Beanbag Sharpness Issues

turkey-vulture-adult-sunning-_y9c3423-indian-lake-estates-fl

This image was created down by the lake near my home at Indian Lake Estates, FL with the Canon 800mm f/5.6L IS lens and the EOS-1D Mark IV. ISO 400. Evaluative metering +2/3 stop: 1/1000 sec. at f/8 set manually.

The 800 was supported by a BLUBB resting on the raised window of my SUV. BLUBB stands for Big Lens Ultimate BeanBag. I custom-designed this large beanbag for use with super-telephoto lenses. The non-slip concave top of this great beanbag makes it easy to keep your lens perfectly still. Nothing out there compares with the BLUBB, especially the cheap knock-offs that cost half the price. A peek at the Bubble Level in the hot shoe ensured that the lens was square to the world.

Lens micro-adjustment: -4. Central sensor AI Servo/Rear Focus AF and recompose….

For a greater appreciation of the image, click on the photo. Then click on the enlarged version to close it.

Beanbag Sharpness Issues

Most folks with long lenses realize the benefits of using their cars as a blind in a variety of situations. If you are not in that group, see “Using Your Car as a Blind” on pages 120-121 of the original “The Art of Bird Photography.” In addition, if you search for the word “vehicle” in ABP II (916 pages on CD only) you will turn up 58 occurrences; many of those relate to tips for using your car as an effective and movable blind.

This afternoon I received the following e-mail from Assaf Gavra:

Hi, I am using a homemade beanbag made from two pillow cases and filled with 5kgs of beans. I have seen that many of your tack sharp images have been created with a big lens and the 1.4X III tele-converter. So I lost my fear of using it on my 500mm f/4L IS :) but some of the images (most of them in fact) are not in focus. Considering that I have this top equipment I really don’t know what to do…. Can you help? Assaf

Needing more info I wrote back asking “Have you ever made one sharp image with the 500 and the 1.4X TC??

He wrote back and attached two nice images asking if they were sharp. Each was quite sharp. I wrote him back as follows:

Assaf, Yes, they are razor sharp. That means that the lens and camera and TC are fine. That’s the good news. The bad news is that I now know why many of the images that you make are unsharp: operator error. That means you. I will address the question of beanbag work and image sharpness in tonight’s blog post. In the meantime I would recommend that you get yourself a copy of ABP II and study the section on advanced sharpness techniques so that you can learn to create sharp images while working on a tripod. There is also lots of info on using your car as a blind in ABP II.

Assaf’s e-mail got me thinking: there are some complex issues involved when using a big lens from the vehicle and working on a big beanbag, issues that I had never written about specifically until now. Consider the BreezeBrowser screen capture below and we will get started.

brbrtvscreencap

I would advise that you read the following material very carefully if you wish to learn to make a higher percentage of sharp images when photographing from your vehicle. In the screen capture above you will note that none of the AF squares are lit up red. That indicates that AF (in this case, AI Servo AF) was not active at the moment of exposure. I focused on the bird’s eye (using rear focus and the central sensor). Then I released the rear focus button effectively locking or setting sharp focus on the Turkey Vulture’s eye. If you have no idea what I am talking about, it means that that you missed the rear focus tutorial; you can find it here. If you know what I am talking about but do not use rear focus, then for this section assume that you are using One-Shot AF and recompose. (That would be Single Servo and recompose with Nikon.)

OK, here we go. Whether you use rear focus and recompose as I did to create the image above or One-Shot (or Single Servo) and recompose as I used to do, you will have arrived at the critical moment. Either way you have set focus. But whatever system and method you are using, focus is never actually locked. It is set. If you turn the manual focusing ring at this point you will change the focus. What most folks do not realize is that when they move the lens up or down or left or right to recompose there is a huge danger of inadvertently turning the manual focusing ring. If you are aware of this possibility and take care not to rotate the lens at all the problem can easily be avoided. So, after focus is set, take great care to ensure that the focusing ring does not turn even a hair else you will throw off accurate focus.

Conclusion: if you are using rear focus and recompose or One-Shot (or Single Servo and recompose) with relatively fast shutter speeds and many of your images are not sharply focused it is likely that you are accidentally turning the manual focusing ring after focusing.

brbrbvscreencap

In the BreezeBrowser screen capture above, note that that the AF sensor in the upper left corner of the array was not only selected but was active at the moment of exposure; you know that because it is illuminated in red. That indicates that I was holding down the rear focus button (with AI Servo engaged) at the moment of exposure. If I had been using the shutter button to focus it would have meant that I was in AI Servo AF (C or Continuous with Nikon) and that focus was active at the moment of exposure. In either case, accurate focus would be pretty much guaranteed for several reasons:

1-The system was focusing when the image was created.
2-Accidentally turning the manual focusing ring (with Canon for sure…) would not have affected accurate focusing as electronic manual focusing is disabled when AI Servo is active.
3-The chance of inadvertently turning the manual focusing ring would be virtually eliminated as you would be happy with the composition created with the active focusing sensor right on the bird’s eye, face, or neck; there would be no need to recompose.

black-vulture-on-dead-tree-_y9c3552-indian-lake-estates-fl

This Black Vulture image was also created down by the lake near my home at Indian Lake Estates, FL with the Canon 800mm f/5.6L IS lens and the EOS-1D Mark IV. ISO 400. Evaluative metering +1 stop: 1/800 sec. at f/8 in Av mode.

As above, the big lens was supported by a BLUBB resting on the raised window of my SUV. BLUBB stands for Big Lens Ultimate BeanBag. I custom designed this large beanbag for use with super-telephoto lenses. Nothing out there compares with the BLUBB, especially the cheap knock-offs that cost half the price. A peek at the Bubble Level in the hot shoe ensured that the lens was square to the world.

Lens micro-adjustment: -4. Upper left corner AI Servo/Rear Focus AF active at the moment of exposure.

For a greater appreciation of the image, click on the photo. Then click on the enlarged version to close it.

Conclusion: if you are able to select a sensor that falls on the subject’s eye, face, or neck and you work with AI Servo AF (or Continuous with Nikon) active at the moment of exposure, you will be virtually assured of an accurately focused image.

Additional Tips

1: When using a Bubble Level (I always do) be sure to point the lens at the subject first. Now set the camera body square to the world and then focus. If you focus first and then square your rig to the world you will turn the focusing ring and screw up the accurate focus that you had set.

2: All else being equal, images made with lens/camera and lens/TC/camera combinations that have been micro-adjusted with the Lens Align Mark II will always be sharper than those those made with rigs that have not been focus calibrated.

3-If time permits, shut off your vehicle’s engine before making a photograph. While this seems obvious, there are times when it is best to take an image or two with the motor running. If you think you know when it is proper to do this, please leave a comment. Hint: there are two qualifications. Only one is obvious :).

4- Leave your pillows on your bed; the BLUBB is the bomb and was designed to help you make sharp images with big lenses when working from a vehicle. We ship them all over the world every week.

Which Image Do You Like Best?

Take a moment to leave a comment and let us know which image you like best, the Turkey Vulture image or the Black Vulture image. And be sure to let us know why.

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Shopper’s Guide

Below is a list of the gear used to create the images in today’s blog post. Thanks a stack to all who have used the Shopper’s Guide links to purchase their gear as a thank you for all the free information that we bring you on the Blog and in the Bulletins. Before you purchase anything be sure to check out the advice in our Shopper’s Guide.

Canon 800mm f/5.L IS lens. Right now this is my all time favorite super-telephoto lens.
Canon EOS-1D Mark IV professional digital camera body. My two Mark IVs are my workhorse digital camera bodies.

And from the BAA On-line Store:

LensCoats. I have a LensCoat on each of my big lenses to protect them from nicks and thus increase their re-sales value. All my big lens LensCoat stuff is in Hardwood Snow pattern.
LegCoat Tripod Leg Covers. I have four tripods active and each has a Hardwood Snow LegCoat on it to help prevent further damage to my tender shoulders :)
Gitzo GT3530LS Tripod. This one will last you a lifetime.
Mongoose M3.6 Tripod Head. Right now this is the best tripod head around for use with lenses that weigh less than 9 pounds. For heavier lenses, check out the Wimberley V2 head.
CR-80 Replacement Foot for Canon 800. When using the 800 on a Mongoose as I do, replacing the lens foot with this accessory lets the lens sit like a dog whether pointed up or down and prevents wind-blown spinning of your lens on breezy days by centering the lens directly over the tripod.
Double Bubble Level. You will find one in my camera’s hot shoe whenever I am not using flash.
Be sure to check out our camera body User’s Guides here.
The Lens Align Mark II. I use the Lens Align Mark II pretty much religiously to micro-adjust all of my gear an average of once a month and always before a major trip. Enjoy our free comprehensive tutorial here.
Canon EOS-1D Mark IV User’s Guide. Learn to use your Mark IV the way that I use mine. Also available for the 7D and the Mark III here.

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13 comments to Beanbag Sharpness Issues

  • avatar Dave Klein

    Greetings Artie,
    In referencing the use of your vehicle as blind I wish to mention that one of many advantages of driving a hybrid vehicle (in my case a Toyota Highlander hybrid) is that the vehicle completely shuts off when stopped so there is no vehicle movement or idling of the engine. Whenever I rent a car when travelling and know I won’t be needing to go significantly off-road I will rent a hybrid for this reason and will have great success using a beanbag when needed. Best wishes, Dave

    Thanks Dave! Do those things have the darned ding noises? artie

  • Hi Giovanni, if the MK IV is like my 7D and other Canon cameras, yes you can shoot without releasing the “*” button first – the shutter button fires the camera anyway.

    That is correct. With all Canon cameras the shutter will fire whenever your press the shutter button completely. Unless it is broken…. artie

  • avatar Giovanni Frescura

    I ask you pardon ..but using rear focus if you would like take a shoot of a moving bird in flight..you press star botton (using Af servo mode) and shoot without release it ? Is it right ?

    Yes, that is correct. If you press and hold the button the AF system will track moving subjects. artie

  • avatar Giovanni Frescura

    Hello Artie thanks. I have your update (you sent me..thanks) but for me all is not simple (off couse for my bad English). Ok I put C.Fn IV 2 and AF servo star when I press star button. If I release it the focus it stopped so my shoot will do with my last setting. Is it right ? The same, I think, if I put the mode Af in one shoot. So this is the rear mode but could better find the mode to pass from Af servo to one shoot only touching a button ? Off couse using Af servo with rear modus is about the same but not far all. For example if you are taking a shoot of a little bird…you use af servo with rear mode and when the bird is stopped you out the central point on the bird, press star botton (activing af ..servo mode…) and shoot. All is ok but when the bird is stopped the Af one shoot isn’t more performing than Af servo mode (also if stopped with rear mode) ? Thanks for your patience. Ciao. Giovanni

    Giovanna, I really had to struggle to understand your questions but I think that I do now…. When using rear focus you do not switch back and forth from AI Servo to One-Shot. You leave it in AI Servo and never change that. If you press the button to focus and let it go you can recompose and the system will not focus. When you do that it acts like One-Shot AF. When you press and hold the button the AF system will track the subject (as long as you hold the button in. artie

  • avatar Giovanni Frescura

    Thanks Artie for your kindly help. Yes I have switched the function of the star and AF-ON buttons as you mentioned in your User Guide. Giovanni

    Giovanni, All that you need to do now to set up for rear focus is to set C. Fn IV-1-2.

    Here is the relevant excerpt from page 26 of the last update of the Mark IV User’s Guide:

    “With C. Fn IV-1-2 (Metering Start/Meter + AF Start) Lock or set focus with the Star button (which is now the AF On button). Metering is real time, that is, the exposure is determined at the instant the exposure is made. In the old days we simply called this set up “rear focus.” As long as you are in AI Servo AF, this technique gives you AI Servo AF when you hold the Star button down. It gives you One-Shot AF (and allows you to recompose without changing the focus) when you set focus (on a bird’s eye for example) by pressing the Star button with the active sensor on the subject’s eye and then release the Star button to “lock” the focus. Once you are focused on the subject’s eye you can recompose as long as the subject stays still. If you need AI Servo AF at any time, simply depress and hold the Star button. C. Fn IV-1-2 can work well when you have a subject that is alternately walking and stopping or with birds in a nest that might or might not be changing their positions or postures.” artie

  • I can confirm that operating with Nikon and a bean bag is a problem when you accidentally move the focus ring (in my case, with the AF-S 300 f/4). Using a “professional” beanbag like the BLUBB is better than home-made one (I don’t have the BLUBB, but a similar one, smaller but ok for the size of my lens), but doesn’t solve the problem. I’ve found that a window mount is ok. It’s a metallic base that clamps on the top of the car door and where you can mount a ball head.

    Thanks Fabrizio. I wrote about using a window mount in the original “The Art of Bird Photography.” artie

    ps: As far as manual focus over-riding C with Nikon, advantage Canon.

  • avatar Giovanni Frescura

    Hello Artie, Very interesting blog. I have your User’s Guide for the Mark IV. But I am in trouble as set your mentioned rear focus. Could you give me the right seting about? At the moment when I use star botton I stop the focus (Af focus) CfnIV 1 n.1. Is it right? Thanks, Giovanni

    I used to use the star button to stop focus but do not do that any longer. Jim Neiger does that. I am pretty sure that you are having trouble understanding the information in the User’s Guide because of language difficulties. The stuff is clearly written. Let go slowly and I will see if I can help you. Have you switched the function of the star and the AF-On buttons? artie ps: Thanks a ton for your purchase.

  • avatar Bill Richardson

    Totally off subject but I had to share the following quote from Carl Johnson’s blog:

    “A photographer went to a socialite party in New York. As he entered the front door, the host said ‘I love your pictures – they’re wonderful; you must have a fantastic camera.’ He said nothing until dinner was finished, then: ‘That was a wonderful dinner; you must have a terrific stove.’” –Sam Haskins

    Been there; heard that (in many different forms). :) artie

  • After doing some tests today on the field i found this post very useful. I like the black vulture image only because I like the way it composed better than the Turkey.

    I am glad for that. I like both compositions; I teach folks that with verticals right in the middle is just fine. Thanks again for inspiring this blog post with your question. artie

  • avatar Michael

    Artie, I may be wrong, but I don’t think so.. Assuming back-button focus, an AFS Nikon lens and AF-C (continuous AF), once you invoke manual focus (intentionally or un-knowingly) you defeat AF, regardless of whether you are using AF-On or a half-press. I scoured available resources to see how long it takes Nikon bodies to re-engage AF, but cant find it. This makes shooting from a bean bag especially challenging if lens design has you resting on the MF ring. I leave a Wimberley flash bracket arm attached to lens plate and rest on that instead of the lens barrel to avoid bumping the MF ring. Any thoughts from your Nikon Comrades?

    Hi Michael, I am Skype-ing with Robert as I type…. Here is what I have confirmed so far. You are partially right; if you are in C and you touch the manual focusing ring the the two AFs will fight each other, Manual focus trying to take over while nudging (messing up) the tracking AF. This in itself is a less than ideal situation as if you are hand-holding and accidentally touch the manual focusing ring you will likely spoil some images. Furthermore, if you turn and hold the manual focusing ring while pressing the shutter button manual focus will over-ride the tracking AF (C). And the system will stay in Manual focus as long as you keep the shutter button depress half-way or more. To get back into C you need to completely release the shutter button (or the button that you are using for rear focus). artie (and Robert).

    By the way, here is huge news: Robert’s Nikon DSLR User’s Guide for the D300s/D700/D3S/d3x will be available for purchase as soon as it is announced in BAA Bulletin #386, coming very soon!

  • Hi Artie, Thank you very much for writing this blog post. It is very helpful. So focusing while exposure is the best thing to do ? I saw that in some cases you move your finger from rear focus before you taking the shot.

    If you can get the sensor exactly where you want it, having tracking focus active during the exposure is a good plan. I should do it more…. And yes, there are lots of times when I focus with the rear button and then release it but I always make an effort not to turn the manual focusing ring. If you have a corner sensor active and the bird takes flight you need to let up on the focus button if you are using rear focus and that is hard to do…. So if you think that the bird is going to take off to the side it might be best to stop focusing actively…. Nobody said it would be easy. :) artie

  • Not sure if this is what you had in mind, but I will sometimes leave the car running if I’m in a big hurry to get a shot off before the subject flies away.

    Having shot the bison here at Maxwell State park I guess another reason would be to ensure the ability to perform a quick getaway! :-)

  • Great tips as always. I like the wing display of the first image, but the piece of the snag going through the bird bothers me. That said I’ll go with the last image.

    A quick question. When using an off-camera flash cord in the camera’s hot-shoe how do you use your bubble level? I suspect you have an elegant solution. :)

    Cheers! David

    Thanks David. My solution is indeed elegant. I keep the bubble in my pocket and hold it against the top of the flash cord as I rotate the lens barrel to square :). Some folks use a dab of epoxy to attach the bubble level to the top of the flash cord. If you do that, take care to ensure that it sits perfectly flat. artie