Tags: @Yaakov @cmartinez @shortbus @Aleph(0) @Jazz2C @theodoravain

Note: This discussion split from 'EHT Power Supply Design and Construction" (HP)

@Yaakov Please be advised that I took the liberty of moving our discussion of photographic technique/camera adjustment to this new thread such that it will not become 'buried' in the 'hurly-burly' of forthcoming construction articles on our EHT thread--- Please note that your kind comments and advice are quoted (in context) on this post -- I plan to continue our discussion on subsequent posts to this thread...

Many thanks!
HP

If your available light photography is rendering things yellow, it may mean you have to adjust your white balance. The best way is with a grey card, but even a piece of white paper will work.

You may find investing in some inexpensive continuous lighting, preferably a couple of soft boxes, is worthwhile.

Two medium soft boxes is enough to greatly improve product photography, three is even better but the third would have to be on a boom to work properly and that becomes bothersome.

Alternatively, though not nearly as effective, a diffuser on your flash will help reduce specular highlights, and you can possibly use bounce flash if the walls/ceiling are a neutral color.

Please let me know if you’d like any help with this, I am happy to assist.

@Yaakov HUGE tnx cuz we definitely need help of someone knowledgeable with _visible spectrum_ photography!

So just 2 explain and describe her setup, cuz she's had bad experiences ruining expensive digital electronics even from just like passive _charge accumulation_ in Garret Lab (which is HP's hobby HV and radiology _play room_ that she's basically made into big lead-lined, Faraday shielded ≈2,500 ft^2 suite to contain high and low PE {so ionizing and Hertizian} EMR + HVDC ion effects) she basically declared it a _non-essential sensitive electronics free zone_ with exception of vry cheap (like ≤$1k) bricks&mortar stocked consumer grade (IMO JUNK) electronics.

Anyhow here's stats I hope can help u help us:

◊Imagining device is Nikon Coolpix (which as far as I can see is just el-cheapo-deluxe camera) But for HP, refusing to causally _mix_ even just inexpensive (but still quality) semiconductor based gear and HV environment is total matter of principle after high voltage fatally bit her high 6-figure test equipment TWICE which cost her more than a week downtime cuz of manufacture lead-time! So anyhow since she now keeps spares I say it's just a case of _twice bitten_ and like that! Now I'm just _smartphone photographer_ so I don't know 4 sure but it definitely looks 2 me like there are vry good cameras available at extremely low price (like $5k?) that could be immediately replaced w/o back-order issues! So I say HP is only hurting herself _boycotting_ quality in her high voltage lab!

◊Main room-level lighting is from 4-400W and 6-175W clear (by which I mean no-phosphor) Hg HID lamps with shades made from white diffuser panels salvaged from 60" flat panel TVs).

◊Table where she does most photography is lit by 60" LED TV panel with LCD removed hanging abt 4' above table so it's just LEDs+light guide panel + diffuser panel so it's VRY bright white (basically like LED-backlit TV displaying totally white screen on brightest setting only a little brighter cuz LCD _sandwich_ is totally removed).

Anyhow HP authorized my publishing these pix showing difference between no flash and flash lighting! (So o/c by _flash_ I mean light from camera's built in xenon flash tube! NOT Flash player!)

So see how flash makes CPVC wells and septum guides look exactly same color as PVC end-caps and PTFE ribs & septum? Also it washes out fine details even though focus is way better than w/o flash!

Here's w/ flash

So pix w/o flash is more faithful to colors except for adding green/yellow _patina_ to everything also focus is vry poor!

So here's w/o flash

@Aleph(0) that’s a very “interesting” lighting setup, to say the least. But, least approach this systematically.

Looking at the two example photos, there are several improvements possible. Some without additional photographic kit, others would improve a great deal with something more capable.

The CoolPix camera isn’t terrible, it can produce decent if not great photos. So let’s deal with the lighting first.

The very first thing is to set the color temperature of the camera. On the CoolPix camera I have available (S9900) it is in the first menu (press the menu button), under White Balance. The option of interest is “PRE”, “Preset manual”. This brings up a framing box, and allows you to set the camera’s white balance using a neutral grey object, The right way to do this is with an 18% grey card but in a pinch, a piece of white paper will work.

The camera will then set the white balance to match the dominant light color temperature. This may not eliminate the green cast, however. The next step, if necessary, is to use a photo processing photo to shift the tint of the photo from green.

With the properly calibrated color temperature and the post processing, the photos will look right, color wise.

Except you have a problem: the photos are actually greenish. The non-flash photo is practically monochromatic, a “green and white” photo. You can desaturate it, and it looks “right” but as a black and white photo. Since you care about color rendition, you’ll need added lighting, but the on camera flash will never please you.

The reason the color rendition is unacceptable with the flash is the exposure. The highlights of that photo are “blown out”. The limitations of the on camera flash are quite severe and it is entirely unsuitable for this purpose.

The options are to get some off camera speedlites (flashes) triggered by the camera, or some continuous lighting. Continuous lighting is somewhat more cumbersome (really not bad at all, though) but much easier to use if you haven’t experience with strobe photography. Lights like these are inexpensive and will make a world of difference. It is a standard configuration of three softboxes, one on a boom. You might not always need all three but for times when the shadows can’t be properly managed with two, it will help a lot.

I selected CFL-based lighting because the cost-benefit is very high. If you wanted to spend more on LED lighting, that would be good in various ways, but it’s considerably more costly for approximately the same outcome.

Lighting for product photography seeks to eliminate hard shadows and preserve the shadows that reveal the contours and textures of the item. The diffusers of the softboxes provide a smooth and effective light source. I believe that you will find the photos so improved you will be happy with the extra effort.

NOTE: there is nothing in those fixtures that would care about the high voltage fields.

Once you have good lighting that permits wide color rendition, we can focus on... well... focus. Part of the problem of using a point and shoot camera is the lens, particularly depth of field. There are ways to compensate to some extent, but physical limitations of the optics will limit results.

First, shoot in A (aperture priority) mode and select f/8. The reason for this is two-fold. The smaller aperture will increase the depth of field and, while it is not a natural law, the general case is that practical lenses are sharpest about about that aperture. Since you will be shooting with a stopped down lens, your camera will adjust the exposure with the shutter speed. Do not allow this to get below about 1/60s or you will have blurry photos due to hand shake.

The camera will also use ISO (sensitivity of the sensor) to adjust exposure, if the ISO exceeds about 400, noise will begin to be a problem and the photos will look grainy. You can set the ISO so it isn’t automatic. I would suggest trying to shoot at ISO100 which is generally the native sensitivity of the sensor.

However, this might lead to a shutter speed too slow to handhold. There are two ways to deal with that, one is to add light. If you can’t do that you can use a tripod. If you choose the latter, be sure to use the camera’s 2-second self timer to avoid introducing camera shake when operating the shutter release (or use a remote release). If you don’t have a tripod, I would recommend getting one. I am happy to help select something that will be flexible enough for your use. You don’t want something cheap, but used is a good value.

In the end, a removable lens camera would be a very nice addition to your kit. You can use a DSLR or a mirrorless camera, the latter a nice idea to the extent it is generally more compact. If you are willing to consider upgrading the camera itself, I’d be happy to help you specify something.

I hope this is helpful, please let me know if I can help further.

@Yaakov -- Many thanks! I apologize that, owing to time constraints/divided attention I've had opportunity to merely 'skim' your reply -- I am looking forward to giving it the through read it deserves and, indeed, heartened by your familiarity with the camera! -- Fair warning - I am the epitome of an 'idiot photographer' -- I'll likely have many questions -- One point (at least) that @Aleph(0) missed --- the 'amber/green artifact' doesn't always appear - even under the selfsame conditions --- In point of fact it can often be seen to 'fade' in and out (at a ≈ 1.5 Hz rate) on the view screen, as if the unit is 'hunting' for the correct 'gamma' level - said behaviour being more pronounced under arc-illumation (e.g. HIDs and linear florescents) than incandescents, LEDs or sunlight --- Perhaps subtle 60Hz 'flicker' 'confuses' the illumination-level firmware? -- Again many sincere thanks!

Very best regards
HP

That’s explainable by the difference in the flicker of the two light sources and the shutter speed of the camera. At some points, the camera probably sees monochromatic illumination. A longer shutter speed could, potentially, reduce that.

I am happy to answer any and all questions you have. I am certain we can get you to the point of taking photos you will be happy with and that exceed the current results substantially. I didn’t mention, though I intended to, the geometric distortion of the lens which can also be corrected to some extent though using a better lens is a better way.

Please do ask, I’ll help however I can.

 

Greetings @Yaakov!

On the CoolPix camera I have available (S9900)

As a 'point of reference' My camera is identified/described as:
Model: 'Coolpix L22'
Firmware version: Ver.1.0

Please note that I have attached a 'soft copy' of the L22's user's manual to this post

So... I've found said device's (well hidden) 'preset manual' white balance adjustment mode/menu -- And will 'experiment' with same as per your advice (in addition to exploring the L22's provision of/access to other features recommended in your posts) --- Then post my results/inquiries here...

Very best regards
HP