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Younger photographer reshoots test shots for IQ180, older photographers give him better advice.

darr

Well-known member
@darr



What am I not saying correctly to have everyone misinterpret my post? Incorrect meter reading? There was no meter reading at all. Did you read anything before commenting? Did you see the pictures? Do you understand that BOTH pictures were taken with the exact same settings (other than the filter)?

I purposefully underexposed the photo to test the sensor's latitude. How do you test noise floors with your cameras? Do you bother? When I get new equipment, my first instinct is to test its limits so that I know what it can and cannot handle.

Let me put this in caps so that no one else can misunderstand what is happening here, because the (willful?) misinterpretation of this post has me questioning my sanity.

THIS IS A TEST/EXPERIMENT TO DETERMINE THE BEST SETTINGS FOR THE LOWEST NOISE POSSIBLE ON AN IQ1 80, and get properly acquainted with how much the files can handle in post, and determine why the second photo's noise level was so much higher than the the first. If you don't have experience with this back, or similar ones. I have a good understanding of photography basics, please don't treat me like I'm stupid. Do you personally own this digital back? Have you ever used one?

I appreciate the response, but I don't think you read the previous comments. This isn't a professional shoot, or anything remotely close to that. I'm trying to see how far I can push the files, and also trying to troubleshoot a strange noise issue. BTW, are you still trying to sell all three Merrills at once? I still want to buy the DP3.
There is no misinterpretation going on here; you underexposed an image and ask why the difference between the two photos you post.

I'm attaching two pictures to this. They are both shot with the exact same lens, with the exact same settings (A Pentax 90mm @ f2.8 @ ISO50) and were pushed in post about 2 stops. After doing a little bit of searching online, I've heard people say that ISO50 is the sweet spot, so I've been trying to see how far I can push that ISO before I see noise, and for the most part it's been performing pretty well. [
You failed to add in the filter factor that made a difference between the two exposures.
You become very defensive when others try to assist you.
No caps needed, we hear you loud and clear.
The fact you seem to forget or not know that heat causes noise makes some of us think you are unaware of some basic digital shooting knowledge.
To get the optimal results from any digital back, shoot it at base ISO with a proper exposure. It is that simple.

The Sigmas all sold, thank you.
 

nikesteam

Member
I've also seen faint streaking on a sensor that was cleaned (not visible to the naked eye, but under a microscope at an oblique angle).
Interesting. I will have it cleaned just to remove this possibility.

You also mention shutter priority? So were you manually setting the camera settings, or were you using shutter priority? If you were not in full manual, the camera would've compensated for the brightness from the window and underexposed more than you expected. If you were in full manual, your exposure should've been set much different than the first shot with the extra light in the room or your underexposure may actually be -3 or -4.
Fully manual, and what I was saying earlier was that if I had exposed the shot with a meter set to a time value of 1/60, then I presumed that the aperture reading it would've given me was around 1.4 (or a two stop difference from what I shot at). Saying this based on the fact that that is the how much I had to compensate in post to get it to the exposure level you see in both photos. Again, this was really just a casual test, hence no readings. When I shoot at home, I don't carry the light meter with me. Haha.

Tiffen filters are horrid. They flare like there is no other and their "mist" filters tend to reduce contrast and induce a touch of flare (it's part of the effect). That flare could be exasperated by the depth (or lack) of hood, angle to specular sources, or in this case, bright white blob in frame. Great for video and when exposure is compensated for (which the camera usually would in aperture or shutter priority). Depending on the filter strength and flaring, you may be causing up to a 50% contrast loss and/or further 1 stop underexposure. Flare of any kind can cause loss of contrast that makes pulling shadows much noiser than normal.
I typically do not trust my camera to expose a scene. 95% of the time I will meter manually (using a light meter). I have one or two cameras, where I trust the metering. Also, this is interesting to hear about the Tiffen filters! I use this particular one for my video camera to take the 'edge' off and give it a more organic look, and wanted to see how it would play with this back. It's literally the lowest density you can get (1/8th), so it's no where near a stop of light, and I actually wanted it to shave off some contrast to see what the results would be. The white spot is a window, and there is a really thick curtain there that was serving as a diffuser (also cloudy outside).

When I shoot any of my CCD backs, I tend to bias the exposure for +1/3 or even +2/3 to be sure that there is enough data for the shadows. I can always pull the highlights back in post. When there is no data, the processor can only compensate by extrapolating mathematically from surrounding pixels and that usually results in noise. I also spot meter, either by hand or using the in-camera meter, for the shadows that require clean detail - just like a Zone System user would. Under studio light, it's not a problem, but in the field, CCD needs much more careful metering like one was exposing transparency film.
That's good to know that the back retains good enough highlight info that you feel comfortable enough leaving some areas overexposed. @chrismuc, and you are both making me realize the delicate balance that needs to be maintained when shooting on this. ISO 35, and 50 are pretty much it for the cleanest settings. If you had to shoot underexposed with this, how far under would you feel safe shooting at, knowing that you could bring those details back in post without minimal noise? One stop? One and a half?

When you run the test again, be sure to meter properly (before you determine your 2 stop underexposure). Record the actual meter reading (in the shadow area where noise would form), then the exposure settings. i.e. meter = ISO50, 1/15s @ f/2.8, camera = ISO50, 1/60s @ f/2.8, metered @ below subject left eye shadow area. To truly determine the cause (if it occurs again), you'll need to eliminate as many variables as possible and record the conditions so that the data can be analyzed with knowns.

If you did actually underexpose more than expected, there's really no way to "clean up" what's not there. Noise reduction is typically smearing the noise pixel to the surrounding, using the surrounding to "create" what the algorithm thinks is there. A large patch of bad/missing data can't just be created out of thin air properly.
I shot today, but couldn't replicate the issue (using the same filter, and having a bright source of light in the frame), so unfortunately I have nothing to share today, but I'm going to try to replicate it again tomorrow, and I'll be sure to have a meter reading for you and I'll upload the pics with the metadata. The issue not coming up again does make me think that it is readout noise as @buildbot mentioned, but just to be sure I'll do a couple more tests. Next time I'll run two scenarios. First, spot metering on my daughter's face, and then one with a reading for the shadows in the scene as you suggested.

Yeah. I see what you're saying about no way to really "clean" it up in post. I think I will have to think of this back, the same way I think of shooting a 50ISO emulsion. I tried the sensor+ settings, but I don't think it really made a huge difference.

Thank you for the VERY helpful feedback! Will check back in tomorrow.
 

nikesteam

Member
You failed to add in the filter factor that made a difference between the two exposures.
It's mentioned in my response to @drevil (1/8th density). It's not even close to a stop or even 1/2 a stop of transmission lost.

You become very defensive when others try to assist you.
No caps needed, we hear you loud and clear.
Not defensive, your response was simply not helpful in any way whatsoever. Just looking for help from people who understand the tool that I am using (i.e. have used it, or own it themselves).

The fact you seem to forget or not know that heat causes noise makes some of us think you are unaware of some basic digital shooting knowledge.
There are instances where temperatures that are too cold also negatively impact the quality of an image, especially on CCDs. Have you experienced that on your singular, unnamed, back-up CCD before?

To get the optimal results from any digital back, shoot it at base ISO with a proper exposure. It is that simple.

The Sigmas all sold, thank you.
Right... I'd love to know what planet you're shooting on where you're never in a challenging light situation where you will need to edit the exposure in post. Do you live in Alaska? Norway? Antartica? Is it sunny 20 out of 24 hours where you live? All of this coming from someone who shot DP Merrills is the cherry on top of this nothing-flavored sundae. You, of all people, should understand the challenges of working with demanding digital equipment. It's not as simple as "shoot the base ISO" in all scenarios.

If you have something constructive to contribute I'd love to hear it.
 

darr

Well-known member
It's mentioned in my response to @drevil (1/8th density). It's not even close to a stop or even 1/2 a stop of transmission lost.
It is the difference between the two images.

There are instances where temperatures that are too cold also negatively impact the quality of an image, especially on CCDs. Have you experienced that on your singular, unnamed, back-up CCD before?
When I shot a P45 in Iceland 10 years ago, I made sure to keep the back warm and out of the weather, and did not experience problems.

Right... I'd love to know what planet you're shooting on where you're never in a challenging light situation where you will need to edit the exposure in post. Do you live in Alaska? Norway? Antartica? Is it sunny 20 out of 24 hours where you live? All of this coming from someone who shot DP Merrills is the cherry on top of this nothing-flavored sundae. You, of all people, should understand the challenges of working with demanding digital equipment. It's not as simple as "shoot the base ISO" in all scenarios.
If you use the proper tools with the right technique, the results show it. I had no difficulties shooting the Merrill cameras and continue to shoot with the SD1. I have been a commercial photographer for 30+ years. Once you have good technique, you know how to shoot the right gear for the job. It appears you think the CCD in your back is unique from other CCD backs. I do not think that is as important as good technique. If you are going to shoot in low light, the CCD chip may not be the best for that. I know you will come back and attack me, and for that, I am sorry for you.

If you have something constructive to contribute I'd love to hear it.
You seem to have all the answers you are looking for. Enough insulting. This is a nice forum and we try to keep it that way. No one will want to help you if you are insulting. I wish you well with your new back.

Darr
 

nikesteam

Member
It is the difference between the two images.
When I shot a P45 in Iceland 10 years ago, I made sure to keep the back warm and out of the weather, and did not experience problems.
I wish it were that simple. Also, as I mentioned before, the P/P+ series (excluding the P65s iirc) were all manufactured by Kodak. Not Dalsa. They are different.

If you use the proper tools with the right technique, the results show it. I had no difficulties shooting the Merrill cameras and continue to shoot with the SD1. I have been a commercial photographer for 30+ years. Once you have good technique, you know how to shoot the right gear for the job. It appears you think the CCD in your back is unique from other CCD backs. I do not think that is as important as good technique. If you are going to shoot in low light, the CCD chip may not be the best for that. I know you will come back and attack me, and for that, I am sorry for you.
Absolutely. We are not disagreeing there. Again, these are test shots to see what this back is capable of in bad situations. Do you understand what I'm saying? I purposefully shot these with the wrong exposure to correct them in post, but when corrected, one was decent, and the other was horrible. It is also seemingly not the filter that caused the issue.

I do think that this is a unique CCD back, and it's imperative to know the limitations of your gear. Technique is important, but no amount of technique can save you from not understanding the limitations of your equipment. Just to clarify, I own the following CCD cameras/backs: Epson RD-1, Leica M9, Leaf Aptus-II 12R, P25, Digital Bolex D16, Ikonoskop, and an old DC-40 Canon camcorder. Each are different in their own respect (the video cameras are the ones that need to 'heat up' before shooting them... I will never use the words 'heat up' again... they have to be at or near room temperature to operate properly). I've owned enough cameras to know that, even if they employ similar tech there are minor things that you have to be aware of in order to really 'know' the gear. The D16 has a KAI-04050 and the Ikonoskop has a KAI-02150, same line of Kodak sensors, and yet my Ikonoskop sometimes gives me a magenta hue that the D16 does not (under similar circumstances). To complicate things even further, I believe P1 actually manually calibrated these backs individually, meaning sometimes you may just end up with one that isn't as good as another one. I just recently purchased this back (used, obviously), and when I saw the drastic difference in quality on two pictures that were shot at the exact same settings, I was reasonably concerned that maybe I bought a lemon. Do you understand what I'm saying? I bought a used piece of equipment, and this post is for testing the limitations (with concerns to noise) of said used equipment. Not a refresher course on photography basics.

Enough insulting. This is a nice forum and we try to keep it that way. No one will want to help you if you are insulting. I wish you well with your new back.
I think the problem here is that you may have thought I was asking a photography question, and not a technical one about troubleshooting this specific piece of gear, albeit with a severe lack of information provided on my part. I would feel very unworthy of the piece of gear I bought if I didn't have the basic understanding of how noise is generated. I actually really like your work @darr, and I do know that there are things that I can absolutely learn from a 30+ year veteran so I definitely don't want any issues with you and I don't want you to turn me away when I really need to rely on your experience and knowledge. I also love that you shoot Sigma, as I also love them as well, and with that particular system, I'm 100% sure that you have a ton of wisdom that I could most definitely benefit from, so I don't want to anger you!! Apologies if my messages came off as rude. Please do not be upset with me.

Alan
 
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docholliday

Active member
If you had to shoot underexposed with this, how far under would you feel safe shooting at, knowing that you could bring those details back in post without minimal noise? One stop? One and a half?
Like Darr, I am also a commercial, production shooter. I simply wouldn't underexpose the shot - I'd light and expose it properly. No lights available? I'd get some then come back for the shot.

I don't spend time "learning my sensor" or "finding the limits" of the camera. I learn to trust my camera and it's meter, as well as learning the *meter* limitations. When shooting, I simply take a scene, meter for it properly, establish the shot, add/remove light as necessary, and produce the image. If the metered range is outside the spec, I'd add light/subtract light. I've used flashes, packs, flashlights, headlights, and even laptop screens to provide the light needed for getting the exposure right and in range for the camera as the scene requires. I've gelled whole windows with neutral density to reduce light as well as placed huge reflectors to add sunlight.

Fully manual, and what I was saying earlier was that if I had exposed the shot with a meter set to a time value of 1/60, then I presumed that the aperture reading it would've given me was around 1.4 (or a two stop difference from what I shot at). Saying this based on the fact that that is the how much I had to compensate in post to get it to the exposure level you see in both photos. Again, this was really just a casual test, hence no readings. When I shoot at home, I don't carry the light meter with me. Haha.
However, I am also a scientist, so I do my share of testing when necessary to prepare for a shoot. I establish norms, perform experiments, and produce results so that I can draw proper conclusions. The biggest issue you have here in your "test" is that you don't have a proper metering to start with. The eye is easily fooled and a horrible light meter. I'd not call this a casual "test", but rather a casual "guess". You really need proper metering to establish your exposure. What your eye saw in the second shot as "probably close" is more likely many stops off due to that window.

I have both spot meters and color meters in addition to my camera meter. I trust my camera to produce results when it's within reason and expectation. When it's outside that range, time to get my spot out and investigate. Color accuracy is very important to my work, so I'll investigate lighting with the color meter until I'm satisfied that the light going into the scene is within spec.

When at home, I trust my camera. When on site, I trust my camera. When in studio...guess what, I trust my camera. If it produces weird results, I'll immediately work to establish whether it was the scene exceeding the camera's capabilities or an unexpected glitch. But, until I run into that, I don't worry about it because I trust my camera.

I typically do not trust my camera to expose a scene. 95% of the time I will meter manually (using a light meter).
You need to learn to trust your camera - that's how it becomes an extension of your arm/eye/brain and not a limitation. It's just a tool, and like any tool, you need to trust it. Look at any industry - construction, automotive, etc. and the people in it. If they can't trust a tool, they'll replace it with something that they can trust. Likewise, I'm a production shooter, so a camera I can't trust and understand is a hinderance and gets replaced. I'm not/never brand loyal - I could care less. I'm result loyal and as long as the tool is not in the way of producing those results, I'm all for it.

Also, once you learn to trust your camera, you'll immediately know when something is wrong or out of spec. Without that trust, you'll always be second guessing whether it's the camera or something else causing issues. You need that baseline and to get it, you practice (or test). If you prefer to test, you need hard evidence and solid technique with real measurements.

Also, this is interesting to hear about the Tiffen filters! I use this particular one for my video camera to take the 'edge' off and give it a more organic look, and wanted to see how it would play with this back. It's literally the lowest density you can get (1/8th), so it's no where near a stop of light, and I actually wanted it to shave off some contrast to see what the results would be. The white spot is a window, and there is a really thick curtain there that was serving as a diffuser (also cloudy outside).
How could one *not* know about the craptastic quality of Tiffen? It's been known, testing and retested, and passed around that Tiffen is one of the worst filters in the world for many, many years!

Yes, we know that white spot is a window - you're missing the point. Which is, that it's very bright and 1) adding enough light that it's changing your perception of the correct exposure (since you didn't actually meter), 2) that it's large and in-frame which is inducing flare, and 3) is changing the contrast in the scene so that your shadows have even less detail which induces more noise.

There are instances where temperatures that are too cold also negatively impact the quality of an image, especially on CCDs. Have you experienced that on your singular, unnamed, back-up CCD before?
There are sooo many CCDs out there that are regularly chilled to the max. I'm talking liquid nitrogen or superconductive coolers that don't experience any of the artifacts you show. Like I've said, I've shot in sub-zero temperatures for hours with my CCD backs and never had a seam appear or color go patchy. Astro photographers chill their CCD cameras as well as many scientific (microscope) photographers. For astro work, the cooling reduces darkfield noise and prevents the CCD from heating when doing hours long exposures. No seams appear for them and color remains accurate - they are more critical about proper color imaging of planets than even studio photographers.

I've had my share of telescopes with CCD cameras that use Peltier chips to cool the sensors. My microscope cameras also have massive coolers built into them to keep the temperature of the chip chilled.

I've never seen temps too cold to affect CCDs. Ask NASA/JPL about how cold they run the CCD chips in space-borne instruments.
 
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lensbian

New member
It's mentioned in my response to @drevil (1/8th density). It's not even close to a stop or even 1/2 a stop of transmission lost.



Not defensive, your response was simply not helpful in any way whatsoever. Just looking for help from people who understand the tool that I am using (i.e. have used it, or own it themselves).



There are instances where temperatures that are too cold also negatively impact the quality of an image, especially on CCDs. Have you experienced that on your singular, unnamed, back-up CCD before?



Right... I'd love to know what planet you're shooting on where you're never in a challenging light situation where you will need to edit the exposure in post. Do you live in Alaska? Norway? Antartica? Is it sunny 20 out of 24 hours where you live? All of this coming from someone who shot DP Merrills is the cherry on top of this nothing-flavored sundae. You, of all people, should understand the challenges of working with demanding digital equipment. It's not as simple as "shoot the base ISO" in all scenarios.

If you have something constructive to contribute I'd love to hear it.
How to keep noise to a minimum when shooting on an IQ1 80?

Darr and docholliday answered the title of this post. Under-exposing an image will produce an under-exposed image with noise so do not do it unless you like the look which looks like garbage. With a 80 megapixel CCD back, you need to expose correctly or suffer the poor results. Testing it for exposure latitude might make better sense to bracket both ways to see what the sensor's limitations are, but never expect good results under-exposing, especially with a CCD sensor. Professionals do not under-expose, we "properly expose" and use the correct equipment to get the best results. A digital back is not the best equipment when its slow process gets in the way. For challenging light situations, a DSLR or mirrorless system would be faster to use and could produce better results depending on the situation.

Your question has been answered.
 

docholliday

Active member
How to keep noise to a minimum when shooting on an IQ1 80?

Darr and docholliday answered the title of this post. Under-exposing an image will produce an under-exposed image with noise so do not do it unless you like the look which looks like garbage. With a 80 megapixel CCD back, you need to expose correctly or suffer the poor results. Testing it for exposure latitude might make better sense to bracket both ways to see what the sensor's limitations are, but never expect good results under-exposing, especially with a CCD sensor. Professionals do not under-expose, we "properly expose" and use the correct equipment to get the best results. A digital back is not the best equipment when its slow process gets in the way. For challenging light situations, a DSLR or mirrorless system would be faster to use and could produce better results depending on the situation.

Your question has been answered.
Correction: "Testing it for exposure latitude [in a controlled environment, with repeatable conditions] might make better sense to bracket both ways to see what the sensor's limitations are, but never expect good results under-exposing, especially with a CCD sensor."

Ain't a single test gonna produce useful information just shooting random pics guesstimating the exposure!
 

Ray Harrison

Active member
You’ve gotten great advice from some supremely talented and very experienced folks. I shot that same sensor on a Leaf Credo 80mp. It’s an excellent CCD sensor in the right situations. The right situations don’t really involve under exposure. Don’t do it. It really wants well exposed base ISO (35), maybe 50 but did surprisingly well in certain situations at iso 100, with work. As regards meters, I shot that back with the DF+ and XF bodies, and in general, exposure problems were self inflicted, and in tough situations, I would use a spot meter. Mostly not though. Camera meters across my different systems - Nikon, Fuji, Phase - are generally really good so I have no problem trusting them.
 

nikesteam

Member
How to keep noise to a minimum when shooting on an IQ1 80?
If I had said, “How to keep noise to a minimum when shooting” then these responses would be justified. With the “on an IQ1 80” bit, one could infer that I’m trying to find out the best settings for this particular piece of equipment. I’ll find an English forum to post that to, and see what they think.

I shoot documentary photography. I don’t have the luxury of lighting an entire wedding venue to my liking, or an artist‘s studio, hell I barely have time to use a tripod (in some cases) which means I’m going handheld most of the time, and I do not like to shoot below 1/60th of a second (hence why I shot both of the example shots at 1/60th). The test is to see what would happen in the worst case scenario when using this back. I have to deal with the light that I get when I arrive. There is no “just add more lights” for my situation. I unfortunately don't have that luxury. If I'm shooting later on in the day, and there simply isn't a lot of light... that's just it. Obviously, I may use a different camera, but I still want to know what this one is capable of. So if I have to underexpose, and rely on the back to give me some latitude later on, I need to know what I’m working with. I don’t think I should have to explain this, but that is my situation.

Look guys, you seem to really be fixated on the semantics of the title rather than actually trying to understand what I’m trying to do here. This has gotten way off topic, I’ll change the title so that people aren’t confused when looking at it. I’m holding up the white flag. You guys win. I will go to Reddit, or LL, and stick to the gear section on this forum when I need something.

I do sincerely appreciate the comments that were actually helpful, and not condescending. Didn’t realize what I was walking into. Really sucks, because this is supposed to be one of the very few places people can come to get decent info on rare equipment like this.

Cheers.
 
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MGrayson

Subscriber and Workshop Member
For good or ill, no one can read your mind nor can you read anyone else's. Communication online is difficult, and almost no one here starts off with a chip on their shoulder. The responders in this thread are some of the most helpful and experienced photographers it has been my pleasure to interact with and to learn from. They do not mean to come across as condescending, patronizing, belittling, or whatever else it is easy to read into ANY comment on the internet.

M
 

nikesteam

Member
Oh! For the sake of people who see this in the future I'll leave this photo. This is what shooting my Ikonoskop cold produces. The instruction manual for this camera, literally says let the camera warm up before shooting with it.

Ikonoskop cold.jpg,


You can also see the issue in this video on the D16 (also CCD, there is a very faint line in the center of the frame, and the two stitched sensors have slightly different colors), along with a comment from the creators of the camera instructing people to let it warm up -
 
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Shashin

Well-known member
When I look at those two pictures, even though they are taken at the same location, they are not under the same conditions (side vs back lighting). They also have been processed to different contrasts--the shadows have been pushed higher in the second. That alone could result in more perceptible noise.

I would shoot more with your camera. I usually have to shot for a couple of months to understand the dynamic of my system and how to optimize it for any particular condition. This type of experimentation is something we all do. For example, the difference between flat and contrasty lighting can alter how i would expose for optimal results.
 

docholliday

Active member
Oh! For the sake of people who see this in the future I'll leave this photo. This is what shooting my Ikonoskop cold produces.

View attachment 187251,


You can also see the issue in this video on the D16 (also CCD), along with a comment from the creators of the camera instructing people to let it warm up -
And this is what Hubble's WFC3 using an e2v CCD sensor at flight operation temperature of -83°C (CCD) and 150K (-189°F, IR) produces:
800px-NGC_6302_HST_new.jpg

Along with the comment from the creators to where it operates...look at the operating temperature:
1628977129396.png

And yes, these are separate wafers butted together - they show absolutely no "seaming" in their image.
1628977209808.png

I think these flight-cleared directions are pretty good indications on what CCDs are capable of. Just because your 2011 CCD scope doesn't work when cold, doesn't mean that the science and physics of how CCDs work changes. It could be that the creators of your super 16 didn't sink it enough and needs it to equalize so that it doesn't stretch?? It could be that they didn't know how to (or couldn't keep it cheap enough) maintain the sensor temperature? Since it's motion, it could be that sensor's readout is slow enough that the processor can barely keep up with it and the sensor slows down even more when cold...again, probably not the tool to shoot in the cold when needed - by design. There's plenty of Arriflex CCD cameras that've shot award winning motion picture work in freezing cold, snowy conditions without issue.

It's just how CCDs don't and do work. Again, my 180 and old Kodak C645 back never needed "heating" to work. Nor do my CMOS backs. The cooler they run, the better the image quality remains. Even shooting the CCD backs in the sun for a period of time caused noise to form. I've had to put an umbrella over the camera to keep the sun off many a time. There's even a few shoots where we kept a cooler with molecular sieve and ice packs to place the back into between shots to lower the temp.

I shoot documentary photography. I don’t have the luxury of lighting an entire wedding venue to my liking, or an artist‘s studio, hell I barely have time to use a tripod (in some cases) which means I’m going handheld most of the time, and I do not like to shoot below 1/60th of a second (hence why I shot both of the example shots at 1/60th). The test is to see what would happen in the worst case scenario when using this back. I have to deal with the light that I get when I arrive. There is no “just add more lights” for my situation. So if I have to underexpose, and rely on the back to give me some latitude later on, I need to know what I’m working with. I don’t think I should have to explain this, but that is my situation.
1) I ain't as old as you think. I've just been shooting a long time from a young age with wonderful guidance from "old guys" who shot a long time on big campaigns. 2) commercial photography is one of the hardest sub-genres of the craft. Why? We don't have the luxury of making excuses. In wedding/portrait, you can excuse a lot to the situation or environment. In landscape, you can come back later or give up because it just ain't right. In documentary, you just go with the flow. But, in commercial work, when a client hands you an object with a brief and lookbook, you have no excuses - you make it work. It better be the exact color, dimension, and quality too when it's all said and done.

Look, we've all tried to show you that the problem you saw was probably a fluke due to a guestimated exposure. You say you shoot documentary...well, I'm going to tell you that you absolutely have the wrong tool for your work. If you were in construction, you just showed up with a powder-driven nail gun to put up drywall. If you were in the automotive industry, you just brought a 1/2" impact to tighten a 6mm screw into plastic. If you were in a kitchen, you just brought a square-shouldered 12" cast iron skillet to an omelet bar.

You need something with much more latitude, like a CMOS sensor, or even neg film, if you want to be laissez faire about exposure. To shoot CCD (or positive film), you need much more attention to the exposure and limits of the medium. You need something that can handle the long exposures. You need something that can focus faster and is designed for that purpose. I have no use for Leica, but that doesn't mean that it isn't *more* optimized for documentary photography. I've shot my share of documentary/journalistic/event work - with my Canon 1DX kit, not my H+P1 kit.

Again, if the whole intention was to "test" what would happen in the worst case scenario, you need to do it scientifically and with facts+data. Your "test" is invalid because there are no norms, control groups, or hard data. You should either chalk it up to being a fluke, or perform your test in a controlled manner. To do so would be to establish a consistent scene, the correct exposure, with no changing light, then go -1, -2, +1, +2, etc. stops on the exposure. You would then repeat the same test with ISO 35, 50, 100, 200. You could then change the shutter (while maintaining the proper EV) to simulate fast shutter vs long exposure. You could even put the back in the freezer or oven to simulate temperature soak. Once you have that data, you can then extrapolate a true limit for the sensor in hand.

I'm done...you obviously aren't listening to what we're trying to tell you. We ain't being condescending or anything near that range. We're trying to analyze what you are providing us from what we've dealt with in the past...and you haven't provided us much to go on. You asked what thoughts on your images were, with little detail, and got responses on what we saw; all based on what we've actually had happen to us in the past, from experience. You can't just change the title to your display your anger because you don't like what we're seeing from the data provided, especially since you aren't listening to what we've already suggested.
 
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nikesteam

Member
When I look at those two pictures, even though they are taken at the same location, they are not under the same conditions (side vs back lighting). They also have been processed to different contrasts--the shadows have been pushed higher in the second. That alone could result in more perceptible noise.
I really messed up by calling this a ”test”, but intended to do a proper one using doc’s recommendations. I think I was just instantly shocked by how different they were given the same post treatment. The shadows were pushed the exact same amount in both photos though.

I would shoot more with your camera. I usually have to shot for a couple of months to understand the dynamic of my system and how to optimize it for any particular condition. This type of experimentation is something we all do. For example, the difference between flat and contrasty lighting can alter how i would expose for optimal results.
For sure. It’s always good. My intention with this post was simply to get knowledge from people who have had this DB, and know of its quirks.

On a totally unrelated note, I just ordered both of your books William. I am actually in Japan now (have been here for 14ish years), and I also used to shoot in Tsukiji when I was in uni with my friends before they shut it down. Your pictures are gorgeous, and I’m excited to receive both of your books!
 

glenerrolrd

Workshop Member
Nikestream

If you want advice you need to stay focused on the problem to be solved ..not on a bunch of hypothetical solutions .(like warming up the sensor ). CCD sensors are sensitive to underexposure . Two stops under and you will most likely have noticeable noise issues . Saying that you used the same exposure just means you don t get it . (You need the correct exposure ). Your have to set the exposure to match the light on the subject . Anyone that has used CCD cameras extensively can see immediately that you under exposed the 2nd picture .

Do your own test using a meter ! You had excellent advice and we understand exactly what has happened in those two photos .

Roger
 
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nikesteam

Member
I'm done...you obviously aren't listening to what we're trying to tell you. We ain't being condescending or anything near that range. We're trying to analyze what you are providing us from what we've dealt with in the past...and you haven't provided us much to go on. You asked what thoughts on your images were, with little detail, and got responses on what we saw; all based on what we've actually had happen to us in the past, from experience. You can't just change the title to your display your anger because you don't like what we're seeing from the data provided, especially since you aren't listening to what we've already suggested.
Doc, I really think that as @MGrayson suggested, there are simply a lot of crossed wires here. I really appreciated your suggestions, and as I said in a previous post, was going to redo the test, to make it an actual test, implementing your suggestions.I also said multiple times that I didn’t provide enough info. The mistake was posting pictures that I randomly took in my living room and asking if anyone else had a similar issue. This was agitated by everyone harping on that fact, assuming I don’t know how to shoot, and not giving me the chance to post pics in a controlled environment with more data for you guys to analyze.
 

nikesteam

Member
Your have to set the exposure to match the light on the subject . Anyone that has used CCD cameras extensively can see immediately that you under exposed the 2nd picture .
Do your own test using a meter !

Roger
The test is to see what would happen in the worst case scenario when using this back. I have to deal with the light that I get when I arrive. There is no “just add more lights” for my situation. I unfortunately don't have that luxury. If I'm shooting later on in the day, and there simply isn't a lot of light... that's just it. Obviously, I may use a different camera, but I still want to know what this one is capable of. So if I have to underexpose, and rely on the back to give me some latitude later on, I need to know what I’m working with. I don’t think I should have to explain this, but that is my situation.
 

docholliday

Active member
Oh, one more thing...

Many sensors, both CCD and CMOS, are created by joining multiple wafers or units together. The difference is that higher quality gear will be mapped by the manufacturer to ignore/stitch the image while mapping out the seam. Each piece is also mapped and calibrated so that the whole unit acts as one. There's been many cases of these calibrations changing, due to age, exposure to cosmic radiation, or other natural phenomena requiring the return of the unit to the manufacturer for re-calibration. Hasselblad CCD backs have had this issue as well as many Arri cameras. It's the nature of the beast.

The single piece sensors without seaming or flaws is often used in very high end scientific devices. These sensors can be $250K for a 21mp sensor because of the waste created to grow that sensor. A whole wafer may produce one tier 1 sensor with 99 others "wasted" or religated to tier 2 usage (consumer cameras). There's even further binning to tier 3 which is used for cheap devices and "toys". The larger the sensor, the harder it becomes to grow one "perfect" tier 1 piece. There's been articles which describe throwing out dozens of full wafers before one was found with no defects.

This is very labor intensive and obviously expensive, so cheap gear just ignores it or tries to put pieces together that are "close enough" in the hopes that they all age the same. Those tier 2 sensors used in our "high end" cameras actually have bad/hot pixels and all that...they're just mapped out after the camera is produced and stored in the firmware before release.

Even LCDs suffer from this binning process whereas the highest quality with no defects are usually used for scientific/miltary gear (could you image what would happen on a missile detection radar screen if a sudden dark pixel appeared in the field?). The next tier goes to high end graphics monitors, then the lesser to "normal" monitors with even lesser quality going to TVs.
 

Geoff

Active member
At the risk of getting into something where giants have tred, one more offering:
It seems that what the OP was doing was a "reasonable" look at what happened, and stumbled into something more complicated. I remember (when first getting a Credo 60), trying something similar - and it didn't work well. The results were terrible. I thought (!) it was a good way to check the lattitude of the sensor - what came out was lousy. Gave up that approach, and went back to "get the right exposure".

Analytically, maybe its that the "bell curve" of reasonable exposures with the CCD sensor is narrower than one might expect - its not that it doesn't have dynamic range (it does), it just doesn't tolerate shots off-exposure. I don't know how to put it better, and don't want to stir a pot that is just now settling down - just the only advice here offered is shoot more, bracket, and try to get the exposure right.

The original posting had a some slightly confusing statements, but thats sorted out (one hopes) by now. Hopefully the OP has some good direction and can get on track with what some of us regard as a very fine digital back, but one that isn't quite as forgiving as one might have thought.
 
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