Test Equipment Anonymous (TEA) group therapy thread

[neo]

@ Cerebus I have to agree it seems to a hell of lot less grainy.

That would be because my camera sucks. Can't do much except work with what i got.

[bitseeker]

Interesting because the file size I quoted for the circuit board of 2.6MB is correct on the original file as it sits on my desktop. You are also correct when you say that the file size under 1MB so it seems that IMGUR when you upload a file to them is automatically resized (not cropped) to make the file optimised for internet viewing and mu st use some pretty powerful algorithms to decide where it can adjust the file without loss of definition.

IMGUR probably just used a higher compression ratio when recompressing the image. Good cameras tend to be conservative with JPEG compression since you can't make up data that isn't there anymore. For online use, you can sacrifice more without the picture becoming a mess. JPEG can easily compress an original, continuous-tone bitmap 10:1 with great results. The algorithm already takes care of what to throw away.

That means that if you wanted to ensure that your photos to remain on the forum, even if they get deleted from IMGUR, all you have to do is load up IMGUR, upload your original photo to their site, then click on images tab, select the photo to attach, is to right click the image, and select "save as" and save it to your desktop, aid its optimed for the internet and our forum.

Yep. You can also grab a simple image viewer like Irfanview or similar and try different compression levels to find an acceptable balance between file size and artifacting for your subject matter. There are other tricks that can boost the compression even more, but simply giving the level a tweak usually gives good enough bang for the buck.

[xrunner]

HP or Agsight bench DMM, dunno which model. 

It reminds me of a Keithley DMM instrument because of the brown color ...

[bitseeker]

That Keithley brown seems to have been multiplying in my lab the past couple of years. Something different from the usual bench-gear black, silver, and gray, I suppose.

[Cerebus]

Bonus points for the TEA addict who correctly identifies the ware in the photo.

HP or Agsight bench DMM, dunno which model. 

No, yes. 

Hints: old, (circa 1980) and British.

[Cerebus]

Brown era Keithley kit was as good as, sometime better, than HP kit of the same era. The thing is that Keithley didn't used to have the same level of name recognition which was a good thing for us TEA addicts looking for a good price. Sadly, from our point of view, people are beginning to recognise Keithley for what they are and the prices have been steadily creeping up over the last few years.

[xrunner]

British kit - Hmmm. Marconi - no they did rf stuff. I'm trying to remember my British lab instruments. Bitseeker help me out please. 

[Vgkid]

Could be racal(racal dana)

[bitseeker]

Brown era Keithley kit was as good as, sometime better, than HP kit of the same era. The thing is that Keithley didn't used to have the same level of name recognition which was a good thing for us TEA addicts looking for a good price. Sadly, from our point of view, people are beginning to recognise Keithley for what they are and the prices have been steadily creeping up over the last few years.

Keithley kit seems to generally be sky high on eBay. Of course, the good thing about that is that the good deals are rare and so slows down the growth of my collection.

[mnementh]

Which is EXACTLY the case here... neo had a really big subject in that Hickok front panel; and a LOT of detail he wanted to show which represents its amazingly good condition. Cropping doesn't work, you just plain need more pixels. Same with me and my posts; MOST of the time I attach my pics directly to the post, unless it's dumb stuff like emojis and tchotchkie pics, or I need more res to convey what I want to show.

Time marches on. What used to be considered acceptable detail is now just fugly-blurry. Minimum standards tend to increase in jumps; sometimes exponentially. C'est la vie!

mnem
Life is messy. Bring a sponge.

I have to beg to differ. Compare this picture, 6 MPixel with maximum compression for a filesize of 432k, against that 32 MPixel picture of Neo's with a filesize of 2Mb. Try downloading both and looking at them side by side at actual pixels/100%. I think you'll be forced to agree that mine is way sharper and more detailed.



Bonus points for the TEA addict who correctly identifies the ware in the photo.

Yes... lets consider this picture. FOV is approx 8" x 8" - 10" x 10".  FOV on that Hickock is easily twice that in all dimensions. That means to manage the same resolution across the FOV, you need nearly 5 times the space, and that's assuming your camera and his are equal and focused as well with similar lighting; clearly none of which are so.

You're not showing me anything new here. I used to take pics of PCBs like that with a flatbed scanner. 


mnem
*poot*

[Carl_Smith]

Hires, who hasn't got a Tb drive in their PC ?

Me.   

Well, a lot of people have gone backwards in the never ending march of increasing hard drive space during the transition from slow as molasses mechanical hard drives to speedy solid state drives.  My "old " laptop has a 1 TB drive. (It's now toast but that's another story.  A long one. That brings up anger and frustration.  And another brand on my do not buy list.)  The "new" laptop has a 500GB SSD.  And then when I got tired of having to do everything on a laptop, and a bit due to my being "conservative" with my spending   I bought a refurbished Lenovo Thinkcentre mini-desktop PC.  But it came with only a 120GB SSD.   Can't get much for $149 delivered.     That one is going to need an upgrade soon.  But I do seem to be going the wrong way in hard drive space.

On the other hand, I keep telling myself that it doesn't matter because what I should really do is get a NAS and store all the large stuff on it, and not worry about not having TBs in my computers. And set it up in RAID and have it do proper backups of my PCs.  But I never get around to that either.

Not that any of this has anything to do with the discussion about picture sizes.

[tautech]

Hires, who hasn't got a Tb drive in their PC ?

Me.   

Well, a lot of people have gone backwards in the never ending march of increasing hard drive space during the transition from slow as molasses mechanical hard drives to speedy solid state drives.  My "old " laptop has a 1 TB drive. (It's now toast but that's another story.  A long one. That brings up anger and frustration.  And another brand on my do not buy list.)  The "new" laptop has a 500GB SSD.  And then when I got tired of having to do everything on a laptop, and a bit due to my being "conservative" with my spending   I bought a refurbished Lenovo Thinkcentre mini-desktop PC.  But it came with only a 120GB SSD.   Can't get much for $149 delivered.     That one is going to need an upgrade soon.  But I do seem to be going the wrong way in hard drive space.

On the other hand, I keep telling myself that it doesn't matter because what I should really do is get a NAS and store all the large stuff on it, and not worry about not having TBs in my computers. And set it up in RAID and have it do proper backups of my PCs.  But I never get around to that either.

Not that any of this has anything to do with the discussion about picture sizes.

Ah, a mini desktop, yeah right probably no room for an extra HD.
Used to run a tower PC to accommodate enough drives before the Tb's came down to affordable prices  but since SSD's were early available been running OS and hungry programs on them. Even my first 60G SSD is tacked into a PC along with others still earning their keep.
Had 2 SSD's and 3 HD's in my last PC that popped a MoBo early this year and need time to condense them all into just another 1 Tb that's on hand to stick in this PC.
With the other HD that's spare now I should upgrade the single drive NAS I use or bite the bullet and go full RAID.
Amazing how much shite one saves onto drives over the years. 

[Carl_Smith]

Ah, a mini desktop, yeah right probably no room for an extra HD.

Nope.  I'd have to pull the 120GB one and replace it.  It's actually quite impressive what they crammed into that PC.  It's maybe a bit over an inch thick and about 7 inches high and deep.  It does run on a laptop type power brick but I'm fine with that - I can hide that under the desk.  It does have integrated graphics so no real gaming either, but I don't do that anyway.  It's great for what I do on a PC these days.

[Cerebus]

Yes... lets consider this picture. FOV is approx 8" x 8" - 10" x 10".  FOV on that Hickock is easily twice that in all dimensions. That means to manage the same resolution across the FOV, you need nearly 5 times the space, and that's assuming your camera and his are equal and focused as well with similar lighting; clearly none of which are so.

My point is, it's not about the number of pixels, it's about resolution. Actual resolution, I know that pixel count is often mis-named as resolution, but resolution it is not. For each pixel in my jpeg there are around 5 pixels in Neo's, but it's quite clear, even from a casual look that those 5 pixels contain less information than each pixel on my photo.

Let's try and zoom in on those pixels at features of similar physical size - the meter legends in the top right and one of the refdes on the board. I've tried to zoom in so that 1 pixel on the right takes approximately the area of 4 or 5 on the left.



The image on the left has more pixels, but they aren't conveying anywhere near as much information, per pixel, as the one on the right. You do not need a massively high pixel count with low compression to deliver a clean, clear, informative photo packed with detail.  By the way, I've just realized that I had not made it obvious but that is a screenshot of both so you can see the JPEG artefacts induced by the compression (i.e. I'm not cheating).

Here's another example. A 22 1/2" by 14 1/2" page of newsprint, probably about the size of that Hickock panel. Again a mere 6 Mpixel, maximum JPEG compression (i.e. worst quality) that photoshop will do and every detail is still visible, right down to some stray scratches in the printing plate on the lower left edge. You can certainly read every word on the page but there are also obvious JPEG artifacts visible, to be expected on such busy matter. That's the price you pay for getting a 17.2Mb original crushed down to 733 kb.

[tautech]

Ah, a mini desktop, yeah right probably no room for an extra HD.

Nope.  I'd have to pull the 120GB one and replace it.  It's actually quite impressive what they crammed into that PC.  It's maybe a bit over an inch thick and about 7 inches high and deep.  It does run on a laptop type power brick but I'm fine with that - I can hide that under the desk.  It does have integrated graphics so no real gaming either, but I don't do that anyway.  It's great for what I do on a PC these days.

You could run an external USB HDD with that tiny thing and then have the added benefit of data portability.
USB3 would be they way to go. 

[mnementh]

Yes... lets consider this picture. FOV is approx 8" x 8" - 10" x 10".  FOV on that Hickock is easily twice that in all dimensions. That means to manage the same resolution across the FOV, you need nearly 5 times the space, and that's assuming your camera and his are equal and focused as well with similar lighting; clearly none of which are so.

My point is, it's not about the number of pixels, it's about resolution. Actual resolution, I know that pixel count is often mis-named as resolution, but resolution it is not. For each pixel in my jpeg there are around 5 pixels in Neo's, but it's quite clear, even from a casual look that those 5 pixels contain less information than each pixel on my photo.

Let's try and zoom in on those pixels at features of similar physical size - the meter legends in the top right and one of the refdes on the board. I've tried to zoom in so that 1 pixel on the right takes approximately the area of 4 or 5 on the left.



The image on the left has more pixels, but they aren't conveying anywhere near as much information, per pixel, as the one on the right. You do not need a massively high pixel count with low compression to deliver a clean, clear, informative photo packed with detail.  By the way, I've just realized that I had not made it obvious but that is a screenshot of both so you can see the JPEG artefacts induced by the compression (i.e. I'm not cheating).

Here's another example. A 22 1/2" by 14 1/2" page of newsprint, probably about the size of that Hickock panel. Again a mere 6 Mpixel, maximum JPEG compression (i.e. worst quality) that photoshop will do and every detail is still visible, right down to some stray scratches in the printing plate on the lower left edge. You can certainly read every word on the page but there are also obvious JPEG artifacts visible, to be expected on such busy matter. That's the price you pay for getting a 17.2Mb original crushed down to 733 kb.

So what you've confirmed, beyond a shadow of a doubt, is that neo's camera took a crappy picture with lots of pixels. We knew that about ummm... 3 pages ago?

So for him to convey the information he wants to convey, he has to publish a lot more pixels. Hence beating his head against the still ridiculously small 2MB limit.

All of that is covered under this part of my statement.

This is the real world: People take pictures with what they have available. It's not always an award-winning camera like my Sony, or whatever you took your pic with. A lot of folks only own the camera in their phone, all of which have horrible lenses due to size (yes there are a few exceptions, lets not go there) and do their best to make up for it with a gazillion microscopic pixels in the sensor, which means lots of software manipulation to counter noise, and not near as much information transmitted for all those pixels, because that camera may have to interpolate information from 4,8,16 or more pixels and average the values to come up with something usable. But the EU end-user STILL expects to see a 16MP filesize, even though there's only about 6MP worth of actual information captured in that crappy little raisin-sized camera. So they do the best they can with software to make it look good to the naked eye, and Aunt Lucy gets what she thinks are awesome pics of your kids chasing each other around the yard with a garden hose. But she's damned lucky if she can get a legible pic of a signed release form to eMail to her insurance company with the same camera. 

AS A RESULT... the STANDARDS of THE REAL WORLD mean that a 2MB TOTAL filesize limit IS ABSURDLY SMALL. You shouldn't have to have professional digital photography expertise to use a freaking bulletin board, dude. Or even "advanced amateur" expertise like myself.

Yeah, sure... you and I can shrink a pic down and make it look good without even thinking about it... I do it all the time. But arguing that you should HAVE to in this age of free terabytes of online storage is ludicrous.

What it really sounds like you're arguing is that it's good to keep it as a rite of passage for the noobs. Same attitude as the "old HAMs fraternity" clinging to the code requirement well past doomsday.


mnem
*poot and a half*

[bitseeker]

So for him to convey the information he wants to convey, he has to publish a lot more pixels. Hence beating his head against the still ridiculously small 2MB limit.

Actually, he doesn't have to publish more pixels, nor resort to self-harm (he needs that head for working on all that gear he just got).

Cerebus' example illustrates that scaling a low-quality/higher-res image can make it look the same as a high-quality/lower-res one. In other words, it makes them convey the same amount of usable information. Since neo's camera uses more pixels than it needs to for what the camera's lens can resolve, the pic can easily be scaled down, still look the same, and require less bandwidth and storage for online use. Archive the originals, of course.

[Cerebus]

I don't get why you (Mnem that is, there was a posting race) are still insisting "more bytes needed". If there are a lot of pixels with little information in each then stuffing them into JPEG to reduce the file size won't lose much (if any) of the information. Did Claude Shannon write in vain? Did the Joint Photographic Experts Group sweat for nothing? There's no great expertise needed here to get an acceptable result, that expertise is already baked into the JPEG compression algorithm. If the source material has excessive redundancy (too many low quality pixels) then that's exactly what all compression algorithms rely on to work with and JPEG (and its cousins) are specifically targeted at doing that while retaining perceptual quality.

I've just tried recompressing Neo's picture and even though I started with an already compressed image I could halve its size without any perceptible change in final quality. I can just tell which is which, but that's down to the fact that JPEG is trying to faithfully record its own artefacts and in so doing creates new ones, but the important perceptual information really is essentially unchanged. Try it for yourself.

[mnementh]

So for him to convey the information he wants to convey, he has to publish a lot more pixels. Hence beating his head against the still ridiculously small 2MB limit.

Actually, he doesn't have to publish more pixels, nor resort to self-harm (he needs that head for working on all that gear he just got).

Cerebus' example illustrates that scaling a low-quality/higher-res image can make it look the same as a high-quality/lower-res one. In other words, it makes them convey the same amount of usable information. Since neo's camera uses more pixels than it needs to for what the camera's lens can resolve, the pic can easily be scaled down, still look the same, and require less bandwidth and storage for online use. Archive the originals, of course.

In a world of lossless compression, yes. But we live in a world of .jpg, which, in a nutshell, sucks detail. Shrinking neo's poor quality image down to fit in the 2MB filesize limit loses what little detail it has; as was easily demonstrated by neo's side by side comparison several pages back. It does NOT look the same.

Again... objectively, a 2MB total filesize limit is ridiculously small in this age. No amount of "But I can shrink it with..." will make that not true.

And it's all a moot point anyways... we've spent much more time arguing this point than neo ever spent making archive copies just for eevBlog's tiny little pigeonholes AND adding links to his IMGUR... so what the eff difference does it make?   


mnem
*Dismounting the dead horse*

[BravoV]

Most of the times I used crappy cheap P&S camera, as the forum's 2MB limitation, we just have to compromise and live with that, and "diligently" use what ever tricks that still good enough to convey our intention to share the details to the audiences.

On few occasions I deliberately managed to custom adjust the JPG compression to fit and hit 2MB limit in a single post such like this (watch the image sizes) -> Tektronix 24x5 U800 Pads , but I rarely used this as consideration helping Dave's to use his storage space as "optimal" as possible as gesture of respect.

If I need to show the whole view and the details, just shoot different shots to tell the story like this -> Fluke PM6306 or this on Tektronix U800 Chips and the board "layers".

Personally, I don't see there is an urgent need to have a single ultimate single shot/image that carries the whole item's view down the micro details.

[mnementh]

Nope... not gonna suck me back in.    Nice try; I'm going to bed. 


mnem
Thanks for playing.

[Cerebus]

Personally, I don't see there is an urgent need to have a single ultimate single shot/image that carries the whole item's view down the micro details.

Actually I have found excessive detail very helpful in the past. If you're trying to figure out exactly what component was used in a bit of kit, and you don't have it to hand but you can find a picture on the forum/wherever the fine detail can become important. It may not be relevant to whatever point the original poster was trying to make with the photo but it can be very helpful to those who come along later. It's also helpful if you're trying to reverse engineer kit you don't have access to.

[tautech]

Nope... not gonna suck me back in.    Nice try; I'm going to bed. 


mnem
Thanks for playing.

There another side to this pic file size issue you might not have considered; ease of viewing !
As a worldwide forum with members/viewers are of all means and walks of life, not all have access to anything like a fast internet connection, I didn't until late last year and although it's now only 30MB/s I'll click on anything now were as previously I was very picky as to what I viewed so to not spend all bloody day waiting for something to load. To want to splatter the forum with large file size pics puts many at a disadvantage, so much so that when discovering a thread of interest that takes so long to load due to obscenely sized pics they raise two fingers to the OP for being SO considerate then go and view something their connection can comfortably manage.

Currently the 2MB SMF limit is fit for purpose.

[mtdoc]

Currently the 2MB SMF limit is fit for purpose.

Exactly.  It’s rare more detail is needed. If so link to an outside site. Many of us do not have fast pipes. I’m limited to about 1 Mbs most if the time at home. Many others are in the same boat.

[Brumby]

Many of us do not have fast pipes. I’m limited to about 1 Mbs most if the time at home. Many others are in the same boat.

This is something many people do not understand - or simply forget.