You learn something new every day

[jasperuk]

I was out looking for an alternative to a 450D canon (something cheap wiht live view) and i came across this variation of the 20D

Canon EOS 20D - Wikipedia, the free encyclopedia

Canon released the EOS 20Da on February 14, 2005 in Japan. It is a variant of the 20D designed for astrophotography. On June 1, 2005 Canon announced that the 20Da would be made available worldwide.

The main differences between the 20Da and 20D are the replacement of the "hot mirror" infra-red (IR) filter which covers the CMOS sensor on the 20D and live view mode.

In conventional photography, the IR filter is used to make the spectral response of the CMOS sensor more like that of the human eye. In this way, the pictures gathered by the sensor more closely resemble the world as we see it. In astro-photography, many objects of interest emit strongly in the red H-α line, which is heavily attenuated by the IR filter on the 20D. The IR filter of the 20Da passes 2.5 times more light at around this 656 nm wavelength as the filter of the 20D, allowing more fine detail to be revealed in long exposures of emission nebulae. As a side effect, the color balance is slightly altered in normal daylight photography.

It is extremely difficult to focus an extremely dim image with a reflex viewfinder; locking the mirror up and opening the shutter (live view) was introduced in the 20Da to address this issue. When used the camera provides a live image of the center of the field of view to allow focusing on a bright star. Live view for this application requires a lens which supports fully mechanical focus in manual mode, and is not suitable for normal daytime use.

Reviews report that image noise in the 20Da is lower than in the 20D.

The EOS 20Da was discontinued when the 30D was introduced in 2006. Canon has produced no similar model for astrophotography since, though many astrophotographers commonly make similar aftermarket modifications to later Canon models to fill the same role.

[palebluedot]

Yeah, they are like hens' teeth! Can't get hold of them for love nor money.

[jasperuk]

Canon EOS - 20DA, 8,2 Megapixels Cmara Digital SLR $500 - JustPost United States Free Community Classifieds

Canon EOS - 20DA, 8,2 Megapixels Cmara Digital SLR $500

(Colorado, Fort Smith)

Posted on: Monday, 14 March, 2011 12:15

Updated On: Monday, 14 March, 2011 12:26

Expires On: Friday, 30 September, 2011 12:15

Reply to: phonebrand2@gmail.com

(When contacting, please mention JustPost United States Free Community Classifieds)

[palebluedot]

Canon EOS - 20DA, 8,2 Megapixels Cmara Digital SLR $500 - JustPost United States Free Community Classifieds

Canon EOS - 20DA, 8,2 Megapixels Cmara Digital SLR $500

(Colorado, Fort Smith)

Posted on: Monday, 14 March, 2011 12:15

Updated On: Monday, 14 March, 2011 12:26

Expires On: Friday, 30 September, 2011 12:15

Reply to: phonebrand2@gmail.com

(When contacting, please mention JustPost United States Free Community Classifieds)

I like the line at the bottom:

God Bless You As You Order.... Regards..... MGT....

[brianb]

TBH you're far better off getting a current camera modified. The 20D is pretty stone age by the standards of modern cameras ... for a start it WON'T accept EF-S lenses; there's no "live view" & the review screen is horrid by current standards; the ISO range is limited, the software doesn't support FAT32 and therefore there is no way of using CF cards bigger in capacity than 4GB, the noise reduction is primitive (best turn it off) ...

[palebluedot]

TBH you're far better off getting a current camera modified. The 20D is pretty stone age by the standards of modern cameras ... for a start it WON'T accept EF-S lenses; there's no "live view" & the review screen is horrid by current standards; the ISO range is limited, the software doesn't support FAT32 and therefore there is no way of using CF cards bigger in capacity than 4GB, the noise reduction is primitive (best turn it off) ...

Agreed, I have one. I just thought for those exact reasons you should be able to pick one up for a song.

[Photohound]

BRianb... The 20D is pretty stone age by the standards of modern cameras ... for a start it WON'T accept EF-S lenses; there's no "live view" & the review screen is horrid by current standards; the ISO range is limited, the software doesn't support FAT32 and therefore there is no way of using CF cards bigger in capacity than 4GB, the noise reduction is primitive (best turn it off) ...

but, but, but... thats not strictly true is it...

The OP was talking about the 20Da not the 'D' - I have a '20Da' and its fully EF & EF-S compat', there is 'live view' its at x5 and x10 mag on 'FC1 & 2' after 'bulb' on the settings wheel, i admit the screen is small but who uses them anyway, a lappy connected at USB2.0 with redscreen will give a bigger sharper easier image to focus and review, and it doesnt naff up your night vision, the ISO100 -3200 is more than adequate for normal DSO work and i always leave NR off when imaging RAW+Large anyway. The FAT32 business is not an issue, i pictbridge from a 4gig card that gives me 310 images at full RAW+L. Hope that gives a better perspective (no pun intended)