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Old 02-01-2012, 11:03 PM
Carl
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Location: Alans Flat
Posts: 375
Increasing magnification for photography

Ok, this may have been done before but i haven't come across it, but for what it’s worth and considering the good will of member’s festive seasonal tolerances, I thought I’d share my experiment with you. If you have already successfully increased magnification for photography by more simple means read no further, or let me know.

I have just purchased a Skywatcher ed120 APO and from initial tests am very impressed. But having just sold a Celestron C8 to appropriate the funds I am some what missing the additional luxury and warm fuzzy feeling of the additional focal length, especially for lunar imaging.

So how do you beef up the magnification for DSLR photography on a scope with 900ml focal length if you do not have special adapters or lenses? (Incidentally, if you do know what adapters or eye pieces are required I would be grateful for your replies)

Try the following if you have the same equipment as I have:
  • Insert your 2” diagonal into the rear of your focuser
  • Unscrew the bottom lens thingy at the end of your 2” 2x Barlow so all you have is the Barlow lens itself
  • Screw the Barlow lens on to the front filter thread of your 2” field flattener; I have an Astrotech and Hotech flattener so the choice is optional
  • Attach the Barlow lens and Flattener to your DSLR camera via the appropriate T ring
  • Insert the whole lot into your 2” diagonal
  • Turn the focus knobs until you have focus
It actually works. My shots of the moon were equal to the Barlow magnification and the image was sharp. I did a further test simply inserting the entire Barlow piece in to the diagonal and simply could not get focus. Also I tried the whole experiment again without the diagonal and could not get focus. I set the capture speed on Nebulosity to between .0100 and .0400 and started to take sharp images of the moon with success.

Now I know many of you out there probably have projection eyepieces of some kind or means of increasing magnification, but at this stage I do not; I simply borrowed a mates Barlow and got bored watching TV over the Christmas break and decided to have a play with things in the shed.

Anyway I thought I’d just share my thoughts. If someone out there can steer me in the right direction to increase magnification for photography with a short focal length scope just let me know.

Best Regards
Carl Rainer
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Old 03-01-2012, 11:09 AM
Karls48 (Karl)
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I have done something similar couple years ago. With Celestron achromat 100mm F5 I took series of images of distant house roof top with 1.25” 2X Barlow, no Barlow, Focal reducer and combination of Focal reducer and Barlow. The sharpest images were with combination of Focal reducer and Barlow. The worst images were with Barlow only. The magnification was bit less with combination then with Barlow alone and focus distance is also less.
I was bit perplexed why by adding extra number of glass surfaces Image quality improve. I’m glad that you have to same results and I was not seeing things.
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Old 06-01-2012, 01:29 PM
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frolinmod
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You did the right thing. Using a barlow is much easier than eyepiece projection. Eyepiece projection is the most difficult form of photography there is. I can't think of any reason to resort to eyepiece projection unless you need magnification factors larger than 5X. And if you're doing that, the image is going to be very dim indeed.
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Old 09-01-2012, 10:50 AM
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Yogie-One (Paul)
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Location: Salisbury Downs, Adelaide
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Magnify

For what it's worth, I found this on EBay, so they are available.

As I see it, it attaches to the camera, and sits into the 1.25inch eyepiece holder.

I was seriously thinking of purchaseing one for my Canon and Skywatcher 12-inch. Has anyone else had any do-ings or dealings with these?

Y/O (YogieOne)
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