Help needed re Plössl lenses and Canon eos60D

[girlracer]

Hi, I have a Sky-Watcher SkyMax-127 SupaTrak telescope, and have successfully connected my canon camera to it using a 1.25" t-adaptor and nose connector. I was quite happy with my first photos of the moon (link below) but would like to know how to make use of the 1.25" Revelation Plössl lenses, and wondered if they can be used with the t-adaptor? I keep reading that the 32mm one will connect but can't for the life of me see how and despite unscrewing all the parts as described the lens will not connect up!

thanks in advance

lisa

Winter Solstice Moon: http://www.flickr.co...157632307205005

[JamesF]

That's a very nice image. Well done. Is it just a single frame or a stack?

I put my 450D on the back of my 127 Mak just by fitting the T adaptor and then screwing that directly to the visual back which has a T thread on the outside. There's no need for a T to 1.25" adaptor. It's possible newer models have changed though.

The 32mm Revelation Plossl has a section at the top that unscrews, removing the eye cup and "shoulder" of the eyepiece body. That thread should also be a T-thread and therefore should screw straight into the adaptor on your camera.

I'm not sure why you'd want to do that though. What are you hoping to achieve by adding the eyepiece into the optical train?

James

[girlracer]

Hi James, thanks for your reply and nice comment re the photo- it was a single shot but sharpened it slightly with photoshop, though it was probably ok without that!

as I'm a novice, not sure really about what I hope to achieve by using the lenses but I read that they can be attached for use with the camera so thought I'd have a play around. I've looked again at the 32mm and the rubber eye piece comes off but it doesn't unscrew apart from the silver nosepiece, guess its just the wrong kind.

[nightfisher]

The 32mm revelation comes in 2 versions, if yours has a small screw on the outer body, allowing the black sleeve to slide up and down, then it can mount onto a T ring after unscrewing the eyecup holder, sounds like yours is the standard 32mm plossl, the photo plossl gives higher magnification to just using the camera, nice image

[girlracer]

Aah thanks, glad I wasn't being stupid! Can any of the plossl lenses be used with a t-adaptor?

[JamesF]

Must be as Jules says, then. I didn't realise there were two versions myself. You're probably far better off just putting the camera straight on the back of the scope anyhow.

Something to try with lunar (and solar, if you make/buy a suitable filter for the front of the scope) is to take, say, 100 images of the moon in quick succession. I then process these with PIPP to centre the image in a cropped frame and convert them to TIFF. Those TIFF images can then be fed into Registax, aligned and stacked to reduce the effects of poor seeing and then have wavelets applied in the same program to drag out even more detail. The result is something even better than you can get with a single frame.

Some examples of mine with the 127 Mak and 450D are here:

http://stargazerslounge.com/topic/163606-full-moon-29-september-2012/

http://stargazerslounge.com/topic/163995-waning-moon-4th-october/

http://stargazerslounge.com/topic/169604-moon-1st-december-2012/

I use AstroPhotography Tool (also known as APT) to help get the image focused, control the camera and download the images to a laptop, but there's no reason you couldn't use a simple programmable remote for exactly the same purpose if you don't have a laptop to take outside or would prefer not to. Being able to display the live view on the screen really does help with focusing though.

James

[nightfisher]

Only the Photo visual one, here is a pic of what it looks like, some other eyepieces have a similar feature, but can be rather expensive

[JamesF]

Aah thanks, glad I wasn't being stupid! Can any of the plossl lenses be used with a t-adaptor?

Very unlikely. Of the Revelation ones the 32mm photovisual Plossl is the only one I know of that allows it. There are some barlows that have a T-thread on the back should you wish to use one. But I really shouldn't worry too much about not being able to image using the eyepiece. I think all you'd really be doing is adding more glass into the optical train (and therefore introducing more sources of potential distortion and light loss) to no real benefit.

James

[girlracer]

Thanks both, you've been very helpful, and James I'll try the things you suggest and post back with results... Your photos are lovely, that's something to aim for! Sadly it's very cloudy over my part of London this evening so no chance of getting out there :-(

Cheers

Lisa

[JamesF]

It seems to have been cloudy over this part of the west country for most of the last month Frustration is running high

I've just realised that I meant to say I use the RAW (CR2) images when I load them into PIPP. I tried working with both the RAW and JPEG images and felt the results were better with the RAW files.

Good luck with your next attempt, and if you get stuck with the processing you'll certain to find someone here who can help.

James

[girlracer]

It's so frustrating isn't it re the weather, was hoping while I had some time off I could get outside but there we go! Thanks against for the extra advice, this forum is certainly very useful :-)