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Photography technical advice, questions, tips and techniques.

Started by Tank, July 30, 2018, 10:37:09 AM

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Dave

Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

hermes2015

Quote from: Dave on September 13, 2018, 02:36:27 AM
Quote from: jumbojak on September 12, 2018, 10:03:52 PM
Which camera do you have Dave?

Nikon D5300

Dave, I found these instructions on a D5300 site I found. You are probably doing it exactly like this already, but perhaps there is some additional info.

Setting up and shooting in Manual mode
1.   Turn your camera on, and then turn the Mode dial to align the M with the indicator line.
2.   Select your ISO by pressing the i button on the back of the camera.
3.   Press up or down on the Multi-selector to highlight the ISO option, then select OK.
4.   Use the Multi-selector to select the desired ISO setting, then press OK to lock in the change.
5.   Point the camera at your subject, and then activate the camera meter by depressing the shutter button halfway.
6.   View the exposure information in the bottom area of the viewfinder or by looking at the display panel on the rear of the camera.
7.   While the meter is activated, use your thumb to roll the Command dial left and right to change your shutter speed value until the exposure mark is lined up with the zero mark. The exposure information is displayed by a scale with marks that run from –2 to +2 stops. A proper exposure will line up with the arrow mark in the middle. As the indicator moves to the left, it is a sign that you will be underexposing (there is too little light on the sensor to provide adequate exposure). Move the indicator to the right and you will be providing more exposure than the camera meter calls for; this is overexposure.
8.   To set your exposure using the aperture, depress the shutter release button until the meter is activated. Then, while holding down the Exposure Compensation/Aperture button (located behind and to the right of the shutter release button), rotate the Command dial to change the aperture. Rotate right for a smaller aperture (large f-stop number) and left for a larger aperture (small f-stop number).

http://www.peachpit.com/articles/article.aspx?p=2182571&seqNum=6
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

Dave

^

Coo, real duffer's guide stuff!

Yes, that is it, but it only seems to work when using standard, automatic, electronically connected lenses. Stick a non-auto, non-connected bellows, adapter or lens in there, when you really need that function, and it goes away!

The info display gives the speed, set by the camera, but though the apperture is also controlled by the camera that part of the display shows just two hyphens and there is no little "graph". There must be a feedback to tell the camera the lens has received and obeyed its instruction.

Will fiddle some more, checking menu settings, to check this is the only case. Problem is there is more thsn one place some things can be set, some with conflicts as in the case of manual focus. Will also look for online instruction re using bellows and the BR-6 reversing adapter. As usual the manufacturer's manual only covers basic stuff.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

Dave

Hmm, nothing found dpecifically on thst but I get the impression that the little graph does not indicate what the internal 'lightmeter' sees directly - as it did on old cameras when you had to line the two indicators in the viewfinder up, but an indication as to what the processor has calculated. As one person commented, an apperture ring stops on a lens ring do not necessarily apply to how much light passes through a reversed lens. However it is possible to measure that light, and still use it to calculate and indicate exposure, with the right programming I am guessing.

Assuming the light through the actual lens is measured of course, some old cameras had a seperate metering lens. With a mirrorless camera measuring the light at the actual focal plane, where it matters, should be a doddle! Wonder if they do so.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

Dave

Yup, all menus checked, all combinations of lens/adapter checked, the exposure guide thingie only works in the "normal" set up - with electrically connected automatic lenses.

Guesswork Experience and/or test shots are required when using other devices.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

hermes2015

Quote from: Dave on September 13, 2018, 10:05:12 AM
Yup, all menus checked, all combinations of lens/adapter checked, the exposure guide thingie only works in the "normal" ser up - electrically connected automatic lenses.

Guesswork Experience and/or test shots are required when using other devices.

I am pretty sure you can set your camera to do exposure bracketing by shutter speed, so that it takes 3 or more shots automatically at different speeds. Then at least one should be close to the correct exposure if your original guess is reasonably close.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

Dave

Quote from: hermes2015 on September 13, 2018, 11:19:28 AM
Quote from: Dave on September 13, 2018, 10:05:12 AM
Yup, all menus checked, all combinations of lens/adapter checked, the exposure guide thingie only works in the "normal" ser up - electrically connected automatic lenses.

Guesswork Experience and/or test shots are required when using other devices.

I am pretty sure you can set your camera to do exposure bracketing by shutter speed, so that it takes 3 or more shots automatically at different speeds. Then at least one should be close to the correct exposure if your original guess is reasonably close.

Hmm, whether automatic or manual bracketting it's still luck > guess work > experience to hit anywhere near the right combination first time. I have had to triple the the exposure time from first try, or go the other way, needing four or more tests. So the inclination is, "if black or damn near go four times slower; if then too bright go down down one at a time . . .".

Once the setup is set up, all variables like ambient and incident light taken out of the equation; a graph of max-min field of view per lens/bellows limits/extension rings; controllable lighting; no wobbly bits etc one might be in the right state!

Today's task is print a 1mm grid with numbered X-Y axes so I can check the fields of view. That can be done just using live view. Now, how to construct a graph of X x Y, as mm x mm,  indicating which lens/extension combination covers that area - interesting problem, just the kind I like! Lots of variables possible there . ..
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

jumbojak

I'm working on a new technique. Lighting my hand after soaking in an alcohol solution. I'll have a few preliminary shots later tonight. It shows some promice.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

Dave

Quote from: jumbojak on September 18, 2018, 01:15:53 AM
I'm working on a new technique. Lighting my hand after soaking in an alcohol solution. I'll have a few preliminary shots later tonight. It shows some promice.

I would seek to advise you not to do that, JJ.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

jumbojak

Why does everybody say that?! It's not like I'm burning myself. I'm just on fire. There's a crucial difference between the two.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

Dave

Quote from: jumbojak on September 18, 2018, 02:49:33 AM
Why does everybody say that?! It's not like I'm burning myself. I'm just on fire. There's a crucial difference between the two.

Yup, but, apart from the fact that the surface of the burning fluid boils,  heat radiates back through the burning fluid onto the substrate. Try it on a pork shank with skin on it first and observe the effects. Pre-CG special effects guys had a layer of insulating gel on their skin and the shots only lasted long enough for that to keep working.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74

hermes2015

It's safer to use a very low-boiling liquid like n-pentane (b.p. 36°C). Less likely to hurt yourself.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

jumbojak



If I can lay hands on some n-pentane I'll try that. For now though I'm going to press on. The lighting is trickier than I thought it would be.

"Amazing what chimney sweeping can teach us, no? Keep your fire hot and
your flue clean."  - Ecurb Noselrub

"I'd be incensed by your impudence were I not so impressed by your memory." - Siz

hermes2015

Quote from: jumbojak on September 18, 2018, 05:32:25 AM
... The lighting is trickier than I thought it would be.

That was my biggest problem when I took this photo.

"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

Dave

Quote from: hermes2015 on September 18, 2018, 05:19:56 AM
It's safer to use a very low-boiling liquid like n-pentane (b.p. 36°C). Less likely to hurt yourself.

Yeah, was thinking that as I tried to get back to sleep!

Boiling point of isopropanol, common industrial alcohol that I have, is 86 degrees, bit warm. Still wondering about radiated heat.
Tomorrow is precious, don't ruin it by fouling up today.
Passed Monday 10th Dec 2018 age 74