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View Full Version : Comparaison between Canon 7D and 50D, not the expected result



softgad
09-01-2011, 04:16 PM
Context: I have two cameras, the canon 50D (15mgx) and the Canon 7D (18mgx). I wanted to know if by using a sigma 8mm 3.5 on a R10 if there will any differences. The R10 set up proposed for -2.5 degree with four shots is 2.95. To test this I have repeated the same steps to get the picture and same software steps. The tripod+the lens on the R10 will not move and I will just switch the camera. The software steps using PTGui (latest beta version)will be simple, 1- align image 2- optimize by pressing F5 3-create at print size 4Mb than resize in photoshop to 1600X800 for each.

Both camera were set up at automatic (non creative) full jpg. I cannot explain the following result. The canon 50 d gives me a very good set up and I cannot find any parallax problem while the canon 7D gives me not bad and has parallax problem. Any of you can explain this result? The lighting and contrast is better on the 7D though

nick fan
09-01-2011, 05:17 PM
Context: I have two cameras, the canon 50D (15mgx) and the Canon 7D (18mgx). I wanted to know if by using a sigma 8mm 3.5 on a R10 if there will any differences. The R10 set up proposed for -2.5 degree with four shots is 2.95. To test this I have repeated the same steps to get the picture and same software steps. The tripod+the lens on the R10 will not move and I will just switch the camera. The software steps using PTGui (latest beta version)will be simple, 1- align image 2- optimize by pressing F5 3-create at print size 4Mb than resize in photoshop to 1600X800 for each.

Both camera were set up at automatic (non creative) full jpg. I cannot explain the following result. The canon 50 d gives me a very good set up and I cannot find any parallax problem while the canon 7D gives me not bad and has parallax problem. Any of you can explain this result? The lighting and contrast is better on the 7D though

how did you turn your R10? by holding on the camera grip? if so, this introduce lots of possibility of twisting the lens and shift it from NPP.

Nick

softgad
09-01-2011, 07:16 PM
Using a RD4 rotator, sorry I forgot to mention set 90 degree, so it is the same. I have tried the same with 6 shoots, and this time there is no difference between the 50D and the 7d. I have repeated the same setting with four shots again with the same first result.

bbc597
09-01-2011, 09:19 PM
Were you using a flash with the 7D?

nick fan
09-01-2011, 09:32 PM
Using a RD4 rotator, sorry I forgot to mention set 90 degree, so it is the same. I have tried the same with 6 shoots, and this time there is no difference between the 50D and the 7d. I have repeated the same setting with four shots again with the same first result.

How do you turn the RD4? if you turn it by pushing the camera, you can twist the lens (or ring) a bit and move it out of NPP. You can turn RD4 using a rotator handle or by holding to R10/ RD4 body.

nick

softgad
09-01-2011, 09:42 PM
BBc597, the flash triggered more easily on the 7D (automatic mode) due maybe by the more focus point it has (15 vs 9). I rotate by the grip of the cameras. Is there a better practice? But the result were consistent.

nick fan
09-01-2011, 10:08 PM
BBc597, the flash triggered more easily on the 7D (automatic mode) due maybe by the more focus point it has (15 vs 9). I rotate by the grip of the cameras. Is there a better practice? But the result were consistent.
when rotating by the grip of camera, you put more stress to the lens mount and lens clamp. This may cause damage to the lens in extreme case. Besides, it may tilt/twist the lens away from NPP. How much is the effect will depend on how gently you rotate it and the rigidity of lens.
A rotator handle is a good solution
http://store.nodalninja.com/products/Rotator-Handle.html

John Houghton
09-01-2011, 11:48 PM
Both camera were set up at automatic (non creative) full jpg. I cannot explain the following result. The canon 50 d gives me a very good set up and I cannot find any parallax problem while the canon 7D gives me not bad and has parallax problem. Any of you can explain this result?
You have not shown any evidence of parallax problems. Stitching errors are not necessarily due to parallax, and in this case are much more likely to be due to the behaviour of PTGui in automatic mode. The subject you have chosen for the test is not static (clouds are moving) so automatic control points generation is going to produce different results that can affect the optimization and hence alignment. Assign control points manually on the same (stationary) features with a wide spread for both sets of images and optimize manually and you will probably get similar results with no stitching errors.

To check for parallax issues, output a layered PSD file and examine the overlap areas in Photoshop, switchng layers on and off to detect any parallax shifts.

John

hindenhaag
09-02-2011, 01:18 AM
Sorry to ask,

did you set everything to manual mode? Focus, WB, Aperture and Shutter Speed?

Did you use the last Beta of PTGuiPro?

Try to loosen the detend knob a little bit more. Check the fixing knob is free. Use the vertical rail of R10 below the clamp and the rotators body to move to the next click stop. If this does not work, use the extra handle as Nick mentioned. Never ever use the camera body to turn to the next click stop, whatever Panohead you use. The lens flange is a sort of sensitive part of a camera-lens system.:th_wink:

Regards,
Heinz

softgad
09-02-2011, 11:42 AM
Heinz it was set in fully automatic mode, the goal of the test was for me to quickly determined any difference between the cameras, so I let the camera decide, the software decide for me. I agree with John I tend to confuse parallax and stiching problems. But I have repeated the test three more times with the same result (this time rotating by holding the rail not the camera)> The canon 50d winning the battle with four shots and the canon 7d outperforming with 6 shots, this does not mean that you cannot correct the stitching with the addition of more points at the bottom and top on fix object in both cases agreed. I was using the latest beta version of the PtGUI. Please find additional pictures with 6 shoots and nadals