View Full Version : Softness related to lens?
Koontsa
23rd of September 2004 (Thu), 14:39
This might be a stupid question, but here I go anyway. I have a Digital Rebel and a 35-80mm Canon Lense(kit lense on the rebel 2000 2 years ago.). I shoot sports for my high school and notice that most of the shots come out soft, like the AF is just a hair off. My question is if I purchase the 70-200 f4L will autofocusing become slightly more accurate? And will this help my softness problem?
kawter2
23rd of September 2004 (Thu), 14:45
what ISO are you shooting at, are you shooting with a flash, if so which one?
Are you sure it is a focus issue, or a shutter speed problem. Can you post some of the pics?
drisley
23rd of September 2004 (Thu), 16:29
Also, if you are new to digital slr's coming from film....
The digital cameras produce images that are soft from the camera.
Most film users are surprised by this. However, this is "normal" as digital sensors have an antialiasing filter over them. The sharpness is easily recovered...
Just open the images in an editing program like Photoshop, and apply some Unsharp Mask (USM) to sharpen the image. Or get a sharpening action.
http://www.luminous-landscape.com/tutorials/smart_sharp.shtml
http://threedee1.tripod.com/sharpnsmart/
Koontsa
23rd of September 2004 (Thu), 16:53
Here are some sample images:
http://www.ltcmdrmatt.com/crod2.jpg
http://www.ltcmdrmatt.com/holly.jpg
ISO = 400
Shutter Speed = >1/1000 sec.
F= 5.6
Ogrt48
23rd of September 2004 (Thu), 19:27
Try changing the f/stop to 8.0 , it really helps with the kit lens for the rebel, might as well try it with that lens too.
kraterz
24th of September 2004 (Fri), 00:56
How are the results with other lenses? Contrary to what most people "believe" even the 35-80 is capable of much better results. I have seen acceptably sharp 5x7's coming from the junky 28-90 kit lens.
sjprg
24th of September 2004 (Fri), 10:41
I just downloaded you images and ran them through Focus Magic.
www.focusmagic.com
Your images are not "soft" they are motion blured. Cleaned up they look really nice. I beleive you should probably shoot with shutter priority instead of Av. Try setting the shutter spead at least 250-350 and let the apurture fall where it must. If you shoot RAW you can recover the exposure with PS or elements.
Koontsa
24th of September 2004 (Fri), 12:52
but they are shot at Greater than 1/1000 of a second. :?:
drisley
24th of September 2004 (Fri), 13:12
The first image isn't bad at all.
I just increased the gamma, and fixed the contrast, and added sharpening and it looks great.
The second image looks like motion blur, but not if shot at 1/1000s.
The camera just may have missed focus.
I think the problem may be with the Rebel Autofocus.
Ideally, for situations like this, you want to use AI Servo.
However, the Rebel uses AI Autofocus, in which the camera determines One Shot, or switches to AI Servo if it senses movement.
Well, often the camera reacts too slowly, or doesnt switch to AI Servo at all.
This was something I experience also when I first got my Rebel. So, I ended getting Wasia's Modded Firmware that allows you to choose AI Autofocus, One Shot, or AI Servo, just like on the Rebel's big brother, the 10D. That fixed most of the problems. However, the modded firmware using AI Servo has one slight glitch. The AI Servo works fine , but when you press the shutter all the way to take a pic, nothing happens. So, what you have to do is quickly release your finger from the shutter, then press all the way down to get it to shoot. With some practice, you can get a very quick trigger finger and it works great! I used this method all summer!
dds
27th of September 2004 (Mon), 05:52
An alternative trick to shoot in AI servo with the 300D is:
1) keep the thumb on the AF/MF switch and then, when willing to shoot:
2) switch to MF
3) shoot!
I feel sometimes it is faster and more intuitive than the other way.
Hope it helps.
DDS
Koontsa
28th of September 2004 (Tue), 20:02
Here is a 100% crop from a 70-200 f4L that I just received. Is this image sharp?(no glasses means I am blind tonight.)
http://www.ltcmdrmatt.com/100.jpg
Ogrt48
28th of September 2004 (Tue), 21:36
It's not sharp at all to me...
DocFrankenstein
28th of September 2004 (Tue), 21:49
Koontsa - are your pictures scaled down, or those are 100% crops?
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