Larry Rexley wrote:
Larry Rexley wrote:
Sittatunga wrote:
J Peters wrote:
timbazi wrote:
J Peters wrote:
I have a selection of native EF-M lenses, up to 200mm but I sometimes hanker for longer reach. I've been considering a Sigma 150-600 C but finding it hard to justify. It's not just the cost, it's the practicality of carrying it.
Would an EF-S 55-250 with a teleconverter be a viable budget (and smaller/lighter) alternative? I realise low light performance would be compromised but I don't expect miracles; just something that's better than severe cropping.
I have the EF to EF-M adaptor already but no other EF lenses, so it's sitting unused. Camera is M5.
There's only KENKO TELEPLUS HD DGX 1.4x and 2.0x that work on that EF-S 55-250 STM without modding the lens (as far as I know) The AF probably wont work with them(?). There's couple people on the site who use TC with the lens and they get really good quality photos, that had basically no reduction in IQ. (I don't recall their usernames right off the top of my head)
(I've also been eyeing for the TCs for that lens. OR the Sigma lens...)
Oh I didn't realise that. I thought you could use a teleconverter with any lens so long as the mount matched.
The Canon Extenders protrude into the lens, so that they clash with the rear elements of the shorter lenses that they are not intended to be used with. This has caused much gnashing of teeth for the owners of the RF 70-200mm lenses.
The Canon EF-S lenses protrude into the body, so that they clash with the focussing screen surround of the full-frame cameras that they are not intended to be used with.
One guy has successfully taken a Stanley knife to the surround of the rear element to his EF-S 55-250 STM so that it can be mounted to the independent teleconverters that don't protrude into the lens. It would be less drastic to use an EF 70-300mm lens but that's bigger and more expensive. The aperture reduction due to a teleconverter isn't a problem with the dual pixel AF of your M5 as it will focus quite happily at f/11. TANSTAAFL.
I'm the guy who took the Swiss Army knife to the mount of the EF-S 55-250mm IS STM so I could use it with third-party teleconverters (and homemade: vintage MC7 teleconverter optics mounted in 36mm EF DG extension tubes).
https://www.dpreview.com/forums/post/64824180
I originally used the EF-S 55-250 + 2x combination on a Canon M6 (same generation as the M5) and the combination could NOT autofocus almost at all, it would focus-hunt at the 500mm f11 equivalent. Only after I upgraded to the M6 Mark II with its much better low light autofocus, was I able to autofocus using the 55-250 + 2x MC7 teleconverter.
For some reason the 55-250 + 1.5x Kenko teleconverter will NOT autofocus even with the M6 Mark ii - the camera does not like this combination. Either Kenko's electronic chip is interfering, or the lower quality 1.5x MC4 optics (compared to the 2x MC7's optics) do not allow the dual-pixel sensor to autofocus with the 55-250.
As for improvement in image quality ---- I have documented that you can resolve more detail in images such as the Moon --- however as you are at f11 or smaller apertures, you are already diffraction-limited which reduces the sharpness at the pixel level, which reduces the 'apparent sharpness' of the image, so you don't really get a full 2x benefit.
Post where I compare Moon photos with and without a 2x MC7 teleconverter on the EF-S 55-250mm IS STM:
https://www.dpreview.com/forums/post/65007506
Since writing the posts in the thread mentioned above, I've gotten more into bird photography (perched; and some birds in flight). For that kind of photography, the 2-stop loss of light (f11) and subsequent increase in noise for a given shutter speed (compensating with higher ISO) made the EF-S 55-250 + 2x combination much more difficult to obtain sharp, noise-free images. Also the TC's resulting loss of sharpness (diffraction and slight IQ loss from the TC optics) made good quality photos harder to get. For still photos, I only use the 2x converters with the EF-S 55-250 in extreme situations now. I would much prefer a sharp dedicated 400-600mm f5.6-8 lens.
Where the EF-S 55-250 + 2x combination works the best for me on the M6ii is video recording (boat races in my case) --- video even at 4k is much less demanding of lens sharpness, and having a 110 - 500mm f8-11 lens that is image stabilized and autofocuses in most light for video is fabulous.
My opinion is that you are better off with a dedicated telephoto lens.
For kicks this morning, I again tried out my modified EF-S 55-250 IS STM with the Kenko 1.5x Teleplus SHQ teleconverter on some perched birds.
It could not autofocus at all, it just kept hunting back and forth. I had to manually focus which is not easy as the EF-S 55-250 focuses by wire, and it is really tricky to manually focus. I was shooting birds from 10-20 yards away so the depth of field was incredibly shallow.
I managed to get a couple shots sharp enough to process, so I could at least see if the combination works 'optically'.
Here are the results --- both photos processed in Canon DPP 4.0 to balance sharpness and noise, both photos cropped from the original 32 MP but they are at full pixel resolution, not downsampled.
Canon M6ii, Canon EF-S 55-250 IS STM with Kenko 1.5x Teleplus SHQ teleconverter, manually focused, lens set at 250mm,f5.6, 1/500s, ISO 800
Canon M6ii,Canon EF-S 55-250 IS STM with Kenko 1.5x Teleplus SHQ teleconverter, manually focused, lens set at 250mm, f5.6, 1/320s, ISO 200
Overall the results appear to be better than what I get with the 2x MX7 teleconverter on the EF-S 55-250 IS STM, but not nearly as sharp as the lens with no teleconverter at all.
If this combination would autofocus, this looks like a usable combination to me. Downsized by 20-50% the images become fairly sharp. However, since it won't autofocus, it would be challenging to get good results with it. I was trying to take a photo of a different bird that was walking around pretty fast, and was totally unable to focus on it and get a shot.
Given the EXIF data --- it looks like this Kenko teleconverter does not have a chip. The inability of the camera to focus with this TC may mean there is something optically about this TC that prevents the camera's dual-pixel autofocus from getting what it needs.
If you look carefully at the images, this combination seems to have a very unusual bokeh that may be affecting autofocus.
[EDIT] - Added images with EF-S 55-250 IS STM with Kiron 2x MC7 teleconverter and with no teleconverter
For comparison, here are some more shots I took tonight of critters using the EF-S 55-250 IS STM with my home-made 2x MC7 EF teleconverter made from a vintage Kiron teleconverter and a Promaster Canon EF DG 36mm extension tube.
Not as good IQ as the 1.5x teleconverter. Samples processed in Canon DPP, cropped but full pixel resolution.
Impressively, the M6ii could autofocus-track that Mallard in flight at 14 fps with the 55-250 and the 2x teleconverter at 500mm f11 equivalent.
Canon M6ii, Canon EF-S 55-250 IS STM with Kiron 2x MC7 teleconverter, lens set at 250mm, f5.6, 1/100s, ISO 800
Canon M6ii, Canon EF-S 55-250 IS STM with Kiron 2x MC7 teleconverter, lens set at 250mm, f5.6, 1/160s, ISO 800
Canon M6ii, Canon EF-S 55-250 IS STM with Kiron 2x MC7 teleconverter, lens set at 250mm, f5.6, 1/1600s, ISO 1250
And finally, a shot with the EF-S 55-250 with no teleconverter at all, all lens correction applied in DPP 4.0. Better IQ than any images I've gotten with a teleconverter.
Canon M6ii, Canon EF-S 55-250mm IS STM with no teleconverter, 191mm, f7, ISO 100
Update to my post --- I took apart my Kenko C-AF 1.5x Teleplus SHQ teleconverter, and removed the electronics and chip. The teleconverter now passes the pin information directly to the lens as if it isn't even there.
After doing this, I am now able to use that teleconverter on my Canon M6 mark II with full autofocus, auto exposure, and image stabilization. It works very well! The EXIF data for the lens focal length and aperture is not changed by the teleconverter, so it's not completely accurate (the focal length should be multiplied by about 1.4x and the aperture should show one stop darker) but this is a small price to pay.
I posted my experience in the following thread, in addition to a series of images showing that the teleconverter works very well, yielding sharp images with the Canon EF-S 55-250 IS STM (which I modified to work with EF teleconverters).
