New mirror mechanisms - how is this a good thing?

[drmikeinpdx]

http://www.canon.com/camera-museum/camera/film/data/1956-1965/1965_prx.html?lang=us&categ=crn&page=1956-1965

http://www.canon.com/camera-museum/camera/film/data/1956-1965/1965_prx.html?lang=us&categ=crn&page=1956-1965

http://www.canon.com/camera-museum/camera/film/data/1976-1985/1984_nf1-hsmd.html?lang=us&categ=crn&page=1976-1985

http://www.canon.com/camera-museum/camera/film/data/1986-1990/1989_eosrt.html?lang=us&categ=crn&page=1986-1990

http://www.canon.com/camera-museum/camera/film/data/1991-1995/1995_eos-1n-rs.html

Thanks for those interesting links, Mt. Spokane! I was completely unaware of those cameras. Now I have some historical research to do.

 

[Frodo]

For a good comparison, check out Ducati's desmodromic valve train versus conventional cam-return-spring engine design.
You can really push those desmo's!

I love it when my passions coincide!
A bit off topic, but the cam valve closing of desmo heads is not so much for increased RPM, as many fours will rev way higher than a desmo twin. It is to allow a faster valve closing rate to fully optimise the valve timing as Ducati is pushing valve overlap.
So yes, a good parallel Aglet, in terms of a cam minimising vibration.
However, I'm not convinced with the desmo technology in Ducatis. Maintenance is a nightmare and so I went from a Ducati to an Aprilia (another Italian) where I can do most of the maintenance myself.

Mirror maintenance is not the issue in cameras that getting valve clearances right in bikes is. It is entirely reasonable to expect that the reduced vibration of the mirror will improve reliability of the more complex mechanism. And having a mirror fall out during a shoot with the original 5D I can speak from experience!

But to come back to the topic. In another thread there was discussion about sensor vs lens to maximise resolution. Vibration (and subject movement) is also critical in these high MP cameras.

 

[StudentOfLight]

Effectiveness???

An interesting comparison would be the 70D vs 7D-II vs 5Ds for example. The 70D presumably does not have the mirror dampening system, while the 7D-II and 5Ds do. Would be interesting to see any differences around the hand-holding rule of thumb as all these cameras have about the same pixel pitch... The 5Ds and 7D-II have about the same body size/weight, while the 70D and the 7D-II have about the same mirror size/weight.

 

[zim]

Thought I read in one of the early reviews that the new design is a limiting factor for fps in the new 5Ds ?
If so I hope it's not in the 5 div

Since it was first used in the 7D MK II, I'd give that review a pretty low grade.

Indeed. I also remember now that it was the reasoning for crop frame not having higher fps but I believe that's not true as crop is taking full fat MP's and binning to reduce file size?

Regards

 

[risc32]

For a good comparison, check out Ducati's desmodromic valve train versus conventional cam-return-spring engine design.
You can really push those desmo's!

yeah, but those springs return that energy on the other side of the cam lobe. desmo is really just a marketing thing, but this talk of dslr mirrors had my mind thinking of bikes and engines also.

Camera makers have been touting mirror slap control systems forever. That's not saying they are nothing, or aren't needed.

 

[Redder]

Thanks to Canon for making improvements on mirror (and shutter) mechanisms to reduce vibration and noise.
I have use the original 5D, then the mark 2 and now the mark 3, for each generation of 5D from the original to the mark 3 there were 'small' but significant improvements in these areas.

My full frame Sony A7 mirrorless has similar vibration level and noise level compare to my 5D mark 3, although the A7 is do without a moving mirror.

If I were to pick between an optical and a electronic viewfinder TODAY I definitely will go with an optical one. It is there no matter if the camera is turned on or not, use no power, with as much definition there is and there is no time lag while turning the camera on.

Many years ago I have owned a EOS-RT with a fixed mirror it was ok with film but I am not sure it is a good idea for a extra high definition sensor like the 5Ds. By taking away a few moving parts now you have a piece of glass between the lens and the sensor and overtime when it is soiled it is almost impossible to clean yourself.

 

[Aglet]

Ducati's desmo was the best parallel I could think of in the consumer world that some people would be familiar with.
Sure, it's got it's drawbacks and limitations and conventional valve trains can be pushed to very high speeds.

But doing something similar for a camera mirror is a pretty good idea, as long as it doesn't accumulate any wear and start to slop around.
The extra space taken by the extra cam hardware is partly compensated by the removal of a large return spring and damping items. Cam profiles can be designed to keep acceleration forces within optical stabilizers' best performance frequencies and this should be more consistent over temperature than passive stabilizers.
I think there are more positives to this than negatives and kudos to Canon for giving this a try. It's likely the last big improvement in mirror-slappin' we'll see before ML & EVF tech overtake more of the market moving into upscale, mainstream products.

Fuji's XT1 has a very good EVF system and their recent firmware update allows, I think, full silent, no vibration electronic shutter to 1/32,000 altho I don't think it's a global type shutter. If we can get global shutter working at this speed on large sensors that'll be another plus for EVIL/MILC systems.
Hmmm.. I'd better install that firmware update and make sure that it works as well as I think.

 

[TAF]

Canon as a company seems to have no corporate memory. A pellicle mirror would eliminate the moving mass entirely, and Canon made and sold them 40 years ago. Surely they could reintroduce them, and perhaps improve them as well.

Whose memory is failing

Canon has made several Pellical mirror cameras over the years. Some were limited editions, but two or three models were mass produced. None of them caught on.

First came the Pellix, then the Pellix QL, then the limited production F1-HS, then the EOS RT, and finally the EOS 1N RS. I think that they remember the failures very well.

Refresh your memory.

http://www.canon.com/camera-museum/camera/film/data/1956-1965/1965_prx.html?lang=us&categ=crn&page=1956-1965

http://www.canon.com/camera-museum/camera/film/data/1956-1965/1965_prx.html?lang=us&categ=crn&page=1956-1965

http://www.canon.com/camera-museum/camera/film/data/1976-1985/1984_nf1-hsmd.html?lang=us&categ=crn&page=1976-1985

http://www.canon.com/camera-museum/camera/film/data/1986-1990/1989_eosrt.html?lang=us&categ=crn&page=1986-1990

http://www.canon.com/camera-museum/camera/film/data/1991-1995/1995_eos-1n-rs.html

Thank you for those links. They make my point for me...Canon clearly has done it (more than 50 years ago, my bad to think it was only 40), it was popular (quoting form the first link - "it was a popular camera."), and having used the later RT, I can state that it worked very well, thank you.

With modern fabrication technology, the limitations of that tech could be eliminated.

Although a high quality EVF might be a cheaper option these days.