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Canon Digital Rebel XT / Canon 350D Frequently Asked Questions
What's the quality of the kit lens?
Where'd the focusing screen go?
How do I connect my Canon Digital Rebel XT / Canon 350D up to my telescope?
Where can I read some reviews?
The Canon Digital Rebel XT / Canon 350D is Canon's replacement for the very successful Canon Digital Rebel / Canon 300D. The camera is a digital SLR (or DSLR) which means that it features an optical "through-the-lens" viewfinder (unlike non-DSLR cameras which may have either a CCD viewfinder or a non-through the lens optical viewfinder). This DSLR also features removeable and interchangeable lenses. It is compatible with Canon EF and EF-S lenses.
It represents a significant upgrade to the original 300D:
Here is a little summary of some of its key features and differences to the original Digital Rebel / 300D:
| Digital Rebel XT / 350D | Digital Rebel / 300D |
| 8MP 2nd generation CMOS sensor | 6MP CMOS Sensor |
| DIGIC II image processor | DIGIC I image processor |
| almost instant start-up | ~3 second start-up delay |
| 3 fps continuos for 14 frames | 2.5 fps continuous for 4 frames |
| USB 2.0 Hi-speed interface | USB 1.0 interface |
| 540g | 110g heavier than EOS 350D |
What lenses can I use? [TOP]
The Canon Digital Rebel XT / Canon 350D is compatible with Canon EF and EF-S lenses. Companies like Sigma and Tamron also make compatible lenses and there have been recent rumours that Carl Zeiss may be making lenses for Canon mounts (the rumours seem to be more definate about Carl Zeiss making Nikon F-Mount compatible lenses).
The sensor used in the Canon Digital Rebel XT / Canon 350D is not a full frame sensor. The smaller sensor results in a field of view crop of 1.6x. A 50mm lens will have an actual field of view of 1.6 x 50mm = 80mm. This is great for wildlife photographers because their 500mm telephoto lens is now an 800mm lens, but bad for real estate agents doing interior shots with their 20mm wide-angle lens now being a 32mm.
If the 1.6x crop factor is a problem, then you need to consider a full frame DSLR like the recently announced Canon EOS 5D or the Canon EOS 1Ds Mark II but expect to pay dearly for the privilege.
What's the quality of the kit lens? [TOP]
The Canon Digital Rebel XT / Canon 350D comes with a 18-55mm F3.5-5.6 EF-S kit lens which is the equivalent of 28.8-88mm field of view when mounted in front of the 1.6x crop factor sensor. This lens is not the same lens as the original Digital Rebel and EOS-20D kit lenses (although their specs seem identical). The Canon Digital Rebel XT / Canon 350D kit lens has a roman 2 "II" after the aperture ranges in white writing on the front of the lens.
Overall user feedback seems to be that the kit lens is a good performer particularly when you consider the price. However, if you're using the kit lens it would be best to avoid higher f-stop numbers (smaller apertures). The lens shows significant softness at f10 compared to f4. See for example these shots at dcresource and these at dpreview.
Where'd the focusing screen go? [TOP]
Anyone used to a quality SLR will have an appreciation for the split focus screen that allowed instant visual checking of focus (particularly useful before the advent of auto-focus).
The Canon Digital Rebel XT / Canon 350D (like the Canon Digital Rebel / Canon 300D before it) does not have a split focus screen and Canon say that the focusing screen is not replaceable. This is not correct - you can replace the screen yourself (although this may void your warranty) with a focusing screen from Haoda Optical Research Group - see image.
For some excellent instructions in english see www.camerahacker.com/Tools/Installing_Haoda_Screen.shtml.
Is there a movie mode? [TOP]
No digital SLR's to date have a movie mode. The usual explaination why is that:
- DSLRs use a large power hungry sensor;
- movie recording requires the sensor to be continously powered while recording the movie;
- that power required is given off as heat;
- that heat causes image problems and potentially failure in the sensor.
That's not to say that DSLRs in the future won't feature a movie mode, but the manufacturers have some technical hurdles to overcome.
How do I connect my Canon Digital Rebel XT / Canon 350D up to my telescope? [TOP]
Firstly, your telescope needs to support a threaded mount (or have an adapter tube available for it). You then need to get a T-mount adapter for the EOS lens mount which replaces your DSLR lens with a T-adapter that connects your camera to the telescope. The T-adapter contains no optics and your images will be flipped/upside down in the viewfinder. If you are having trouble focusing you may need an extension tube. You can try hand holding the camera a little further away than the T-adapter may allow to test if you can get focus.
For more information, have a look at scopetronix.com. They have some good information in the Digital SLRs area under the "Digital Camera Adapters" section.
Where can I read some reviews? [TOP]
Here are some links to online reviews of the Canon Digital Rebel XT / Canon 350D: