save the mirror?

[@imagesBV]

As reported by some of the (not as good as eos magazine) photo magazines, some manufacturers are planning the end of the mirror.

Is this a good thing?

I once ruined the CCD on a video camera while recording an eclipse, the crescent image of the sun burnt into the sensor permanently.
Obviously the sensor is not exposed in an dSLR until the shutter is released - is this going to be a problem with mirrorless cameras?
CMOS sensors are used rather than CCD but the potential might still remain.

[colin C]

Re: save the mirror?

............. some manufacturers are planning the end of the mirror.

Is this a good thing?

It could be.

In the days of film, there were some Canon cameras with a pellicle mirror that allowed light to go through it to the shutter. Because the mirror didn't have to lift and get out of the way, it was a very fast camera with high shutter speeds ............... for it's day.

You only need the mirror to see what is happening through the viewfinder and via the submirror, to focus. With the increasing use and reliability of electronics, there is no reason why these functions couldn't be achieved electronically.

Colin

[George Bear]

Re: save the mirror?

Yes it's called EVIL (Electronic Viewfinder Interchangeable Lens) and is becoming popular in entry level DSLRs from Tier 2 manufacturers ... so not before the Tier 1 manufacturers (Canon x000 series?) has no mirror?

But IMvHO ... there is not substitute for seeing things via just glass optics (as is the case now) until such time that electronic displays (I'm talking viewfinder, not rear screen) improve.

[Google[bot]]

Re: save the mirror?

It will be a while before mirrors are dispensed with yet.

For the following reasons:
1) Looking through the viewfinder cost nothing in terms of battery power. Having a FF sensor and 3" rear screen "ON" when composing a shot will drain the battery fast.
2) The rear screen resolution and visibility in bright sunlight isn't quite there yet.
3) Having the sensor powered up will result in a LOT more noise. To see how much, take a pic at ISO 6400. Now use video mode or live view for several minutes and take another photo at ISO 6400.

[@imagesBV]

Re: save the mirror?

'Having the sensor powered up will result in a LOT more noise.... '

I use live view when taking landscapes with the camera on a tripod .....didn't know this makes more noise.....perhaps not at ISO100?

[MX5]

Re: save the mirror?

'Having the sensor powered up will result in a LOT more noise.... '

I use live view when taking landscapes with the camera on a tripod .....didn't know this makes more noise.....perhaps not at ISO100?

I think it's because the sensor warms up when in continous use ... which == noise. They'll be providing air cooling or N2 cooling ;-)

[DrJon]

Re: save the mirror?

I have a 5DmkII as my main camera and a Panasonic GF1 as a light-weight walking around and holiday camera (with 20/f1.7 and 14-140 lenses - double the numbers for 35mmm equiv), so here are my thoughts on the subject, in case of interest...

I'll start talking about the EVIL GF1, for those that are unfamiliar with the cameras.

While the GF1's sensor is a quarter the size (though with less pixels) it still takes low noise high detail pics at ISO 400 and can be carried around without any major effort. I used to use a Canon G7 for this and the GF1 is in a different league other than in very good light. You can't do this with cameras with a mirror (well, and a decent sized sensor). Note the new GF2 is quite a bit smaller (but I'm not swapping, I like my GF1).

While you suffer a bit from the smaller pixels (vs. the 5DmkII) you gain on Depth of Field. Adding the 20mm (40mm equiv) Pancake lens (which is very sharp even wide open) you get a lens that passes light as f1.7 but gives depth-of-field of f3-ish. This is very handy and the combination will fit in my jacket pocket (okay, just, the G7 was better at that) or a small camera bag.

For holidays I can put the 28-280mm equiv lens on it and stay with that all day, plus have the f1.7 in a pocket for when it gets dark. The 28-280 is 3.3" long, the 40mm 1".

Focusing... the GF1's Contrast detect focusing is very fast, although not quite as fast at DSLR phase-detect focus. (Panasonic seem to have nailed this, they are miles ahead of everyone else, but I'm sure the others will work out the trick at some point.) It's in a different league to the Canon Contrast Detect live-view focusing (I keep mine set to use Phase Detect in Live View, despite all the faffing about with mirrors). Oh, and it can auto-focus while shooting video (not that I do much of that, but is very handy on very rare occasions).

BTW Pixel sizes: 5DmkII = 41um2, GF1 = 20um2, 7D/60D/550D = 18um2, S95/G12 = 4um2

Sensor heating from operation isn't a big issue, I suspect ambient temperature is more of an effect, unless you are keeping the LCD on continually for some reason. (Based on the pics I've taken and how cool the camera feels.) Anyway, as I said (elsewhere on the forum), the 5DmkII easily beats it in low light (at super low light it wipes the floor with it) but you would expect that. I think Panasonic try to keep as much detail as they can, so the pics can look a little noisier, but overall I think it's a pretty fair compromise. Compare the ISO400 church interior pics, it doesn't suck (look at both noise and detail, as they are a trade-off):
http://www.dcresource.com/reviews/ca...review/gallery -> IMG_0034
http://www.dcresource.com/reviews/pa...review/gallery -> P1000012
(I've posted these links before, but I'll include them again rather than cross-referencing, to keep everything in one place. Personally I think the GF1 shot is better than the 7D one, which seems to have lost more detail. It's only one pic, any more analysis would make this even longer than it already is, but at a minimum it suggests there isn't a great deal in it.)

I'm happy with my lenses, and it is my second camera so I have no plans for a large collection, although there are a couple of upcoming ones that look interesting (focal lengths in 35mm equiv):

The Cosina-Voigtlander 50mm f0.95 seems sharper and less "dreamy" that other lenses that open that wide (anyone seen any pics from the Canon 50mm f1.0? Not good!) and is very tempting, remembering the extra DoF you get with a GF1.
Pics: http://ganref.jp/magazines/index/1/0/378 (Japanese site but pics are still pics - they are from a beta lens).

The Panny 200-600 f4-5.6, which is exactly 5" long. (Yes, 600mm f5.6) I'm still not sure about the sharpness, I'll wait for some more reviews.

I mention these to give you an idea of why the little cameras are catching on. You get pixels bigger than a 7D in a teeny package (not so many of them, but there isn't so much in it, 29% across and 15% down). You lose the optical viewfinder, which I much prefer if I'm on a serious photography day, but your shoulder will love you at the end of the day. Also it looks less desirable to a thief and less in-the-face of anyone in-shot (unlike the 70-200 f2.8 on the Canon).

I really like the 5DmkII's huge and bright optical viewfinder, as you can really see what's going on, which is kinda handy when taking photographs. (Also if you are at a major event it's nice to see what happens, rather than just watch it on what effectively is a tiny TV). However I will pay the price of losing it to get the pocketability of the GF1, when that's what I want. I will say the EVF that fits in the flash shoe is really too low-resolution (the rear LCD is good), but when it's very bright it's a must-have, although it's more a case of showing you what you are pointing at, rather than exactly what you are photographing (you need to work that out first).

The GF1 has a huge battery compared to the size of the camera and does really well for battery life. I usually don't even bother with a spare. (Although I did run out when shooting the Elephant Parade in London, but it was after 458 pictures, and the camera was on basically continually while I was doing that.)

BTW the GF1 sensor defaults to having the shutter open, so when you take the lens off you see the sensor (well, through the ultrasonic dust filter). As an aside I do wonder why are Olympus, whose technology Panasonic use, the only people to make an ultrasonic dust filter that actually works? I'm quite unimpressed with Canon's dust shaker and the tests I've seen support this. (My GF1 is miles better than my 5DmkII for picking up dust, despite the exposed sensor and greater depth of field.) The last time I did the party piece of taking the lens off to show someone the sensor they promptly sneezed, without turning away or getting their hand there in time. Luckily they missed the sensor, but you should have seen my face...

In summary I think Canon have a problem here, although only in one market segment, the size of which is still being determined. I can't see they would be thrilled to have to come up with another range of lenses for an EVIL camera. The EF-S lenses probably aren't small enough to compete. The Micro 4/3 cameras eat the lunches of the S95 and G12 as soon as it gets even slightly dull, or sooner if you want the background out of focus. (Also if I buy a newer body I get to take the lenses with me.) I don't think they will be worried about the bigger cameras (G2, GH2, and other manufacturers' similar ones), as the 550D is close enough in size and is an excellent camera. If you want the best pictures the bigger cameras are the way to go, if you want to travel lighter but still get good quality pictures the smaller EVILs own that space. If you want something you won't even know you're carrying then the compact cameras come into it. There's also the price issue, bigger sensors always mean more money for good lenses, so the compact cameras will own the volume business, fighting off the cell-phones at the lower end.

All IHMO of course.

Oh, and don't go picking a GF1 up, especially if they start selling them off cheaply, it's a mini work of art and it could prove to be an expensive experience...