The decision the subscribe, is of course an individual one dependent upon our individual shooting methods. For example, do you shout raw or jpeg? If you shoot raw and buy a new camera, you will need the most current version of Photoshop and Lightroom. If you use the lens correction feature to remove chromatic aberrations or other lens distortions, you will need to upgrade as you upgrade your lens kit. Are there features, improvements, enhancements to the program that impact your images, such as the ability to do panoramas in Lightroom? If you run a high speed computer with a top end graphics card, you may want to take advantage of most current programs.

With regard to my shooting, I am constantly pushing the the boundaries of my technique, equipment, and software. A subscription to my two most used programs, Lightroom and Photoshop for $10/month is reasonable in view of the prior upgrade costs for both programs, given my equipment upgrade practices, my use of new features, etc. Sure I wish I could buy a lifetime subscription, like I did with my third most used software, Zerene Stacker.

A high end pro who shoots with an extreme megapixel cameras and professional 2.8 aperture zooms probably has a different set of expectations and demands than somebody shooting consumer lenses on older bodies. I hope this forum has room for this wide range of photographers.

Often I can find a horizontal or vertical feature that shows as a line, such a a door jamb, window sash, shutters, downspout, on the plane of focus I want. I then more my focusing square over the line or use the center focusing square and recompose (Whether the individual focusing points work on horizontal, vertical, or multidirectional mode is camera specific). If that didn't work and my cloud cover did not come, I would use live view, magnify the image 10x, and then focus my tripod mounted camera. A brief aside, when your 7d is in servo mode, it will fire regardless of focus. I haven't tried it, but it may also be possible to use your flash to aid focusing.

I don't think the experiment addresses the OP's concern. In the experiment, the change in depth of field is due to the changing the focal length of the lenses. A 500mm lens at f4 will have a different depth of field than a 14mm lens at f4, even if they have the same fov. To test whether the depth of field changes by using a cropped sensor, I would set up a tripod and attach a lens that had a tripod mount (to minimize inadvertent position shifts and ensure the sensors of the test cameras remain in the same position) Then I would focus, choose my aperture etc and shoot. I would then change cameras, dial in the same aperture and shutter speed and take the image (in manual mode) without changing the focus of the lens. What you should see is that the two images have the same depth of field (a function of the aperture) but different fovs. By keeping the lens settings constant, the image circle remains the same for both cameras and should exceed the size of either sensor. The size of the sensor determines how much of the projected image the sensor sees, with the full frame sensor seeing a larger portion of the image circle than cropped sensor.

Having read the Nikon article, I will defer to the more experienced aquarium shooter and eliminate the recommendation of flash.

Try the rubber lens shade pressed against the glass on all sides and flash. The lens shade will eliminate any reflections (from both the flash and from the room)and the flash will provide sufficient light to stop the motion. More interesting lighting angles can be used if the flash is taken off the camera and used with a patch cord. Wireless flash connections are even easier. If I was up against the glass with my lens shade I would not as a general rule use a polarizing filter as you will not have the same problem with surface reflections that you would if you were a distance from the glass or water. With a polarizing filter you will lose between 1 to 3 stops of light.

When I first started photography, back in the day of external light meters and manual focusing, the camera was just a light-tight box whose function was to hold the lens and film in their proper position. The role of the camera has changed in two respects. Now the camera takes the place of film and also automatically performs many of the manual tasks (such as setting exposure and focus). In the old days, the answer was easy. Buy the lens. Now that the camera does so much more, you have to analyse your photography and see where the weaker links are for your type of shooting. Would the "extended reach" of a cropped sensor be helpful? Will some of the features of the camera, such as better high ISO performance, faster focusing, etc mean you will get shots that you would otherwise miss. For the question of which the lens/camera combination will yield better quality for a "normal" daylight exposure, a local camera store may be the answer. If you have a local camera store that you do business with, they will probably let you take a few test shots with the prospective lens on your body and your lens on the prospective body. Then compare results, then decide and buy.

With regard to your question of whether you will get comparable quality with the same lens on the two cameras you mentioned, the answer is sadly no. There is a substantial difference in noise and resolution between the Rebel and the 5DmarkIII.

I use live view for focus stacked macros on a daily basis. Live view with electronic first curtain prevents two types of movement: the previously mentioned mirrors slap, and the vibrations caused by the opening the shutter (some cameras don't electronically start the exposure in live view so check your manual.) Particularly with higher magnification macros, the live view results in a sharper image. Early implementations of live view seem to have had more problems with heat build up and noise. I have shot tens of thousands of live view images without any problems arising, but as a Canon shooter, I can't address your camera specifically.

If the choice is between moving the camera lens combination to focus or using the focusing ring, I will use the focus ring, It avoids the perspective change of moving the camera. To avoid camera movement, I use a Camranger to control the focus ring adjustments. Usually, I use the focus ring method in magnifications up to about 1.5 to 1. Higher magnifications I usually move the whole rig by using a motorized rail. There is a tutorial on the Zerene (one of the main stacking software used by stackers) website that show why you ring focus adjustment is preferred when possible.

Back in the day of slide film, I experimented with reversed 50mm and 24mm lens. I thought some of the results and perspectives were interesting. With the 24mm, I got substantial magnification, well over 1 to 1. You have to be able to stop the lens down manually for the reversal to work, unless you have a sophisticated electronically coupling with the lens. Reversed enlarger lenses have been a longtime staple for macro photographers. Some reversed lenses are capable of very high quality. Depending upon the magnification you want, you can add also extension such as either tubes or bellows. Go ahead and play. It's so important.

If it's one of those gray, gray coastal Oregon days, try eliminating as much sky as possible or coming back when there is a better sky. Also I find the heavy blue cast in the shade dulls the greens down and takes the sparkle out of the falls. Correcting the color cast in the shade portions would add life and punch. Also the scene look like it could use a bit of clarity +/or contrast.

Apaflo, I think were are pretty much in agreement. The point I was trying to make is that there is a magnification range in which changing focus by moving the camera by macro rail yields inferior results to changing focus by using the focus ring (either manually or by automatically by certain programs) Since the emphasis of this forum is general (unlike the photomacrography site we belong to), I suspect that the overwhelming majority of the stacking attempted by the members here will be in those lower magnification ranges, where moving the camera usually yields inferior results.

As to perspective distortion in those higher magnification macro/micro stacks. Agreed. How much a "problem" it is in a well done stack at higher magnifications, depends on individual preferences, what aspects of an image are important to us, and the tradeoffs we are willing to accept in this less than perfect passion of ours.

The primary reason you get a blur around the hole in the example of a focus stack on a piece of paper with a hole in it is that the edges of the hole will expand and soften as the edges go out of focus. You get a similar result in by moving the camera to focus and turning the focus ring of the lens to focus.

I suspect the change in perspective may be one of the reasons that stackers have better success at magnifications of less than 1:1 by using the focusing ring and reserve using a focus rail for higher magnifications. At higher magnifications, your subjects tend to be less deep and the amount of total movement of the rail is not so great that the software can't track what is happening (or at least Zerene can, I have not used Helicon in a long time so I can't comment.

In the past 7 years, I probably have stacked at least a thousand macro images, many of which were done using a macro rail. I don't recall having a problem with shifting perspective in magnifications greater than 1:1.

But Apaflo is correct. With a lens on a bellows, you can maintain the same perspective by keeping the lens in the exact same position throughout the stack and moving the camera either closer or further from the lens to change focus.

Many of the key tools for macro and micro image stacking, such as the Canon mpe65mm lens (for 1x-5x) and infinity focused microscope objectives are incompatible with a bellows approach. If you check the macro sites that feature many image stackers, you'll find superlative images that lack perspective problems can be made with these lenses mounted on a rail, like Stackshot, that can be moved in small, precise increments. The primary problem of using a bellows focusing system it that it becomes increasingly difficult to work with the precision necessary for higher magnification, but that is another story.

Yes it changes the perspective but the stacking programs account for that.

I do a substantial amount of stacking. A stack of 10 is a very thin stack. Most of my stacks tend to involve 50 or more images, some far more. I have a rule of thumb that I use to determine whether to advance focus by moving the lens on a rail or by turning the focusing ring. If the magnification is 1:1 or less, I find that turning the focus ring works better. At magnifications greater than 1:1, I advance focus by using a macro rail.

If your stacks are not sharp, the first two culprits to check for are: 1. insufficient images to get everything in sharp focus; or 2. camera movement. I would try to make you steps thinner using 2 to 4 steps for every step you presently use. See if that helps. Stackers are also strict about minimizing camera movement. At a minimum, they will lock their mirror up when stacking because the mirror slap of an slr causes movement that impacts the sharpness of the image. Most stackers I know use Canons or Nikons that have a live view mode where the shutter is opened before the shot and the sensor starts recording electronically, which eliminates the internal movement caused by the shutter opening. Electronic first curtain shutters are common in in Canon dslr's and have been included in some of the new Nikons. In short I would try smaller increments on my steps and I would minimize movement by using live view with electronic first curtain shutter. Also, I use a steady tripod and a remote trigger as additional steps to avoid camera movement.

I think you will find that stand alone programs like Zeren Stacker, do a far better job and are far easier to use than PS. I believe you can download a free trial copy at their website.

I am an active focus stacker. Presently I use Zerene stacker which is a wonderful program. For my work, it has yeilded the most consistent results with the fewest artifacts. In term of whether to move the camera or to change the focus setting on the lens: I have a rule of thumb based upon magnification. If I am at 1:1 magnification or less, then I advance the focus using the lens focusing ring or software that controls the lens forcusing ring. If I am at magnifications greater than 1:1, I advance the camera on a focusing rail.