topic Re: EOS 90D Mirror lock up good for long exposure? in EOS DSLR & Mirrorless Cameras

EOS 90D Mirror lock up good for long exposure?

Ramsden — Tue, 14 Apr 2026 13:34:51 GMT

Hi folks

After my successful street photography trip on the silent mode, I came across the Mirror lock up option on my EOS90D.

I've not used this before and just been giving it a go. To my untrained eye it seems a lot faff with marginal benefits in the photo. Pressing the shutter button twice feels strange.

Would you suggest its a good tool to use and I should stick with it for long exposure etc. Any tips, advice welcome.

And one tip for starters, is remember to turn it off!

Ramsden

Re: Mirror lock up

kvbarkley — Tue, 14 Apr 2026 11:55:22 GMT

That is totally up to you. It is just a way to ensure that you can achieve perfect sharpness.

Frankly, I don't think it does much. I think the camera mfgs. put it in there so sticklers for sharpness could not complain "My picture would have been perfectly sharp, but mirror slap *ruined* it!"

Re: EOS 90D Mirror lock up good for long exposure?

jrhoffman75 — Tue, 14 Apr 2026 13:56:04 GMT

https://support.usa.canon.com/kb/s/article/ART136786

Re: EOS 90D Mirror lock up good for long exposure?

stevet1 — Tue, 14 Apr 2026 14:01:18 GMT

Ramsden,

One thing you can do is add a 2 second time delay to your shutter. That way you only have to press the shutter once to lock up the mirror, and 2 seconds later the shutter fires by itself. That gives you a chance to step back away from the camera/tripod and eliminates camera shake caused by you pressing the shutter button yourself.

Steve Thomas

Re: EOS 90D Mirror lock up good for long exposure?

Ramsden — Tue, 14 Apr 2026 14:02:04 GMT

Thanks Steve

That sounds very sensible, I'll give it a go

Thanks

Re: EOS 90D Mirror lock up good for long exposure?

jrhoffman75 — Tue, 14 Apr 2026 14:53:42 GMT

II don't have my DSLR anymore, but 'm not sure the two second delay moves the mirror initially. The two second/ten second delay modes are a self-timer. Gives time to press shutter and then get into the photo location. If the mirror moved camera couldn't focus. Does give time for camera to stabilize if on a tripod.

Re: EOS 90D Mirror lock up good for long exposure?

kvbarkley — Tue, 14 Apr 2026 15:00:36 GMT

Yeah, on my T6S, the mirror goes up after the delay. The delay prevents "shutter-button-press-bounce".

Re: EOS 90D Mirror lock up good for long exposure?

FloridaDrafter — Wed, 15 Apr 2026 23:07:49 GMT

@Ramsden wrote:

Hi folks

After my successful street photography trip on the silent mode, I came across the Mirror lock up option on my EOS90D.

I've not used this before and just been giving it a go. To my untrained eye it seems a lot faff with marginal benefits in the photo. Pressing the shutter button twice feels strange.

Would you suggest its a good tool to use and I should stick with it for long exposure etc. Any tips, advice welcome.

Hello, Ramsden!

I only use mirror lock to clean my sensor. If I want to take long exposures, I'll either dial in a long shutter delay or use Bulb mode with a remote shutter trigger. I use the 2 or 10 second timer when stacking or sometimes for macro.

I'm not sure why, but I've never had problems with mirror or shutter shock. I don't deny it bothers some folks, it's just never been a concern for me.

Newton

Re: EOS 90D Mirror lock up good for long exposure?

stevet1 — Thu, 16 Apr 2026 02:40:46 GMT

Hi John,

With the DSLRs, (which have a mirror), you set the mirror lock up in one of your custom functions in your menus.

As Ramsden said, you have to press the shutter button once to lock the mirror up, and a second time to actually take the picture.

With the 2 second time delay, you can avoid that manual second shutter press. The camera will do that for you.

Steve Thomas

Re: EOS 90D Mirror lock up good for long exposure?

Waddizzle — Thu, 16 Apr 2026 09:03:28 GMT

“ Would you suggest it’s a good tool to use and I should stick with it for long exposure etc. Any tips, advice welcome. “

A robust tripod and a robust tripod head is a must have for long exposures. You don’t want the rig to wiggle in a breeze. You don’t the head to exhibit backlash when you tighten it down. That means the head will shift the direction the camera is pointing as you tighten it down.

The heavier your gear, the stronger the support needs to be. A high quality head is the most important investment you can make for long exposures.

I haven’t used a DSLR in several years. But I believe that the LV mode used for silent shooting on the 90D raises the mirror at the start of the shutter delay, not at the end.

Re: EOS 90D Mirror lock up good for long exposure?

Ramsden — Thu, 16 Apr 2026 09:18:04 GMT

Thank for all your advice and explanations on how this works. As ever, I've learnt something new from my Canon friends across the pond.

I'm also giving my rig and tripod head a good examination and I guess a more sturdy version will soon be in my cart.

I expect that we're not allowed to promote equipment on this website- but apart from it looks and feels sturdy any tips welcome.

Ramsden

Re: EOS 90D Mirror lock up good for long exposure?

Waddizzle — Thu, 16 Apr 2026 10:47:54 GMT

“ I expect that we're not allowed to promote equipment on this website- but apart from it looks and feels sturdy any tips welcome. “

Posting links to third party gear violates forum rules. I have never experienced an issue the gear I actually use in a photo. The previous image is Really Right Stuff BH/55 ball head with a lever locking clamp. The clamp works great, but it does have a lot of resistance to flip. I wish I had gotten the screw clamp.

Most quality ball heads have little to no backlash when the camera is pointing level horizontally. The rubber hits the road when you angle the camera away from horizontal, like up at the Moon. The BH-55 has zero backlash at any angle, even with several pounds of gear.

But ball heads are most susceptible to backlash. For less than half the cost of the RRS BH-55, this Benro geared head has zero backlash as you tighten it down. The downside is that it takes far more time to set up and orient the camera. It’s great for capturing the Moon and macro shots.

My only complaint with the Benro geared head is that I needed to add a Manfrotto spacer accessory to raise the head 3cm above the droid spider.. The lowermost handle is too close to the tripod.

Both heads are mounted on the same Benro Series 4 video tripod. The tripod doesn’t have a center column. It uses a 75mm flat plate. Heads mount on the plate.

The flat plate has a quick release. I have different types of heads mounted on their own plate. I can change heads in just a few seconds. I have ball, geared, video, and gimbal heads.

The video head actually mounts to a 75mm bowl. The tripod accepts 75mm plates or bowls. Those same plates and bowls are compatible with my hi/hat mini tripod.

Re: EOS 90D Mirror lock up good for long exposure?

Ramsden — Thu, 16 Apr 2026 12:02:14 GMT

Thanks Waddizle

Thats really helpful. My standard tripod has a ball head with a screw and I also have an attachment for macro work. So I'm good to go (for now!)

Best

Ramsden