I took this photo of the blood moon this morning and I am finding many of my photos, especially landscape photos, have a significant lack of clarity. I'm not looking for a photo critique because I know this particular photo is crap. I'm looking to identify my source of failure to nail a significantly clear photo.

enter image description here http://www.joshuabelden.com/images/portfolio/public/super-blood-moon-belden.jpg


Canon EOS 70D with a 100-300 telephoto lens (I'm sorry I don't know the exact model. It's from Canon but not one of their professional quality lenses.)

  • Aperture: f/5.6
  • Shutter: 1 sec.
  • ISO: 1000
  • Focal Length: 300mm
  • Metering mode: Spot
  • White Balance: I manually set the WB to 5500 kelvin, it looked fine in live view.
  • Focus Mode: Manual
  • Drive: 2 sec timer delay

Mounted on a decently stable tripod


I turn on live view, and square up the target in the display. I then set my focal length, focus in using live view, adjust the focus as sharp as possible and take the pic. I've noticed that in this case, the picture was incredibly grainy, which doesn't translate to the final photo, but wonder if it has anything to do with it.

This particular shoot I found it difficult to balance out the variables with a dark sky and a moving moon that starts blurring after 1-2 seconds of exposure, which is why I had the aperture wide open and the ISO cranked up.

I can't tell where I'm failing:

Equipment: The 70d takes great photos but the telephoto is not great when it's totally zoomed in. My wallet doesn't hold enough cash for a motorized mount to track objects in the sky.

Circumstance: I've seen great photos of the moon with the use of a camera and a tripod, so I know this is possible. Although, I keep seeing pictures of this big gorgeous moon over the landscape, and when I use my wide-angle, the moon shows up as a dot. What the hell are people doing to get the moon so big?

Beginner skill level: I know this is the biggest culprit, but being the beginner, I'm unable to know where to adjust.

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    \$\begingroup\$ If you are going to tag this as a [landscape] question, perhaps you could also provide a more typical example of your landscape photos. Shooting dim astronomical objects (the moon is not normally a dim object, but it is during totality) challenges even the very best lenses. \$\endgroup\$
    – Michael C
    Commented Feb 1, 2018 at 0:03
  • \$\begingroup\$ My guess is that the biggest contributor to your perceived issues with the image (although you don't really state what you don't like about the image) is the higher ISO. I probably would have opted for ISO 400 (~2.5 stops different) and a corresponding change in the shutter time to 6 seconds or so... Higher ISO leads to more pronounced noise, which seems to me to be the most obvious "issue" with the shot. \$\endgroup\$
    – twalberg
    Commented Feb 1, 2018 at 2:34
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    \$\begingroup\$ @twalberg You can already see the trails of the two bright stars to the left at one second. The moon would have also moved roughly the same amount during exposure. Increasing the Tv to 6 seconds would have multiplied that motion blur by a factor of six. \$\endgroup\$
    – Michael C
    Commented Feb 1, 2018 at 3:05

2 Answers 2


Some possible reasons, arranged in the likely order of influence, for the lack of clarity in the example photo:

1) The optical limits of your lens. The EF 100-300mm f/4.5-5.6 was released as a budget telephoto zoom lens in 1990 at the dawn of the EOS era. Compared to the current EF-S 55-250mm f/4-5.6 STM, at the longest focal lengths and widest apertures there's a significant difference in sharpness.

35mm film is much less demanding of a lens in terms of resolution than modern digital sensors such as the one in your 20MP 70D. From an answer to a question about the difference between "digital lenses" and "film lenses"¹:

Although not universally the case, most lenses designed and introduced during the digital age are better than their older film era counterparts, especially in the consumer and mid grade sectors. Manufacturers of the top tier lenses have also been forced to introduce newer versions of old classics. The new consumer lenses may not be as good as the old "L" glass (but sometimes they get close), but they are much better than yesterdays consumer lenses. Especially zoom lenses which have benefited tremendously from computer aided design and modeling. What used to take weeks or even months to test by making a physical prototype can now be accomplished in a few hours using supercomputer simulation.

Users of digital cameras tend to expect more out of their lenses due to primarily two factors:

  • Digital sensors are perfectly flat. Film isn't. Some of the most expensive film cameras actually had mechanisms that created a vacuum behind the film to aid it in laying as flat as possible while being exposed. Even then, with color film the emulsion layer for each color was at a slightly different depth. So if focus was perfect for one color, it would be slightly off for the other two!
  • Pixel peeping has raised expectations to a ridiculous level. Take a 20MP image and display it at 100% (1 pixel per screen pixel) on an ≈23 inch HD (1920x1080) monitor and the magnification is equivalent to printing at 56x37 inches! No one expected a 35mm consumer grade lens to be perfect at 56x37! But a lot of folks now seem to.

2) Shooting a very dim object that is moving across the frame. One second is far too long to expose the moon using a 300mm focal length without a tracking mount if one is going to critically look at the image at 100% magnification. At 100%, it is easy to see the trails of the two bright stars in your example photo. The moon is also blurred by approximately the same amount of movement.² The moon is not normally a dim object, so we usually do not need to worry about our shutter times being too slow. Even though we usually shoot it at night, the moon's surface is being directly illuminated by the sun. At ISO 100 and f/8, we would normally expose the moon for about 1/125-1/250 second. But during a total eclipse, when the earth blocks the sun's direct light from illuminating the moon, the moon's surface gets a LOT darker.³ The earth still rotates at the same rate underneath the sky. The reduced brightness pushes us into a very tight corner regarding how to collect enough light for a usable image without the apparent motion of the moon making it blurry. The most obvious solution is to use a wider aperture - if one is available. But even moving from, say, f/8 to f/2.8 only gains us three of the thirteen-plus stop difference between a full moon and totality. Going from 1/250 second to 1/15 second only gains another four stops and at 300mm we are already going to start seeing motion blur when pixel peeping. At that point we're still about 3-6 stops dimmer than when the moon is full. Going from ISO 100 to ISO 1600 gets us back in the ballpark, but we have given up a lot in terms of clarity due to:

  • The much slower shutter time allows some motion blur
  • The wider aperture (most lenses are sharper stopped down than when used wide open)
  • The higher noise associated with using higher amplification (ISO) to make up for less light entering the camera, and the resulting noise reduction we use.

3) Atmospheric interference. If you were shooting from the location indicated in your user profile, the moon was fairly low on the horizon at the time. Just as the sun is much more distorted by the earth's atmosphere at sunrise and sunset than when it is high in the sky, so is the moon. Not only is the light having to travel further at an angle through the ocean of air surrounding our planet, but the temperature differentials near the terminator (the line between daylight and dark) tend to increase atmospheric turbulence in the times around dawn and dusk.

4) Letting the camera make all of the decisions about how to process the raw data from the sensor. This is particularly the case with a dim object, such as the moon during totality, that is moving across the frame. This limits our exposure time. Most great moon photos (when it is not in the earth's shadow) you see are saved in a raw file format and post-processed to fine tune the contrast between darker and lighter areas on the surface of the moon. Color temperature and white balance adjustments, sharpening, and in some cases even digitally applied color filters, can bring out the contrast between different areas of the moon. This is even more critical when the photo in question is taken during a total eclipse.

5) The noise reduction applied to using ISO 1000 with a Canon EOS camera. I'm a Canon shooter because, overall, Canon works for what I do. Every system, though, has advantages and disadvantages. One of the things where Canon falls a little short is in the way their cameras handle the "partial" stop ISO settings. For a comprehensive look at how Canon cameras handle the "partial stop" ISO settings and why using the "+1/3 stop" ISO settings (such as ISO , 250, 500, 1000, 2000, etc.) can make your photos noisier than other ISO settings that are even higher, please see Is it really better to shoot at full-stop ISOs?. The amount of NR the camera applies to ISO 1000 by default will reduce the detail in the image.

¹ Back near the beginning of the consumer digital SLR era, APS-C only lenses were often marketed as "digital" lenses.

² The moon moves roughly 1/2° less per hour than the stars as viewed from the earth's surface. That also happens to be approximately the moon's angular size in the sky. So for a one second exposure, the moon would move across the frame 1/3600 of its own diameter less than the nearby stars would during the same exposure.

³ This article from Space.com says anywhere from 10,000 to 100,000 times dimmer, depending on the earth's atmospheric conditions. That's between 13 and 17 stops darker than a full moon!

  • 1
    \$\begingroup\$ Wow! Michael, thank you for taking the time to write every word here. I've read them all and they not only sum up and answer all of my questions, they've nailed perfectly a lot of the doubts I've had about certain pieces of equipment or scenarios I'm trying to shoot. \$\endgroup\$ Commented Feb 1, 2018 at 13:47

Michael's excellent answer addresses the reason your moon photo lacks clarity. However, regarding one thing you said in your question,

My wallet doesn't hold enough cash for a motorized mount to track objects in the sky.

Depending on your willingness, desire, and/or ability to take a DIY project, that is not necessarily true. A barn door tracker can be made very inexpensively. However, for stable tracking when using a long focal length, you'll definitely want the tracker motorized and timer controlled.

Even a basic, simplest tracker design will improve your results. But for longer exposures, and especially when using longer focal lengths, they can still leave you wanting more. In those cases, you need to be aware of the errors introduced by the barn door design's geometry, such as the so-called tangent error that gets worse the longer the tracker is running. These errors can be mitigated to varying degrees with modifications to the geometry (depending on which design was chosen (as shown in the Wikipedia link above), or with nonlinear rate control of the lead screw motor's speed.

See also:

  • \$\begingroup\$ Basic barn door trackers are good for relatively short exposures at wider angles. As the exposures lengthen and the angle of view narrows, the errors become more noticeable. The extra design considerations needed to offset the basic flaw of a straight bolt rotating at constant speed become more and more complex. They're great for Milky Way photos, not so much for dim deep sky objects (or very near VERY dim objects) where we want lots of magnification. \$\endgroup\$
    – Michael C
    Commented Feb 2, 2018 at 22:23
  • \$\begingroup\$ @MichaelClark good points. However, with careful attention to the design, selection of tight-fitting hinge (or making your own), you can make very serviceable barn doors. For instance, the PetaPixel link shows a very good composite of Andromeda shot with a 135mm, with stacked 90-second exposures. \$\endgroup\$
    – scottbb
    Commented Feb 2, 2018 at 23:10
  • \$\begingroup\$ Yeah, but 135mm is still a long way from 900-1200mm (or cropping to get the equivalent) to fill most of the frame with the moon. Andromeda has a larger angular size than the moon and is also bright enough to be naked eye visible. \$\endgroup\$
    – Michael C
    Commented Feb 2, 2018 at 23:32
  • \$\begingroup\$ @MichaelClark Naked eye visible, but not so bright as to make detailed images easy. Also, within the context of the question, 135mm is much closer to the OP's 300mm lens. I would never suggest a hardware-store hinge-using barn door tracker with such a long focal length as 900-1200, either. =) \$\endgroup\$
    – scottbb
    Commented Feb 2, 2018 at 23:57
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    \$\begingroup\$ @MichaelClark lol. Your point is spot-on, and I know from experience. I kinked 3 threaded rods on my first modified barndoor before I figured out how to bend it smoothly. =) \$\endgroup\$
    – scottbb
    Commented Feb 3, 2018 at 1:39

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