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GSO ED 2X barlow (1 Viewer)

P

Paul Corfield

Well-known member
I don't think we have a thread just on the 2" GSO ED 2X barlow so thought I'd post some images of this very obliging Blackbird taken using just the GSO barlow today. These are all from around 9m range, Canon 450D and 600mm Skywatcher Pro 80ED. All photos are uncropped.

Paul.
 

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is there a 1.25" version of that barlow?

Have a pentax pf65 scope arriving this week, and wanting to see how far i can push it)

`Canon 450D and 600mm Skywatcher Pro 80ED` interested to see a pic of that setup, from ur mobile or other digi camera.
 
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There's no 1.25" ED version as far as I know. Also it shifts the focus by about 20mm so you would probably run out of focus travel with a spotting scope.

There's a photo of my set up in the link at the bottom of my posts where it says 'My digiscope gallery'.

Paul.
 
Remounted my GSO and been experimenting with various types of light baffles in front of the barlow. Got it working pretty good at the minute, certainly as contrasty as the Kenko TC now and sharpness is better than I've been getting before. The extra sharpness may be down to the baffling restricting the size of the image circle and using only the sharpest part of the glass.

Three images with text on photos.

Paul.
 

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yes Pol. the 393 is a great piece of kit.

I've also fitted a Katzeye Plus screen which is equally fantastic. The brightness in low light is magnificent
 
Here's a front and rear view. I've mounted the glass from the barlow in the rear of a Pentax macro tube. I used to have a Pentax camera hence I still use some of my old gear. The hole in the rear of the macro tube is much smaller than the Canon one and it's much closer to the diameter of the barlow glass. Around the barlow glass I have a knurled rubber ring from an old eyepiece and this makes it a perfect (quite tight) push fit into the rear of the macro tube. On the front you can see what I've done to baffle the light and also reduce by about 50% the barlow diameter. I'll have to do a before and after photo but the photo with the baffle is so contrasty, there's must be at least twice as much contrast to the photo and the colours are very rich. See the Robin photo I took today, I had to reduce the contrast a little because it was too good.

For my 40th birthday in a few weeks time I was thinking of splashing out on the Kenko 3X TC but I may get a couple of barlows instead, maybe even a 2.5x Televue Powermate as I've always wanted to try one. Powermate photos I've seen have been ok for sharpness but slightly low on contrast and I wonder if I could do a similar mod to boost it. There's some Powermate photos in the gallery, click here to see them.

Paul.
 

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You seem to have no trouble with Barlows + TC's but i cant get the scope to focus sharply with the 2x DOI.

I've had the scope locked down solid, and used a static target ( Chimney Stack ) remote release and the result is just rubbish.

I've had better shots taken at further distance @ 600mm ( no TC's ) than with the DOI mounted and at closer distances.
 
Musoman said:
You seem to have no trouble with Barlows + TC's but i cant get the scope to focus sharply with the 2x DOI.

I've had the scope locked down solid, and used a static target ( Chimney Stack ) remote release and the result is just rubbish.

I've had better shots taken at further distance @ 600mm ( no TC's ) than with the DOI mounted and at closer distances.
Click to expand...

Strange as the DOI should be fine. You have it mounted squarely and the correct way round?

Paul.
 
Pretty sure Paul, yep

I should elaborate... the DOI ( including its housing but minus the original Oly mounts ) is fixed to an EOS mount taken from an EOS Ext. Tube
so i would say its pretty square on.

But lets say i epoxied the DOI back to front, surely I wouldnt see much of anything with it the wrong way round ?

I can get close to achieving proper focus, but it simply wont go the extra yard. Looking through the VF and you can see the fuzziness of the image before even taking the shot. The image never really becomes clear
 
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I just tried the DOI reversed and there's not a bit of difference

That was about 14 metres, shooting a drainpipe on an opposite wall, so doesnt get more static than that.
 
Usually need to photograph a tree or something to spot the difference. The edges will be softer with the teleconverter reversed. Either way, not sure why you are having difficulty. Maybe try getting the 1.5X Vivitar mounted up.

Paul.
 
Yes, i need to get that Viv sorted in case its a good 'un

I'll maybe shoot a tree or telegraph pole or something , so we can see what those edges look like

I'll post a RAW here like before and maybe you can run your eye over it.

I'll eliminate shake by using a tripod and 2 second mirror lock up.
Unfortunately my wireless remote batteries have died and the transmitter section takes a weird L1028 23a 12v which i had to get off ebay, and havent received yet
 
DOI just de-expoxied itself from the mount. The scope and camera rolled off the bed and hit the floor. No damage done - camera and scope are fine, but the DOI isnt usable till i re-expoxy to the mount.

:eek!:
 
Rather than tie up the macro tube with the TC epoxied in, why not strip it down further and mount it in the max dslr like mine. It's a more flexible set up leaving the macro tube to be used for other stuff.

Paul.
 
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