Turning a standard 300D, 350D, 400D into a "live view" focussing system....

[Tim]

I bought a new wireless shutter release today, and in the packaging was a leaflet, which gave a link to this product;

http://www.zigview.co.uk/prdzigs2a.htm

It seems to attach to the viewfinder, and provide a live image screen for focussing. Has anybody heard any reports about these? Or better yet, seen one in action for astrophotography?

On the face of it, it would be an ideal upgrade to a standard DSLR, if the CCD was sensitive enough to pick up the light from just a few stars or star. I imagine it would take a bit of experience to make sure the image you see is exactly what is heading for the CMOS, but at first glance it seems the ideal option for those (like me) struggling to focus a DSLR once it is mounted, and pointing at a not necessarily bright object. In fact, with the CLS filter fitted, focussing is more or less impossible without heading for a star like Arcturus or Vega.

Anyone got any info/experience/reports on these?

Thanks very much

TJ

[Tinkerbell]

Lo TJ

Daytime they work quite well. Astro they are worse than useless

[barkis]

I think Cloudwatcher had one of those, and he kindly did some astro testing with it, and I don't think the results turned out very encouraging. If he does not enter this thread, you could PM him for more info TJ.

Ron.

[Beyond_Vision]

I have to agree with Moon Plodger on this one TJ. The sensitivity of the Zigview is no where near good enough for night time use. I came across it when I first got my 400D and was finding it difficult to focus. I concluded that a right angle viewfinder was better and a lot cheaper.

Regards

Kevin

[cygnusx1]

Also for the extra £200, you may as well flog the current DSLR and purchase a 450D, they're down to paltry £380 ish atm.

[George]

I just use http://www.dslrfocus.com/ , does the job for me. Takes minutes and only has to be done once per session.

[Paxo]

TJ,

I posted a similar thread in November last year:

http://stargazerslounge.com/index.php/topic,19123.msg197337.html#msg197337

and was led to the post:

http://stargazerslounge.com/index.php/topic,17925.0.html

I think it has already been summed up by most, a good idea in daylight, but not so good for astro use.

Steve..

[Tim]

Excellent feedback, thanks guys.

I see that the 450D is a doddle to modify (comparitively), so am extremely tempted to get one of those when I can afford it. But do the bigger chips make for even worse vignetting?

Thanks again

TJ

[beamer3.6m]

DSLR focus does not support the 400d according to the website.

I appreciate my way of focussing is basic but I just mark the actual focuser with a pen. That way when I connect the DSLR I rack the focusser in until I get to the pen mark and voila - focussed.

The finer the marks you make on the focusser the better.

[Tim]

At present I only have the standard focus knob on my SCT, I understand it may be easier if I get a crayford style?? They are pretty pricey though.

Interestingly, whilst researching the Zigview yesterday, I came across a guy who was using a toucam attached to his viewfinder for the same job, and a modified toucam should give enough sensitivity to do that.

A Meade DSI Pro chip certainly has enough sensitivity, but the damned thing is as big as the camera.....

Cheers

TJ

[cygnusx1]

Excellent feedback, thanks guys.

I see that the 450D is a doddle to modify (comparitively), so am extremely tempted to get one of those when I can afford it. But do the bigger chips make for even worse vignetting?

Thanks again

TJ

I've modified 300s, 350s, 400s and 450s.

Its not a doddle, don't be fooled by the pictorials, and a lot more expensive if you screw up.

p.s Also be aware, you must remove the AA low pass filter if you intend to do any IR imaging.

But in the process then you lose autofocus.

Swings and roundabouts.

[Tim]

Well, compared to the 350D, with those bits to de-solder, (which I have done), the 450 should be a lot more straightforward.

The fiddliest part is re-attaching those b***** ribbons. The low-pass can stay in for astro use though right? And if a camera is butchered in this way for astro-use, then it is unlikely to be used much for daylight photography, so the auto-focus becomes pretty much obsolete. The low pass filter is the one that the anti-dust mechanism works on though if I recall correctly, so probably wanna keep that in there.

TJ