light metering technique

[pellicle]

Hi

over the years I've tried a both incident and reflectance metering techniques, and have settled largely on reflectance metering (unless flash metering, which I don't do anymore anyway

For reasons not worth going into, when I left home to go abroad for a year or so I decided to leave my pentax spot meter (among other things) at home to save weight on the flight. I figured that I could get by with another technique which I'd like to ask about here. I've been using my compact digital camera as a "light meter" and basing my camera settings on what I finally settled upon preferring as the exposure that adequately exposed the shadows in the preview / histogram analysis.

I've put my thoughts and methods on this topic up here , however my view is that the digital camera is essentially showing a linear responce just as my pentax spot meter would do, but being 5 megapixels its perhaps finer than 1°. I'd be interested to hear from anyone wiser than me (well, that'll probably be pretty much anyone reading this ;-) if I've missed something or made some errors based on my lack of fully grasping the media (the film media that is).

A last point is that for neg I've been finding that there is quite a lot more head room in there than I'd expected. I'm now waiting for some dektol and paper to arrive to try and contact print some of these negatives and see how well this translates to the paper print.

Thanks in advance.

 

[Ian Grant]

Technically its a forbidden subject, but as the meter systems in Canon & Nikon film cameras are similar

I have used my SLR meter when shooting LF, but it's not as good or accurate as using a spotmeter, or a decent hand held incident meter. As you've pointed a metering system which ensures good shadow exposure is important.

You have to use what suits you, but I've found my spotmeters or other hand held meter to be faster, more accurate and less risk of errors.

Ian

 

[pellicle]

gosh

ok ... with Ian's warning in mind I'm not asking about anything more than metering here, and what might be missing from my 'new' and under evaluation metering method. Essentially with my trusty rusty gossen meter (and a little judgment) my pentax spot meter (understanding how to use it) and lastly my coolpix 5000 (and again understanding what it's telling me) I eventually come down to one set of numbers (f and shutter) which I dial onto my copal shutter to make the exposure.

I never really found N+1 development significantly beneficial (perhaps I was not using sufficient + development?) I got this difference when scanning film (ADOX CHS 100) processed in D-76 neat N = 6min and N+ = 13 min. Below are the differences in density when plotting the same negative.

I reguard my scanner as basically a densitometer (assuming that I've set my scanner appropriately for a linear output)

 

[Ian Grant]

To be honest N+1 & N-1 are only marginally useful, if you are printing on Kentona which is only made in one grade then they become highly significant, likewise if you're doing Platinun/Palladium prints or similar. Many photographers only use N & N-2 or N+2 development (exposure) using paper grade to cover in between.

Ian

 

[pentaxuser]

Hi

essentially showing a linear responce just as my pentax spot meter would do, but being 5 megapixels its perhaps finer than 1°.

I currently know enough about digital to recognise that I have five of them at the end of each arm It's about all I want to know.

However I have to risk straying into foreign territory by asking what the connection is between megapixels and the span of 1 degree in a spotmeter. Does it mean that a 10 megapixel camera has the equivalent of less than half a degree of a spot meter?

A short simple explanation will do - nay is in fact essential for my brain and I promise not to turn it into a "you know what debate". Just simple curiosity.

Thanks

pentaxuser

 

[pellicle]

Hi Pentaxuser

well if I have a lens which gives me something like 65°of view (something like my 90mm or my coolpix at its widest), then if I were to divide that across the width of the image (2560 points of recording wide and 1920 recording points high in my case) then I'd say that each 'spot metered point' is 65 / 2560 = about 0.02° give or take ...

unless my maths sucks

 

[pellicle]

ohh (not that you asked) but the histogram is a 'summary' of how many points are recorded at each value ... so Y axis of the graph is number of points and X axis of the graph is what level they were 'attributed' to between 0 and 255. My pentax gives a 'number' which needs to be refered to a scale around the barrel (which is a slide rule) taking into accound the ISO setting to then convert that to an EV. I can't recall what my highest number is on the thing, but it has . and then .. after each one to give me 1/3 EV stops (assuming something like 25) 25 * 3 = 75 the other 'meter' has more finely graduated steps.

 

[Christopher Walrath]

Sweating bullets. This is a close one. When I got my Mamiya M645j w/o metered prism, I used to take my Minolta XG-M along to meter with so I wouldn't have to fly blind on the Mamiya. Seemed to work out just fine for me.

 

[Ian Grant]

Returning to the thread, I haven't the time or patience to use a digital camera histogram to guide me with my film camera exposures.

In the time it takes to get the data I'll have used my Spotmeter or Lunatic meter made a decision, taken the photos and moved on, meanwhile you'll still be puzzling out the exposure.

Ian

 

[pellicle]

Ian

I really need to work on my setup pull down technique. I guess my Toho is frustrating to alter from portrait to landscape (requiring me to rotate the front standard, bellows and back standard). Often wondered if a 'field camera' would have been better than the lightweight monorail.

sigh

(pardon me hijacking my own thread here folks)