Posted by Andy Brehm on August 19, 2008 at 9:15 PM
I have been struggling with image sharpness and detail for a while now, actually the whole time I have taken photography seriously. I have always noticed that even though objects in the foreground are pretty sharp, many times objects in the background are very soft, to blurry. Here are some links to show what I am talking about. Info on the picture is:
Canon 1Ds Mark III
ISO 100
24mm on 24-105 f/4 L
f/16
1.3 sec exposure
Shot on tripod using MLU
Anyway, if anyone can spot what I am doing wrong, or can give me some advise on how to improve I would love to hear it!
Thanks,
andy
Posted by Mel Ladewig on August 19, 2008 at 10:13 PM
Andy,
I suspect you just aren't stopped down enough to provide that amount of DOF. Those sharp foreground objects are awfully close and that background very far away.
One option is to use tilt to alter the plane of focus to align better with the scene.
The other is to just keep stopping down, but eventually diffraction will just make everything blurry.
Mel-
Posted by Mark Stahlke on August 19, 2008 at 10:35 PM
How far into the scene did you focus? DOF is approximately 1/3 in front of the plane of focus and 2/3 behind it. Better yet, try the hyperfocal focusing method wherein the focus is manually set to the hyperfocal distance for the lens. A search on NPN or Google should yield a good description of hyperfocal focusing.
Posted by Todd Caudle on August 19, 2008 at 10:53 PM
I suspect that either lack of DOF or too small an aperture causing diffraction is causing your background to look less sharp than you'd like. But seriously, that example of the far away portion of the photo is such a small portion of the whole photo that you're looking at the equivalent of a HUGE print, at which point the viewing distance would be greater anyway. Perhaps you're wanting too much out of your image. I think it could be printed quite large as is, and no one viewing it would even have lack of sharpness cross their minds.
Posted by Andy Brehm on August 19, 2008 at 11:58 PM
On this particular image I was using hyperfocal distances so I was focusing from ~1.5-2 feet away which should give a ton of depth of field. But maybe I am asking for too much out of a 35mm camera...???
Posted by Les Barstow on August 20, 2008 at 12:02 AM
If all of the above don't solve your problem - you've got a reasonable aperture (or the one you absolutely need for the shot), hyperfocal settings still don't focus the whole image... - then you could try combining shots digitally to get a single in-focus blend. Helicon Focus and programs like tufuse and enfuse can blend shots by local contrast maximization to achieve a "larger" DoF image. This is obviously not the preferred technique, but if it's your only option...
Posted by Momo Vuyisich on August 20, 2008 at 1:23 AM
In my opinion, your lens is causing this "problem". I get the exact same effect with my 10-22 when I look at my images at 100% (and they are slightly sharpened). With my 28-135, which I think is an outstanding copy, everything is perfectly detailed and crisp, even at 100% magnification. Have you tried comparing the same scene shot with this lens and a sharp prime?
I think everyone here got a part of the over all issue. I see the images abit over saturated, which coming from me must seem weird. Anyway, when working with a lens like the one you used, the image quality is usually best somewhere in the middle of the focal range. Also the Dynamic range is a bit extreme as well.
Shooting digitally I started off under exposing a lot then bringing the image back to the tone i wanted in PS. But I ran into what you're facing here. f/16 is a good F stop but just guestamating, I would say you needed more DOF and more exposure time as well to punch up the exposure and natural contrasts and sharpness.
Posted by Les Barstow on August 20, 2008 at 2:16 AM
Andy, you say you were using the hyperfocal distances, but a 24mm lens on a 1Ds Mk III has a hyperfocal of 4ft @ f/16 (per the charts...); if you were focused in to 1.5 - 2 feet, focal distance sounds like your problem...
Posted by Craig Schultz on August 20, 2008 at 10:03 AM
Andy, I agree with Les. The hyperfocal distance is 4ft@f/16 with a very relaxed 1/150 circle of confusion. And that's in a 8x12in print with only 4 line pairs per mm on the print. That's a small print compared to 100% on your monitor.
You will need to focus at 4ft the next time you take a picture like this, but only if you want 8x12in prints. To go out to 12x18in you will need to up the CoC = 1/275 and focus at 7.5ft, which means everything from 3.75ft - infinity will be in focus. The only other option is to get a wider angle lens which will allow you to get closer.
Hopefully, all the comments have helped.
Posted by Andy Brehm on August 20, 2008 at 11:35 AM
Thank you all for your comments. I will have to look into the hyperfocal distance, I thought my chart said to use 1.5 feet for f/16 but I could be wrong. In the future what CoC would be good to use if I plan on printing around 20x30?
Now I need to start saving for the 16-35, or better yet a MF system, though I guess that won't help much with increasing DOF. It would still be nice to use MF glass though, and I find 35mm aspect ratio to be annoying.
Posted by John Mumaw on August 20, 2008 at 12:43 PM
The best hyperfocal charts that I've seen for a variety DSLRs (incl. yours) are available as downloadable PDF files here. There are separate charts for large prints, as well.
Note that the distances used are in metric lengths.
Posted by Don Grall on August 20, 2008 at 12:52 PM
Andy, medium format will give far worse results than 35mm when it comes to DOF. That's why I sold my Pentax 67 a couple of years ago. I also have the 1DsIII and the 24-105 lens. With all those extra pixels available, I will sometimes take an insurance shot by backing up a bit if at 24mm, then crop in PS to get the comp I want with the DOF I need. If at a longer focal length, I'll just zoom to a slightly wider setting for that insurance shot.
Posted by Grant Collier on August 20, 2008 at 2:13 PM
The hyperfocal distance is twice the distance of the nearest object in your shot. So that's where you should start your calculations and set your focus. It sounds like you're trying to calculate the hyperfocal distance some other way, which may be leading to confusion.
For the shot you posted, if you focused at 2 feet at f16, with a 24mm lens, you will have a depth of field extending from 1.34 feet to just 3.91 feet. If you focused at 1.5 feet, you're only getting things in focus up to 2.35 feet. So, as others said, that is the problem. To get calculations for DOF with various camera settings, you can go to: http://www.dofmaster.com/dofjs.html
If you're not sure about the DOF, I'd recommend also taking shots of the scene at smaller apertures, like F22. Any loss of quality from diffraction will be minor compared to rendering part of the scene out of focus. However, even at F22 focusing at 1.5-2 feet is not going to get things in focus to infinity, though it will look better.
And as Don said, 35mm isn't the problem. I've gotten shots with more extreme DOF in almost perfectly good focus (even though I was certainly pushing it). Here's two examples:
Posted by Andy Brehm on August 20, 2008 at 2:33 PM
Maybe 1.5' was not my focusing distance but the closest distance of in focus objects...not sure, i just have 1.5' in my head. That might make more sense since the mid ground of the image seems to be in focus to me.
In any event, it appears that focus and more specifically hyperfocal distance might be to blame for the softness. Like someone here already said what I see in this picture is not horrible, but I would like to make it better if possible in the future. I have printed slightly softer images to 20x30 in the past and they look pretty good. I just want to make the most of the pixels I have.
I will always have a 35mm camera, but I would like to transition to MF at some point. Some of the images I have seen from digital backs are amazing, I just need to wait out the price point for a while to make the jump in.
Andy
Posted by Andy Brehm on August 20, 2008 at 2:37 PM
Maybe 1.5' was not my focusing distance but the closest distance of in focus objects...not sure, i just have 1.5' in my head. That might make more sense since the mid ground of the image seems to be in focus to me.
In any event, it appears that focus and more specifically hyperfocal distance might be to blame for the softness. Like someone here already said what I see in this picture is not horrible, but I would like to make it better if possible in the future. I have printed slightly softer images to 20x30 in the past and they look pretty good. I just want to make the most of the pixels I have.
I will always have a 35mm camera, but I would like to transition to MF at some point. Some of the images I have seen from digital backs are amazing, I just need to wait out the price point for a while to make the jump in.
Andy
Posted by Mel Ladewig on August 20, 2008 at 3:08 PM
Andy,
Medium format is not going to make this situation any better for you. Those lenses have even less DOF at a given field of view because the focal lengths are a bit longer.
I truly believe the best answer to this fairly simple example is front tilt and you can do that with the Canon TS-E 24L. But not all examples are this simple (where the scene exists mostly on one plane), so know in advance that tilt/swing functions cannot resolve all of these problems. Eventually the only solution is to stop down further and live with the diffraction.
Mel-
Posted by Jesse Speer on August 20, 2008 at 3:54 PM
Andy, one of my favorite features of the 1dsIII (and other new models) is the ability to zoom to 10x in Live View. It allows for some extremely precise focusing, using the large Mark3 LCD. Do some experimenting with this focusing technique (jumping around from foreground to background elements) while stopped down - or while using your DOF preview button. Takes the guesswork out of the process, troubleshooting, etc.
Posted by Andy Brehm on August 20, 2008 at 5:20 PM
Mel, my desire to eventually try out MF is not only because of DOF considerations, rather overall image quality and a personal preference for the 645 aspect ratio. In the mean time I will try to get the most out of my 35mm setup.
Jesse, I have been playing around with the live view quite a bit and enjoy it. I do however wish that Canon had put a high resolution screen on the Mark 3 as Nikon has done with the D3. On a side note, I have tried using the DOF preview button while in live view but have found that it makes it too dark to be useful. Have you found a way around this?
Andy
Posted by Jesse Speer on August 20, 2008 at 8:08 PM
Andy, I haven't run into a problem in the field where DOF preview has been too dark for magnified live view ... not yet anyway. But I avoid anything above f/13 if I can help it. That's probably a big factor.
I guess nail down your hyperfocal method and see if it helps. Good luck!
Posted by Andy Brehm on August 23, 2008 at 7:34 PM
Yeah using f/13 is probably it. Your able to get all the DOF you need from only f/13?
So I have been playing around a bit with hyperfocal distances using a CoC of 0.015 around the house to "hone" the method. Something I have found out pretty quick though is there seems to be very little tolerance for error. At one point I pulled out a tape measure to make sure I was getting pretty close to the exact distances in stead of just eye-balling it and I found out that I was apparently off enough on measurement that the entire image was unacceptably out of focus.
How do you guys combat this, do you take out tape measures in the field and measure down to the nearest fraction of a foot to make sure you have the distance is spot on? If that is what is required I might just let the AF take over because I'm afraid I will miss too many opportunities measuring out distances when I could be taking pictures! Do you guys have any hints? I know you get better at it with practice, but here at home I was only a few inches off and I don't think I will ever get better than sub-inch estimation in the field.
Discussion
20 repliesCanon 1Ds Mark III
ISO 100
24mm on 24-105 f/4 L
f/16
1.3 sec exposure
Shot on tripod using MLU
http://www.andybrehm.com/picture_uploads/1DS3_5947.jpg
http://www.andybrehm.com/picture_uploads/zoom_near.jpg
http://www.andybrehm.com/picture_uploads/zoom_far.jpg
Anyway, if anyone can spot what I am doing wrong, or can give me some advise on how to improve I would love to hear it!
Thanks,
andy
I suspect you just aren't stopped down enough to provide that amount of DOF. Those sharp foreground objects are awfully close and that background very far away.
One option is to use tilt to alter the plane of focus to align better with the scene.
The other is to just keep stopping down, but eventually diffraction will just make everything blurry.
Mel-
Shooting digitally I started off under exposing a lot then bringing the image back to the tone i wanted in PS. But I ran into what you're facing here. f/16 is a good F stop but just guestamating, I would say you needed more DOF and more exposure time as well to punch up the exposure and natural contrasts and sharpness.
You will need to focus at 4ft the next time you take a picture like this, but only if you want 8x12in prints. To go out to 12x18in you will need to up the CoC = 1/275 and focus at 7.5ft, which means everything from 3.75ft - infinity will be in focus. The only other option is to get a wider angle lens which will allow you to get closer.
Hopefully, all the comments have helped.
Now I need to start saving for the 16-35, or better yet a MF system, though I guess that won't help much with increasing DOF. It would still be nice to use MF glass though, and I find 35mm aspect ratio to be annoying.
Note that the distances used are in metric lengths.
For the shot you posted, if you focused at 2 feet at f16, with a 24mm lens, you will have a depth of field extending from 1.34 feet to just 3.91 feet. If you focused at 1.5 feet, you're only getting things in focus up to 2.35 feet. So, as others said, that is the problem. To get calculations for DOF with various camera settings, you can go to: http://www.dofmaster.com/dofjs.html
If you're not sure about the DOF, I'd recommend also taking shots of the scene at smaller apertures, like F22. Any loss of quality from diffraction will be minor compared to rendering part of the scene out of focus. However, even at F22 focusing at 1.5-2 feet is not going to get things in focus to infinity, though it will look better.
And as Don said, 35mm isn't the problem. I've gotten shots with more extreme DOF in almost perfectly good focus (even though I was certainly pushing it). Here's two examples:
http://www.gcollier.com/American-Basin-Columbine.html
http://www.gcollier.com/San-Juan-Mountains-Waterfall.html
In any event, it appears that focus and more specifically hyperfocal distance might be to blame for the softness. Like someone here already said what I see in this picture is not horrible, but I would like to make it better if possible in the future. I have printed slightly softer images to 20x30 in the past and they look pretty good. I just want to make the most of the pixels I have.
I will always have a 35mm camera, but I would like to transition to MF at some point. Some of the images I have seen from digital backs are amazing, I just need to wait out the price point for a while to make the jump in.
Andy
In any event, it appears that focus and more specifically hyperfocal distance might be to blame for the softness. Like someone here already said what I see in this picture is not horrible, but I would like to make it better if possible in the future. I have printed slightly softer images to 20x30 in the past and they look pretty good. I just want to make the most of the pixels I have.
I will always have a 35mm camera, but I would like to transition to MF at some point. Some of the images I have seen from digital backs are amazing, I just need to wait out the price point for a while to make the jump in.
Andy
Medium format is not going to make this situation any better for you. Those lenses have even less DOF at a given field of view because the focal lengths are a bit longer.
I truly believe the best answer to this fairly simple example is front tilt and you can do that with the Canon TS-E 24L. But not all examples are this simple (where the scene exists mostly on one plane), so know in advance that tilt/swing functions cannot resolve all of these problems. Eventually the only solution is to stop down further and live with the diffraction.
Mel-
Jesse, I have been playing around with the live view quite a bit and enjoy it. I do however wish that Canon had put a high resolution screen on the Mark 3 as Nikon has done with the D3. On a side note, I have tried using the DOF preview button while in live view but have found that it makes it too dark to be useful. Have you found a way around this?
Andy
I guess nail down your hyperfocal method and see if it helps. Good luck!
So I have been playing around a bit with hyperfocal distances using a CoC of 0.015 around the house to "hone" the method. Something I have found out pretty quick though is there seems to be very little tolerance for error. At one point I pulled out a tape measure to make sure I was getting pretty close to the exact distances in stead of just eye-balling it and I found out that I was apparently off enough on measurement that the entire image was unacceptably out of focus.
How do you guys combat this, do you take out tape measures in the field and measure down to the nearest fraction of a foot to make sure you have the distance is spot on? If that is what is required I might just let the AF take over because I'm afraid I will miss too many opportunities measuring out distances when I could be taking pictures! Do you guys have any hints? I know you get better at it with practice, but here at home I was only a few inches off and I don't think I will ever get better than sub-inch estimation in the field.
Any input appreciated.
Thanks,
andy