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ctfchallenge | all galleries >> Challenge 194 - Flat Light >> Challenge 194 Eligible > Seventh Place (tie) - *My Good Side* - by Techo
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12-SEP-2009 Techo

Seventh Place (tie) - *My Good Side* - by Techo

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ctfchallenge19-Sep-2009 15:18
With the full frame camera I know I need to be closer to the subject than if I were using the same lens on the rebel. And yes, that changes the DOF and the bokeh. The ratio stuff is still all mixed up in my head so I'm not much use a.
I just didn't want you think I didn't read all this.
Penny Street
ctfchallenge19-Sep-2009 03:54
Nice explanation Rod in very practical terms. I try to think more simply that for the same f-stop, the dof increases as the the focal length decreases. We all know that a short focal length of say 18mm has a very deep dof at almost any aperture, so just imagine the dof increase for a 7mm focal length of a small sensor camera - all at the same f-stop. This makes sense if we remember that the f-stop is a ratio of focal length to aperture diameter.. I think. -tv
ctfchallenge18-Sep-2009 23:36
Rod
I'm not so sure this doesn't fit Techo as it has been a given for as long as I can remember that overcast light is the best light for colour photography. The diffused light doesn't necessarily mean you will get a flat looking picy as a lot of diffused light picys have highlights & nice soft shadows. The look of this picy has all the traits of diffused light I reckon & the topic is really overcast light rather than flat looking picys a.
ctfchallenge18-Sep-2009 04:51
Now back to the discussion about this shot...

I like it as is. Even though it was shot under grey skies I have a feeling it doesn't quite fit within the spirit of the challenge. Mainly because it looks like directional light was used. It just came to me, because unlike the other two pics, here I was shooting from the top, I blocked some of the light.

-Techo
ctfchallenge18-Sep-2009 04:46
I'm glad we've come to an agreement :) I agree with all of what you wrote in that last post. I'm just not an eloquent enough communicator. It's just that, the full frame cam would force me to come closer to the subject thus minimizing the DOF. Why didn't I just say that from the start. I'm also finally thrilled that the crop DSLRs are getting viewfinders that are close to the brightness and coverage of the full frame cams.

-Techo
ctfchallenge18-Sep-2009 04:32
Thats a good link, thanks Techo. Dougy the sensor has no bearing on DOF or bokeh as it's all lens driven by the Fstop, focal length & focusing distance. If we bring equivalence into it then the sensor starts to have a bearing on the DOF outcomes. So if you put a 50mm lens on your full frame camera & I put the same lens on my crop camera & we both stand 20 feet from the subject both our picys will have exactly the same DOF & bokeh. If we bring equivalence into the equation which we would in the real world then for you to get the same picy (field of view) as me you would have to move closer to the subject than me to get the same looking shot or use a longer lens. By moving closer you have to alter your focusing to suit which will give you a narrower DOF. So in practice because we all seem to compose in a similar way it would be more natural for you with a full frame to always being closer to the subject than me with a crop camera so your DOF will always be less. In a pratical way it can be said that the full frame sensor gives you a smaller DOF but in a scientific way it has no effect on DOF it's just that the operator by being closer to the subject is causing the narrow DOF, not the sensor size. It almost becomes one of those circler arguments in a way as you can say the sensor size made you stand closer to the subject so sensor size does have a bearing on DOF.
ctfchallenge18-Sep-2009 02:52
I think this link here pretty much explains it all
http://www.bobatkins.com/photography/technical/digitaldof.html

-Techo
ctfchallenge17-Sep-2009 21:51
My understanding was that the DOF was narrower on a full frame for the same reason that it's closer to infinite on a digicam. I thought that sensor size played a large role in DOF. Either that or I am going to have to start using both hands to count the number of times I've been wrong. (Kidding of course.) -Doug
ctfchallenge17-Sep-2009 15:06
With the same lens on both crop & full frame cameras there's no difference in the DOF or bokeh. There is a perceived difference when viewing both picys at the same size though as the full frame will show the subject smaller & further away from the camera. If we crop the full frame picy to the same field of view as the crop sensor & then view them both at the same size the DOF & bokeh will be the same. The misunderstanding comes in because we tend to use different focal length lenses to get the same picys. Say I want to photograph a bird to fill my frame on a full frame camera I can use a 640mm lens to achieve that but for the same bird to fill the frame on on a crop camera I only need a 400mm lens so the crop camera will have a bigger DOF & less smooth bokeh because of the focal length of the lens used not the size of the sensor.Penny will correct me if I'm wrong:-)
ctfchallenge17-Sep-2009 14:14
Thanks for the comments, folks.
Rod, well perhaps for macros and wildlife people mostly prefer the crop cams. I usually have problems getting enough DOF with macros close as this, but shot at 2.8 for most of the day to get a whole different effect. But for full length portaits , getting those expensive 1.2L lenses, you'd probably want a full frame cam to reap all the benefits of that. I have yet to see a sample shots comparing the same lens on two different bodies, to see how much the DOF bokeh differs. Would be interesting to find out.

-Techo
ctfchallenge17-Sep-2009 04:32
Rod
People say they want full frame cameras for the narrow DOF but who in their right mind would want less than this. Did you shoot wide open?
ctfchallenge17-Sep-2009 04:08
Oh my Techo. This and the original serve to show how a flat lighting picture can be made otherwise. -Doug
ctfchallenge17-Sep-2009 02:58
Very nice - great macro! Lovely color, and I like the composition. Penny Street
ctfchallenge17-Sep-2009 02:27
Here's the orginal resized:http://www.pbase.com/image/117371633 . The edited version does look a bit smoother. I only happened to get three shots while it was on the flower like this. Was shooting down at the flower. I wanted to highlight it's body shape instead of going just for the eye. This is pretty much the full frame, so I was really close to the bug.

-Techo
ctfchallenge17-Sep-2009 02:14
Howdy m8. Thanks for the comment. No smoothing in particular was applied to create the effect. I only applied slight noise reduction and boosted the contrast and sharpened. I'll post the original in a bit. As for the frame. I thought you'd say something. I like the seperation ;)

-Techo
ctfchallenge17-Sep-2009 01:46
Rod
This smoothing doesn't seem to be just DOF. Did you use some blurring or smoothing thingy to get this? I thik if the eye was in focus instead of the hairy body it might have worked better I think, although the large border helps to make it look like a proper picy a:-)