Friday, September 21. 2007Ultimate lens considerations, IV![]() I noticed that a 24-70mm lens definitely cannot be a standard walkaround lens for a 1.6× crop camera, as the equivalent 38mm are definitely not wide angle. I’d have to switch to the dedicated wide angle lens too often. Sure, my PowerShot also starts at only 35mm, but most compact cameras simply lack wide angle focal lengths. Therefore I was thinking about a lens that starts at 17mm or 18mm, what equals 27-28mm on a crop camera. There were several candidates, and I was struggling a lot, as each had its advantages and disadvantages. One promising candidate was the Canon EF 17-40mm f/4 L USM, but although it is a Luxury (L) lens and has an ultrasonic motor, it is rather slow and has no Image Stabilizer, what actually makes it a worse choice compared to the 24-105mm f/4 L IS USM that I was considering earlier. Competing lenses from other manufactures are faster and cheaper, but they lack an ultrasonic motor and are calculated for the APS-C circle only. In addition, the upper limit of 40mm would have made a dedicated 50mm lens almost inevitable.
The main reason for considering the f-stop of 1.2 or the IS for the other lenses is that my PowerShot also has an IS, what actually decreases the aperture values as if the lenses were faster. The following plot of focal length and aperture coverage of the desired lenses considers this by indicated dashed lines:
Posted by Stephan Paukner
in Photography
at
08:22
| Comments (0)
| Trackback (1)
Defined tags for this entry: photo gear
Thursday, September 6. 2007Ultimate lens considerations, III![]()
Btw, that private tester also compares the 24-70mm f/2.8 lenses of Canon and Sigma to each other. I drew the following picture of focal length and aperture coverage of my desired lenses: I chose a logarithmic scaling for the horizontal axis, as slight changes in the lower focal lengths already produce a large change in FOV, whereas focal lengths in the high range have to be doubled or even tripled to yield a higher view detail in the same amount. There’s now a gap in the range between 20 and 24mm (@32-38mm), but I don’t consider that as problem. But the big advantage is the wider FOV, what I assume to use more often than its wide end of 20mm (@32mm). Notice the difference:
Posted by Stephan Paukner
in Photography
at
08:28
| Comments (0)
| Trackbacks (0)
Defined tags for this entry: photo gear
Monday, September 3. 2007Ultimate lens considerations, II![]() I thought a little more about what my first lenses could be, and I got inspired by one photographer’s gallery on the web. He shows many pictures living from narrow depths of field and low f-stops e.g. at f/2.8. He even shows some portraits taken with a 50mm f/1.4 lens at low light or showing awesome narrow depths of field. Therefore I noticed that having a faster lens is more important than high focal lengths, and a DSLR camera body can be used for several years without leering towards FF sensors, what that photographer showed by using an EOS 20D. After some searching I found a different scenario of lenses while coming to lower prices due to the preference of Sigma to Canon. Btw, I found out that the teleconverters can only be used for tele lenses.
Now I could draw the following picture of focal length coverage and aperture values of the mentioned lenses (on an APS-C sensor with crop 1.6): Continue reading "Ultimate lens considerations, II"
Posted by Stephan Paukner
in Photography
at
12:37
| Comments (0)
| Trackbacks (0)
Defined tags for this entry: photo gear
(Page 1 of 1, totaling 3 entries)
|
AboutCalendarArchivesCategoriesShow tagged entriesandroid antenna anti-spam apache austria automobile ballooning bash bluetooth bug career cloud collecting cooking crypto cw debian diy dreams education electronics event fail fashion finance flickr fuerteventura fun gentoo geography german gnu-linux gnucash google google earth graphics guitar hardware history image processing internet kernel kids language lanzarote lhc lifestyle linkroll literature ltd machine learning making mallorca mathematics matlab migration munich music nautilus numismatics octave perl philately philosophy phone photo gear photography physics podcast politics postfix private programming public transport rant religion review salzburg samsung science security social web software statistics storage sustainability symbian tablet time lapse transceiver tv usenet venice video virtualization wordplay work www yahoo youtube
Syndicate This BlogFollow meBookmarks
Powered by |