Canon 100mm Macro question

Hey

I know that the Canon 100mm Macro lens has internal focussing, but what I would like to find out from anyone who owns this lens is the following:

Lets say the subject is something like a remote control, with buttons right close to the lens in the frame & ones in the distance, your taking it at an angle, DOF will be very small & while you could use F22 it would be softer than normal.

This is the question!

If you want to do a series of shots with the focus starting at the buttons nearest to the lens in the frame & then re-adjust the focus in steps until you finally have a series of shots covering the entire focus range, does the distance to the subject change at all? as whenever ive tried this the actual subject gets larger as you focus, but ive never tried an IF macro, does it overcome this problem or is it basically still doing the same tube extending method but inside a sealed barrel instead.

Does any of that make sense?

Nick

You should be able to focus the lens and the image size remains the same. The barrel of the lens does not move out or in with focusing on the 100mm macro lens, though you would need a very good tripod for what you are attempting and a very still subject! I've never found a need for f/22, probably because it requires an immaculate sensor! I assume you are attempting to do focus stacking?

Simon

Nick_C wrote in post #3644093
Hey

If you want to do a series of shots with the focus starting at the buttons nearest to the lens in the frame & then re-adjust the focus in steps until you finally have a series of shots covering the entire focus range, does the distance to the subject change at all? as whenever ive tried this the actual subject gets larger as you focus, but ive never tried an IF macro, does it overcome this problem or is it basically still doing the same tube extending method but inside a sealed barrel instead.

I have tried this with my Canon 100 macro, and the subject size does change some as you vary the focal length.
However you did not mention what you were going to do with the resultant series of shots. Have you considered Helicon Focus?

http://www.heliconsoft​.com/heliconfocus.html

this software allows for some image size change and wind movement over the series of images, but takes the sharpest portion of each image and merges the series together. It helps to have a lot of shots in the series (more than 12) if focal legth changes are significant. How well it works for changing image size, I am not sure, but there is a free download on the site, so you can try out the software before buying. Again, lots of images in a series provides better results. And it works with RAW too.
Mke K

Yes, ive had good results despite the fact my subject enlarges the more further I focus.

I was just wondering if the 100mm is the same, I know the actual lens doesnt extend but it could just be doing all the extending inside the main lens case.

Your right you would only be able to see this on a tripod with a still subject, im not into bugs :-p

Nick

Mike K wrote in post #3644526
I have tried this with my Canon 100 macro, and the subject size does change some as you vary the focal length.
However you did not mention what you were going to do with the resultant series of shots. Have you considered Helicon Focus?

http://www.heliconsoft​.com/heliconfocus.html

this software allows for some image size change and wind movement over the series of images, but takes the sharpest portion of each image and merges the series together. It helps to have a lot of shots in the series (more than 12) if focal legth changes are significant. How well it works for changing image size, I am not sure, but there is a free download on the site, so you can try out the software before buying. Again, lots of images in a series provides better results. And it works with RAW too.
Mke K

Yes ive been using combinez for a while now, I had a feeling the 100mm might be the same, so it appears while it physically doesnt extend, its still doing the same but all inside, I guess you cant escape this then.

Nick

Nick_C wrote in post #3644093
Hey

I know that the Canon 100mm Macro lens has internal focussing, but what I would like to find out from anyone who owns this lens is the following:

Lets say the subject is something like a remote control, with buttons right close to the lens in the frame & ones in the distance, your taking it at an angle, DOF will be very small & while you could use F22 it would be softer than normal.

This is the question!

If you want to do a series of shots with the focus starting at the buttons nearest to the lens in the frame & then re-adjust the focus in steps until you finally have a series of shots covering the entire focus range, does the distance to the subject change at all? as whenever ive tried this the actual subject gets larger as you focus, but ive never tried an IF macro, does it overcome this problem or is it basically still doing the same tube extending method but inside a sealed barrel instead.

Does any of that make sense?

Nick

This is called focus stacking, the combination of frames can be done in software like CombineZ or done manually with Photoshop and layer masks.

However you do it, by moving the lens or changing the focus (set magnification) the out of focus bit in one frame will have a slightly different magnification than when it is in focus, CombineZ tries to compensate for that and translation movements also, it can't compensate for rotational movements.

In any event something being out of focus tends to blur larger than it is when it is correctly focused. This and the inevitable change in magnification can tend to cause artifacts.

Although I used to use CombineZ I now tend to stack manually as I can control the artifacts easier. Alternatively it is possible to save, edit and reload the Combinez depth mask ; however I find this fiddly.

Below is an example of a 3 frame manual focus stack:

HTTP response: 404 | MIME changed to 'text/html' | Byte size: ZERO

Nick_C wrote in post #3644550
Yes ive been using combinez for a while now, I had a feeling the 100mm might be the same, so it appears while it physically doesnt extend, its still doing the same but all inside, I guess you cant escape this then.

Nick

No, you can't, because closer by or further away, especially at shorter distances, the magnification changes relatively rapidly, and with focusing you do just that, if you think about it.

The only way to overcome this, is using a (macro) focusing rail, where you don't adjust focus anymore, just whatever you are focusing on, by moving the whole setup of camera and lens further or closer away, with the aid of said macro focusing rail.

Kind regards, Wim

wimg wrote in post #3645076
The only way to overcome this, is using a (macro) focusing rail, where you don't adjust focus anymore, just whatever you are focusing on, by moving the whole setup of camera and lens further or closer away, with the aid of said macro focusing rail.

Kind regards, Wim

Hi Wim,

I don't think that solves the problem; as you move the plane of focus forward you are still increasing the magnification of the section now in focus compared to when it was slightly oof behind the plane of focus, similarly with oof sections in front of the plane of focus.

It is probably slightly preferable to keep the focus (magnification) the same, however the change of magnification either side of the plane of sharp focus still can cause artifacts except with the most simple subjects.

PS: A good way off doing this with subjects like insects in the field when handheld is you use the continuous drive and move the camera forward as you fire frames sweeping the plane of sharp focus into the subject, the trick is to avoid any significant rotational movement.

Lester Wareham wrote in post #3650457
Hi Wim,

PS: A good way off doing this with subjects like insects in the field when handheld is you use the continuous drive and move the camera forward as you fire frames sweeping the plane of sharp focus into the subject, the trick is to avoid any significant rotational movement.

I will have to try that next time, ive been "having a go" at focus stacking from time to time & I get perfect results on indoor stuff when every aspect is under controlled conditions but ive yet to get decent results outdoors handheld.

I dont do bugs, im more into flowers & stuff, but even they can be a challenge to get everything in focus.

I managed to get some tubes today from jessops & I was quite suprised by how well my 24-105 & 70-300IS work with these, so much so that im sending the Sigma 50mm Macro lens back for a refund, I prefer to use my IS lenses as for still subjects it just gives me that edge over a standard non IS lens.

This was my very first attempt today, handheld at F14 I believe, ISO200 with IS on as the shutter was a little on the slow side for 105mm.

I think once I get used to the best combination of tubes I will get some decent shots, this was with 1 tube, with more I found I could get just the centre of the flower in focus, but the main problem as with any macro lens is the lack of DOF, also to be honest my main interest is in landscapes, I really just wanted my 24-105 & 70-300IS to focus a little closer than the standard 1:4 macro, well these tubes have certainly done that.

Its hard to see how small this flower really was as there is nothing to go by but I would say it was about 20cm, not that small but small enough so that 1:4 wouldnt fill the frame as well.

This isnt focus stacked incase your wondering, all that is yet to come

HOSTED PHOTO
please log in to view hosted photos in full size.

Expensive but easy answer is the 90 TS-E lens. You can tilt the plane of focus down onto the keyboard of your remote and get all the buttons in focus at any f/stop.

gasrocks wrote in post #3651325
Expensive but easy answer is the 90 TS-E lens. You can tilt the plane of focus down onto the keyboard of your remote and get all the buttons in focus at any f/stop.

You can tilt the plane but it does not give more depth of field in the same plane as the sensor, a T&S solves a different problem, and yes it is ideal for that.

Lester Wareham wrote in post #3650457
Hi Wim,

I don't think that solves the problem; as you move the plane of focus forward you are still increasing the magnification of the section now in focus compared to when it was slightly oof behind the plane of focus, similarly with oof sections in front of the plane of focus.

It is probably slightly preferable to keep the focus (magnification) the same, however the change of magnification either side of the plane of sharp focus still can cause artifacts except with the most simple subjects.

PS: A good way off doing this with subjects like insects in the field when handheld is you use the continuous drive and move the camera forward as you fire frames sweeping the plane of sharp focus into the subject, the trick is to avoid any significant rotational movement.

Ok, that is an option. However, certainly for micro photography, what I described is exactly what you do, and it does work great, looking at the examples I have seen.

Guess I'll have to play with this stuff a bit more, time permitting ...

Kind regards, Wim