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-   -   Wide Aperature Question (https://forums.steves-digicams.com/general-discussion-11/wide-aperature-question-47982/)

normc Mar 1, 2005 7:29 AM

Many cameras will go to F2.8, but are there any that go to F1.7 or F1.4 ?

Meryl Arbing Mar 1, 2005 8:25 AM

Did you ever see 'This is Spinal Tap' where the guy had an amp that went up to '11' even though all other amps were labeled from 1-10...HIS went to '11'.

I don't have much faith in the accuracy of the numbers that the marketing departments put on thier cameras. They could SAY that an f2.0 lens is f1.4 and who would know?

We already know that they label ISO400 as ISO800 to pretend that the camera is better in low light than it is!

[email protected] Mar 1, 2005 8:37 AM

I think it's the lens that determines the max aperture.

I have a 50mm F1.4 lens, and it opens to F1.4.

I can tell, because I take indoor track pictures and can do them without the need of a flash, whereas with my F2.8 lens the camera would warn that there is not enough light.

So, you can experiment and feel the difference!

normc Mar 1, 2005 10:32 AM

OK...sure I have film camera that go below F2.8 and it is the lens that determines the "F". But with the exception of DSLR's everything else comes with the lens attached.....so the question was do any of these go below F2.8?

perdendosi Mar 1, 2005 12:13 PM

Well...


Quote:

F-Stop is theratio is between the diameter of the aperture in the lens and the focal length of the lens

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http://www.uscoles.com/fstop.htm

And on digicams, that ratio is the ACTUAL ratio of the ACTUAL focal length of the lens (not the 35mm equivalent) to the ACTUAL diameter of the aperture of the lens (so instead of a 50 mm focal length and a 25mm aperture for an f/2, we're talking like a 5.8mm focal length with a 2.07mm aperture diameter (the specs for a Canon S1IS) for a maximum f-stop of f/2.8.

Searching Steve's reviews, you will notice that (1) they're not just making up the numbers and (2) yes, there are cameras with a better max f-stop of 2.8:

The Olympus C-8080 has a max f-stop of 2.4; I'm sure there are others, but I am at a loss to find them right now.

calr Mar 1, 2005 1:07 PM

The problem with making auto-focus lenses with a larger aperture than f2.8 is the physical size of the lens. A f1.2 or f1.4 manual, fixed-focal-length (prime) lens is a big lens. Now add zoom capability to that and you get an even bigger lens. Wait...we haven't added the autofocus, and auto exposure mechanim, yet. Ok, still getting bigger. Now if this brand of camera has the focus drive motor in the lens rather than the camera body....well you get my point.

You may have also noticed that most zoom lenses have different maximum aperature at opposite ends of the zoom range. This saves cost and makes a smaller lens but can cause problems in certain shooting situations. Zoom lenses with fixed maximum aperture are available but are much more expensive and larger than the variable types. I have a Sigma 28-70mm f2.8 lens. Physically, this is a large lens. It is big enough that I can't use the on-camera flash at wide angle because the lens causes a shadow.

Bottom line, if you want a large aperture lens and are willing to forego the automatic features and zoom, you can probably get a good buy on a prime lens for your camera. If you want all the bells and whistles with the big glass, you better get a heavier tripod!

Good luck to you.

Cal Rasmussen

Puck M Mar 1, 2005 1:27 PM

F2.8 seems to the be the widest aperture that most of the current crop of consumer cameras go. MY old Epson 3000z has an F2.0- F2.5 3X zoom lensas does the old Sony S-70. I see a couple of newer Sony's , the CD-500 and the F-828 which have F2.0 lenses. I guess if you need a really fast lens youhave to go to a dSLR. Large aperture lenses = larger size and more money.

normc Mar 1, 2005 4:02 PM

Thanks to every one

pianoplayer88key Mar 1, 2005 4:27 PM

The Canon G6 has an F/2.0 lens which stops down to F/3.0 at telephoto.

Some of the Olympus C-x0x0 cameras had lenses that opened up to F/1.8

Sivaram Velauthapillai Mar 1, 2005 4:35 PM

Of the recent models, Canon G6 is probably the best at f2.0 at wide-angle...


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