View Full Version : This may be a dumb question, but I'll ask anyway...
08-01-2005, 12:19 PM
I am borrowing a friends Canon rebel, and I can't seem to get the f-stop any lower than 3.5. Why is this? I tried to find something about it in the manual, but didn't find anything. I don't want my shots to come out blurry, so I want to use a relatively fast shutter speed, but I can seem to open the iris up...
I'm guessing it isn't a manual iris lens?
08-01-2005, 12:49 PM
no it's not...I thought you changed iris through the cam?
I can't say for Canon but only the newer Nikon lenses will have a digital iris feature. I'm not sure if the older manual Canon lenses are the correct mount or not. I personally dislike the whole digital iris control (It annoys me on the newer Nikon lenses) but that doesn't help you much!
I have no idea how to change the iris through the camera :(. Sorry!
08-01-2005, 01:38 PM
Well that's the thing, I can change the iris. I know how to do that, but I can't get it any wider than 3.5. I have no idea why they would limit you from having full control in manual mode. I too dislike this digital iris thing. I have an old pentax spotmatic, and that thing is the balls. Having iris control on the lense is deffinetly a better deal.....
Maybe the lens is only capable of 3.5 at its widest aperture setting?
08-01-2005, 02:02 PM
08-01-2005, 02:02 PM
F3.5 is pretty wide open....F22 would be closed. F3.5 isn't letting enough light in for you?
What is your shutter speed to get the meter in the middle at F3.5?
BTW...An F-stop such as F3.5 will give you a shallow depth of field...in other words, if the foreground is in focus, the background will be blurry.
08-01-2005, 02:50 PM
Did you try the other lense? I would assume he let you borrow both of them.
Also, if you're shooting outside, the iris won't need to go any wider. I was shooting the other day outside at f8 with the shutter speed at 1/1000. Worked beautifully. 3.5 should give you plenty of latitude.
08-01-2005, 03:04 PM
IF you're using the kit lens, I'm pretty sure 3.5 is the widest ap. And that's fully zoomed out. Fully in is 5.6, I believe. Do you have access to other faster lenses? The 50 mm mark II is only about $75 or less with a 1.8 aperature. Cheap build but very very good glass for such a cheap price. Maybe you can talk your friend into buying it? You can also up the ISO setting to get a faster shutter speed. Gets pretty noisey as you approach the higher ISO's; 1600 is very noisey on my 300d. I've heard the new XT model has much better noise reduction.