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Author Topic: Out of the focus with RZ and 180mm  (Read 3471 times)

andreagenor

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Out of the focus with RZ and 180mm
« on: February 12, 2012, 10:10:44 pm »

Hi,
Today I did some photos and I had difficulty or trouble when I changed lens.
I'm using 110mm lens and all images is OK, sharpen and focus is good, but when I changed for 180mm I had many problens, I do the focus and he is sharpen in different place, a little near than I would like.

The target is about 5meter distant from camera and I was using f8, not bad but the focus appear so short.

There is possibility of the lens is out of calibration?
Because seemed in focus in viewfinder.


There is another problem that may have caused this focus erro, but I really don't know. I was using a bad tripod and head and I mounted the camera with Motor Winder II + Left Grip, with this group I realize little moviments between Motor and LGrip.

Do you find that out of the focus is caused for camera shake or bad tripod?

Mamiya RZ ProII + Leaf Aptus 75
Shutter = 1/125
Apperture = f8
ISO = 50

Sorry my bad English!

Here the sample.
I did the focus on the eyes, but he is more near you can see in the grass.
http://andreagenor.com/client/preview.jpg
« Last Edit: February 12, 2012, 10:40:54 pm by andreagenor »
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darr

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Re: Out of the focus with RZ and 180mm
« Reply #1 on: February 13, 2012, 09:03:31 am »

You have a shallower DOF with the 180mm than compared to the 110mm making it harder to find the DOF area. I find it especially harder to get sharp photos with a digital back than film, so I had to learn how to shoot my RZ for digital. You did not say if you were using a prism finder or not. I found using the Adjustable Diopter Magnifier on my prism finder when shooting and always a sturdy tripod and head (Gitzo + RRS Head) works. I think most RZ users eventually upgrade to using the magnifier which does flip up and out of the way when not wanting to look through it and I also shoot at f/11 with the 180mm and one subject portrait.

Here is a link to the magnifier.



« Last Edit: February 13, 2012, 09:05:45 am by darr »
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bpepz

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Re: Out of the focus with RZ and 180mm
« Reply #2 on: February 13, 2012, 10:06:30 am »

Interestingly I have had most trouble getting the 110mm f/2.8 in focus, the 180mm is the easiest by far to focus. here is a 100% crop from the rz67 180mm f/4.5 I did yesterday with a model.

« Last Edit: February 13, 2012, 11:34:11 am by bpepz »
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andreagenor

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Re: Out of the focus with RZ and 180mm
« Reply #3 on: February 13, 2012, 10:18:57 am »

Thanks Darr Almeda,
I'm shooting with waist level viewfinder and eventually I remove it and use a 10x loupe over the screen. I did it yesterday but not work correctly.
Today I print some focus test chart and I will test lens.

bpepz,Your focus is perfect, for some reasons I can't do it.
Yesterday I saw perfect in viewfinder, but when I look the image, focus is not perfect in place.

I will try test lenses and I post results after
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andreagenor

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Re: Out of the focus with RZ and 180mm
« Reply #4 on: February 14, 2012, 01:19:02 pm »

All is ok with lenses, the problem is with tripod and head, simply does not support the weight.
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MarkoRepse

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Re: Out of the focus with RZ and 180mm
« Reply #5 on: February 14, 2012, 04:10:12 pm »

It seems you might have a front focus issue. This is quite easily fixed by adjusting your focusing screen. Front focus means you need to adjust the screen UP, towards you. You can remove the screen and see if the screws it is sitting on turn. You can adjust it that way or simply add some tape to them. Repeat until focus is perfect!
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andreagenor

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Re: Out of the focus with RZ and 180mm
« Reply #6 on: February 14, 2012, 05:22:35 pm »

It seems you might have a front focus issue. This is quite easily fixed by adjusting your focusing screen. Front focus means you need to adjust the screen UP, towards you. You can remove the screen and see if the screws it is sitting on turn. You can adjust it that way or simply add some tape to them. Repeat until focus is perfect!

Great tip, I will try!

Thanks a lot.
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lance_schad

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Re: Out of the focus with RZ and 180mm
« Reply #7 on: February 14, 2012, 10:28:33 pm »

Did you try and shoot it with the Mirror Up?

I had someone in today and could not get a sharp file with a P45+ and his RZ ProII . As soon as we shot with the Mirror Locked Up , the images were razor sharp.

Lance

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marcel b

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Re: Out of the focus with RZ and 180mm
« Reply #8 on: February 15, 2012, 04:10:47 am »

I had lots of focusing problems with my RZ in the beginning with my back. after adjusting the screen at my mamiya dealer things improved a lot. the 65 is still quite hard to focus, the longer the lens, the easier it gets. on the other hand, take care of the mirror slap, everything longer than 125 I shoot with mirror up, and with available light, I prefer even shorter times.
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billaudet photography
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andreagenor

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Re: Out of the focus with RZ and 180mm
« Reply #9 on: February 15, 2012, 06:35:46 am »

I had lots of focusing problems with my RZ in the beginning with my back. after adjusting the screen at my mamiya dealer things improved a lot. the 65 is still quite hard to focus, the longer the lens, the easier it gets. on the other hand, take care of the mirror slap, everything longer than 125 I shoot with mirror up, and with available light, I prefer even shorter times.


Hi marcel B, thanks for your testimony.
I will try ajust the screen, I did not know it could happen.
I shoot normal with 110mm and 1/60 and some times 1/30, but careful sure , but with 180mm not work because this lens is so weighted that camera shake all time.
I need a better tripod and head.
I don't like shooting with mirror up, because sometimes I have some problems, the image is tarnished, tomorrow I put some images with this trouble for you see.

I'm doing a custom viewfinder with aluminium and loupe 10x.
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