Posts Tagged ‘autofocus’

Sigma DG OS APO HSM 50-500mm F4.5-6.3 Autofocus Lens

This Sigma 50-500mm f/4.5-6.3 DG OS HSM APO Lens is for digital SLR cameras with a Canon and Nikon lens mount. The lens has a standard to ultra telephoto zoom range that is perfect for nature, wildlife, or sports photography. The range translates into an equivalent 75-750mm when used with digital SLR cameras with an APS size chip. The lens is also compatible with full frame cameras. You can even increase you telephoto range by using the Sigma APO teleconverters.

For many photographers, having an “all-in-one” lens is an absolute dream. Especially for nature photographers, the idea of a lens suitable for landscape photography at the short end of the zoom range, while still having enough reach for wildlife is a great option. Add to that, the ability to close focus on small objects in the field such as flowers and it’s the perfect backpackers’ lens. Four SLD (Special Low Dispersion) glass elements provide optimum colour correction & sharpness throughout the entire zoom range and super Multi-Layer lens coating reduces flare and ghosting and assures high image quality throughout the entire zoom range. With no need to change lenses, there is less chance of dirt or moisture entering the camera and fouling the imaging sensor.

This lens covers a wide range of focal lengths from 50mm to 500mm ultra telephoto. The OS (Optical Stabilizer) function offers the use of shutter speeds approximately 4 stops slower than would otherwise be possible.

The OS (Optical Stabilizer) system minimizes image blur caused by camera shake, and offers the equivalent of shooting at a shutter speed 3-4 stops faster. This allows handheld telephoto zoom shooting even in poorly lit conditions.

The use of the OS (Optical Stabilizer) system, HSM (Hyper Sonic Motor), APO Chromatic design, four elements of SLD (Special Low Dispersion) glass, and multicoated optics all enable this lens to provide a high level of performance throughout its entire zoom range. A rear focus system ensures quick, convenient manual focus and a non-rotating front barrel.

This lens has a maximum magnification ratio of 1:3.1 (at the focal length of 200mm) making it ideal for close-up photography. This lens incorporates HSM (Hyper Sonic Motor), ensuring quiet and high speed AF as well as full-time manual focus potential. The addition of the optional 1.4x EX DG or 2x EX DG APO Tele Converters produce a 70-700mm F6.3-8 or a 100-1000mm F9-12.6 MF zoom lens respectively.

The improved DG lens design corrects for various aberrations. This lens is particularly coated to get the best colour balance, while cutting down on ghosting caused by reflections from the digital image sensor. The lens provides the utmost correction against lateral chromatic aberration, which is a serious problem for digital SLR cameras.

The filter size of this lens is Diameter 95mm and the lens is supplied with a step down ring enabling digital cameras with an APS-C size image sensor to use an Diameter 86mm filter.

Canon Xsi Rebel ? Inconsistent Autofocus And Busy Indicator

I wanted to love this camera so much. It takes great pictures and the colors are vivid WHEN THE AUTOFOCUS work properly. I would get 6 shot of unfocused pictures out of 10. I tried all the settings (Manual, P, ATV, AV, A-DEP) and the results are the same. One would think that by setting the camera to AUTO MODE you would at least get consistent good pictures but it’s not the case. Also, there is this BUSY indicator which appears for no valid technical reason. I was taking picture of the San Francisco BAY at around 4:30 pm. It was slightly cloudy and the sun was just peeking through the clouds. I set up the ISO to 200, shutter speed to 1/1250 (I was also focusing on the small waves and that’s why I went for the faster shutter speed) and sometimes to 1/50 , wb to daylight, and also cloudy. There were a several shots where I got the BUSY indicator when I didn’t even use the flash. The BUSY indicator delays your shooting significantly, and it performs like a P&S camera.

I have P&S digital cameras (sony, panasonic, and Canon) and their autofocus are dead on.. no problem whatsoever. For a DSLR, although entry level, one would assume that the autofocus will be accurate on auto mode. I am disappointed with this camera. I think canon cameras are great unfortunately, I probably got a defective one. I also ordered the Nikon D40 last month. It was a great camera but focusing was bad as well. It is just frustrating. By the way, I have very steady hands so camera shake is not an issue. I hope Canon will fix this problem soon, or at least during production so it will be fixed when the camera is out for sale.

Canon XSi Rebel – No Eexpert, But a Great SLR Camera for a Noob

My first SLR camera and I really like the feel and the large LCD screen on the back. I find it is very user friendly. Has a lot of automatic features so you don’t have to be a expert to take some good quality photos. You can grow with the camera as you learn more of it’s basic features. I picked up a couple of lens to go with this camera and can’t wait to explore more of what it has to offer. I’m so glad I choose this model. I’ve been wanting to get a SLR camera for years and finally I got one and I couldn’t be happier!

Canon XSi Rebel – Very Good Camera

This review comes from a novice looking to learn more with a good camera. I really do like this camera but I gave it 4 stars because the automatic setting does NOT allow you to use the display screen to view your shot, you have to use the viewfinder. I do not know why Canon did this. In this way it does not function like a typical digital camera – in auto mode. I believe you can use the display in manual mode, but I am not competent enough (yet) to use that mode. It is a nice view finder though and accurate.

Canon XSi Rebel – Reviews

This is the first camera I’ve ever owned – including point and shoot cameras…yes, i popped my cherry with a canon Canon XSi Rebel.

This camera has me wishing that I could relive some moments of my life just to be able to capture them with the Canon XSi Rebel. The best advice I got was to steer clear from the automatic modes and dive headfirst into the different settings to get a feel for what they can accomplish. The pictures are remarkable to say the least, especially the close of shots of inanimate objects. Enough of the objectivity-

price – very good value – a deal ! 8/10
comfort/handgrip/ease-of-use – 8/10
design/layout of buttons – 8/10 (never used a camera before, but for a beginner, pretty decent)

zoom – limited by use of lens….i.e. buy a zoom lens – for the kit lens I’d say 7/10
replication of real life – 8/10 – RAW format is amazing
Canon software – I’m very new to it, initial 5/10.

More Detail…

Indoor portraits with a Nikon D50

Many digital SLR users also end up taking loads of pictures of their friends and family, often indoors, which can cause lots of problems. This guide should reduce the likelihood of poor exposures and wasted opportunities.

Shooting Mode

Set the mode dial to A (aperturepriority). Then use the command dial to select f/5.6 to give a relatively shallow depth-of-field to blur backgrounds.

ISO

Press and hold the ISO button on the back. Use the command dial to scroll until you reach 200 on the top LCD display. 200 is the lowest setting on this camera.

Red-Eye Reduction Flash

Press the flash button once to pop it up. Press and hold it again and use the command dial to scroll to the eye symbol on the top LCD display.

Autofocus

Press Menu. Use the multi-selector at the back to select the pencil (symbol). Scroll down until you reach 03 AF-Area Mode. Select Dynamic Area. Now the camera will recognise where your subject is in the frame better and focus accordingly.

White Balance

Hold the WB button on the rear of the camera and use the command dial to select fl ash on the top LCD display in order to get the right colour balance for healthy-looking skin tones.

Custom Colour

Press Menu, go to the camera menu and select Optimise Image. Press right, go down and select Portrait Mode which is optimised for people pictures and hopefully your skin tones should improve.