Edmund Dworakowski

It's very much like if you are able to tell the difference the difference between a Pilsner Urquell and Budweiser...it's sometimes a matter of quality and taste.

muggins88 Loc: Inverness, Florida

Enjoyed the websites as a reminder and especially the cartoon. It certainly hits home.

oldtool2 Loc: South Jersey

Yes, it is true you can make up one stop fairly easily by adjusting the ISO. But eventually you get a Catch-22, the higher the ISO the higher the noise.

I shoot a late night rodeo at times and would adjust my ISO to a higher speed as it would get darker. It would eventually reach a point where I could not get good photos. I started using my Sigma 120 – 300 mm lens which is an F2 .8 lens. This allowed me to lower my ISO that one stop and it was enough to eliminate a lot of the noise and let me get decent shots.

A lot depends on how much light you have to work with and what body you are using. If you were using a full frame it may not make that much difference but I often shoot with my 7D II and believe me when I say using an ASP-C body it can make a difference.

Last year I tried to get a shot of a green Heron and the only time I could find him was in the very dim light in the morning. In order to get the shot I had to put on my f2.8 lens. Without it and just by jacking up the ISO the photo looked almost black and he blended in very well!

All depends on the conditions you are shooting and what you're shooting.

Jim D

EE

THERE IS SENSOR NOISE FROM FILM GRAIN OR PUSHING THE electronic sensor to extremes. SOMEONE ELSE POINTED OUT MORE LIGHT MSAKES THE focusing faster/easier as well
with film plus-x was about 125. and trix 400 so the difference in iso was like having a lens that was one stop bigger! example difference like between a f/8 and f/11 lens.( (bad pun?), usually, bigger is better except for weight and cost!

tomw

I agree with most of what people have said.

It matters only at the margins, but then it really matters.

Aperture is to photography as height is to basketball.

bendanjoe Loc: Cardston, Alberta Canada

From my experience, low light situations call for my fastest lens which is a 50mm f1.7. I can capture an image of an owl in a tree at dusk and see that there is actually an owl in the tree. If I use any other lens whether it is my 50mm f2.8 macro that works perfectly in normal lighting, or my 100mm f2.8 macro, or my 200mm f4 lens will not work at all. To get sharp photos with the highest quality F4 lens I use this lens in full sun light, I call these my sunshine lenses. As another contributor has mentioned that your creativity increases so much in a top quality fast lens over even the highest quality f4 lens. So if you have a specific requirement for your f4 lens and you can use it in full sun you will have great results.

George Kravis

Yes, it does make a difference,paulrph1. In the case of auto focus, which occurs with the lens at max aperture, the lens with the larger f stop will focus quicker over a lens with a smaller aperture, which might not be able to focus at all in low light conditions. So, if you're shooting in low ambient light conditions and are using auto focus, that one f stop could make a difference in getting the picture.

imagemeister Loc: mid east Florida

You are basically correct in your thinking. As mentioned, the speed difference in a lens also affects speed and accuracy of focus as well as potential shutter speeds and out of focus blurring though.

Desert Gecko Loc: desert southwest, USA

A lot does depend on how you use your lens, and what you try to get from it. I own a Tokina ultra wide f2.8 (constant) which I use mostly for astrophotography, with ISOs of usually about 1600. At f4, that ISO would necessarily jump up to 3200 because I cannot change the other variable, shutter length, because of unwanted trails a longer shutter would cause. In this case, one stop is HUGE, and I settle for edge imperfections for the sake of overall brightness, or light gathering. However, on my newer body (the a77ii) I can get away with stopping down to f4 to improve the edge sharpness (mostly coma) while still collecting sufficient light, or a respectable signal to noise ratio at a higher ISO, because the new sensor handles higher ISO better, with less digital noise.

Also, as another stated, a lens usually is not at its best wide open (although there are exceptions, such as my Sony 70-400 f4 G lens which is as good at f4 as it is anywhere.) The general rule, though, is that you need to stop down at least one full stop to get the quality image the lens is known for, especially edge/corner sharpness that usually suffers wide open.

Reinaldokool Loc: San Rafael, CA

As we used to say when flying planes, "When you are stretching, the extra fuel you have on board is worth more than all the fuel you left behind at the airport."

I usually shoot with an f4.0 lens, but I also set the ISO manually to be sure that the camera doesn't choose a lower one and drop the exposure to compensate. I try to stay close to the 1/focal length. (Though with VR, or whatever you call stabilization, that can be exceeded carefully sometimes.) That means missed focus and missed action.

I also carry an f1.8 35mm for the low-light.

gemlenz Loc: Gilbert Arizona

:thumbup:

Latsok Loc: Recently moved to Washington State.

Well said.

ole sarg Loc: south florida

How true!

Rickyb

Lens widest aperture is more than iso. It more about the lens itself as far as refracting light,sharpness and color contrast. Unlike film you can jump the iso up to3200. The noise level sharpness are lost, and forget the color contrast and color realization. Yes it hurts to buy these lenses, but a 2.8 is better than a f4 especially in a 1.8 situation. If we all had f16 days then photo life would be a no brainer. Pay the buck, you will be glad in the end.

cjc2 Loc: Hellertown PA

In my opinion, the answer lies in what you normally, or want to, shoot. For the kids in the backyard I don't think there is any big difference. For your kids playing basketball indoors in a typical school gym, the faster lens and the better performing camera will give you significant advantages, but you will have to learn how to employ them. Expensive equipment usually requires more knowledge to operate to take advantage of what it is capable of. Learning what to do is the fun part as it requires lots and lots of practice.