Ask Tim Grey

Today’s Question: I need some help deciding which [aspect ratio] format to pick in my camera’s menu. I shoot with a Canon and have the choice of 3:2, 4:3, 16:9 or 1:1. I’m guessing nothing really changes with the sensor; it just changes how the image is cropped in the camera. My thought is to choose the format that gives me as much possible image area and then do any cropping in Lightroom. Are there any advantages to one format over another that aren’t readily apparent?

Tim’s Quick Answer: The “native” aspect ratio of the image sensor in Canon digital SLR cameras (as with many other cameras) is 3:2, and so I recommend this option for purposes of capturing the maximum pixel dimensions, with the understanding that you can always crop later. However, it is also important to keep in mind that the option to change the aspect ratio on Canon cameras will not affect RAW captures.

More Detail: As many photographers are aware, most of the various adjustment settings available on digital cameras will not affect RAW captures. They will, however, affect JPEG captures. This holds true for the aspect ratio setting available on some cameras.

If you’re using JPEG capture, you can certainly adjust the aspect ratio setting on your camera, and the image will be cropped in the camera based on that setting. But again, since the native aspect ratio of the sensor is 3:2, that setting will ensure that you are capturing the maximum pixel dimensions for the image. Thus, in general I recommend using this option.

If you’re shooting in RAW mode then the images will always be captured in the 3:2 aspect ratio. The Live View preview will reflect the aspect ratio you have set, but the RAW capture will still be in the native 3:2 aspect ratio. You can, of course, crop the image to any aspect ratio you like when processing the final image.

 

Today’s Question: I am in the process of cleaning my hard drives and consolidating backup files on a newer and faster external drive. In this process, I opened the folder where my weekly Lightroom backup catalog is stored. I was surprised that I have backups that date all the way back to 2010. My question is simple. When I use Lightroom’s weekly catalog backup feature am I creating an incremental file or an entirely complete backup?

Tim’s Quick Answer: The Lightroom catalog backup feature is a complete backup for the catalog file itself. Thus, you can absolutely delete older backup copies of the catalog.

More Detail: Lightroom now creates a compressed ZIP file that contains a copy of your catalog when you use the backup feature. Previous versions simply created a copy of the Lightroom catalog file (the “lrcat” file). However, the backup copy of the catalog compressed within the ZIP file is a full copy of the catalog file. Thus, to restore from a backup catalog you simply need to extract the “lrcat” file from the ZIP file, and then open the “lrcat” file in Lightroom.

It is worth noting, by the way, that in some cases the catalog file contained within the ZIP file will be larger than the “master” copy of your Lightroom catalog. This can be a little alarming if you extract the backup catalog from the ZIP and find that the file size differs from the size of the catalog you backed up.

However, the larger backup file size relates to the option to optimize the catalog after the backup is complete. With this option enabled the catalog will first be backed up, creating a backup copy that will be the exact same size as the existing catalog file (though compressed without loss into a ZIP file that will have a smaller file size). Then the master catalog will be optimized, which will often result in a smaller file size by cleaning up unnecessary records in the catalog file.

Because each backup of your catalog created by Lightroom is a complete catalog, there is no need to save multiple backup copies from the standpoint of being able to restore from a backup copy. Of course, you may want to retain a few backup copies from different dates as a precautionary measure, but older copies of your catalog can be deleted safely when you have deemed those additional backup copies are not needed.

Today’s Question: I am currently using Lightroom 6. I have just returned from a Photo Safari and would like to create a slideshow using the Lightroom Slideshow Module. I see that I can have an Intro Screen and an Ending Screen, but what I would like to have is blank slides with text, spread randomly throughout the slideshow to separate different locations of the safari. Is there a way to create blank slides with text from within the Lightroom Slideshow Module?

Tim’s Quick Answer: There isn’t a native way to create blank title slides in Lightroom’s Slideshow module (other than the Intro Screen and Ending Screen options). However, you can easily create empty images to use as the basis of title slides.

More Detail: What I have done for this purpose is to create blank images using Photoshop and then import those blank images into Lightroom to use as title slides. I generally create black, middle gray, and white slides, and size them based on the intended output size. For example, I often create slideshows at a high definition (HD) output size of 1280×720 pixels, so those are the dimensions I would use for the blank title slides.

Once you have created these images and saved them in a folder, you can import the images into Lightroom. Then add the desired blank title slide to a Collection in Lightroom that contains the images you want to use in the slideshow. You can then arrange the images in the desired order, with the blank slide positioned where you want the first title. Then create a new Virtual Copy of that blank slide for each title you want in your slideshow, arranging each title into the desired position. Then add the applicable title text to each of those images, such as by using a metadata field for this purpose.

In concept you could also capture a black frame on the camera, and apply an extreme Exposure adjustment to make sure that the images is pure black (or whatever color you desire). But I’ve found it can be helpful to create my own custom blank title slides so that I can exercise a bit more control over the specific look of those slides. For example, in some cases I might create blank title images with a texture or other graphic element included.

Today’s Question: In reference to the recent question involving Xume Adapters, do these introduce any issues with vignetting on extreme(16-35mm) wide angle lenses? These adapters seem like a great idea but I’m concerned that the Xume system will position the filter farther away from the front of the lens than it would be if it were normally attached.

Tim’s Quick Answer: Yes, for focal lengths shorter than about 24mm on full-frame sensors there is some vignetting introduced by the Xume Adapters, due to the filter being positioned further from the front lens element than would otherwise be the case.

More Detail: I know that the fine folks at Xume Adapters are aware of this issue, and that they are exploring options for mitigating the vignetting with wide-angle lenses. In the meantime, the Xume Adapters are best used with lenses with focal lengths of about 24mm or greater, or the equivalent focal length for cameras with other than a full-frame sensor.

For those photographers who are interested in learning more about the potential for Xume Adapters, you can see them in use in an episode of Tim Grey TV found here:

https://youtu.be/qfOdqsC457s

Today’s Question: Please, help me clarify a big doubt. I have a Canon 5D Mk III (22.6 Megapixels, 5760 x 3840). With an image that “big” (22 megapixels), if I were to print it using a printer with a maximum printing resolution of 2880 x 1440 dpi, how big can I print an image without any interpolation? The printer is an Epson and the maximum printing area is 17×22″.

Tim’s Quick Answer: The dot per inch (dpi) resolution indicated for the printer (for example, 2880 dpi) relates to print quality, not to the maximum potential output size. To determine the output size without resizing the native capture, you need to calculate based on the resolution used to render the image. In general you can assume a resolution of somewhere between 300 and 400 pixels per inch. Thus, your 22 megapixel captures can be printed at 11×16 inches without resizing (and even bigger with some resizing).

More Detail: The actual resolution used by the printer software to render image data for printing varies from one printer to the next. In general this resolution falls somewhere in the range of about 300 pixels per inch (ppi) to about 400 ppi. Many Epson printers, for example, use a resolution of 360 ppi, although some newer models actually use 720 ppi.

The reason the “advertised” resolution for the printer is higher then the “actual” image resolution is that the printer specifications refer to droplets of ink rather than pixels in the image being printed. As you can imagine, it requires multiple droplets of ink to produce the specific color for each pixel in a photo.

So, in this case let’s assume an image resolution for printing of 360 ppi. You can then divide the pixel dimensions by the resolution value to determine the native output size. So, 5760 pixels divided by 360 ppi is 16 inches, and 3840 pixels divided by 360 ppi is about 10.7 inches. Thus, a native maximum output size of about 11×16 inches.

However, it is very important to keep in mind that you can enlarge an image and still retain excellent print quality. As a general rule of thumb I would say you can feel very comfortable doubling the dimensions of a photo, as long as the original capture is of very good quality. That would enable you to produce a print of about 22×32 inches in this case, for example. And in reality, the larger the print size the greater the typical viewing distance, so you can often “get away with” an even larger print size.

To be sure, it can be very helpful to understand the “native” print size potential for the images you’re capturing. Just don’t forget that you can still achieve excellent results when enlarging a high-quality photo to produce a larger print.

Today’s Question: Perhaps I’m just being stubborn here, but I don’t like the new welcome screen that is included in the latest version of Photoshop. Is there a way to disable this new feature so I just have an empty interface when I start Photoshop?

Tim’s Quick Answer: Yes, you can disable the new “Start” screen. Simply turn off the “Show ‘Start’ Workspace When No Documents Are Open” checkbox on the General page of the Preferences dialog and restart Photoshop.

More Detail: In the latest version of Photoshop the new Start workspace appears in when you launch Photoshop without any images open. This new Start screen provides quick access to recently opened images, links to educational tutorials, and other options. While this new screen can certainly be helpful, it can also be a little distracting. Fortunately it is easy to disable this new Start screen.

To get started, go to the Edit menu on the Windows version of Photoshop or the Photoshop menu on the Macintosh version. Then choose Preferences > General from that menu. Turn off the “Show ‘Start’ Workspace When No Documents Are Open” checkbox and click OK to close the Preferences dialog. Quit Photoshop, and from that point forward when you launch Photoshop the “Start” workspace will no longer be displayed.

Today’s Question: I’m working on improving my understanding of the Clone Stamp tool in Photoshop, including the options on the Clone Source panel. But I can’t figure out what the “Auto Hide” option does. I’ve searched and searched, but every explanation I can find pretty much just says that “Auto Hide” will automatically hide the source, which doesn’t really explain much of anything. I’m not seeing any effect! What am I missing?

Tim’s Quick Answer: For typical use with a photographic image, the “Auto Hide” checkbox on the Clone Source panel won’t have any visible effect for the Clone Stamp tool. That is because under normal circumstances you are painting the same pixels that would otherwise be previewed. But if you alter the behavior of the Clone Stamp tool, such as by reducing the Opacity setting or changing the blend mode on the Options bar, you will see that with “Auto Hide” turned on the “Show Overlay” preview will hide when you start painting.

More Detail: The “Show Overlay” checkbox for the Clone Stamp tool can be found on the Clone Source panel, which in turn can be brought up by selecting Window > Clone Source from the menu bar. With the “Show Overlay” checkbox turned on, your mouse pointer will show a preview of the pixels that will be painted with the Clone Stamp tool, based on the source of pixels you have selected.

This option can be tremendously helpful when you need to align the source pixels into the destination area with precision, such as to maintain alignment of textures in the photo.

The “Auto Hide” option will cause the overlay preview to be hidden as soon as you start painting with the Clone Stamp tool. However, as noted above, under normal circumstances this translates into hiding the pixels you are painting while at the same time showing you the pixels you are painting. In other words, there is no visible effect with the “Auto Hide” option turned on compared to when it is turned off.

However, that is only because the preview and your painting will be a perfect match with each other. If you reduce the Opacity on the Options bar for the Clone Stamp too, the “Show Overlay” preview will be presented at full opacity, while the actual painting you perform will appear at a reduced opacity. In this scenario, having the “Auto Hide” option turned on will cause the “Show Overlay” preview to appear at full opacity when you are not painting. Then, when you start painting the full-opacity overlay will be hidden, and you will only see the painting you are performing with the Clone Stamp tool appear at the reduced opacity. The same concept applies to other settings that alter what you are painting with the Clone Stamp tool, such as the blend mode option.

What this all means for most photographers is that you can pretty much ignore the “Auto Hide” checkbox. But it may also be helpful to understand the specific behavior of this option, in the event it is ever useful for the specific cleanup task you’re performing for an image.

Today’s Question: A while back you commented on the watermark ‘issue’ that your preference was not to use any type of watermark as it detracted from the image, and does little to deter ‘theft’ of the photo. While I agree for the most part with your statement, I also felt that it ‘could’ add to the photo, and ‘credibility’ of the photographer. I do enjoy posting my photos on line (e.g., Instagram), but have always been leery of someone using/taking a photo without my permission. However, I noticed the other day that you posted a photo to Instagram with a watermark. Now I’m wondering if you’ve changed your perspective on this, and if not, why the watermark?

Tim’s Quick Answer: I have not changed my perspective on watermarks. I generally prefer not to have watermarks on my images. I also don’t personally worry about theft of my images. When I add a watermark to an image it is only because I either was hoping for a little self-promotion, or was teaching someone how to add a watermark to a photo.

More Detail: To be sure, a watermark on a photo can be valuable for promotional purposes. From this perspective, since I do very much want to promote myself through my photography, it would make perfect sense for me to include a watermark on photos when I share them. That watermark could simply feature my name, or my website address, for example.

However, in general I prefer not to have a watermark on my photos for purely aesthetic reasons. My hope is that I will get enough of a promotional benefit by virtue of the context of sharing the photo, even without a watermark. So, for example, when I share a photo on Instagram (http://www.instagram.com/timgreyphoto) my hope is that if someone sees a photo they like they will follow me and look at my profile and perhaps visit my website.

Much of this is philosophical, of course, and not necessarily the most effective approach in terms of self-promotion. But personally I prefer to take an approach that is a bit more subtle in terms of promotion (even though I’m not exactly subtle in most other ways).

And again, my personal preference is to not employ a watermark for purposes of deterring theft. I don’t believe that theft will really be prevented by a watermark that doesn’t significantly interfere with the photo, and I prefer not to have a watermark that interferes with the enjoyment (I hope!) of my photographic images.

Obviously all of this represents my personal preference. I prefer to only use a watermark when it provides some degree of promotional benefit, not as a theft deterrent. But I certainly understand the desire to take more significant steps to prevent the theft of photos. I simply define my priorities a little differently than other photographers (and I certainly realize that my priorities don’t necessarily align with those of many other photographers).

Today’s Question: Could you explain more this statement that was in a prior “Ask Tim Grey”:

“back button autofocus enables you to separate the metering functions of your camera from the focus functions”

Am I right that only the shutter button meters the scene? So if I want to meter a spot on the upper left of the scene but want to focus on low center, how would I do that?

Tim’s Quick Answer: The “back button” focus option available on many cameras obviously enables you to separate the focus and exposure metering features. If you also want to lock the exposure, you’ll either want to employ the auto exposure (AE) lock feature, or employ the Manual exposure mode.

More Detail: In most cases exposure metering on a camera is triggered by the shutter release button. You can generally press the shutter button halfway to initiate the automatic exposure, and then press the button the rest of the way to actually take the photo. But in your example you want to be able to re-frame the scene after establishing exposure settings based on metering in a specific area of that scene.

Obviously you could employ the Manual exposure mode to lock in specific exposure settings. Then it doesn’t matter how you reframe the scene, because the exposure won’t change based on the changes in lighting as you change the framing.

If you want to use one of the exposure modes that enable automatic exposure, you’ll need to actually lock that exposure. Otherwise when you reframe the scene you’ll also cause the metering to update and the exposure settings to change.

The specific options available and method of employing auto exposure lock will differ from one camera to the next. But the basic idea is very straightforward. You can point your camera to the area you want to meter on and press the shutter release button halfway to actually establish exposure settings based on that metering. Then press the “AE Lock” (or similar) button to lock the exposure based on those settings. You can then reframe the scene without the exposure settings changing.

In some cases you simply press and release the AE Lock button to lock the exposure for the next photograph. In other cases you need to press and hold that button. And in some cases you can change the behavior through menu options on your camera. But the point is that many cameras do indeed feature an AE Lock feature.

Making use of “back button” focus along with AE Lock enables you to exercise considerable control while still taking advantage of the automatic features of your camera. You can set focus in one area, establish exposure based on another area, and then frame up the scene without altering focus or exposure settings.

Today’s Question: When I talked to you at an event a few months ago, you mentioned a lens cap that attached magnetically. Can you remind me where I can find that lens cap?

Tim’s Quick Answer: The lens cap I’m using is from a company called Xume Adapters. They produce magnetic filter holders (which I love), as well as a lens cap (which is incredibly convenient). You can find the 77mm version of the lens cap here: http://timgrey.me/77xcap.

More Detail: To my knowledge, the lens cap is not currently available in sizes other than 77mm. And it is important to note that the lens cap is really an accessory to the filter adapters offered by Xume Adapters. So, for example, if you get a set of adapters so you can easily swap filters on a given lens, in place of a filter with a magnetic adapter you can place the Xume Adapters lens cap on the lens, provided the magnetic adapter for the filters is already attached to that lens.

In other words, the lens cap from Xume Adapters makes use of the same functionality as the filter adapters they offer. You can see the Xume Adapters in action (though only for filters, not the lens cap) in an episode of Tim Grey TV via YouTube here:

https://youtu.be/qfOdqsC457s