Aperture: DSLR Know-How with Tamron Episode 3
In this week’s video, Andre explains just what the aperture function on your camera does and how you can use aperture to get the results you are looking for.
A full review of Tamron’s super useful high quality F2.8 17-50mm lens, one of the most affordable and best walk around lenses around,
How do I work out the magnification of a zoom lens for a DSLR?
Question by mouse_spinach: How do I work out the magnification of a zoom lens for a DSLR?
I recently got a Canon EOS 400D digital SLR camera and I am looking to upgrade the lens for one with a more powerful zoom. However separate lenses are new to me so I am struggling to figure out which lenses are more powerful than others.
I was hoping someone would be able to tell me how you can either work out the strength of the optical zoom on Canon lenses, or give me suggestions of lenses to look at.
Any help is greatly appreciated.
Many thanks,
Martin.
Best answer:
Answer by Edwin
Hello Martin.
Suppose you are using a 50mm lens. You focus on a subject 30′ away. Now you switch to a 300mm lens and focus on the same subject 30′ away. The image will appear as though it is 6 times closer – or 6 times bigger – as though you had used the 50mm lens at 5′. A zoom of 50-300mm would have a 6x zoom ratio. A zoom of 18-200mm would have an 11.11x zoom ratio.
Simple, isn’t it? Just divide the large number by the small number.
A note of caution: Pay particular attention to the f-stops on zoom lenses. If its a 50-300mm and says f3.5/f6.5 that means it is a slow lens at 300mm (f6.5) – and its not all that fast at 50mm (f3.5). Unfortunately, lens speed costs $ $ $ – usually lots of it.
Give your answer to this question below!
Sony Alpha NEX Camera – Available Low Light (NEX-5, NEX-3) dslr
Video featuring David McLain, Sony Artisan of Imagery. Visually demonstrates feature of the Alpha NEX cameras: Great shots with available light photography. Video Program Manager: Lisa Gonzalez. Live Action Production Company: Merge Group (www.mergegroup.com)
Video Rating: 4 / 5
Should you use zoom lenses for DSLR filming? -DSLR Film NOOB
www.dslrfilmnoob.com I don’t recommend using zoom lenses for filming unless the zoom covers a focal length that is hard to find or not available. Two such focal lengths are covered by the Tokina 11-16mm f2.8 and the canon 16-35mm f2.8. I’ve already done a review on the tokina 11-16mm, but i thought it might be nice to compare the Canon 16-35mm f2.8 and the Tamron 17-50mm f2.8. The Tamron 17-50mm f2.8 is a budget zoom that you can pick up for around 0. http The Canon 16-35mm f2.8 is a ruffly twice that price: rcm.amazon.com The benefits of using a nicer Zoom can be seen in the full time manual focus, the longer travel of the focus ring, the stationary barrel, and the smooth operation of the zoom. These are all very nice to have but 0 in your pocket might help you forget about many of these short comings. Other zooms in my collection include the Tamron 28-75mm f2.8: rcm.amazon.com And the canon 24-70mm f2.8: rcm.amazon.com Although i don’t generally use these last 2 lenses for filming, they are great for photography. If you must use a Zoom lens for filming make sure it is a constant F-stop across all focal lengths or your lens will automatically stop down as you zoom causing unwanted color changes and dimming of your video image. Equipment used in this video: Canon 7d & t2i Canon 16-35mm f2.8 Canon 35mm f1.4 Tamron 17-50mm F2.8 CPM film tools mounting parts Sennhieser G2 Wireless mic system
Video Rating: 4 / 5
Cool Dslr images
A few nice dslr images I found:
2011-08-04 Comet Garradd 1:16am-2:40am PST
Image by Ken_Lord
Comet C/2009 P1 Garradd
One more version, stacked by DeepSky Stacker to simulate tracking the stars and a stationary comet. 78 – 30 second exposures taken between 1:16am and 2:40am GMT-7
The comet is magnitude 8.7, and 1.5AU from Earth.
Skywatcher Maksutov Newtonian 190mm F5.3. LXD75 Mount. Canon T1i DSLR, ISO800
First astrophotos shot from my new darker backyard!
A Colourful Night
Image by A.Al-m3oosherji
Camera Sony DSLR-A550
Exposure 0.5
Aperture f/1.7
Focal Length 50 mm
ISO Speed 200