Hi all,

I'm new to bird photography but with retirement coming I want to pursue this hobby. I have been a photographer for a number of years shooting family portraits, travel and events but have no experience of wildlife. Anyway,I just sold a fair amount of gear and my DSLR to buy an R5 and also bought the Canon 500mm f4L IS II lens used from a reputable dealer here in the UK. I have two weeks on the return period to test it. As I said, I'm new to this This is my first super tele lens and I'm out of my depth here. Also I don't really know the R5 well so I'm on a bit of a curve. Please excuse my ignorance.

I very quickly tried the combo out in the garden in a spare hour at the weekend, and it seemed to give sharp images in the few shots I tried, however, I did notice on a few of the test shots I've done so far, the AF seemed to hesitate/be sluggish a few times but maybe it's my technique or maybe I chose a poor area to focus? I will need to try more carefully. I intend to give it more of a test in the next couple of days.

I'd like some advice on how to test this lens properly. I'm not planning to set up lab conditions to define its characteristics, but I'd like advice on a basic process I can go through to make sue all is as it should be. I'm pretty much limited to my garden as we are in lockdown here. It's also dull and overcast for the foreseeable where I am but I will do my best

My initial ideas are as follows:

I will try the AF for responsiveness and accuracy but taking random shots here and there. Preferably some garden birds. I believe there should be no need to worry about micro-adjustment as I'm using the Canon R5 but I'm curious as to why it seemed sluggish as above.

I will also probably photograph a wall from just over MFD at f4 and try to make sure the wall is sharp over all the image and that both sides are equally clear to check for de-centring.

I will also try some shots at infinity to see it works there.

I will use a tripod with low ISO at static objects with IS off. for AF testing I will crank up the ISO to get good shutter speed on moving birds, if I can avoid scaring them off. I will then process shots in C1, probably driving myself mad with some heavy-duty pixel peeping!

I usually don't bother with all this stuff and I've only ever been unhappy with one Canon lens but i've spent so much on this lens and I'm so ignorant of the process I should use and expectations I should have I want to reassure myself.

In addition to returning due to potential dealbreakers, the lens has a 12month warranty so if there are issues that are fixable I would like to find them out so I can get them sorted.

Sorry for the list of anxieties, but thank you for your patience and help.

Bill