Contax 645 w/ DB: 35/3.5 vs. 45/2.8?

[carstenw]

I am (very) slowly building up a Contax 645 system (for non-professional use, at least initially), and am wondering about the 35 vs 45 issue. I would like to do dusk-HDR-type architecture shots with it (going easy on the HDR...), and will likely need to stitch with either lens (?), as I expect to have to start with a Kodak DCS 645 Pro back, or similar, due to cost, so does it really make much of a difference? I have read that the 35 has more mojo, but then it is also about twice as expensive, so given the crop issue, I thought that maybe I could save a bit and go with the 45.

I guess the DCS Pro for dusk shots might also be a problem, due to the lack of long exposure time ability?

Does anyone have some experience to share?

 

[Guy Mancuso]

Carsten if your after stitching than the 45mm could be just perfect around 35mm in 35 FF world and you can keep any barrel out of it with a longer lens. I am just talking lens choice , don't know the quality of these two lenses.

 

[carstenw]

(Using Nikon's FX as a short-cut to full-frame 35mm, since I can't think in MF yet)

The question is how long it is on a DCS 645... I think the sensor is 36x36mm (51mm diagonal), which means that compared to a 60x45mm (75mm diagonal) sensor, the crop factor is about 1.5, making the 45mm a 67mm lens, which on MF is equivalent to about 42mm in FX. The 35mm lens would be about a 32mm equivalent in FX, a much nicer fit, requiring less stiching.

I would much rather spring for a P25+ or something like that, but the cash just won't be available for a while. Is there a decent, long-exposure-capable, 36x48mm DB for not much more than a DCS 645, resolution not so important, but >16MP? (My WATE and 90AA M lenses are in the B&S to help finance this

 

[David Klepacki]

Carsten,

If your budget allows, the Distagon 35mm is the better choice for your intended use. It is more expensive than the 45mm, but it will hold its value longer due to its wider and more desirable focal length. Both lenses are highly flare resistant due to the Zeiss T* coatings.

The signature of both of these lenses, in terms of color rendition and tonality are almost identical. The major difference is really in the DOF. The Distagon 45mm is capable of a shallower DOF than the 35mm. Also, the 45mm does not hold the edge and corner detail nearly as well as the 35mm.

Since you are coming from a 35mm background, maybe a comparison with the Contax Zeiss Distagon 21mm lens for the RTS cameras might help. The Contax Zeiss 645 35mm lens is really the 645 version of this famous lens. It is the same design with roughly the same angle of view, and made with the same materials and coatings. And, even though the MTF chart looks very different, the larger 645 format compensates perfectly. In fact, I believe Son Minh Pham may have done side by side shots with both of these lenses showing the 645 version to be every bit as sharp and detailed, but of course capable of larger prints due to the format.

Another option is to consider the 45-90 zoom. In my opinion, the 45mm end of this lens is actually sharper than the prime, if you do not require the extra speed of that prime. I think this lens costs as much as the 35mm, but you may get more for your money. You will get perhaps the sharpest normal focal length in any lens lineup. At 70mm, you get a normal lens that is extremely sharp and with no distortion. And at the 90mm end, you get a nice 1:4 macro as well for convenience. This may be the only lens you need for awhile. I know fellow photographers who shoot entire weddings with just this one lens.

As far as the back, long exposures is going to be a challenge with the Kodak back. I used to own one. That back does not have the thermal engineering to support long exposures. You should be able to find a good deal on a more modern used 22MP back. If not, you may be better off shooting this camera with film for awhile, until you can afford a better back. I do not recommend the Kodak back for what you want to do. That back is notorious for developing bad pixels over time.

 

[Jack]

Carsten, the DCS sensor factors relative to 35mm are approximately .83x if used full-frame square and .93x if used as a 3:4 (28x37) rectangular.

Cheers,

 

[carstenw]

...hmm, so how is the crop factor calculated here...

Generally, it is the ratio of diagonals, but I read somewhere that a more perceptually accurate measure is the ratio of horizontal angles, rather than diagonals, due to the way we read images. Is that how you get .83 rather than .67, and so on?

I will see if I can afford a 35mm, David. I have already read somewhere that the 35mm lens is more special, and the effective focal length seems more useful anyway. Do you know what the distortion is like for each?

 

[David Klepacki]

Carsten,

You used the word "architectural" in your original post, which generally places severe constraints on distortion. I would not classify either of these lenses as architectural lenses, and they both have a touch of nonlinear distortion at the edges.....which can annoy some photographers. However, since you are willing to stitch images, you can cheat the lenses by overlapping more images and cropping out the edges, but it is a lot more work. Also, neither of these lenses offer any relief of converging verticals as there is no perspective correcting shift ability. There are software solutions available that can correct distortion, the most famous being the work of Helmut Dersch (search on panotools).

There is plenty of debate about the effective removal of distortion via software. As a rule of thumb, the more linear type of distortion characteristic, the better the result from software. I have not removed distortion from these lenses, but I would say that the distortion is minimal enough, that software removal should work quite well for either one, especially if you will be using a cropped sensor to capture the image in the first place.

 

[carstenw]

As I mentioned, this is not for pro use, so I am not concerned about absolute perfection, although I would like to get a decent solution. From what I have heard, the 35 lens seems more desirable in general, and not only for its wider view, so I will see if I can scare one up at a reasonable price.

Does anyone here have one they want to sell?

 

[Chuck Jones]

Carsten, I've owned both of these lenses for a long period of time, as well as shot both extensively. They are both great lenses, in my opinion. My personal favorite of the two is also the 35mm, but be warned, it is a tank. Big piece of glass. Not that the 45 is a small lens, just smaller than the 35.

 

[Digitalcameraman]

I am (very) slowly building up a Contax 645 system (for non-professional use, at least initially), and am wondering about the 35 vs 45 issue. I would like to do dusk-HDR-type architecture shots with it (going easy on the HDR...), and will likely need to stitch with either lens (?), as I expect to have to start with a Kodak DCS 645 Pro back, or similar, due to cost, so does it really make much of a difference? I have read that the 35 has more mojo, but then it is also about twice as expensive, so given the crop issue, I thought that maybe I could save a bit and go with the 45.

I guess the DCS Pro for dusk shots might also be a problem, due to the lack of long exposure time ability?

Does anyone have some experience to share?

You may be limited for these long exposure kind of shots due to the type of back you are trying to use.

Check out www.sargentphoto.com

Kim Sargent has been using the Contax system for 4 years now with the 35 and 45mm leses. He is one of the most acomplished Arch photographers in the world, publishing in Arch Digest and Florida Design often. I have many of Kim's images and I can see how beautiful the 35mm and 45mm lenses render detail with the Phase One P25 camera system. He also prefers a longer lens but sometime the space is small so 35mm lens has to be used. The majority of his site is digital but not all of it.

You will be very happy with both but I would go for the 35mm. And considering the crop of your current digital chip, the 35mm would be the correct choice.

Good Luck,




Chris Snipes
Image Production, Inc
Phase One Expert

www.imageproduction.com
[email protected]

813-335-2473 Cell
727-823-8909 Studio

 

[carstenw]

You may be limited for these long exposure kind of shots due to the type of back you are trying to use.

I am aware of this, but there isn't so much I can do about it. I am not a professional, and my budget for this doesn't extend very far. Can you recommend a Phase back capable of long exposures, which comes in at around the same price as a Kodak DCS 645 Pro, second-hand?

You will be very happy with both but I would go for the 35mm. And considering the crop of your current digital chip, the 35mm would be the correct choice.

I will try to find a 35mm lens, but with the prices hovering around or just below 2000 Euro, I might have to stick with the 45mm for now and upgrade later.

Do you, or does anyone here, have any experience with the Arsat 30mm f/3.5 for Contax?

 

[David Klepacki]

Carsten,

Since you are looking at the Arsat, there is one more lens that you might want to consider, since the price is right. You should check out the Hartblei 45mm Super-Rotator, which is available in Contax 645 mount. This lens is much softer than either of the Contax lenses, except at F16. The obvious benefit is that you will have shift and tilt capability, and so can produce images that the Contax lenses cannot. Neither the Arsat nor the Hartblei lenses will have the color rendition and brilliance of the Zeiss glass, but that does not mean these lenses may not be useful to you.

 

[carstenw]

I would love to get the Hartblei, but I cannot find one. I read somewhere that Phase (bad bad Phase) bought up the rest of the stock, and there are none on eBay. Do you know where I could find one, and what the price might be? Using a Hartblei instead of the Contax 35mm lens would certainly be more than acceptable, until I find the money.

 

[David K]

I would love to get the Hartblei, but I cannot find one. I read somewhere that Phase (bad bad Phase) bought up the rest of the stock, and there are none on eBay. Do you know where I could find one, and what the price might be? Using a Hartblei instead of the Contax 35mm lens would certainly be more than acceptable, until I find the money.

You might drop Chuck Jones a note and see if he's interested in selling his... unless he's already sold it. I just sent him an email pointing him to this thread... hope it works out.

 

[robmac]

FYI - ffordes in UK has two copies of the C645 35mm for 1200 pounds (including 17.5% VAT on the profit margin) or roughly 1600 euros.... To get the ex-VAT price you'll need to drop them an email or call.

 

[carstenw]

I think they heard you writing, and raised the prices to 1299 That is almost 1700 Euro, or about 2-3 times what I can find a decent 45mm for, and much more than a Hartblei as well, I presume. I will try the Hartblei route first. It is a useful lens, and stitching 4 images with it should be easy, to get some wide going

 

[robmac]

There is also the chance a typing error might have been involved. Just a chance of course...;>

 

[carstenw]

Btw, I found an Arsat 30mm for about 180 Euros, so I just bought it. It will be fine for lo-res needs, since I will lose resolution via distortion removal from an already low 16MP of a Kodak or similar DB. I still want something more serious for panoramic architectural uses and so on.

 

[irakly]

i have an impression that 35 is a better lens overall, but these two are not substitutes for each other. don't forget that 45 is a half stop faster. although, i should say, 45 is pretty freaking good in its own right.
if you plan on shooting with DCS 645c consider buying a 55mm as your normal lens. it is amazing.
this is the shot a took the other night with 55mm on p25 back.

 

[carstenw]

Well, it seems that a 35mm is on its way to me. I'll report back when it gets here and I have some results (only film to start with).

The camera itself, with waist-level finder and 80/2 has arrived, as well as a 120/4 macro and a hood for it.

My first impression is that it is really well built, but not like the M8. The lenses are solid and smooth, but again, my M8 lenses feel better. The camera is similar to the Leicas I have used in its simplicity. The film back removal lever/button took me a couple of minutes to figure out Everything else is obvious. Now for the less obvious features...

I have one question though: when half-pressing the shutter, it focuses. The button on the rear which I thought would be one-shot focus doesn't do anything, but I probably have to set that up somehow. The question is this though: the first time I half-press the shutter after powering up the body, the motor just spins and does nothing. After that it works fine. Is that normal?

---

Irakly, if I can take shots like this, I will also get a 55 Seriously, I am not sure what I would do with a standard lens on this camera. I have an M8 for that, and will have 35/80/120 for the Contax 645. Maybe after a while I will change my mind, but for now, I am done (once I pick up the Hartblei 45). Oh, there is an Arsat 30 on the way, just for fun. Less than 200 Euro, so what the hell.