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10-02-2014, 12:49 PM   #1
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Variable aperture continous exposure

I am sure this is possible, but haven't figure it out yet. I would like to be able use a combination of bracketing and variable aperture exposures for certain applications. Here is an example:


1. Shot one. f4 @ 1/250
2. Shot two. f5.6 @ 1/125
3. Short three. f8 @ 1/60


If there was some way of combining bracketing with this combination that would be great.


Obviously I would like to be able to program this as a user defined mode... thoughts or suggestions welcome.

10-02-2014, 01:12 PM   #2
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If K-3 supported tethering and if Ricoh were to publish a programming interface and if you had some coding skills...piece of cake...


Steve
10-02-2014, 01:23 PM   #3
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If you use the AE-L button and edit the f-stop or shutter speed depending on the mode you use, this kind of works as you want.
10-02-2014, 01:43 PM   #4
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Question on your answer ...

QuoteOriginally posted by Tjompen1968 Quote
If you use the AE-L button and edit the f-stop or shutter speed depending on the mode you use, this kind of works as you want.
Can you explain in more detail how that would work?

10-02-2014, 02:43 PM   #5
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If for example you use Av-mode; You point your camera towards your subject. The camera gives you 1/250 @ f/4. Press AE-L button and an asterix * lights up in the view finder. This means you now have locked the exposure. If you now dial in f/5.6 the shutter speed becomes 1/125 no matter how you point your camera. Take a shot and go to f/8 and so on.

This works like this in Tv, Av and M mode
10-02-2014, 03:11 PM   #6
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QuoteOriginally posted by Tjompen1968 Quote
If for example you use Av-mode; You point your camera towards your subject. The camera gives you 1/250 @ f/4. Press AE-L button and an asterix * lights up in the view finder. This means you now have locked the exposure. If you now dial in f/5.6 the shutter speed becomes 1/125 no matter how you point your camera. Take a shot and go to f/8 and so on.

This works like this in Tv, Av and M mode




I see. Yes, I did know that trick. What I am looking for is being able to point at a subject, focus and then have the camera take 3 exposures (correctly without bracketing) at one stop either side of what the initial setting was. So I would have 3 pictures with different depth of field but essentially the same composition.


Ideally then with bracketing around those three shots, but first of all just to get the three shots. To manually change the exposure is doable, but will likely disturb the camera setting while composing the shot, particularly with candid and portraits.


Hope that explains in more detail what I was looking at.
10-02-2014, 04:15 PM   #7
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I do understand.

One way to get what you want is to set the camera to Tv, lock the exposure and do a three shot bracket with 1 or 2 stops. Shoot RAW and fix the exposure in post.
10-02-2014, 04:28 PM   #8
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QuoteOriginally posted by Tjompen1968 Quote
I do understand.

One way to get what you want is to set the camera to Tv, lock the exposure and do a three shot bracket with 1 or 2 stops. Shoot RAW and fix the exposure in post.
I considered suggesting that option except that his requirement is that both the aperture and shutter speed vary by a prearranged pattern, sort of like a form of programmed M-mode.


Steve

10-02-2014, 06:15 PM   #9
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Preprogrammed mode

QuoteOriginally posted by stevebrot Quote
I considered suggesting that option except that his requirement is that both the aperture and shutter speed vary by a prearranged pattern, sort of like a form of programmed M-mode.


Steve
Yes, Steve, that is what I had in mind, but an "incorrect setting" to perhaps 1/2 stop on bracketing might do the same thing. Only negative is have to do PP to get a correctly exposed image.
10-03-2014, 01:02 AM   #10
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QuoteOriginally posted by stevebrot Quote
I considered suggesting that option except that his requirement is that both the aperture and shutter speed vary by a prearranged pattern, sort of like a form of programmed M-mode.


Steve
Not sure I understand you...

If I use Tv, set 1/500 and it gives me f/8. Lock the exposure with AE-L. Then do the bracketing and only the f-stop will be the variable.
1/500 f8, 1/500 f5.6, 1/500 f11
10-03-2014, 05:37 AM   #11
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Response to suggestion

QuoteOriginally posted by Tjompen1968 Quote
Not sure I understand you...

If I use Tv, set 1/500 and it gives me f/8. Lock the exposure with AE-L. Then do the bracketing and only the f-stop will be the variable.
1/500 f8, 1/500 f5.6, 1/500 f11

What you suggest is true, but each exposure will be incorrect. What I am looking to do is have the shutter speed drop in sync with the increase in f-stop so each exposure would be optimum.
10-12-2014, 09:21 PM   #12
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QuoteOriginally posted by mikeodial Quote
What you suggest is true, but each exposure will be incorrect. What I am looking to do is have the shutter speed drop in sync with the increase in f-stop so each exposure would be optimum.
Have you ever tried setting the camera on Sv mode and then bracketing?
The lens I have with me now is a manual lens, so it's not possible to test this! But I guess it may work for you.
10-12-2014, 09:51 PM   #13
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QuoteOriginally posted by mtux Quote
Have you ever tried setting the camera on Sv mode and then bracketing?
The lens I have with me now is a manual lens, so it's not possible to test this! But I guess it may work for you.
Bracketing won't work because the camera creates images that are either above or below the optimum exposure setting. In this case I am looking to have the same correct exposure e.g. f4 @ 1/100 sec shot again at f2.8 @ 1/200 sec and again f5.6 @ 1/50 sec.


So there are three consecutive shots, correctly exposed but with different f stops to get different DOF from a focus perspective. I am surprised other cameras don't have such a feature.

I think I will have to use my flu card and do this manually via a tripod when needed to see the potential results when focusing.
10-12-2014, 10:27 PM   #14
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QuoteOriginally posted by mikeodial Quote
Bracketing won't work because the camera creates images that are either above or below the optimum exposure setting. In this case I am looking to have the same correct exposure e.g. f4 @ 1/100 sec shot again at f2.8 @ 1/200 sec and again f5.6 @ 1/50 sec.
Ah, sorry, I didn't get this fact. So I guess you have to do it manually.
10-13-2014, 05:21 AM   #15
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QuoteOriginally posted by mtux Quote
Ah, sorry, I didn't get this fact. So I guess you have to do it manually.
Yep, the OP is wanting the camera to do something like sample multiple program lines for an exposure value (EV). There was at least one film camera that could easily do this (Ricoh XRP), but it still required user intervention between exposures.


Steve
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