peter_langfelder

I skimmed the paper. They solve a problem of correcting the spherical aberration caused by the first surface of a lens by the second surface, for imaging a single dot. The first surface can be arbitrary, e.g. a wavy form but cannot induce ray crossing within the lens. This seems to be very different from optical lens design where the object and image is not just one point but a (usually planar) surface; and the first surface of a lens is not arbitrary (and certainly not wavy).

I'd try not to get too stand-offish right away (especially not with a supervisor ;)). Try to see why the supervisor wants the raw photos - it could be he's thinking of reprocessing everything using the same style which would make a website look more professional, but does not want to bother you with it. You could offer to do yourself since these are your photos, or try to explain that the style is part of your artistic expression and you don't want the style changed.

Within 3-4 hours you can also get to the Sierra Nevada mountains if you like mountains. Lake Tahoe is great, so is, of course, Yosemite although the waterfalls will be nearly or completely dry. Even Lassen Volcanic National Park is just about 4 hours away. Big Sur, a scenic coastal area, is also under 4 hours.

I gather that you don't want a flash on the camera, even one that you can tilt and swivel to bounce. My suggestion would be to look into 3rd party iTTL-capable radio triggers. I have and use the Yongnuo 622N-tx transmitter (on the camera) to have full iTTL control over off-camera Nikon SB900 (attached to a 622N transceiver) and another Yongnuo flash. A set of a transmitter and 2 transceivers should run about $120 or less. They are not negligibly small but I don't find them so large that the size becomes an issue. The system works fairly well if not completely consistently (and reliability has been a bit of an issue with the Yongnuo products I own). I cannot guarantee they will work with SB-600 but that shouldn't be hard to check on the world wide web.

No need to be overly self-critical, the photos could be improved but they don't look all bad. A few points... The individual portrait is not focused well which could be an issue of camera not focusing very accurately, but it could also be the result of focus-recompose which you would have used. On the 6D the center point is more reliable but focus-recompose has its own pitfalls. I personally shoot Nikon but sometimes encounter the same problem. If you want to be sure of focus and have a stationary subject, use Live View focusing without recomposing. The same photo would likely be more contrasty if you did not shoot straight into the small window behind the man's head. Try not having strong backlight sources in or just outside of the frame; it will do a world of good for contrast. If you can put the window at 90 degrees and have it provide some sidelight, it can give the photo a more 3-dimensional look. The window is also distracting, but that's more about esthetics than technical issues. You may get better sharpness and contrast (assuming focus is accurate) by stopping the lens down a stop (to 5.6). Also, for photos where the depth of field needs to be larger (the gentlemen sitting on the sofas), you may try to stop the lens down to f/8 and increase the ISO. Noise would be higher but the photo would look sharper. HTH, Peter

I assume you double-checked that the camera was not switched to continuous focus... apart from that, cleaning the contacts could not hurt since a dirty contact may have a higher resistance, causing a higher voltage drop which in turn may become a problem when the battery voltage drops some. Of course, you could also have some parasitic resistance somewhere in the camera (e.g., battery contacts) or in the lens and it may only manifest itself with the particular lens (or camera) since the electrical properties of different cameras and different lenses may differ.

I would first try replacing the backup battery unless you have changed it relatively recently. Certainly cheaper than sending the lens for a potentially unneeded repair. A weak backup battery will cause the camera to misbehave in weird ways.

Would it work to sit in the back seat and have the second camera sit next to you?

I thought the OP didn't mean sharing exclusively over the internet? I shared my photos, in print form, by showing and giving them to friends and relatives, long before I started posting them on the internet. I know that friends generally like me to take photos of them/their kids, and part of my motivation to take those photos comes from them liking my photos. If I had no one to show my photos to, I would still take photos, but fewer and of different subjects.

I dropped my D750 off at Nikon service center in Los Angeles, and had it back in about a week (dropped it off on a Friday and got an "it's ready for pickup" call from them next Thursday or so). But different centers may have different wait/work times, and those could vary even for one center depending on demand.

Why don't you post this question on the Wedding and social event forum? I think quite a few of the regulars there are old timers (e.g., Marc Williams), although I am not sure they use (or have used) auto mode.

Perhaps you should post some examples so we can better guess what may have gone wrong. I find the Nikon system a bit confusing at times but fairly reliable. I assume you are aware of the fact that, depending on custom setting e4, ambient exposure compensation may get added to the dialed-in flash exposure compensation. Thus, if you change the ambient EC, you may also be changing the effective flash EC.

<p>FWIW, I don't see a change in angle, I see a slight shift - the 750 image seems rotated slightly to the left. In terms of color, you are viewing the images in Lightroom which applies a (presumably different between D750 and D810) camera profile. Thus, even with all controls zeroed out, the processing is different for different camera models. This is in addition to the sensor differences.</p>

<p>I think this review by Dustin Abbot has a bit of a comparison: <a href="http://www.canonrumors.com/reviews/review-zeiss-milvus-50mm-f1-4-t/">http://www.canonrumors.com/reviews/review-zeiss-milvus-50mm-f1-4-t/</a></p>

Don't worry about it. I think you are seeing Newton rings, although I may be wrong on this.

<p>FWIW, my D750 behaves the same way - a 32GB card typically takes some 1200 images (in my shooting), but an empty card shows 570 or so images remianing. I learned to multiply the number by 2 to get a good estimate of how much space remains. By comparison, my old Canon 5D (Mark I and Mark II) were much more accurate in their estimates.</p>

<p>As Jeff said, look into Yongnuo flashes. For TTL, you have two major options - either go with clones of Canon flashes (YN600-EXRT) and controllers (YN-E3-RT), or with flashes (YN-565EX, YN-568EX II, YN-685) that are compatible with Yongnuo's "original" controller YN-622c. The newest Yongnuo 685 flash, in the canon version, has everything you need, including a radio receiver built in so you only need the YN622 controller. If you get the matching Yongnuo battery pack with it, it will recharge very quickly. You'd be looking at a total of less than $200 for a new set.</p> <p>The Canon clone products are a bit more expensive but should be compatible with other Canon flashes (600EX-RT) should you decide to get one in the future. The 622 controller and flashes that are compatible with it are not compatible with the radio control of the 600EX-RT.</p> <p>I have used Yongnuo products (YN-622 controller, 565EX flash and the battery pack) in their Nikon versions and they are not flawless but they mostly work fine. Make sure buy from a retailer with a reasonable return policy and test everything as soon as the gear arrives.</p>

<p>I would not worry about the noise which is not really objectionable at this magnification (in fact, I had a hard time seeing any of importance). I would work on getting the contrast and brightness right first (the image looks very dull to me), then check the noise in the final result and keep in mind that (1) at a normal viewing distance and resolution, typical noise levels make very little difference and (2) excessive noise reduction will degrade the fine detail in the image (for example, in the bride's hair).</p>

<p>(apologies for duplicate posting...)</p>

I am not the most knowledgeable, but AFAIK the 420EX should be compatible with both the Elans and the 40D. The 300TL is definitely not compatible with the 40D. If the 420 is consistently overexposing, its circuit board may be bad.

<p>Have you changed the backup (a.k.a. date) battery in the last few years? If not, try changing it. When that battery goes, it can make the camera act out in unexpected ways. Here's a description from Canon: <a href="http://cpn.canon-europe.com/content/education/infobank/batteries/care_of_batteries.do">http://cpn.canon-europe.com/content/education/infobank/batteries/care_of_batteries.do </a><br> It may also help to gently clean the aperture contacts with an eraser.<br> If neither helps, a trip to a Canon repair center is in order.</p>

<p>Some of the photos have a strange, water-color-like grain, which is probably the result of scan oversharpening. To see whether your negatives are underexposed, look say at the one with darker trees in the background and see how clearly you can see the trees on the negative itself. Is anything within the negative "clear", meaning it has the same color and density as the borders that receive no exposure? If so, you are underexposing; if no part of the negative is clear, your exposures are probably fine. <br> The camera indeed does not seem to allow any kind of exposure compensation/modification. You could try to point at something darker, press the shutter half way to lock exposure, then recompose and shoot, but the half-press also locks focus, so you have to be careful not to focus incorrectly when doing this.</p>

<p>First, get a loupe and small light pad and examine the <strong>negatives</strong> directly. Are they sharp (in which case you have problem with the scanner film holder not holding the film flat while scanning), or blurry? If the negatives are blurry, my guess is that the film is not flat in the film back, which would explain why the middle is blurry but the edges are sharp. Make sure the film is loaded properly, all rollers are in place and keep the film flat in the film gate. Search the net for how the film should loop over the rollers. If this does not solve the problem, shoot some test exposures against a flat wall, make sure the image is sharp in the viewfinder across the screen, and see what comes out on the negative. Hope this helps and enjoy the camera!</p>

<p>It seems your WFT Utility is not quite compatible with the particular OS version you use (you probably updated the system between the last time WFT worked and now).<br> Check Canon web site for updates to the WFT utility (don't install from the disk, that will only give you the same version). Canon may have updated the software for the newer OS X versions. If there's an update availabe, try that. Otherwise, this link: <a href="https://discussions.apple.com/thread/5522353?tstart=0">https://discussions.apple.com/thread/5522353?tstart=0</a> contains a workaround but I cannot vouch for it.<br> HTH,<br> Peter</p>

<p>Technically, the number of stops is log2(40/25) = 0.68 = 2/3 (approximately), so 1/40 is 2/3rds of a stop less exposure than 1/25.</p>