I would not recommend any version of the EF 75-300mm F/4-5.6 lens lineup. They're very poor optically and use very slow AF motors. Your camera natively mounts EF-M Mount lenses only 8 lenses were made for the EOS M system. This lens mount has been discontinued by Canon along with the EOS M series camera lineup in favor of the RF Mount and EOS R series mirrorless cameras. Not many 3rd Party lenses were made for the EF-M Mount either. EF & EF-S lenses can be adapted to the EOS M via an adapter EF-EF-M (EF- EOS M) adapter. RF lenses cannot be adapted to the EF-M cameras. Nor can EF-M lenses be adapted to RF Mount cameras. If you're looking at the Canon EF-S 18-200mm F/3.5-5.6 IS lens it uses a very slow AF motor. The kit lens uses a faster AF and quieter AF motor. Also battery life takes a hit when adapting EF & EF-S lenses. The battery life drops when using adapted vs native lenses.
- EOS: Electro Optical System (What EOS stands for)
- EF: Electronic Focus: lens mount ALL EOS DSLRs & Film SLRs use (original EOS Mount) (Red Circle Mounting Index, 12 o’clock position)
- EF-S: A separate lens Mount designed for APS-C DSLRs NOT compatible and won’t mount to any Full Frame Digital, 35mm Film SLRs or APS-H DSLRs. Note this is a DSLR Crop Sensor ONLY Mount. (White Square Mounting Index, 1 o’clock position)
- EF-M: Lens Mount for EOS-M series Mirrorless cameras. Incompatible with DSLRs or EOS Film SLRs & EOS R Series. (White Circle Mounting Index, 11 o’clock position) (2012-2023, DISCONTINUED).
- RF: Lens Mount for EOS R series Mirrorless cameras. ALL RF & RF-S lenses use focus by wire for Full Time Manual Focus. Regardless of USM or STM in the name. Incompatible with EOS DSLRs or EOS Film SLRs. (Red Oval Mounting Index, 12 o’clock position)
- RF-S: Lens is optimized for EOS R series APS-C cameras. Can be used on EOS R series Full Frame cameras but the image is cropped to the APS-C image circle. Note this is NOT a separate lens mount.
- Full Frame Digital: Image sensor is the same size as a single negative of 35mm Film which measures 36x24.
- APS-H (Advanced Photo System Half Frame): Image sensor is 1.3x smaller than 35mm Film. An APS-H image sensor measures (27.7x18.5). This format was previously used by Canon in older 1D series cameras.
- APS-C (Advanced Photo System Classic): Image sensor is 1.5 or 1.6x smaller than 35mm Film. An APS-C image sensor measures 22.6x15 Canon uses a 1.6x crop factor.
- L: Canon's professional grade lenses only available in Full Frame lenses NO APS-C lenses available. Lens has a RED ring on the lens barrel.
- DO: Diffractive Optics uses Fresnel lenses. Lens has a GREEN ring on the lens barrel.
- I, II, III, IV, V: Some lenses have multiple revisions such as the EF 28-80 F/3.5-5.6 V USM (ONLY lens to have a Version V)
- Ring Type USM: AF motor type. Provides fast focusing stands for Ultrasonic Motor. Ring Type USM is the original USM AF motor. Shaped like a ring inside the lens. Allows Full Time Manual Focus either Focus by Wire or mechanical. ALL RF Mount lenses use focus by wire for Full Time Manual Focus.
- Micro Motor USM: Cheaper and slower AF Motor doesn't allow Full Time Manual Focus. Lens uses gears to adjust focus. EXCEPT for the EF 50mm F/1.4 USM lens (refer to Ring Type USM Mechanical Focus override). EF/ EF-S Mount ONLY. (1993-2008 retired, replaced by Nano USM)
- Nano USM: Combines STM and Ring Type USM technology for fast AF. Allows Full Time Manual Focus is Focus by wire. (2016- Present)
- STM: Stepper Motor for quiet AF. Allows Full Time Manual Focus which is Focus by Wire. ALL EF-M lenses used an STM AF motor. RF 10-20mm F4L IS STM (First L series lens to use an STM AF Motor) (2012- Present)
- AFD: Arc-Form Drive original EOS AF motor. No longer in use was replaced by Micro Motor in 1993 for new lens designs. No Full Time Manual Focus. ONLY used in the EF Mount NO EF-S, EF-M or RF Mount lenses. (Retired 1987-1992)
- Micro Motor: Older least advanced AF motor slower AF used in cheaper lenses. No Full Time Manual Focus. ONLY used in the EF/ EF-S Mount. (Retired, 1993-2012) Replaced by STM in 2012.
- VCM: Voice Coil Motor provides fast AF. The RF 35mm F/1.4L VCM is the first lens to use this new AF motor.
- IS: Image Stabilization available in the lens.
- IBIS: In Body Image Stabilization available in select EOS R Series cameras.
- Macro: A macro lens with 1:1 magnification
- Compact Macro: Lens is able to focus closer than a normal macro lens.
- MP-E: Manual Focus only electronic aperture control no focus to infinity.
- TS-E: Tilt Shift lens with electronic aperture control no Autofocus.
- Soft Focus: Lens is designed to provide a creamy bokeh effect.
- PZ: Power Zoom lens. Only 1 lens released with this feature. Only the EF 35-80mm F/4-5.6 PZ lens used this.
- TTL: Through The Lens Flash metering. Flash system relies on light reflected off the film. NOT compatible with EOS Digital cameras.
- A-TTL: Advanced Through The Lens Flash metering system in EOS film bodies released in 1986 with the FD Mount T90 SLR. Replaced by E-TTL in 1995. System uses a pre-flash measured by a sensor on the speedlite itself. NOT compatible with EOS Digital cameras. Uses EZ series speedlites.
- E-TTL Version 1: Evaluative Through The lens Flash metering system. System uses a pre-flash measured by the camera body to calculate flash exposure. System also relies on AF point selection too. Compatible with EX or EL series speedlites. Replaced by E-TTL II in 2004.
- E-TTL II: Refer to E-TTL Version 1. System was released in 2004 and works similarly to the original E-TTL. But uses focus distance information from the lens. Via a distance encoder in the lens. E-TTL II doesn't rely on AF point selection. Note E-TTL II is IMPLEMENTED in the camera body NOT the speedlite.
- EOS M Series: A discontinued APS-C mirrorless lineup of cameras (2012-2023). Replaced by EOS R Series APS-C cameras in 2023. EF-M lenses CAN NOT BE ADAPTED to EOS DSLRs or EOS R cameras.
- EOS R Series: Originally released in 2018 with Full Frame cameras only. Later in 2023 with APS-C cameras. New APS-C lenses were released.
- Z: Lens has an optional attachment to allow power zoom. Only the RF 24-105mm F/2.8L IS USM Z lens has this feature.
- Automatic Brightness Adjustment of LED AF Assist Beam: Feature IS NOT SUPPORTED on the R3, R7 & R10 camera bodies when the speedlite EL-5 is used. LED AF Assist Beam is projected at FULL BRIGHTNESS ONLY. Or will switch to Intermittent Flash Firing. All other cameras with a Multi-Function hot shoe will automatically adjust the LED AF Assist Beam depending on the ambient brightness.
- AF Assist Beam: An AF Assist Lamp to aid the camera’s AF system in low light or low contrast situations.
- IR AF Assist Beam: A red grid pattern projected by the speedlite to aid an SLR/ DSLR camera’s AF system. Note this red grid pattern IS NOT Infrared. This AF Assist Beam type is compatible on all EOS SLRs & DSLRs. This type of AF Assist Beam IS INCOMPATIBLE with mirrorless cameras.
- Intermittent Flash Firing AF Assist Beam: Camera rapidly pulses the speedlite for AF Assist. This AF Assist Beam type IS SUPPORTED ON ALL EX & EL speedlites when used on the EOS R Series. Note speedlites that have a PERSONAL FUNCTION for IR & Intermittent Flash Firing. Always use Intermittent Flash Firing on the EOS R series regardless of the projection method. When set to Intermittent Flash Firing. If a color filter or flash diffuser is used. The camera body emits an LED AF Assist Beam on the EOS R series. Intermittent Flash Firing is DISABLED when a color filter or flash diffuser is used. Speedlites without a PERSONAL FUNCTION between IR and Intermittent Flash Firing. The speedlite WILL use Intermittent Flash Firing on the EOS R series. Note depending on the ambient lighting an AF Assist Beam may be projected by the camera body instead of the speedlite on the EOS R series. This AF Assist Beam type ONLY works on cameras released from 2007-onward.
- LED AF Assist Beam: Bright white light (on a speedlite) or orange LED light (on an EOS R series camera body) that aids the camera for AF Assist. This AF Assist Beam type ONLY works on cameras released from 2007-onward.
