Group: rec.photo.equipment.medium-format

Medium format cameras and lenses

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Post Subject:

Exposure with macro lens

Reply from: piterengel
Date: 01 Apr, 06:38
Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
ordered it and soon it will be here. I have a question. Because I've
not an AE prism finder, how can I calculate the right exposure when
lens is completely extended to have the maximum macro efffect? Are
there tables for this?
Thanks all

Reply from: van dark
Date: 01 Apr, 13:15
exposure factor:
x=(m+1)*(m+1)
"m" is an enlargement
The enlargement you can count by means of the some ruler.
object = 50mm
image (on film) = 25mm
exposure factor x = (0,5+1)*(0,5+1) = 1,5*1,5 = 2,25x
you add 1 diaphragm number (e.g. from 5,6 on 4)
All is okay?
van

piterengel napsal(a):
> Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
> ordered it and soon it will be here. I have a question. Because I've
> not an AE prism finder, how can I calculate the right exposure when
> lens is completely extended to have the maximum macro efffect? Are
> there tables for this?
> Thanks all

Reply from: van dark
Date: 01 Apr, 13:17
I own a SQ-Ai. And I use a Gossen Lunasix. All is okay. Van

piterengel napsal(a):
> Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
> ordered it and soon it will be here. I have a question. Because I've
> not an AE prism finder, how can I calculate the right exposure when
> lens is completely extended to have the maximum macro efffect? Are
> there tables for this?
> Thanks all

Reply from: piterengel
Date: 01 Apr, 16:48
On 1 Apr, 13:17, van dark <van.d...@yahoo.co.uk> wrote:
> I own a SQ-Ai. And I use a Gossen Lunasix. All is okay. Van
>
> piterengel napsal(a):
>
> > Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
> > ordered it and soon it will be here. I have a question. Because I've
> > not an AE prism finder, how can I calculate the right exposure when
> > lens is completely extended to have the maximum macro efffect? Are
> > there tables for this?
> > Thanks all

Very useful. So, if I have a 1:1 macro, x=4 so I have to increase
exposure of 2 stops. Right?
Thanks

Reply from: Q.G. de Bakker
Date: 01 Apr, 17:35
piterengel wrote:

>> > Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
>> > ordered it and soon it will be here. I have a question. Because I've
>> > not an AE prism finder, how can I calculate the right exposure when
>> > lens is completely extended to have the maximum macro efffect? Are
>> > there tables for this?
>> > Thanks all
>
> Very useful. So, if I have a 1:1 macro, x=4 so I have to increase
> exposure of 2 stops. Right?

Have a look at this page:
http://www.hasselbladhistorical.eu/HT/HTComp.aspx

Don't let the theme of the site throw you off: the basic calculations are
the same for all lenses.

Only when you want to take lens asymmetry into account, you will need
Bronica specific lens data.
But the general formulae usually get you close enough, no worries.



Reply from: van dark
Date: 01 Apr, 17:41
yes, all right. 2 stops. van

piterengel napsal(a):
> On 1 Apr, 13:17, van dark <van.d...@yahoo.co.uk> wrote:
>> I own a SQ-Ai. And I use a Gossen Lunasix. All is okay. Van
>>
>> piterengel napsal(a):
>>
>>> Hi, I'm waiting for the arriving of a Zenzanon macro lens, I've
>>> ordered it and soon it will be here. I have a question. Because I've
>>> not an AE prism finder, how can I calculate the right exposure when
>>> lens is completely extended to have the maximum macro efffect? Are
>>> there tables for this?
>>> Thanks all
>
> Very useful. So, if I have a 1:1 macro, x=4 so I have to increase
> exposure of 2 stops. Right?
> Thanks




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