Three cheers! Your solution turned out to be the right one! Thanks, mas24!

Well, I am finally off the road! Dug my camera out to take a shot of my problem and go to work with you on some of your suggestions. The first thing I did was to blow the sensor with my rocket, put on my 15-300mm lens, take a shot of a white wall at 300mm, and take a look at the display. NO GRAY CHECKMARK!! Took a few more to be sure. Same result. Thank you all for your time spent on what should have been an obvious solution! Guess it must have been a tiny bit of lint or dust on the sensor. Sometimes the most simple solution is the right one!

I greatly appreciate all of your kind responses and offers of help. I am traveling on the road at present, but when I get home I will post a photo that shows the problem!

I have noticed something that looks like a broad very light gray check mark in white sky in some of my photos, most apparent in long range shots with my Olympus M5 MarkII using my Olympus 75-300 mm lens. Does this indicate sensor damage, perhaps pixels that have been burned by the sun? If so, can it be repaired?

That’s one of the best cameras made for a wide variety of purposes!

Another interesting discussion on how important gear is to getting great photos: http://www.diyphotography.net/five-pros-say-gear-matters-agree/

Thanks to all of you for such a spirited and wide ranging discussion. I think I have the answer to my question. A good photographer can get excellent pro level shots under a wide range of conditions with many of the cameras available today, just as good photographers have done with the equipment available to them in the past. When he or she faces conditions that exceed the ability of a particular camera or lens to get a particularly difficult or unusual shot, that photographer, if able, moves on and rents or buys the equipment needed to get that shot. Real needs drive the move. It seems that what we need an be determined by mastering the equipment we already, learning all the skills necessary to maximize its abilities, then deciding if a camera or lens with even more capabilities will actually help us get the photo we want or need that our present camera and lens actually cannot capture. Such people don't believe that equipment will make them great photographers. They are already great photographers. Equipment to them is simply a tool to maximize and extend the range of the abilities they already have.

That having been said, some people just enjoy finding, collecting, owning, exploring and enjoying the best, newest, most unusual, and often the most expensive equipment available. I say more power to them. They keep us and the industry on the cutting edge and moving forward! They may not actually do a lot of photography, and that is fine. They no doubt know that just having great equipment will not make them great photographers, any more than a pen collector's pen will make him or her a great writer. However, great equipment never made anyone a less able photographer, at least not after learning how to use it!

In the end, our purposes and desires in regard to buying equipment vary quite widely, and that's as it should be in a free society!

Great reason for having more megapixels, Desert Gecko. Don't worry about storage -- disks are getting much larger and pc processing much faster!

Rich1939, I couldn't agree more!

How true! We can continue to benefit from the advance of technology, but we should always remember that great equipment alone will never make a great photographer or great photograph, in any time period.

JPL, I'm actually not very political -- it's not a very inspirational scene right now. Politics that try to fit everyone into the same size photographically or otherwise certainly does not appeal to me. If I was headed into the dark jungles of the Amazon to shoot wildlife, I'd want to take the best camera Canon makes and its EF 600mm F4L IS II USM lens as well as one of its fastest and best zooms for changing situations! I don't like the idea of actually being up close with some of those jungle critters! I certainly wouldn't want someone limiting me to a less sophisticated outfit!

Sorry if I hit a nerve! The purpose of this post is not to lecture anyone on how they should spend their money. I certainly would never tell anyone that I think they shouldn't be entitled to have the camera equipment they have freely chosen! All of us are free to spend our money for whatever reasons or purposes we choose. I also agree that I have found from the posts of this board that members are very frugal and financially responsible. It is actually for that reason that I asked the question. You can spend for whatever purposes you choose, but if your specific purpose is to be able to take pro level photos, the question simply is how much camera "mega" do you really need for that purpose? The corollary question then would be, is it possible that people may be spending more than necessary on camera outfits to achieve that particular purpose? I do apologize for using the term "lazy." I simply meant that it is no doubt easier to let a high end camera do work that we could actually do with less complicated cameras. There is nothing wrong with that, any more than it is easy to get a lot of great shots with the automatic setting on a camera. That actually works in the majority of situations. Mea culpa!

Well said, Photocraig! There are other processes available to create large billboard displays from normal photos! You don't need a big expensive camera for large beautiful reproductions! As you say, "end purpose of producing a quality image reproduction is well within the state of the art as we knew it yesterday. The new bigger better and WAY more expensive bodies and lenses make it easier to capture normal images and possible to capture images at the extremes of dynamic range, very low light or insanely fine details. A very high percentage of very good enthusiasts and and a majority of working pros will never need or use those capabilities. A well exposed image, properly framed, composed, focused and processed by a skilled photographer will suit 99% of the needs they or their clients will put before them. In those few cases the use of the fine equipment rental companies will prove very cost-effective... Often over the years, the most expensive, latest and greatest gear was introduced to meet the extreme requirements of fast sequences, frame rates, large buffers, wide apertures with optics to match etc.". How much time do most photographers spend taking shots in situations that have "extreme requirements?" How many times do most of us try to capture images at the extremes of dynamic range in almost blackout conditions? Do we really need extremely fine details when fine details work very well? You are right -- most very good enthusiasts and working pros do not need or use the extreme capabilities of high end cameras. The average photographer buys them simply for status and bragging rights -- "see what I can afford" and "this is evidence that I am a serious and great photographer." Any capable and well prepared photographer doesn't need fast frame sequences, frame rates and big buffers to capture great shots. Those capabilities are primarily for lazy photographers who want the camera to up the probability of getting one fantastic shot. That does away with the challenge of upping one's own skills.

Of course, as the next comment observes, no one can tell us what camera we must buy, or how much money we can throw away unnecessarily, or how profligate we can become while ignoring true needs. My question is simply how much "mega" do we really need to get and reproduce excellent and pro level photos? I still think the cameras I mentioned are representative of the maximum lengths we really need to go.

Could we stick to the essential question and not digress into which cameras have or do not have micro four thirds cropped sensors? The question is how much do we really need in a camera to get all the quality and performance that can reasonably be perceived and utilized by most people? I believe the cameras I have referenced are as far as we need to go and the most we need spend -- there aren't many roads where you can demonstrate, much less utilize, Dodge Demon performance. There are many cars that can give you all the performance thrills you can possibly realize at very reasonable prices. Actually, it is amazing what an iPhone camera can do in terms of online publishing and most common prints in the right hands (have you seen iPhone Photography School? Google it!)

Too funny, BebuLamar! You are right -- 16 megapixels are plenty! We don't need to supersize when we go to our local camera stores because most cameras are already supersized beyond 16 megapixels and, as rehess observes, sometimes counterproductive as a result! I think the Olympus M5 Mark II raw files, with post processing in the hands of a professional, could produce prints that would stand up very well to any produced by a D800e, at least in the eyes of most viewers.