Focus Stacking

[grotte]

Shooting say a 6" long Honey Mushroom

You are overthinking this: everything else being equal the step size is subject dependent. That is why HB suggests to experiment. A smooth mushroom may get away with medium size steps, while a ripe sunflower would require extra small steps for smooth DOF.

[MGrayson]

Thanks but it really does not help me at all.
I'm a simple 60+ fellow who does not care about coc or pp - I want the camera to do the job as efficiently as possible AND the X2D MISSES the mark by a mile.u

I'm sorry that this does not help you at all. I am also 60+, and it is my passion (and profession) to provide the best methods for people to solve their problems using the tools that they have.

I hope you find a system that does what you need.

Matt

[Andy Miller Photo UK]

You seem to be consistently unhappy in a variety of ways with what you have. Why not get a different camera which works the way you think it should?

By WHAT right do YOU make such a miserable comment as this !!!

[SrMi]

Thanks but it really does not help me at all.
To start it is only helpful if you provide lens, aperture and subject distance information. Then ne can understand what the camera is seeing. 2nd your example is not remotely similar to mine.

I'm a simple 60+ fellow who does not care about coc or pp - I want the camera to do the job as efficiently as possible AND the X2D MISSES the mark by a mile.
The best/simplest approach is to set the near and far distance and have the camera work out how many shots it needs to take — the user can set a % overlap or this can be left to and auto setting.
This is 2023 not the 1970s -it is not like the processing power is absent from the camera.
The XF + IQ4 does something very similar to this but with a wee bit more manual input — no coc or pp knowledge required. So do almost every mirrorless body.

If you are shooting landscapes, it is best to start at infinity and focus bracket toward the near. AFAIK, all cameras that implement focus bracketing sometimes miss focus at infinity (stop too early).
If I am shooting a small object, I prefer starting at the approximate middle point and focus bracket away from it. Too often, I found that my near point was too far and a part of the subject was blurry. For cameras that do not implement that nifty Hasselblad feature, I wing it by moving the focus point a bit closer manually, hoping I will get the whole object in the bracket.

[MSuser]

You seem to be consistently unhappy in a variety of ways with what you have. Why not get a different camera which works the way you think it should?

By WHAT right do YOU make such a miserable comment as this !!!

None. It's just a question. You don't have to answer it. I'm just curious why you aren't using something else which has the features you want, works the way you'd like, from a company in which you have confidence. That's all, nothing more to it. Just curious whether there's a better solution for your needs with which you would be happier.

Moving along... here's a link to an hour long webinar discussing focus bracketing in some detail which you may find useful. It's from 2 years ago, but the principles and methods discussed are the same as today.

www.youtube.com/Hasselblad Webinar: Focus Bracketing

[Andy Miller Photo UK]

You seem to be consistently unhappy in a variety of ways with what you have. Why not get a different camera which works the way you think it should?

By WHAT right do YOU make such a miserable comment as this !!!

None. It's just a question.

It was not a question rather it was an attack on a fellow member

Of course I watched the video -- AND still I have the same issue with how H has implemented this feature in the X series bodies -- I have owned all 3 -- they appear to wish to do the absolute minimum AND you can bet I have explained my concerns to them directly.

YOU NEED TO TAKE FAR MORE CARE with your choice of language.

[MSuser]

Wishing you nothing but enjoyment in your photography and the images you make. I'm confident you'll find that along with good light.

[SrMi]

You seem to be consistently unhappy in a variety of ways with what you have. Why not get a different camera which works the way you think it should?

By WHAT right do YOU make such a miserable comment as this !!!

None. It's just a question.

It was not a question rather it was an attack on a fellow member

Of course I watched the video -- AND still I have the same issue with how H has implemented this feature in the X series bodies -- I have owned all 3 -- they appear to wish to do the absolute minimum AND you can bet I have explained my concerns to them directly.

YOU NEED TO TAKE FAR MORE CARE with your choice of language.

As I wrote before, Hasselblad has more focus bracketing feature then most other manufacturers.

[mikaelo67]

Here is a good tutorial from Mathphotographer on YouTube about focus stacking with the new firmware 2.0. Hopefully this might help with your questions.

https://www.youtube.com/watch?v=oT_eeStCrTY

Be good 👍

[NickT]

No one is attacking anyone, not everyone uses the same conversational style, let's keep it civil please.

EDIT

This post (by me) was just reported (to me) for showing bias apparently...

Just thought you'd all like that

[Ikarus]

When I started photography (according to my daughter, dinosaurs had recently gone extinct), I was taught that depth of field was roughly 1/3 in front of the subject and 2/3 behind (assuming a properly adjusted lens).

For focus bracketing, all I have tried to do is to stay within the depth of field for each distance - which will vary for focal length, aperture and subject distance.  Do you really need more than this?  In each case, try to step the aperture down; you will most likely be using a tripod anyway.  Then, for close subjects, select a shorter step - the depth of field range on the lens barrel will give you a guide.

While I agree that this should be something the software should calculate for you, it actually isn't that difficult in practice.

[Andy Miller Photo UK]

With Jim Kasson's help I built a spreadsheet and have some numbers for a range of lenses and distances.

SEE HERE for details - https://andymillerphoto.co.uk/blog/f/focus-bracketing-with-the-x2d-100c

As noted I sent this to Hasselblad CS who have sent it on to H R&D for checking.

[pdprinter]

When I started photography (according to my daughter, dinosaurs had recently gone extinct), I was taught that depth of field was roughly 1/3 in front of the subject and 2/3 behind (assuming a properly adjusted lens).

For focus bracketing, all I have tried to do is to stay within the depth of field for each distance - which will vary for focal length, aperture and subject distance.  Do you really need more than this?  In each case, try to step the aperture down; you will most likely be using a tripod anyway.  Then, for close subjects, select a shorter step - the depth of field range on the lens barrel will give you a guide.

While I agree that this should be something the software should calculate for you, it actually isn't that difficult in practice.

That 1/3 front 2/3 back rule is applying only to the subject side of the lens at longer distances but not close up where it become  symmetrical. On the lens side (i.e. lens extension) it is always symmetrical (I learned it through focusing large format cameras).

[pdprinter]

With Jim Kasson's help I built a spreadsheet and have some numbers for a range of lenses and distances.

SEE HERE for details - https://andymillerphoto.co.uk/blog/f/focus-bracketing-with-the-x2d-100c

As noted I sent this to Hasselblad CS who have sent it on to H R&D for checking.

Great investigation into focus stacking. One problem I see is that most lenses have some sort of internal focusing (the only XCD lens which focuses as a hole unit is the 45mm/4.0 with maximum extension of about 10mm). Internal focusing is mostly used because by moving only some internal subgroup less glass mass has to be moved leading to faster autofocus. I noticed that the effective focal length is shorter at closer focus and also the effective f/stop is not constant as the pupil ratio changes (maybe quite variable depending on specific lens design?). How much that would have an effect on DOF and focus bracketing calculations?

[Bob Foster]

For my work I elected some time ago to generate a rough table for the XCD 120 based on depth of field calculations at varying magnifications and apertures. For all magnifications except those very closely approaching the highest magnification that this lens is capable of (1:2) my results tally closely with those generated by Andy's calculating table referenced above at f8 (this is close to the optimal aperture for this lens.

For the highest magnification work with the XCD 120 I did find, as is characteristic of many internal focus macro lenses, that the apparent focal length was reduced. My copy produces 1:2 magnification at 433 mm (or ~87.6mm apparent focal length), however, by the time the subject is at 490mm magnification ratio is about 1:2.62 (or ~115mm apparent focal length).  Even with these numbers change is considerably more rapid between 433 mm and 460 mm than it is between 460 mm and 490 mm.

Given that I'd rather discard out of focus images that have no use from a close up stack as taken, and given that there are other variables in play, Andy's calculating table is not in my opinion, excessively conservative - despite the shorter apparent focal length at near the maximum magnification.

I will note that for close up work with the XCD 120 that if the "finished product" is to be displayed  only digitally perhaps a slightly larger C of C might be used. Personally, however, I'd rather stay with the extra small Ø3.76μ C of C just in case a large print was wanted at some future date.

Bob