Larger diameter close-up filter and corner image quality

gardenersassistant wrote:

RGBRGB wrote:

gardenersassistant wrote:

RGBRGB wrote:

gardenersassistant wrote:

RGBRGB wrote:

Wow! Amazing shot!

Thank you.

Which macro lens do you use for photographing insects?

This is the setup I use.

Do you consider the working distance enough?

Yes.

I asked because I would usually get a shorter working distance with a DSLR than with a bridge camera + Raynox. The DSLR + lens is also much heavier and harder for me to take pictures without a tripod.

A couple of weeks ago I read that if you use a teleconverter, you can get more working distance.

Adding a teleconverter does not alter the minimum focusing distance. So for example with my Laowa 100mm 2X macro lens, the working distance is around 72mm with the bare lens for its maximum magnification of 2X. With the pair of 2X teleconverters I get the same 72mm minimum working distance but with 8X magnification. At 2x magnification the working distance is around 170mm.

It makes sense.

You have just showed me that! I will definitely try my teleconverter + extension tube (my lens is EF-S and it is not directly compatible with the Canon teleconverter).

That's a pity, because you will lose infinity focus. Just using a teleconverter you get the full range from minimum focusing distance out to infinity focus. That let me go for example from this

It's so versatile! Do you use only manual focus lenses? Do you use focus peaking to nail the focus?

Can you tell me your kenko teleconverter model? Do you know if the Kenko MC7 2.0 DGX is good?

to this, just by turning the focus/magnification ring by 120 degrees or so (and turning the flash off).

I will also test my Raynox MSN202 with a much smaller aperture to get more DOF.

You can use small apertures to increase DOF, but there are a couple of things to bear in mind.

• The smaller the aperture, the greater the loss of fine detail from diffraction, the softer the image, and the more important post processing becomes.

Can you tell me about your post processing workflow? In a nutshell, do you resize (shrink) the images, adjust contrast and add sharpening to the subject?

• Macro lenses, extension tubes and teleconverters decrease effective aperture as magnification increases. This means for example that if you set the camera lens to f/22 and then shoot at 1:1, the effective aperture will be f/45. On the other hand close-up lenses don't decrease the effective aperture as magnification increases, so for example if you put your MSN-202 on a bridge camera and set the aperture to f/8, the effective aperture will still be f/8 even though you are getting all that magnification from the MSN-202. That is why I switched to using a macro lens with teleconverters after so many years using close-up lenses, because especially with small subjects I couldn't get enough DOF for my liking. Images like that springtail that you liked depend on using very small effective apertures (probably around f/100 for that springtail) and then using post processing to make the best I can of the very soft image that results from using such a small aperture. In contrast, the minimum effective aperture I could get with my close-up lens setups was around f/45 in full frame terms (and that was true whether I was using a close-up lens on bridge camera or on telezoom lenses on APS-C or MFT). f/45 gives a bit less than half the DOF of f/100.

Thanks for your detailed explanation about the effective aperture. You just explained why the DOF was so shallow with the MSN-202. That's why I rarely used it. I will test it with another equipment that allows me to use smaller apertures.

• Thanks for inspiring me to try new things!

Glad to be of help.

I noticed that the Canon 250D does not work very well with focal lengths longer than 135mm.

I wasn't at all happy with the image quality from a Canon 250D, both the one I have now and the one I had before but sent back because I thought it was faulty (but the later one was no better).

I wasn't happy either, so I rarely used it. Now I know that it is good with a lens up to 135mm.

I don't remember what focal length I tested it with, but I wouldn't expect the problems I saw to go away with a different focal length.

Did you like the results from the full frame lens + close-up filter?

I'm afraid I haven't used it enough to know.

Thanks for sharing your knowledge!

You are very welcome.