough of them to throw away bad quality pics, but i'll keep at it Steve..she or he is a beauty and i'd love some closer shots so the scope and myself are not struggling with focusing
mooreorless
Well-known member
I see you fellows posted about the same time. After reading Paul's post I see it is stray light issues more than anything with these barlows . I understand this a lot more Thanks!!
BTW Musoman keep trying with that Barn Owl, very interesting bird. I just got a 100ED with 900mm Fl I want to play with, still have the 80ED of course. There is a Red-shouldered Hawk that sets up in a dead oak about 180 meters away in my back yard. Not a recent picture. We have a Sandmound septic system in back, tank lid showing and mound behind it.
Regards,Steve
After reading Paul's post I see it is stray light issues more than anything with these barlows . I understand this a lot more Thanks!!BTW Musoman keep trying with that Barn Owl, very interesting bird.
I just got a 100ED with 900mm Fl I want to play with, still have the 80ED of course. There is a Red-shouldered Hawk that sets up in a dead oak about 180 meters away in my back yard. Not a recent picture. We have a Sandmound septic system in back, tank lid showing and mound behind it.Regards,Steve
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Musoman
PETE - Nikon/Sony Shooter
Will get a good shot of the Owl eventually Steve
Meanwhile, myself, the GSO 2x and scope took another trip to the Reserve and got some shots of some large Shelduck. A first for me, and not seen too often at the Farmoor reserve either, so the Farmoor Bird website decided to featured one of my shots. Fame !!
The photo is the 2nd one down the page, and under the photo it says Shrike Meadow, but this is just an area where the bird hide is situated at the Farmoor Reserve.
http://farmoor-birding.com/LOG-BOOK
Meanwhile, myself, the GSO 2x and scope took another trip to the Reserve and got some shots of some large Shelduck. A first for me, and not seen too often at the Farmoor reserve either, so the Farmoor Bird website decided to featured one of my shots. Fame !!
The photo is the 2nd one down the page, and under the photo it says Shrike Meadow, but this is just an area where the bird hide is situated at the Farmoor Reserve.
http://farmoor-birding.com/LOG-BOOK
Attachments
Paul Corfield
Well-known member
Well done Musoman. I see they have a Yellow Wagtail as the image for the 14th. You should have sent your Yellow Wagtail in last week as they aren't all that common a bird either. I photographed a couple of Shelduck last week at my local lake as they are a bird I don't see all that often locally.
Paul.
Paul.
Musoman
PETE - Nikon/Sony Shooter
Thanks Paul..i thought those wagtails were not seen that often, but there's loads of them at the the Farmoor site. I didnt realise this till the other day.
I did send in the YW and even though mine was a slightly better shot, the webby used a different one.
Addendum...quick google earth calc and ducks were at 312 ft
I did send in the YW and even though mine was a slightly better shot, the webby used a different one.
Addendum...quick google earth calc and ducks were at 312 ft
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Musoman
PETE - Nikon/Sony Shooter
Paul, there was something i meant to ask..can you work out the approx. magnification of the GSO with my set up?
I have 30mm of Ext Tube from the flange face on the camera to the MAX dslr. The MAX is 30mm, then the GSO screws in to the end of the MAX. The GSO is 30mm but half of it is covered by the next attachemnt, which is the 50mm Revelation Astro Ext Tube...so 30mm + 30mm before the GSO.....+ 15mm of GSO + 50mm after the GSO. But i dont know whether the Astro Ext is a full 50mm, because the end of that disappears some way into the scope
Tricky isnt it ? :king:
I have 30mm of Ext Tube from the flange face on the camera to the MAX dslr. The MAX is 30mm, then the GSO screws in to the end of the MAX. The GSO is 30mm but half of it is covered by the next attachemnt, which is the 50mm Revelation Astro Ext Tube...so 30mm + 30mm before the GSO.....+ 15mm of GSO + 50mm after the GSO. But i dont know whether the Astro Ext is a full 50mm, because the end of that disappears some way into the scope
Tricky isnt it ? :king:
Paul Corfield
Well-known member
The easiest way is to photograph something at fairly close range with just the scope at 600mm and this gives me a base image to work from. Then put the barlow on the camera and photograph the same object from the exact same position. As long as there's an obvious target in the photo to reference it will be fine and also make sure the target is in the middle of both images. Then post both the images on here and I'll work it out.
The ducks came out very well for the range.
Paul.
The ducks came out very well for the range.
Paul.
Paul Corfield
Well-known member
They will be fine like that, cheers.
Paul.
Paul.
Paul Corfield
Well-known member
You are getting 2.18X so it's almost 2.2X but not quite.
The way I do it is I open both images in Photoshop. Then I change the size of the small image making sure it's set to a percentage increase. I had to increase it 218% in size to get a perfect match. Once the small image is enlarged I drag it on top of the larger image and set the transparency of the top image to about 55% so I can see the one below and the one on top at the same time. I move it around and see if it matches. If it doesn't match then I undo all the previous steps in the history palette and try a different increase in size.
It's a proven method and I've tried it with both 1.4X and 2X teleconverters. For example a photo taken at 600mm needs an increase of 140% to match an image taken with a 1.4X TC and when you try it in Photoshop it works exactly. It's the same with a 2X TC.
Paul.
The way I do it is I open both images in Photoshop. Then I change the size of the small image making sure it's set to a percentage increase. I had to increase it 218% in size to get a perfect match. Once the small image is enlarged I drag it on top of the larger image and set the transparency of the top image to about 55% so I can see the one below and the one on top at the same time. I move it around and see if it matches. If it doesn't match then I undo all the previous steps in the history palette and try a different increase in size.
It's a proven method and I've tried it with both 1.4X and 2X teleconverters. For example a photo taken at 600mm needs an increase of 140% to match an image taken with a 1.4X TC and when you try it in Photoshop it works exactly. It's the same with a 2X TC.
Paul.
mooreorless
Well-known member
Musoman, I really like your pictures of the Shelducks beautiful bird. Thanks for the feet distance quote for us USA folks.
Paul, Neat trick to figure out how much extra magnification you get with the GSO.:t:
Regards,Steve
