Problems using a DSLR on a SW120 f/5

[raymo]

A DSLR will come to focus when attached directly to the focuser of my
SW120, but will not when using a diagonal. Putting a 2x barlow into
the optical train fixes this, but of course makes the f/l of the system
around 1200mm instead of the native 600mm, which is the last thing I want.
Does anyone know where I could get a divergent lens of substantially less than 2x, say somewhere in the 1.2 to 1.5x range, although even at 1.5x it
still becomes 900mm, which is too long really.
Thanks in advance.
raymo

[Atmos (Colin)]

You're better off not imaging through the diagonal anyway.
Is there a particular reason you want to use a diagonal when using your DSLR?

[raymo]

I have a fixed LCD screen on my DSLR, which would make "Live View Focusing," and framing images etc, excruciatingly awkward for an oldie
like me at anything higher than about 25-30 degrees above the horizon.
I suppose I could lower the tripod and lay on my back underneath it.
I'm looking at attaching a mirror to the DSLR. At the moment I hold a small mirror at the appropriate angle adjacent to the LCD screen. I do sorely
miss my Newt that I could just rotate to whatever position put the focuser
into a comfortable position.
raymo

[Stardrifter_WA]

Originally Posted by raymo

I have a fixed LCD screen on my DSLR, which would make "Live View Focusing," and framing images etc, excruciatingly awkward for an oldie
like me at anything higher than about 25-30 degrees above the horizon.
I suppose I could lower the tripod and lay on my back underneath it.
I'm looking at attaching a mirror to the DSLR. At the moment I hold a small mirror at the appropriate angle adjacent to the LCD screen. I do sorely
miss my Newt that I could just rotate to whatever position put the focuser
into a comfortable position.
raymo

Had the same problem as you Raymo.

If you have an iPad, that problem is easily solved. Manfrotto Digital Director.

See here: https://www.youtube.com/watch?v=Cnae6YSzt3Q

I have one and it is awesome.

Got my Digital Director from B&H for USD$300 and bought a superseded iPad Mini from Officeworks for a couple of hundred. There are other cheaper alternatives, but the Digital Director can be viewed live and having a higher resolution screen makes for easy focus.

Although it is great with the Mini iPad, had I known how good this thing is, I probably would have gone for the larger iPad. It only works with iPads.

There is also this one but I haven't tried it, so I don't know what it is like. https://www.bhphotovideo.com/c/searc...op+Nav-Search=

I was considering the Freewave when I found the DD on B&H website.

[barx1963 (Malcolm)]

If you have a laptop, just use Backyard EOS ( assume it is the 1100d?) puts the Liveview image on your screen and much bigger.
Great piece of software

Malcolm

[raymo]

Can't afford one of those, and the Freewave is not compatible with my 1100D.
I have Backyard EOS Malcolm; thanks for reminding me. I haven't used it
for several years.
I would still like to get a weaker Barlow or equivalent, if anyone knows
where I might get one.
Thanks everyone.
raymo

[rcheshire (Rowland)]

Can you lay your hands on an angle finder. Might be an easier option?

[raymo]

Hi Rowland, yes, target acquisition is also a problem, but I mount the
straight through finder at the front of the scope just like I do on the 8" SCT,
which makes it much easier to use. I think Malcolm is right, and will use
Backyard EOS. Would still like to put a low powered divergent lens into
my diagonal to make the 600mm f/l around 750-850mm.
raymo

[OzEclipse (Joe Cali)]

if you have backyard EOS, that may be your best bet. I'm not familiar with it.

Another approach is to use the HDMI port to extend to an auxilary display. The 1100D has an HDMI connector. You could buy a 12V HDMI car display. These displays are 7 to 10 inch across, cost between $70 and $300 and will mirror the rear display on the screen. You still don't have access to all the controls.

This 8" monitor costs $90 with postage.

http://www.ebay.com.au/itm/8-TFT-LCD...cAAOSwmLlX2KHp

Joe

[raymo]

Thanks Joe, yes BYEOS will be the best bet, as I can control the camera with it. Still looking for info on a 1.2 to 1.5x lens to screw into the diagonal.
raymo

[Camelopardalis (Dunk)]

Antares used to do a 1.6x in a 2" raymo, may be worth searching on the used market?

But that then that bumps f/5 to f/8...

[skysurfer]

Originally Posted by Stardrifter_WA

Had the same problem as you Raymo.
If you have an iPad, that problem is easily solved. Manfrotto Digital Director.

See here: https://www.youtube.com/watch?v=Cnae6YSzt3Q

I have one and it is awesome.

Got my Digital Director from B&H for USD$300 and bought a superseded iPad Mini from Officeworks for a couple of hundred. There are other cheaper alternatives, but the Digital Director can be viewed live and having a higher resolution screen makes for easy focus.

Although it is great with the Mini iPad, had I known how good this thing is, I probably would have gone for the larger iPad. It only works with iPads.

Much simpler: when you have iOS, use a Canon Remote app from Canon themselves which allows downloading JPEGs, but no CR2s, so set image format to 'both RAW and JPEG' to allow downloading the JPEGs over wifi. But iOS lacks USB connectivity which is possible with Android (OTG adapter for a few dollars) which allows you to view the CR2 files on the cellphone / tablet screen.
I use DSLR controller which is awesome for AP.

Using a diagonal for AP is a bad idea.

[ZeroID (Brent)]

BYEOS will do it all for you at relatively cheap if you haven't already got it. Having used it for quite a while I wouldn't be without it. It is the only reason I've bought a couple of Canons for Astro imaging.
Live focussing with indicators, still and video mode with various crops, scheduling, even dithering if you feel the need.

Photographically I'm a SONY man. If they ever bring out something similar then ......

[ChrisV (Chris)]

Sorry butting in. I use the freeware eos utilities. What extra stuff does byeos have ?

[bojan]

How about this:
http://www.iceinspace.com.au/forum/s...61&postcount=3

[raymo]

Thank you everybody; great device Bojan. Chris, BYEOS does so much more
than EOS Utilities its hard to know where to start. Your entire imaging
session can be planned within BYEOS, and then carried out by it, go
indoors and have a beer or whatever. It also has a super accurate digital
focussing program. Google it and have a look at all the features.
raymo

[ZeroID (Brent)]

Got it running at present on M20, while I compute and play with the cats. First night in AGES that I can see the sky. Transparency is pretty bad but no clouds is no clouds so got to catch photons, I was going stir crazy.

[sil (Steve)]

Just a comment on how I deal with the same sort of problem as Raymo. I shoot DSLR, with lens on camera tripod mostly, not attached to scope due to my own physical limitations. My camera has a fixed screen and I cant get my eye to the camera above about 10 degree ALT. So I have the camera up high on my tripod with a heavy weight hanging under the center column to dampen vibrations. I can stand an focus manually on stars I can point to comfortably. I use a trigger grip ball head to point the camera. I can then sit and point the camera with live view to get a reference bright star in view to frame my target capture (got to get used to how far the field of view is and I try to find something I can get i the corner of the shot so I know the field of view covers my target. I crop after integration anyway so composition doesnt matter to me at the camera, i just want to get my target, the rest is all post production work. So I can line up easily from a comfortable chair, focus will still be good. Then I take a fewtest shots so I can double check my framing and check settings are good, I ride the fine line between round or football stars closely depending on my target size and brightness. eg Nebula I'll accept football stars for a little longer exposure time and in the final image usage its not very noticable and i'm happy with that. Plus there are ways to round the stars if i want later that wont effect the image i want.