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how to set up the camera for testing aquarium lights

parotet

parotet

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Joined
12 Oct 2013
Messages
1,695
Location
Valencia, Spain
Hi all

I have purchased a pink coloured tube for my 2x24w T5 light fixture which holds right now 6.500K and 10.000K tubes. I want to try different combinations and see how the tank looks like. I think the best way to do this is to take some shots as our (human beings) visual memory is very bad. The problem is that the camera will have to take images as close to reality as possible and the different shots should be comparable.

I can imagine the first part: tripod, full tank shot, ISO 400-800... but what about white balance? I have a LUMIX bridge camera (FZ48) and I can chose between daylight, cloudy, shade, incandescent, fluorescent, flash, automatic balance or manual (setting temperature).

The aim is doing what is shown in the lighting tutorial comparing cheap T5 bulbs...

Cheers,
Jordi
 
Looking at jamesc thread he used the sunshine setting, maybe start with daylight then try a few other settings to see which gives you the best colour representation, then stick with that setting for the different bulb combinations, don't use the auto setting because it will change every time (stating the obvious :rolleyes:) post up your results jordi, I'll be interested to see the different combinations :thumbup:
 
I would take shots on daylight setting and the correct temperature manual setting.
Problem will be those settings wil not be the same as your eye will see (and intepret) them. Any chance to get a "grey card" to correct them all in a photoshop like program?
 
Edvet said:
Any chance to get a "grey card" to correct them all in a photoshop like program?
Click to expand...
I lost the one I owned... can I use the black background to correct the picture on photoshop indicating that this is the black? (not sure if I will be understood :confused:)

Jordi
 
Close the lights in the room leave only the sun as a light source, set the camera to daylight and take the photos.
If you correct the wb with the gray card they all will look more or less the same and you don't want that.
 
That's why i said take all pics in daylight and the correct temp too. But with a camera the hues will be exagerated, Your eye doesn't see like the camera does

Black point only will probably give to much variation, maybe if you have a black and a white it could work, make sure the points are not in the tank (water color has an extra influence, as does the glass)
 
Ok, so daylight setting, take pictures and then correct the pictures in Photoshop indicating a black point (background) and a white one (wall behind tank)... Does it sound right?

Just one doubt: the cloudy and shade settings for white balance give a much more real colour (the difference between what you can see and the picture is less). Shall I use them instead of daylight? I guess the key point is to use the same setting in all the shots and the correct using black and white references.

Jordi
 
Assuming you have live preview, I would use manual white balance and adjust it on the screen to look as near as possible to what your perception of each set of tubes is. Obviously you're then relying on the camera screen to give a fair representation of what you'll see on your computer, which will depend on how well calibrated everything is but it should get you close.

Use manual for everything else and don't change it between shots.

Sent from my LT30p using Tapatalk
 
BigTom said:
I would use manual white balance and adjust it on the screen to look as near as possible to what your perception of each set of tubes is
Click to expand...
Curiously when I do this I got the best results setting the temperature at 6500K, even if my fixture has a 6500 and a 10000K tube.
Thanks everyone for the feedback, tonight I will try to do my best

Jordi
 
I find tube ratings to be all over the place really.

I don't think you should correct WB in PS or use a grey card - all that will do is attempt to mitigate the differences in color rendition which is the opposite of what you want. Just go by sight.

Sent from my LT30p using Tapatalk
 
Problem i see is that what the eye sees (or percieves to see) is hard to catch in the camera. Using one daylight (or cloudy or shady) setting will give one way to differentiate, setting to the tube color (or adjusting it through live view to what you see) will give another and color correcting it (through grey card or through black and white point) will give a third set. Comparing these should give you the widest range of images to compare.
The sensitivity and wavelength respons in the human eye is rather different then the sensitivity of a filtered CCD device. If you want to choose on the basis of pics just one set might not be optimal.
(i personaly wouldn't choose on the basis of pics, but on what i see)
 
Could always do it in two steps if your computer is in the same room as the tank... close as possible in camera as described previously, then tweak the colour balance in PS to match what you can see even closer. The colour balance sliders are often better for this than a simple white balance adjustment, albeit mildly more fiddly. The aim surely is just to get it as close to possible on screen to what you're perceiving when looking at the tank.
 
Luckily the tank and the computer are on the same room. I will try to see on screen the most accurate image of what I see... It's going to be fun , I will make sure I have enough beer on the fridge (I think you need it when doing this kind of things, isn't it? )
 
To do this really accurately you need a graycard or colour test card, to shoot in RAW (to avoid jpeg processing) and have a properly calibrated monitor capable of displaying sufficient gamut

If you can connect the camera to the screen and adjust from there so life and screen match that would help. As above keep the camera on full manual so the setting are the same for each image.

Will be interested to see the final photos :snaphappy:
 
Don't expect too much mates... I can only shot jpeg and I cannot connect my camera to the computer. I will also take only a partial view of the tank including plants of several colours because the tank is only half planted (in the middle of a rescaping process)

Jordi
 
Hi all

No sicence, no grey card, no RAW shoot, no calibrated monitor. This is what I've done: place my tripod in front of the tank, chose manual settings (f/5, 1/10s, ISO 400, exp. -1) and adjust in each case the white balance manually to see on the camera and PC monitor exactly (well... more or less) what I was seing. Not easy at all. Then I opened the pictures on Photoshop and the only thing I did was selecting a black area (background, always the same one) to correct the contrast.

And the result is this one:

T5HO 10.000 K + T5HO 6.500 K
15128089331_e31c7844b9_b.jpg

T5HO 10.000K + T5HO pink
14944501278_6a25358d06_b.jpg

T5O 6500K + T5HO pink
14944373949_9e2b37196e_b.jpg

It is obvious that the 10.000+6500 combination gives very sharp greens and poor reds. It is also obvious that the addition of the pink tube enhances red colours. What is not clear to me is why the combination 10.000+pink gives yellowish greens, more than the combination 6500+pink which I thought was going to be the most artificial combination (well, actually it is when go backwards and you you look the tank from the distance).

My two references for judging the colour rendition are: the under leaves of Limnophila aromatica on the top left corner of the picture (the second stem that is starting to show some brownish colours) and the under leaf of Alternanthera reinickii rosaeifolia (in the top center-right). I think that in both cases the combination 10.000K+pink is giving to these spots the best colour rendition, but... what do you think? (in Spanish we have a saying that translated would be more or less: colours were created to suit every taste / para gustos, los colores :))

Cheers,
Jordi
 
BigTom said:
Nice one. I think I like the 10k + pink rendition least actually
Click to expand...
Really? I would be interested in knowing your reasons... you know "para gustos, los colores" :p

I forgot to mention that the three tubes are cheap T5HO ones from the aquarium trade. The 10.000K bulb is an Odyssea and the 6.500K is an Aqualight (both came with the Odyssea 2x24w T5 light fixture which is very cheap, so the tubes must also be very cheap also). The pink one is a Blau Colour Extrem that I purchased this week for 9.90€

Jordi
 
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