MCTuomey
Veteran
great thread - now i comprehend why i do what i've done for awhile with my M8. i've always compensated by about a stop when scale focusing, just my gut-feel based on the crop-induced change in effective focal length.
Finder
Veteran
Math is really hard for you. You realize that that calculator is only accurate to two decimal places and the Dof for those conditions cannot be shown within those values. However, if you were not in a rush to prove Leica was correct, you would have noticed that the hyperfocal distance changed at the bottom of the results.
Go back and try again.
DRabbit
Registered
I'm a visual person. Hate charts and calculators 
I took these photos a while back when someone asked a similar question about depth-of-field and the difference between an E-P1 and M8.
I took some test shots. Nothing scientific. I sat on the kitchen floor and shot my refrigerator. On the E-P1 was the Olympus 25mm f/2.8 Pancake lens. On the M8, the Zeiss 50mm f/2 Planar (shot at f/2.8). I moved back slightly with the M8 to get the same FOV.
E-P1, 25mm f/2.8 Pancake at f/2.8
M8, 50mm f/2 Planar at f/2.8
If you want to switch back and forth between the two, here's the URLs...
http://www.dangrabbit.com/photography/albums/test/EP1_25mmf28.jpg
http://www.dangrabbit.com/photography/albums/test/M8_50mmf28.jpg
There's clearly more DOF in the E-P1 shot. I suspect if you did the same comparison with the M9, the difference would be even more drastic.
I'd love to SEE the same type of comparison done with the M8 and M9. I suspect there would be a difference, but not so quite pronounced.
I took these photos a while back when someone asked a similar question about depth-of-field and the difference between an E-P1 and M8.
I took some test shots. Nothing scientific. I sat on the kitchen floor and shot my refrigerator. On the E-P1 was the Olympus 25mm f/2.8 Pancake lens. On the M8, the Zeiss 50mm f/2 Planar (shot at f/2.8). I moved back slightly with the M8 to get the same FOV.
E-P1, 25mm f/2.8 Pancake at f/2.8
M8, 50mm f/2 Planar at f/2.8
If you want to switch back and forth between the two, here's the URLs...
http://www.dangrabbit.com/photography/albums/test/EP1_25mmf28.jpg
http://www.dangrabbit.com/photography/albums/test/M8_50mmf28.jpg
There's clearly more DOF in the E-P1 shot. I suspect if you did the same comparison with the M9, the difference would be even more drastic.
I'd love to SEE the same type of comparison done with the M8 and M9. I suspect there would be a difference, but not so quite pronounced.
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ferider
Veteran
Probably in agreement with all three but not with you. WRT DOF, it shows 0.01m in front, 0.01m behind of subject, 0.01m total ............... How did that happen ??? (total = front + behind)
Answer: rounding errors.Dofmaster clearly shows different Hyperfocal distances:
M8: 173m
M9: 132.7m
Roland.
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Finder
Veteran
I took this photos a while back when someone asked a similar question about depth-of-field and the difference between an E-P1 and M8.
I took some test shots. Nothing scientific. I sat on the kitchen floor and shot my refrigerator. On the E-P1 was the 25mm f/2.8 Pancake lens. On the M8, the Zeiss f/2 Planar (shot at f/2.8). I moved back slightly with the M8 to get the same FOV.
E-P1, 25mm f/2.8 Pancake at f/2.8
M8, 50mm f/2 Planar at f/2.8
If you want to switch back and forth between the two, here's the URLs...
http://www.dangrabbit.com/photography/albums/test/EP1_25mmf28.jpg
http://www.dangrabbit.com/photography/albums/test/M8_50mmf28.jpg
There's clearly more DOF in the E-P1. I suspect if you did the same comparison with the M9, the difference would be even more drastic.
Nothing wrong here. This is expected when you are changing both focal length and object distance. But this is not the discussion.
The test would be to shoot both the E-P1 and M8 with the same lens and from the same distance. The depth of field will not be the same in the resulting images--the angle of view will be different as well.
So, when you use the depth of field scales on a 35mm lens on your E-P1, are the scale still accurate. Or are they off by two stops--for example, the f/5.6 scales are correct for when the lens is set to f/11.
DRabbit
Registered
What I was after was comparing same FOV at the same aperture.
Can't argue it because in practical terms it doesn't mean much. A 50mm lens on an E-P1 has the field of view of a 100mm lens, so it's highly unlikely I'd use the same lens on each camera to accomplish the same photo.
That's a question I've been trying to figure out, and I'm not sure. But since a 25mm lens on an E-P1 would effectively be a 50mm lens, I'm going to be a whole lot less likely to try to use it at a hyperfocal setting.
It APPEARS, from my limited shooting with the CV 15 on the EP-1 that to get hyperfocal you don't need to adjust by 2 stops... however, I'd ask someone with a whole lot more experience using that combo than me...
Of course, I'm guilty of going off topic here... The comparison was the M8 to the M9/MP, and in that case the difference is a whole lot less. Going from a 1.3 crop to full-frame certainly isn't going to yield such drastic differences.
Finder
Veteran
I shoot a cv 12mm on my E-P1 using scale focusing. And yes, I have to compensate when using the scales. I think some of the "smearing" criticism of the wide cv lenses comes from not understanding the scales.
Yes, you are right the going from an M9 to an M8 is not going to have as great a difference. I am just trying to give the OP the best answer I can to his question about the lens DoF scales.
ampguy
Veteran
My point exactly. If any of you had bothered to read the link I posted above, you would have realized that the calculations used to derive the DOFmaster results are based on multiple variables and constants that vendors have not standardized on.
Besides hyperfocal distance, did you also notice for one camera they used .023 mm coc, and for another camera .03 ?
Leica (Gunther Osteroloh Advanced M book) says Leica lenses are designed for .023 coc.
But I think we're diverging here, and should have another thread if you want me to go step by step through the science.
For the OP, it would not hurt, whether film, FF digital, or crop digital to use the innermore stops for your DOF zone focusing, whether that is 1 stop, 1.4x stops, or 2 stops.
But I urge you to spend a few dollars and do the print tests that I suggested earlier.
Besides hyperfocal distance, did you also notice for one camera they used .023 mm coc, and for another camera .03 ?
Leica (Gunther Osteroloh Advanced M book) says Leica lenses are designed for .023 coc.
But I think we're diverging here, and should have another thread if you want me to go step by step through the science.
For the OP, it would not hurt, whether film, FF digital, or crop digital to use the innermore stops for your DOF zone focusing, whether that is 1 stop, 1.4x stops, or 2 stops.
But I urge you to spend a few dollars and do the print tests that I suggested earlier.
ferider
Veteran
The coc difference is due to the crop factor. QED.
ampguy
Veteran
Amy, there are multiple variables going on here. What you could do easily, would be to isolate out the lens and focal distance.
So to compare DOF effects with M8 and EP1, stay at the same distance, and use the M lens on both cameras, focus on the same spot.
Of course the EP1 shot will appear to be "zoomed in" so for the purpose of DOF comparison, mask off the excessives of the M8 shot. Don't use photoshop, or cropping, just print them and block them off with paper and examine.
So to compare DOF effects with M8 and EP1, stay at the same distance, and use the M lens on both cameras, focus on the same spot.
Of course the EP1 shot will appear to be "zoomed in" so for the purpose of DOF comparison, mask off the excessives of the M8 shot. Don't use photoshop, or cropping, just print them and block them off with paper and examine.
Finder
Veteran
You don't even know what rounding errors are. :bang::bang: How are you going to go through the science.
ampguy
Veteran
To point out the ridiculousness of trying to quantify DOF to the 2nd or 3rd digits of a mm, imagine this scenario:
Imagine if all readers of this thread printed out Amy's 2nd image, for example at our local Walgreens, CVS, Costco.
Then independently, we tallied our results on which words were in focus vs out of focus, and observed our differences. After this proposed exercise, do any of you think dofmaster is something you want to use for critical photography??
Imagine if all readers of this thread printed out Amy's 2nd image, for example at our local Walgreens, CVS, Costco.
Then independently, we tallied our results on which words were in focus vs out of focus, and observed our differences. After this proposed exercise, do any of you think dofmaster is something you want to use for critical photography??
Finder
Veteran
If you crop the M8 shot, you change DoF. That just means both cameras will not match the DoF scales on the lens. That gets you absolutely nowhere.
Jeff S
Well-known
Distance, yes, but you do realize that focal length alone (assuming constant magnification, i.e., object size occupying same portion of frame) does not change depth of field...http://www.cambridgeincolour.com/tutorials/depth-of-field.htm (You can also click on the Luminous Landscape link at bottom of the article for another visual presentation of the same principle.)
Jeff
PS General observation for the OP...the DOF markings on all modern lenses haven't been close to accurate for some time. This article is useful...http://www.trenholm.org/hmmerk/DOFR.html
Finder
Veteran
Yet, the Leica DoF scales on the lens are perfect.
ampguy
Veteran
Well...
Well...
This gentleman may not know all the little trivial facts about geology, but it is nice of him to give us a warning ...
http://www.youtube.com/watch?v=dPHdk6WgbUg
Well...
This gentleman may not know all the little trivial facts about geology, but it is nice of him to give us a warning ...
http://www.youtube.com/watch?v=dPHdk6WgbUg
Finder
Veteran
Jeff, "object size occupying the same portion of the frame" is not having the same magnification. You are simply fixing field of view, which is not what we are talking about.
You "expert" source that DoF scales are wrong is wrong. DoF scales is only a guide. You can change the criteria for sharpness if you are not satisfied with it. However, it still does not change what DoF is nor the conditions that affect it. Having zone focused with modern cameras, their DoF scales are very good.
SimonSawSunlight
Simon Fabel
lol...
.
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Mister E
Well-known
This is incorrect. DoF doesn't change based on sensor size, but the working distance for a given focal length to get the same perspective does. For a 1.5x sensor you would have to stand 1.5x further away to achieve the same framing. Because you are 1.5x further away you will have MORE depth of field. This has nothing to do with the magnification for prints, etc. The hyperfocal markings on the lens still apply to crop sensors because of this. A 50/1.4 Lux has the same DoF at 10' on the M8, M9 and m4/3.
Makten needs to show up in here. He is DoF explainer number one fan.
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ampguy
Veteran
Exactly
Exactly
Same lens, same photons, same medium, same angles of rays, same lens to sensor medium distances, same DOF.
Exactly
Same lens, same photons, same medium, same angles of rays, same lens to sensor medium distances, same DOF.