Pete aka UFO,
The reason that folks like Pondria and others including myself that have reported that the wide open F stops with aperature metering is very accurate but when we stop down to F5.6 we have overexposure value. My belief is that in wide open F stops there is no different whether your lens is a Canon or an adapted lens from other brand like the Zeiss. However, as you stop down the metering system built into the Canon DSLR especially the newer model requires input information from the lens to let the metering system know that the lens is stop down thus the built in metering system should compensate/take into the account for the Canon lens. On the other hand the Zeiss has no information to tell the Canon built in metering system to compensate for the stop down f stop. Thus, the metering system thinks that there is less light and thus it requires a slower shutter speed yielding overexposure. This is like in the day when folks used reflective metering on the black object the metering interprets that there is not enough light and thus requires a slower shutter speed yielding overexposure with black objects like the groom's black tuxedo and under exposure the white objects like the bride's white dress.
When you use the grey card the information is accurate thus no compensation information is required. This is probably why you do not see the error in your metering. It is like using wide open f stop where there is no difference between Canon and Zeiss lens opening for the light to enter.
In some cases as Erik's image below. You can see that green is interpreted in the Zone system as 18% grey and the ground that surrounded the plants is relatively interpreted as 18% grey with Zone metering system. This is why Erik shots still works out well even without grey card here. Trust me try to shoot lanscape with a wide angle lens where the scenary is not anywhere close to 18% grey the stop down metering will have problem metering the scene.
-Son
Edited by PhotoCinematic on May 31, 2005 at 12:26 AM GMT
pondria, i use a pocket-size whibal 18% card. but, in most cases i've been able to go without using a card. either i'm lucky or my 1Ds meters very well -- or perhaps both.
either way, here's a shot from today while playing with my zeiss 28 f/2. there was no surprise that this lens performed extremely well. aperture was f/5.6. http://www.flatdraft.com/outgoing/2C8V1894_edit.jpg
-erik
Edited by flatdraft on May 31, 2005 at 12:20 AM GMT
Has anyone done a comparison of the zeiss 50mm f/1.7 and the Canon 50mm f/1.4? I have the zeiss 50 1.7, but haven't used it on my 20D yet. No adapter, but soon...
So far, only Two C/Y mount Zeiss have impressed me.
Distagon 21/2.8 - I wish I had bought it before the price jump.
Distagon 28/2.8 - Solid. So cheap that you can fogive any inconveniences that it brings in.
Not a good story.
I bought Planar 85/1.4 after reading many legendary stories about it over the web. It is a solid performer but I am still waiting for the "mythical" magic images will show up someday.
Yes, Pondria unfortunately the myths of the Zeiss 85mm F1.4 was on film camera but never cross the border for digital sensor. The Zeiss 85mm that will bring magic to the table is the Zeiss 85mm F1.2 Anniversary. Here the combination of Zeiss T* coating, Aspherical element and built in Floating elements bring myths to reality.
I would be curious to know if the RMS metering is being fooled by the contacts being shorted out by the adapter. There is an insulative tape that has light residue on the glue side, called Kapton.
It is often the "little yellow tape you have to pull out to activate XYZ product" that comes with a pre-installed battery. Some types have big-time glue.
It would be a cool experiment to see if one applied it (glue side to adapter) to the adapter and the camera acted differently. As an engineer I can imagine that the firmware developers actually handled the "open" state in the firmware, whereas the "low resistance" state is too flakey to read right.
Pondria wrote:
UFO and Erik,
Thank you very much for trying it out. Was it a solid gray card ? Can you put a vertical bar kind of object that you would use to focus with the split screen ?
I have small white and black squares in the corners of my grey that I used to set the focus on and then metered on the middle of card. The card is 8.5 "x 11" and the small squares are 2".
I will repeat this experiment on a scene with more contrast. I don't understand how a black object (that may not be metering correctly for exposure) will meter differently stopped down versus wide open. The meter doesn't know that it is black and is metering it to be 18% grey. It will only be off in terms of the "correct" exposure and not the relative change in exposure settings when stopping down.
It has been amusing reading all the comments on this thread. I've been a working pro nature photographer for 30 years now, often using Zeiss glass, and Canon, and Nikon, and Schneider, and Pentax, and Leitz, and Minolta. The glass you use, how much you spend on your camera equipment, or how you focus, has nothing to do with whether you are a pro or not, or how good your images are. I've seen some incredible images taken with a point and shoot, and some really crap taken with a $40,000 rig. (I see a lot of photog's work in my workshops, and one of the greatest nature photogs that I know of at the moment uses an old Pentax 1000 and print film - I've been trying to get him to switch to the magic of digital, but that is what he is most comfortable with, and that is what he will continue to make the best photos with. Good for him.)
I almost always use manual focus on my 1ds2 (or whatever camera I happen to be using) no matter if it is a MF Zeiss or AF Canon - like Guy and others I prefer to do the focus myself most of the time, and speed really has nothing to do with it (unless it is moving wildlife or a model that is bouncing around), but that doesn't make my photos any better or worse than the guy standing next to me using AF - it really is all what you get used to and good at. There was a time when I could stop the car, get out my Zone IV 4x5 rig, take an exposure reading, and make a photo AS FAST as anyone else with me using 35mm gear - practice makes perfect. And as far as exposure goes, goodness, I've got a historgram on my camera...
Lots of wonderful images displayed here, and I hope everyone continues to shoot and post, no matter how you focus or what glass you use...
stuuke wrote:
Anyone have a direct comparison with the Zeiss and Canon/Sigma wide angle lenses? Or any other lenses while you're at it.
Read my earlier post.
If possible I would like to see some shots that would be considered great shots comparing the two brands. I realize when people take test shots they are not necessarily looking for great photos but sometimes it is hard to to look at an image that is a good image and know if it is the equipment or just a great well composed and exposed shot.
Folks, the Zeiss 21mm F2.8 goes beyond high price gear versus low price gear. It is the ANSWER to digital sensor problem for wide angle lens; the light angle is too acute at the edges of the full frame sensor. This discusion of the Zeiss lens did not come up when the recording medium was film or folks that still using film do not see the importance of the Zeiss glass.
The following paragraph is reportedly in the Canon focus screen instruction, which I do not have. Can anyone that has it check ?
"The Ec-A, Ec-B, Ec-I and Ec-L focusing screens have a prism at the center of the center. A correct exposure reading cannot be obtained with evaluative metering or spot metering based on the center area where there is a prism. Use centerweigthed average metering or off-center spot metering with these focusing screen."
charlesk wrote:
Without weighing in one way or the other on the Zeiss glass issue I can only say that viewing 800-pixel-wide resizes on the Web doesn't really tell you much. Pretty much any lens can produce sharp results at that resolution. --c
I was just thinking that charlesk...without wanting to enter the debate myself, I'd say any shots wanting to demonstrate a sharpness of a lens should include 100% crops.
How I got here! First I just got a bit green next I was looking like a lime! These photos makes me feel like there's too low sugarlevels in my blood no strength to compete! There's only some of us who got this magic eye to do special visual work, it's a gift have this 3d way of thinking what you see is what you can get out of it! Persons who have it does'nt need any adoration from me they just know what they are capable of! Like I formerly said here's very talented people with very nice equipment to make even dog poop in dumping area just look interesting!
aperture was f/5.6.