P&S for exposure

[hjoseph7]

<p>Would using a Point and Shoot camera with an LCD to figure out exposure and composition be a good alternative to the Polaroid instant film Backs ?</p>

[lachaine]

<p>Not really, because few point and shoots have the full range of apertures available. It would only be practical if you were using only the shutter speed and aperture combinations the P&S camera has.</p>

[vick_vickery]

<p>Harry, as long as your P&S will easily feed back the exposure data it could certainly be used...once you have one f/stop-shutter speed combination for a good exposure, you can easily convert that to any stop or speed you want to work with, i.e., f/16 at 1/125 is the same as f/8 at 1/500, or f/32 at 1/30, etc. I do think, though, that you would be better off with a good hand-held meter...it would be faster and easier than having to reason out the changes each time.</p>

[starvy]

<p>How about one of those cheap Russian light meters?<br>

I have used my 8 years old Canon S30 as a light meter for film cameras in the past. It worked out alright, however, my own experience is that even in manual mode, this particular camera added some form of compensation unbeknown to me.</p>

[spodzone]

<p>Composition would work best if the cameras are the same aspect-ratio, and nothing else is 5x4 apart from 5x4" LF, so that's not completely helpful unless you're going to shoot LF wider and crop, which is wasteful. (It's not unforgivable, of course: I do it myself, cropping 5x4 to square, occasionally.)<br>

Exposure is 4 values: there's the aperture and a shutter-speed combining to give you an Exposure Value number (EV, the brightness of the scene), and ISO sensitivity. Chances are, you can use the same ISO on your P&S as LF film; the EV rating of the scene will be the same; however, because of the larger format, the apertures required to attain the same DoF will be completely different, therefore the shutter-speeds will be that much longer, potentially resulting in motion-blur. That's not a great suitability match unless you constrain yourself to using the EV reading off the P&S (or, as Vick says, work in terms of exposure-equivalents). </p>

[john_a5]

<p>Composition help--only in a very gross way. Only instant film can really tell you what is going on from the point of view of the lens, even being over a few inches changes relationships and things at the edges, but on a gross basis, your eyes can tell you just as much probably.</p>

<p>Exposure, it can give you rough numbers that you will have to interpolate to proper fstop/shutter speed for your scene and the depth of field you need. But it will not figure out bellows extension factors--or if you are shooting anything very close, the shift of lens position can cause issues.</p>

<p>Better than nothing, sure, better than instant film, no, better than a meter, probably not but could be acceptable if you can actually see the lcd and the screen is not set too bright or too dark, otherwise, the meter will always out perform it.</p>

[dave_redmann]

<p>A digital P&S will work fine to set or check exposure, with some limits.</p>

<p>First, with your digital P&S you need to be able to <em>either</em> (1) manually set the exposure (sensitivity, aperture, and shutter speed) (and check for over- or under-exposure), or (2) verify what the exposure was (and then check for over- or under-exposure). Is there a P&S that neither offers manual exposure, nor tells you afterward what the exposure was? Maybe. If so, it won't work.</p>

<p>Second, you need to be willing and able to (mentally) adjust for the differences in working aperture; most digital P&S will not stop down past f/8, which is wide open on some LF lenses and not usually the working aperture. So if the P&S set to ISO 100 and f/8 needs 1/60 s exposure, you need to be willing and able to mentally figure that you need, say, 1/8 s at f/22 for ISO 100 film.</p>

<p>Third, the P&S will not tell you anything about compensating for bellows extension or film reciprocity. So if you shoot at very close focus distances, or in fairly low light, you will need to compensate separately. Of course, the same would be true of my modern Sekonic light meter, so not so much difference there.</p>

 

[lachaine]

<p>Obviously, anyone could use any kind of metered camera that has severe limitations in terms of available apertures or shutter speeds, and then extrapolate them to the settings the lens on the large format camera has. Personally, I think I would tire of having to do that in about one minute.</p>

[craig_shearman1]

<p>Besides exposure per se, a P&S's averaging or even souped up metering is not going to reflect the metering you would do with a spot meter, trying to use the zone system, pushing and pulling in development, decisions in printing, etc., etc., Also the angle of view, perspective, depth of field are all likely to be different in the P&S than what you're getting through your view camera lens, to say nothing of not reflecting swings, tilts, etc. A P&S might be a rough guide, but rough in contradiction to the precision and care of working in large format in the first place.</p>

[hjoseph7]

<p>My P&S does not have Manual shutter & aperture adjustments, but those values do appear on the LCD after the shot is taken. This is not something I made up, I think I read it somewhere from a photographer who uses LF cameras extensively and uses a P&S to determine exposure. Even if it could be done that way my guess is that the angle of the lenses would be different as well as everything else that was mentioned above. <br>

I have a pretty good Light/Flash meter, but sometimes you need that little extra reassurance which can only come from owning a Polaroid back. Even if I could find a Polaroid 545 back and some Polaroid/Fuji 4x5 film, it would be about $3 per exposure. On the other hand, I don't think Ansel Adams ever used a Polaroid back as far asI know. </p>

[noah]

<p>I don't use it to determine exposure, but on my last trip I did carry a small P&S when shooting MF film. I used it sort of as a sketchpad, something I could use for a quick snap to see if I like a composition. Also, on an extended trip, having a record of which photos were taken which day and in which location is important, since I need to match my caption notes with film images I may not see for a while. When you're working on a series it's nice to be able to review what you have and what photos you may be missing. This is very helpful for my documentary projects.</p>

<p>The screens on the point and shoot seem quite variable. Without a histogram it's tough to tell what actually is a good exposure. I use a handheld meter for exposure, though my negative films are pretty forgiving and if in doubt I err on the side of overexposure.</p>

<p>Now that I'm shooting 4x5 I'm not sure if I'll stick to the digicam or start shooting instant film proofs. For travel the digicam sure is smaller than a 'roid back and a bunch of film!</p>

<p> </p>

[colin carron]

<p>If you use the longest zoom setting on your P&S it turns into a spotmeter (sort-of). You can then meter several areas from the whole scene within the 4x5 frame and arrive at an exposure value for the shot. I always used a film SLR but it is the same idea. Or if it has a histogram you can adjust that until te exposure is right.</p>

[debejyo]

<p>Here is the truth. I have been using my DSLR with a 300mm (cheap lens) in the "spot meter" mode as a light meter and have successfully used it as a meter to use zone systems (I had to remember the zones in my mind :) ). Everything works fine but these meters have a limited range. These meters do not work fine when the light is low (dimly lit room/restaurant) or extremely bright. So, for regular conditions you can use the spot meter.<br>

You can never judge the exposure from the histograms. The digital encoding and the film responses are quite different.</p>

[dan_south]

<p>It could work in some situations as long as you keep a few caveats in mind.</p>

<p>If you look at your digital camera's LCD screen in bright sunlight, a properly exposed picture will appear to be underexposed. You might think that you need to increase the exposure, but if you do you'll end up overexposing your film.</p>

<p>The same problem in reverse happens if you are looking at the LCD in darkness. You'll make adjustments that underexpose the film image.</p>

<p>Histograms aren't useful in this application, because every film has a different latitude than digital sensors (print film has more, slide film has less).</p>

<p>You need to make certain that Auto ISO is off or the P&S's exposure values will be worthless. Set the ISO of the camera to the ISO of your film. If that's not possible (e.g. your digital camera's lowest ISO is 100 and your film is 50), you'll need to calculate the difference for every exposure.</p>

<p>You'll also need to compensate for f-stops that the digital camera cannot support. If you are shooting at f/32 and you mini P&S only goes to f/8, you'll need to calculate the difference and modify the shutter speed accordingly. This can be confusing if you have to calculate an ISO offset as well.</p>

<p>Example:</p>

<p>P&S, ISO 200, 1/60 @ f/8</p>

<p>Add two stops for ISO 50 film:</p>

<p>1/15 @ f/8 (ISO 50)</p>

<p>And add four stops to get to f/32:</p>

<p>1 second @ f/32 (ISO 50)</p>

<p>Last but not least, your point and shoot camera must have the ability to display exposure values in Image Review Mode. I'm not sure that all of them do.</p>