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Forum: Pentax Medium Format 04-15-2012, 02:44 PM  
645D & D800 The question?
Posted By Makten
Replies: 80
Views: 8,110
You have obviously not understood what equivalence is and I'm not gonna spend time (again) trying to explain it. At the same DOF, any format have collected the same amount of light per time. Period.
Forum: Pentax Medium Format 04-14-2012, 04:52 PM  
645D & D800 The question?
Posted By Makten
Replies: 80
Views: 8,110
Exposure is irrelevant when comparing different formats. The mentioned examples collects the same amount of light; photons, at a certain shutter speed. ISO 100 on APS-C is NOT equivalent to ISO 100 on FF.



I found that FF was a lot cheaper than APS-C, since I could use old, manual focused and fast lenses on the D700, while their equivalents on the D300 would cost a fortune.
Forum: Pentax Medium Format 04-14-2012, 04:47 PM  
645D & D800 The question?
Posted By Makten
Replies: 80
Views: 8,110
55/2.8 on the 645D eqauls a 43/2.2 on 24x36. If you want short DOF, that's not very impressive. There are plenty of f/1.4 lenses for the 24x36 format, and from that perspective f/2.8 might be "too slow".



And the Pentax is four times the price of the Zeiss.



Yeah, if your pockets are deeeeeep and full of gold, just buy the 645D (and a tripod). But if you want to shoot mostly handheld and/or get the blurriest background, a D800 is a better choice.
Forum: Pentax Medium Format 04-14-2012, 09:05 AM  
645D & D800 The question?
Posted By Makten
Replies: 80
Views: 8,110
It's not the APS-C sensor that's not good enough. It's the lenses that are too long and/or too slow because they were made for a larger format, just like those for the 645D.
Then of course cost is a significant factor. An APS-C pro camera with pro lenses isn't much cheaper than ditto FF (35/1.4 on APS-C equals 50/2 on FF), while the 645D is muuuuuuch more expensive.
Forum: Pentax Medium Format 04-14-2012, 02:23 AM  
645D & D800 The question?
Posted By Makten
Replies: 80
Views: 8,110
You could say the same about the Nikon system. There are plenty of manual focus lenses that are outstanding and costs nothing. Even a brand new Zeiss ZF lineup is really cheap for what you get and they will easily outresolve the D800 sensor.

--------------

Personally, I'd choose the D800 because of the lenses. The difference in sensor size is just not enough since the 645D is cropped and the lenses are slow. I also hated the Pentax viewfinder when I tried one.
Forum: Pentax Medium Format 02-21-2012, 10:17 AM  
Pentax 67ii service manual
Posted By Makten
Replies: 22
Views: 6,118
Ah! Failure of the aperture mechanism would make a lot of sense, because the problem came when I attached my extension tube, which doesn't have a coupling for the aperture. So maybe something went wrong there. But still, the aperture works fine in manual mode. :confused:
Forum: Pentax Medium Format 02-20-2012, 10:08 PM  
Pentax 67ii service manual
Posted By Makten
Replies: 22
Views: 6,118
I don't know if it is the prism, but suddenly an error message ("PErr") appeared in the display and then the camera was stuck. This happened once before, but fixed itself after a while, but not so the last time.
Now I have to isolate the contacts between the prism and the body, and I can only use the camera with manual shutter speeds (full stops) without metering. This seems to be a fairly common problem with no solution. :(
Forum: Pentax Medium Format 02-19-2012, 04:53 PM  
Will the 645D last?
Posted By Makten
Replies: 164
Views: 17,134
That's what I meant. Of course I'm not doing it all, and no one else does either. :)
Forum: Pentax Medium Format 02-19-2012, 06:37 AM  
Will the 645D last?
Posted By Makten
Replies: 164
Views: 17,134
I'd definitely prefer to have ONE camera to do it all, if it's small enough to carry with me all the time. Neither the 645D or the D800 is, but the D800 comes close when you consider everything else and the low price.
Forum: Pentax Medium Format 02-19-2012, 04:58 AM  
Will the 645D last?
Posted By Makten
Replies: 164
Views: 17,134
Ummm, no. 6x7 is 4.5x larger than 24x36, while 33x44 is only 1.7x larger than 24x36.
A more relevant comparison is between APS-C and 24x36 and the related prices.
Forum: Pentax Medium Format 02-18-2012, 04:38 PM  
Pentax 67ii service manual
Posted By Makten
Replies: 22
Views: 6,118
I'd really want one! My metering prism is dead. :( PM?
Forum: Pentax Medium Format 02-18-2012, 04:35 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
P67II with 90/2.8 @ f/8, 1/125 (handheld) – Tmax 400 @ 800...


Hunched by Martin Hertsius, on Flickr
Forum: Pentax Medium Format 02-11-2012, 04:55 PM  
Nikon D800E vs Pentax 645D
Posted By Makten
Replies: 148
Views: 28,634
I know what I wrote so I don't have to read it. If you don't want to discuss, don't start with claiming things you don't know anything about.


Yeah, but it could also be better lenses, better de-Bayering interpolation, or a combination of lots of things. Comparing images from different sources is seldom fair.
Forum: Pentax Medium Format 02-11-2012, 02:47 PM  
Nikon D800E vs Pentax 645D
Posted By Makten
Replies: 148
Views: 28,634
Still you claim that small pixels "degrades the image". Interesting.

Please, don't speak for me, will you?

That difference is because of the sensor size increase, not because of larger pixels. Now, if that FF frame was 20 mpix and you scaled it down to 10, most likely it would have been even better.

When did I mention "1 to 1 pixel peeping"? :confused: You said smaller pixels are worse, I said they are not. Now you are into comparing different pixel sizes without considering the sensor size.
Just to prove you are wrong: How about making a sensor with only one, large pixel. Would that be better than let's say 100 pixels? No, of course not.

Smaller pixels give more noise per pixel, but also less readout noise. And smaller pixels means more pixels and thus more signal, more information per image height. In the end you get something that is fairly equal but with a little bit of different look. There's no reason for pixel peeping if you don't know the total amount of pixels, whatever size they have.

You can do both, but you don't seem too interested, right?
Forum: Pentax Medium Format 02-11-2012, 01:24 PM  
Nikon D800E vs Pentax 645D
Posted By Makten
Replies: 148
Views: 28,634
It's the other way around. You are confusing high pixel pitch with small sensors. Or are you seeing "image degradation" in every new camera with more pixels than its predecessors? :lol:
Forum: Pentax Medium Format 02-11-2012, 11:59 AM  
Nikon D800E vs Pentax 645D
Posted By Makten
Replies: 148
Views: 28,634
Not over here, but one third is still an extremely large difference.


Of course it is, as it increases the chances for you finding the lenses you want, even if it might just be one.


Exactly, but there are plenty of f/1.4 lenses in the Nikon lineup. I wouldn't call it a problem; it's about possibilities.


Personally, I'd choose the one with AA filter because of "smoother" look, even if I'd lose some resolution. I don't like the artefacts (aliasing) that are often produced by AA-less cameras.

I'm not saying that the D800E will be as good as the 645D, but still it would be really, really stupid not to compare them.
Forum: Pentax Medium Format 02-11-2012, 11:41 AM  
Nikon D800E vs Pentax 645D
Posted By Makten
Replies: 148
Views: 28,634
In my opinion, NOT comparing them would be ridiculous. The D800(E) is one fourth of the cost of a 645D with almost as large sensor and almost as many pixels, PLUS a huuuuge range of lenses that are also much faster (shorter DOF, et cetera).
Forum: Pentax Medium Format 02-10-2012, 05:05 PM  
90 f2.8 thread
Posted By Makten
Replies: 25
Views: 2,238
Depends on the image circle, yes. But of course you can use it on a smaller format than intended (you don't make a 300 mm lens with a larger image circle than necessary, I can assure you).

A smaller image circle can actually give a little bit higher (center) resolution, so there are benefits with using an as small image circle as possible. But you'll lose corner sharpness and get worse field curvature as well.
Forum: Pentax Medium Format 01-25-2012, 03:02 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
On topic this time, with the P67II!


Crossroads by Martin Hertsius, on Flickr



Shoes by Martin Hertsius, on Flickr


Both shot with 105/2.4 stopped down to f/11 and f/8, Tmax 400 in Tmax developer 1+4.
Forum: Pentax Medium Format 12-28-2011, 05:37 AM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
I use Tmax developer @ 1+4 and use the standard procedure with agitation every 30 seconds. I have only tried D-76 and Rodinal (Fomadon R09) before, and I didn't get as good results then. Rodinal is nice, but gives a boost to the midtones that doesn't really fit what I want to get. D-76 on the other hand is a bit "muddy" but a bit more forgiving when it comes to high contrast scenes.



ISO 1600 is two stops underexposure, but since you can still dig out very much in the shadows when scanning, developing for 800 (+1 stop) works fine. This also means that you can expose for 400-1600 on the same roll of film with decent results. Developing further will only increase contrast since it won't do anything more to the shadows if you don't use a special developer or stand development (which often gives uneven development across the frames).
When it's dark I just expose as high as possible and don't use the meter at all, since it will be fooled by point lights anyway. Down to 1/30 second is fairly safe with the Bessa.
Forum: Pentax Medium Format 12-27-2011, 03:31 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
I haven't shot any MF since october or so, but I managed to get myself into it again recently, at christmas.
Voigtländer Bessa III 667 and Tmax 400, exposed for ISO ~1600 and developed for 800...


Stora Mossen by Martin Hertsius, on Flickr



Stora Mossen II by Martin Hertsius, on Flickr



Julafton by Martin Hertsius, on Flickr
Forum: Pentax Medium Format 11-12-2011, 01:10 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
I know that very well, but f/16 is seldom necessary. The 645D has only a 1.27x (linearly) larger sensor than 24x36, which equates to an 1.27^2 = 1.6 stop difference in DOF. Not at a given focal length, but at a given angle of view. ;) The difference between 645D and 6x7 is ~2.6 stops. Which means that f/22 on 6x7 gives the same DOF as 22/(1.4^2.6) = f/9 on the 645D.

Largest possible DOF might be a nice thing, but one should remember that most lenses give their highest contrast and sharpness at about 2 stops down from wide open. So the 120/4 Macro is probably much better at f/8 than at f/16. And then we haven't even considered diffraction, which can be an issue if you want to squeeze the best out of the fairly small 645D pixels.
You might as well get the same softness in the background from diffraction at f/16 that you would have gotten from limited DOF at f/8, while the subject in focus is just as smeared by diffraction as the background. I can't see how that would be a good thing.

So, don't stop down further than you have to! :cool:
Forum: Pentax Medium Format 11-12-2011, 12:22 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
Itshimitis, not to underestimate your talent, but have you tried not stopping down so darn much? :D Even if diffraction is of little influence on these small images on the web, I'm sure your lenses will perform better if you choose a larger aperture; say f/8 and thereabout. You'll have plenty of DOF in most cases of the above images anyway. I seldom use f/16-22 even when shooting 6x7.

----------------------



I don't know what scanner you use, but with the V700 I can't get even close to pure black or white even with a clear film base or pitch black densities of an overexposed negative. So the "raw" scan will always look dull, regardless of the contrast of the negative.



That's beyond my skills. I just try to place something in the middle of the tonal range of the scene at middle gray, and the latitude of the film usually takes care of any error. One stop above or below perfect exposure is really no problem with Tmax 400 or Tri-X.

----------------

More Bessa and a scene I wouldn't even try with a digital camera. :)


Bornsjön by Martin Hertsius, on Flickr
Forum: Pentax Medium Format 11-10-2011, 02:00 PM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
No no, when I shoot at daylight in full sunshine, the negatives hold much lower contrast than that. As a matter of fact, it took me several minutes to even see the ground below me at the beach. It was close to pitch black, while the buildings on the other shore were quite bright. I actually thought the ground would end up unexposed.

Edit: The Digiflash didn't read anything at all when pointed at the sand or the sky, but I think it was -2 EV @ ISO 400 on the water.
Forum: Pentax Medium Format 11-10-2011, 11:36 AM  
Post your medium format photos!
Posted By Makten
Replies: 12,533
Views: 2,045,305
Thanks! This time I used my handheld Gossen Digiflash, because the center weighted meter of the Bessa is probably not good at all for this sort of scene with very high contrast.
It was my third ever night shot with film, but it obviously turned out well. :) I metered at the water edge and placed that at medium gray.

I post-process all of my images severely. For this image I masked the sand and wooden horse and applied separate tone curves for the top and bottom of the image.
This is what the negative looked like, straight out of the scanner, just flipped to positive (I scan as slide film to get as "raw" data as possible):

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