Focus Stacking with Canon EOS R5

Focus Stacking with Canon EOS R5
Daisy - stack of 30 photos

The Canon R5 and R6 offers a new func­tion in its menu, the “Focus brack­et­ing”. The cam­era takes an editable num­ber of pic­tures in quick suc­ces­sion and shifts the focus back­wards in adjustable steps. The plane of sharp­ness thus moves from image to image towards the beck­ground.

Some optical basics

All lens­es focus on only one plane at a cer­tain dis­tance, called the “focal plane” and the dis­tance to this plane can be read direct­ly from most lens­es. In front and behind of this plane, all objects are dis­played more and more blurred with increas­ing dis­tance.

Our eyes are no dif­fer­ent. For accom­mo­da­tion, it they can change the refrac­tive pow­er of the eye lens to make us see sharply either near or far (i.e. an inter­nal focus­ing 😉 ). With increas­ing age, our eye lens gets more and more rigid, then the only thing that helps is wear­ing glass­es - Ok, I’m digress­ing…

So back to the cam­era: The range of sharp­ness depends on the lens aper­ture, the focal length and the dis­tance to the sub­ject. The area in front and behind of the focal plane which is still suf­fi­cient­ly sharp is called “depth of field”.

Fur­ther infor­ma­tion on this top­ic can be found in the Wikipedia arti­cle. I do not want to go into fur­ther details here. But what you should know is,

that the depth of field decreas­es when

  • the aper­ture is opened fur­ther (small­er aper­ture num­ber)
  • a longer focal length is used (tele­pho­to lens­es)
  • you get clos­er to the object (macro pho­tog­ra­phy)

You can con­trol the depth of field dur­ing shoot­ing by select­ing the aper­ture. In many cas­es, a depth of field as shal­low as pos­si­ble is even desired in order to iso­late a sub­ject. Fast lens­es are par­tic­u­lar­ly suit­able for this pur­pose.

Things are dif­fer­ent if you want to dis­play a three-dimen­sion­al object com­plete­ly in focus. In some sit­u­a­tions even the small­est aper­ture is not suf­fi­cient. This is espe­cial­ly com­mon with macro shots, i.e. small objects, where only a min­i­mum depth of field can be achieved even with a very small aper­ture. For exam­ple, the depth of field in the 1:1 macro range is only 2 mm at an aper­ture of 16. A depth of field cal­cu­la­tor for the macro range can be found here, for exam­ple.

An example

But even when pho­tograph­ing with tele­pho­to lens­es, the depth of field is some­times not suf­fi­cient. This is shown e.g. in the fol­low­ing pic­ture, which was tak­en at 600mm focal length at an aper­ture of 32:

Croc­o­dile, “Ferme aux Croq”, Pier­re­lat­te, France

Even at aper­ture 32, the depth of field is only about 30cm at a dis­tance of approx. 8m from the croc­o­dile at 600mm focal length. So I took an addi­tion­al man­u­al focused series of 9 pic­tures at aper­ture 8 with dif­fer­ent focal planes, at that time man­u­al­ly focused with my Sony Alpha 7R III and the Sig­ma 60-600mm DG OS HSM. I then “stacked” the 9 images in Pho­to­shop (more about this lat­er), result­ing in the fol­low­ing image, which is now sharp from front to back:

Crocodile focus stacking
Croc­o­dile at the “Ferme aux Croc­o­diles”, Pier­re­lat­te, France (Focus stack­ing from 9 shots)

Man­u­al adjust­ment of the focus planes is prone to error. A step size suit­able for the select­ed aper­ture must be select­ed so that the indi­vid­ual images fit togeth­er seam­less­ly. In addi­tion, it is time-con­sum­ing and there­fore only works rea­son­ably from a stur­dy tri­pod and with objects that hard­ly move at all. For­tu­nate­ly, the croc­o­dile kept rel­a­tive­ly motion­less, but while stack­ing, I noticed some arti­facts due to breath­ing move­ments, which required man­u­al post-pro­cess­ing in Pho­to­shop. But all in all, it worked out quite well, I was lucky. But since then, I have com­plete­ly for­got­ten about Focus Stack­ing.

First (focus) steps with the EOS R5

Now the Canon EOS R5 (and also the R6) has a Focus Stack­ing auto­mat­ic built in. After the EOS RP and the EOS 90D, which were capa­ble of this, but which I per­son­al­ly have nev­er used before, this is a nov­el­ty with Canon bod­ies. Oth­er man­u­fac­tur­ers, like Olym­pus and Pana­son­ic, have been sup­port­ing focus stack­ing already for years. This new option made me curi­ous again.

Menu options

The cor­re­spond­ing menu item “Focus brack­et­ing” can be found in the SHOOT5 menu. When the menu item is select­ed, the fol­low­ing mes­sage appears on the dis­play:

Menu “Focus brack­et­ing”

On the first line, the func­tion first has to be acti­vat­ed. In the fol­low­ing three lines, the num­ber of expo­sures (up to 999), the size of the focus steps and an expo­sure smooth­ing can be select­ed.

Number of shots

The num­ber of steps required depends on the select­ed aper­ture and the desired range of focus. Unfor­tu­nate­ly, Canon does not pro­vide any clues, so there is no way around try­ing it out. The focus run always starts at the set dis­tance. In the fol­low­ing shots, the focus is shift­ed back­wards by the select­ed step size. As soon as the “infi­nite” set­ting is reached, brack­et­ing stops, even if the num­ber of set steps has not yet been reached.

Focus increment

The size of the adjust­ment steps can be select­ed on a scale from 1 to 10. Accord­ing to Canon, the step size depends on the aper­ture set, but unfor­tu­nate­ly there are no more pre­cise selec­tion guide­lines. To be on the safe side, I have cho­sen the step size “2” in my recent exper­i­ments, but Canon seems to rec­om­mend the step size “4”, at least this val­ue is marked grey in the scale.

Exposure Smoothing

This option com­pen­sates for bright­ness vari­a­tions between indi­vid­ual images. This is espe­cial­ly rel­e­vant for macro lens­es, since the effec­tive aper­ture dif­fers from the set aper­ture at high repro­duc­tion scales. For exam­ple, at 1:1 macro set­ting with a dialed-in aper­ture of 8, the effec­tive aper­ture is 16, so only 1/4 of the amount of light reach­es the sen­sor as it would, if the lens were set to “infin­i­ty”.

Focus bracketing with the Canon EOS R5

The Canon EOS R5 auto­mat­i­cal­ly switch­es to the elec­tron­ic shut­ter dur­ing focus brack­et­ing. This has the advan­tage, that with suf­fi­cient light and a cor­re­spond­ing­ly short expo­sure time of 20 frames/second, the process is very fast, silent and free of vibra­tions. 40 pic­tures are so cap­tured in just 2 sec­onds. The series starts direct­ly with the shut­ter release and con­tin­ues to the end, even when the shut­ter but­ton is released.

This high speed, the good sta­bi­liza­tion by the IBIS and the lack of vibra­tion due to the elec­tron­ic shut­ter, allows to use the focus brack­et­ing with­out the need for a tri­pod. The dis­ad­van­tage of the elec­tron­ic shut­ter, how­ev­er, is that it only sup­ports expo­sure times up to 1/2 sec­ond (for rea­sons I don’t under­stand, the Sonys don’t have this lim­i­ta­tion). Focus brack­et­ing at night is there­fore not pos­si­ble with the R5 😉 .

I tried out the new option sev­er­al times dur­ing my vaca­tion with­out using a tri­pod. Here are a few exam­ples:

Fly agric with focus stacking
Fly agar­ic, Stack of 20 sin­gle images, 105mm, f/5.6, 1/320
Stack of 30 images
Miss Willmott’s ghost (Stack of 30 shots)

In the fol­low­ing I show a sin­gle image from the series to illus­trate the low sharp­ness range. For these tests I took all shots with the RF 24-105 f/4L at open aper­ture:

Miss Willmott’s ghost, sin­gle pic­ture: 105mm, f/4, 1/100, ISO 100

I took all these pic­tures with the RF 24-105mm f/4L IS USM with­out tri­pod and stitched them togeth­er in Pho­to­shop and Heli­con Focus 7. Since I was pleas­ant­ly sur­prised by the result, I decid­ed to take a clos­er look at it.

Stacking, how does that work?

If you are inter­est­ed in more infor­ma­tion after the first results, as I was, they are com­ing here:

After the Focus-Stack­ing series has been tak­en, the real work begins: the stack­ing of the pho­tos. I will present two approach­es I have tried so far.

Adobe Lightroom + Photoshop

If you, like me, use the Adobe Pho­to Sub­scrip­tion with Light­room Clas­sic*, you already have every­thing you need. The Stack­ing Series can be import­ed into Light­room as usu­al and stacked in Pho­to­shop.

Tip: If you take a black image before and after the Stack­ing Series, the Stack­ing Series is much eas­i­er to iden­ti­fy

In Light­room Clas­sic I have got used to edit one of the images of the series first (white bal­ance, bright­ness, con­trast, highlights/shadows, col­or cor­rec­tions / masks etc.) and then syn­chro­nize the set­tings with all images of the stack. If the images are pre­pared in this way, they must be trans­ferred with the menu item

Pho­to| Edit in | Open as Lay­ers in Pho­to­shop…

to Adobe Light­room. The images are then ren­dered in Light­room and trans­ferred to Pho­to­shop (in my case in the set high res­o­lu­tion 16bit TIFF for­mat) as sin­gle lay­ers. With the EOS R5 this means 256MB per image, which is a total of 7.5GB of data with 30 planes. Depend­ing on the num­ber of focus planes and the per­for­mance of your com­put­er, this takes some time. On my 16 core AMD Thread­rip­per 2950X with fast NVMe SSD and 32GB Ram the process takes almost 3 min­utes for 30 images.

Light­room - Selec­tion of the pic­tures of the stack

Three more steps have to be done in Pho­to­shop. First, all import­ed lay­ers must be select­ed. You can do this by press­ing CTRL+ALT+A (Win­dows) or CMD+ALT+A (Mac­in­tosh) or direct­ly by select­ing them with the mouse in the lay­er selec­tion box.

Then, by select­ing

Edit| Auto-Align lay­ers…

the shots can be placed exact­ly one above the oth­er. The “Auto” default set­ting in the dia­log box is well suit­ed for this pur­pose. In my case with 30 lay­ers, this process again takes about 3 min­utes.

Last, but not least, there is the third and last step, the cross­fade. This is done in Pho­to­shop with the menu item:

Edit| Auto-Blend Lay­ers…

In the dia­log box that appears here, the default set­ting “Stack Images” can also be used again. I acti­vate the option “Seam­less Tones and Col­ors”. Whether the “Con­tent Aware Fill Trans­par­ent Areas” is select­ed for or not is a mat­ter of taste. If the trans­par­ent areas are not bor­dered by impor­tant details in the image, this usu­al­ly works quite well. After con­firm­ing the dia­log box you have to wait again. In the case described above, the process took about 4 min­utes until the final image is ready:

Pho­to­shop - Stack pho­tos loaded as lay­ers

Pho­to­shop cre­at­ed masks for the indi­vid­ual lay­ers, which let only those parts shine through in each image, which are in focus. Usu­al­ly this works quite well, but stack­ing errors (like dou­ble con­tours or blurred areas) can occur which then have to be painstak­ing­ly cor­rect­ed in the indi­vid­ual lay­er masks. This is pos­si­ble, but is extreme­ly tedious.

The result is very accept­able, but a clos­er inspec­tion reveals small defects at the edges:

This error occurred because there was no sharp image in the series of the respec­tive part of the leaf. Since the shots were tak­en with­out a tri­pod, the cam­era moved slight­ly between the indi­vid­ual shots and this detail was not includ­ed in the shot of the cor­re­spond­ing lay­er. These mis­takes can now be cor­rect­ed in detail, but the eas­i­est way is to crop the image accord­ing­ly, that’s how I did it. When you are final­ly sat­is­fied with the result, the lay­ers can be com­bined. This is done by the menu item:

Lay­er| Flat­ten image

Then you can leave Pho­to­shop, accept­ing the ques­tion “Save changes to Pho­to­shop doc­u­ment XXX before exit­ing? Pho­to­shop then saves the new­ly stacked image in the same fold­er where the stack is locat­ed and pass­es it back to Light­room, where it appears in the film strip.

All in all, the result with Light­room and Pho­to­shop is quite good, but in this case the edit­ing took a good 15 min­utes - that has to be done faster, right?

Yes, is it actu­al­ly pos­si­ble, for exam­ple with

Helicon Focus from HeliconSoft

Heli­con Focus is a pro­gram spe­cial­ized in Focus Stack­ing. It can be down­loaded from the Heli­con­Soft web­site and eval­u­at­ed for 30 days. I have tried ver­sion 7.6.4. The pro­gram comes with a plu­g­in for Adobe Light­room, which is auto­mat­i­cal­ly set up dur­ing instal­la­tion and is avail­able imme­di­ate­ly after restart­ing Light­room. So the pro­cess­ing of the stack can be start­ed com­fort­ably from Light­room, sim­i­lar to the way it works with Pho­to­shop. The first steps are there­fore the same as with Light­room. When all images in the stack have been processed, they are again select­ed and Heli­con Focus is acti­vat­ed via the menu item:

File| Plug-in Extras| Export to Heli­con Focus…

Light­room now exports the images of the stack to a tem­po­rary direc­to­ry (the path can be select­ed in the Light­room Add-on Mod­ule Man­ag­er if desired) and starts Heli­con Focus, if nec­es­sary:

Helicon Focus
Heli­con Focus - Ready to ren­der the focus stack

This process alone is much faster, it takes only about 1 minute for 30 images of the R5 on my com­put­er (AMD Thread­rip­per 2950X with 16 cores, 32GB Ram, NVMe SSD).

If the images have been trans­ferred to Heli­con Focus, there are now 3 ren­der­ing meth­ods to choose from

A: weight­ed aver­age
B: depth map
C: pyra­mid

In addi­tion, dif­fer­ent para­me­ters can be select­ed for the indi­vid­ual meth­ods. So far, I got the best results with method C (pyra­mid). But in Heli­con Focus the dif­fer­ent meth­ods can eas­i­ly be tried one after the oth­er and the results can be com­pared. The indi­vid­ual results are stored tem­porar­i­ly and can be dis­played at any time by select­ing them in the small film strip at the bot­tom. There you can choose the best result and save it.

The ren­der­ing of the stack is blaz­ing fast com­pared to Pho­to­shop. Heli­con Focus appar­ent­ly uses the exist­ing proces­sor cores much bet­ter than Pho­to­shop can. My exam­ple stack with the 30 images of the Miss Willmott’s ghost was ren­dered in 15 sec­onds using method C, Pho­to­shop need­ed 6 min­utes (align­ing and blend­ing).

Stack­ing with Heli­con Focus- Method C - Pyra­mid

Nice is that Heli­con Focus dis­plays an ani­mat­ed image of the ren­der­ing process dur­ing the cal­cu­la­tion. With method B - depth map, the process is also fin­ished in 15 sec­onds:

Stacking with Helicon Focus
Stack­ing with Heli­con Focus - Method B - Depth map

After com­ple­tion, the images can be viewed enlarged in Heli­con Focus and, if nec­es­sary, post-processed. In this case, both meth­ods were well-suit­ed. The pro­cess­ing is much faster and more com­fort­able than with Pho­to­shop.

In the ” Retouch­ing ” mod­ule, Heli­con Focus dis­plays a select­ed sin­gle pho­to of the stack in the left win­dow and the com­plete image on the right. Using the mouse, a part of any select­ed sin­gle lay­er can be copied to the whole image. This is much more dif­fi­cult to describe here than it is in real­i­ty. In any case, it is much eas­i­er, more intu­itive and faster than in Pho­to­shop. In my expe­ri­ence, post-pro­cess­ing in Heli­con Focus is also much less nec­es­sary, since the results are usu­al­ly bet­ter than with Pho­to­shop.

All in all, edit­ing with Heli­con Focus is much more fun and much more pow­er­ful than with Adobe Pho­to­shop. Heli­con Focus cur­rent­ly costs $30 per year as an annu­al sub­scrip­tion and $115 once as a “Life­time License”, where all future updates are includ­ed for free.

Some more examples

The above expe­ri­ences with the Focus Stack­ing of the EOS R5 now made me want to try out my macro lens again.

My good old EF 100mm F2.8 Macro USM* has been lying unused in the box for quite some time. I had always con­sid­ered to exchange it for the 100mm F/2.8L IS at some point, since the IS seemed to me to be inter­est­ing espe­cial­ly in the macro range, but I refrained from doing so, since I use it very rarely and the L-lens is opti­cal­ly not bet­ter. It was worth the wait: Now my old macro has a sta­bi­liza­tion by the built-in IBIS of the EOS R5, which works real­ly well 😉 .

As a train­ing object I chose a fam­i­ly heir­loom from the vit­rine, which is over 80 years old. It is a gold­en pock­et watch, which my grand­fa­ther received in 1937 on the occa­sion of his 25th anniver­sary of employ­ment at the GHH, the “Gute Hoff­nungs Hütte” in Ober­hausen. The good old piece is still ful­ly func­tion­al after more than 80 years. I rewound it and it worked!

This time, I used the cam­era on a tri­pod for stack­ing. The light­ing came through the win­dow, I put the clock on a white sheet of paper. Then I took up to 40 shots at aper­tures 5.6 and 8, edit­ed them in Light­room and stacked the series in Heli­con Focus:

Open pocket watch with etuit
Stack of 40 images, 100mm, f/5.6, 1/160, ISO 100
Stack of 26 images, 100mm, f/8, 1/15, ISO 100
Stack of 30 images, 100mm, f/8, 1/6, ISO 100

I am quite hap­py with the results, Focus Stack­ing is fun! These were my first steps with Focus Stack­ing. I would be very hap­py about com­ments and sug­ges­tions for improve­ment.

If you are inter­est­ed in fur­ther infor­ma­tion about the Canon EOS R5

You can find my first test report on the EOS R5 here. On my web­site there are also many oth­er arti­cles about the EOS R5.

*=Affil­i­ate Link

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