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Forum: Pentax Medium Format 1 Day Ago  
Would Pentax have been better off with a different proportioned 645 digital body?
Posted By TDvN57
Replies: 51
Views: 1,944
There is the big question of the lens mount diameter and image circle size. I'm sure for the cropped 645 it should not be a problem, but for full frame 645 it still needs to be confirmed that the mount diameter and image circle is large enough for a moving sensor.
Forum: Pentax Medium Format 2 Days Ago  
Where to store original 645Z focus screen when removed?
Posted By TDvN57
Replies: 6
Views: 311
I stored mine in a TC, also known as a trash can. :-)
Forum: Photographic Industry and Professionals 2 Days Ago  
Now that the competitor has pixel shift
Posted By TDvN57
Replies: 23
Views: 782
On expeditions I usually take a lot of multi panel compositions which often result in dng files 300mb and larger. With PS I will definitely adjust my workflow. I've only played a little bit with PS on the KP and was pleasantly surprised.

Whether it should be four frames or 16 I can't tell, but I assume that at some point there will be diminishing returns as the number of frames increase.

We do large prints and squeeze every pixel out of a picture. Only about 5% of pictures make the technical cut to be concidered for printing. So I think PS will improve that. The largest print we've done so far is in multi panels abt 3m high x 20m long.

Large files had a number of knock on impacts. Using the cloud as a safe storage medium became impractical and too expensive. I closed my unlimited storage cloud accounts and installed a 60TB home cloud Synology system. Already 25% used.

For offsite backup storage I installed a slightly smaller version with upgrade/expansion capability later as needed, located far from me. Actually on another continent. These two systems sync as needed.

This my storage problem is resolved for abt 10 years at 1/3 of the cost of a conventional cloud system. Plus at home the cloud becomes a nas with transfer speeds close to 100 mB/s.

The next was my editing computer. I'm a PC guy but seriously considered a mac, if it could deal with these large files. Eventually settled on a full house HP laptop with a price tag of a motorcar. That was almost two years ago.

This year my wife became so tired of dealing with slow editing on her computer with large files that she also got an updated laptop, she chose the Lenovo full house, paid a bit less for a newer version, latest tech and faster than my now aging HP.

So if you are thinking of getting into large prints and plenty pixels, be prepared to deal with editing hardware and solving storage issues, they all go together.

All I need now is more talent and skills in taking the pictures :-)
Forum: Pentax Medium Format 2 Days Ago  
Post your medium format photos!
Posted By TDvN57
Replies: 15,572
Views: 2,580,874
Mike I think the lens trumps and makes it MF :-)






As the sun was starting to draw lower the moths (I think they are moths) came flying around the flowers, twisting and turning so fast that actually seeing what they look like is impossible. I pulled out the 645z with 6x7 400mm and handheld with elbow support took a couple of lucky shots.

Shutter speed was 1/4000 and the initial shots were f8 and then I switched to f16 and upped the ISO from 2500 to 4000. Took about 40 shots in total with only one really clear where you can see the legs and mouth etc. But considering these things are so fast that by the time you realize to trigger the shutter they are already gone, so a success rate of 8% is not bad and I'm smiling.... Gotcha moment.

I think the four I got was because they made turns within my frame area and I got them on the tail end after the first twist/turn.[
Forum: Pentax Medium Format 4 Days Ago  
Old shooter with new 645D
Posted By TDvN57
Replies: 72
Views: 5,280
Congrats on the expansion of the business Stan.

I use the Epson P9000 and P800 with Hahnemulle paper and they have a protective spray which if combined with the Epson inks are supposed to give 400 year archival quality. I'm sure that is a calculated durability instead of imperical.

So far prints in canvas and matt paper seem to hold color, but need to wait another 398 years to verify :-)
Forum: Pentax Medium Format 4 Days Ago  
Would Pentax have been better off with a different proportioned 645 digital body?
Posted By TDvN57
Replies: 51
Views: 1,944
I'm beginning to think that shake reduction is perhaps less valuable than better low light performance. I know this sounds contrarian, but think about it for a second. The best SR system advertise 5 stops benefit. Well for starters, 5 stops from what kind of shaking? Obviously is based on some lab designated shake standard. How does that standard compare to realistic in the field conditions? And do I really get 5 stops SR or actually only 3 or at best 4 based on my reality. Maybe it's because I may shake more than what I used to.

On the other hand, if the camera development is done with better low light performance ie. cleaner pictures at higher iso, well then I can crank up my shutter speed say 3 or 4 f-stops and then I know I have a realistic reduction in shake effect on the picture. Not some promised lab based standard 5 stop SR.

So if I have two options, get the 5 stop SR, or get 3 or 4 stops better iso performance, I'll take the iso option.

Just my 2 cents...
Forum: Pentax Medium Format 5 Days Ago  
Post your medium format photos!
Posted By TDvN57
Replies: 15,572
Views: 2,580,874
Went hiking this past weekend and tackled a tough hike made worse with carrying my camera and two lenses. The day promised to be cool with cloud cover as shade.
This only lasted until about 30 minutes before we reached the mountain when the clouds suddenly disappeared and the cool breeze stopped blowing.
At the last resting place before the summit ascend the temperature spiked to 40 deg C which made things rather difficult. At that point you don't have an option to turn around
there is only one way and that is forward.

Sharp Peak as seen from the approach. The pathway on the ascend is very steep and slippery with loose gravel.

645z 28-45 - multi panel panorama



As we descended we heard someone behind us shout as they slipped and fell. The rescue helicopter on the approach to pickup the injured person. I hope he/she is OK.

645z 80-160



One of the views as a reward for tackling this hike/climb. I took a multi panel panorama with the 28-45 to try to capture the view.

Forum: Pentax Medium Format 5 Days Ago  
Would Pentax have been better off with a different proportioned 645 digital body?
Posted By TDvN57
Replies: 51
Views: 1,944
Perhaps ergonomics has a role to play in the shape of the 645z. From memory the handling and feel is very similar to the film 645. With the larger 645 lenses the whole kit feels balanced and easy to walk around with, at least for me.
Forum: Pentax Medium Format 11-12-2020, 07:25 PM  
Post your medium format photos!
Posted By TDvN57
Replies: 15,572
Views: 2,580,874
Nice one Ed. I can imagine the white-knuckle ride those passengers are experiencing. The waves in the foreground makes the ferry experience 'tangible'.
Forum: Pentax Medium Format 11-10-2020, 11:36 PM  
Weird question re. 645 and 67 mount adaptation
Posted By TDvN57
Replies: 26
Views: 936
I like your taste in long glass. Oops goes my budget.... again. :cool:
Forum: Pentax Medium Format 11-10-2020, 05:08 PM  
Weird question re. 645 and 67 mount adaptation
Posted By TDvN57
Replies: 26
Views: 936
Thanks Ed, very helpful info here.

---------- Post added 2020-11-11 at 08:11 AM ----------



Thanks Kaseki, I never thought of a lens in this perspective. Would you venture an opinion on the maximum practical focal length for the 645z sensor, versus say the 100mpx sensor?
Forum: Pentax Medium Format 11-10-2020, 04:08 AM  
Landscape lenses for 645z
Posted By TDvN57
Replies: 29
Views: 1,503
Many moons ago I did some tests to see which setup gives me more stability with the 300mm lens on a tripod.

From memory, I found that mounting the lens on the tripod gave more balance but much less vibration attenuation.

However, mounting the camera on the tripod introduced a tension which was just enough to dampen the vibrations from the shutter. Unfortunately this will not help with the heavier lenses like the 600mm, but the 300mm is still in the 'light' category.

Further stabilization was achieved with a bean bag on the lens. The location of the bean bag I found to be lens specific, because the bean bag adds mass that absorbs the vibrations from the camera traveling through the lens. I know this is an old trick used effectively by many.

For on the field use I mounted the camera on a gimbal and mono pod and cranked up the shutter speed, that works really well, especially wildlife. I found the same with the 300mm, 400mm (camera on tripod mount) and the 600mm lenses (lens mounted).

Earlier this year my second gimbal gave up the ghost and I went back to a fluid video head on a medium tripod. Seems to work much easier and as practical as the gimbal. The video head also uses a much bigger mounting plate, which helps dampening the vibrations from the camera. I also found vibrations to be much less if I don't use a ballhead, especially the ones with a thin leg ( not sure what the thingy is called that connects the base with the ball).

In tests I confirmed my intuition that hanging a weight from the tripod, does not do much to dampen vibrations, it may help to keep the rig being blown away in strong winds, but does very little to dampen shutter vibrations.

I suppose to solve shutter vibrations, it helps to start as close to the source as possible.

Sorry if I'm slightly of topic here...
Forum: Pentax Medium Format 11-09-2020, 04:55 PM  
Weird question re. 645 and 67 mount adaptation
Posted By TDvN57
Replies: 26
Views: 936
I've also been keeping an eye on that 800mm. My reservation is that I don't know how practical it would be. At f6.7 you are already at a disadvantage to focus it, add the 1.4 TC and you will be at f11, which from experience on other lenses is a true challenge to focus.

So I'm wondering what is the practical use? Birding or astro or perhaps the rare landscape at a far distance. Making a large panorama with a 800mm lens will be another challenge because of the difficulty of placing each frame.

Hence my reservation.

So lately I was wondering if I get the 6x7 400mm, add the 6x7 TC 2x, then I'll be at 800 f8, which is only a half stop worse than the 800mm lens at f6.7. Price, weight, ease of use and versatility makes for a strong case in my head.... Or not... :-)

I've even considered the 6x7 400mm with the 6x7 TC 1.4 as an alternative to my 645 A* 600mm, because of less weight, etc when traveling. The 600mm on a monopod has become my preferred setup for wildlife, works really well for me.
Forum: Pentax Medium Format 11-08-2020, 05:20 AM  
645z Preferred Portrait Lens
Posted By TDvN57
Replies: 12
Views: 517
Chris, thanks for these. I looked at your website and your portfolio is fantastic. It's an honor to get input from you, thank you.
Forum: Pentax Medium Format 11-07-2020, 07:38 PM  
Post your medium format photos!
Posted By TDvN57
Replies: 15,572
Views: 2,580,874
Growing up in South Africa, cars were always an important part of life. If a friend bought a new car we would gather around and first open the hood (bonnet) and look at the engine. Everything else were secondary to that.

Seeing Ed's camera reminded me of that, and the words that came to my mind were: ah nice picture but let's first look at your camera. :-)

Thanks for sharing Ed. You are an inspiration...
Forum: Pentax Medium Format 11-07-2020, 07:16 PM  
645z Preferred Portrait Lens
Posted By TDvN57
Replies: 12
Views: 517
I really appreciate all the contributions.

Some years ago I had the FA 150mm 2.8 and loved it, I regret selling it.

The Cinelux lens is interesting, however I see the same problem in close up portraits with fast lenses in mf, that you need to stop down a bit, the model's one eye is in focus, the other not due to shallow dof.

Comparing bokeh I would say the 105mm 67 lens has a very nice and smooth bokeh, which is what I remember from the early 80's when I had a 6x7 and only one lens, the 105mm. The 645 150mm is certainly not far behind if not on par.

On my short list is the 150mm 645 and the 105mm 6x7 and I'm leaning towards the 105mm.

Further advice and experience based comment will be most welcome.
Forum: Pentax Medium Format 11-07-2020, 06:55 PM  
Equivalent focal length - 67 lens on 645
Posted By TDvN57
Replies: 16
Views: 2,685
You are correct if you compare field of view, or crop factor. As others have said the focal length, or magnification does not change.

Some people also refer to the field of view as perceived magnification.

On a side note, also keep in mind that typically with a 22mm lens on 35mm it will have more distortion than a 28mm on a 645z/d.

If you use the lens on 35mm and using only the center portion of the lens, you may also see less distortion. Will be interesting if someone has done some comparative tests.
Forum: Pentax Medium Format 11-06-2020, 11:12 PM  
645z Preferred Portrait Lens
Posted By TDvN57
Replies: 12
Views: 517
I want to ask the forum for advice and learn from your experience.

What would you recommend as the ultimate portrait lens 645 or 6x7 formats for use on the 645z. Could also be non Pentax brand to be used with adapter.

Will appreciate your advice.
Forum: Pentax Medium Format 11-05-2020, 10:01 AM  
Does anyone shoot medium format video?
Posted By TDvN57
Replies: 9
Views: 532
I think the only one that offers proper 4k video is Fuji gfx100. Although it only offers 4:2:2 color on external recording, which is a pity.

They can drop the quality to 4:2:0 on internal recording, but for external recoding you want to have the option to go 8k 4:4:4 color. With a 100mpx or 150mpx sensor, it is a wasted opportunity not to give raw (4:4:4) 8k plugin for an external recorder.

At present these recorders are super expensive, but they just need to give a compatible signal, do that the recorder can be third party.

At the moment the only options for high end video in 8k raw is the canon c500 or the equivalent Sony, or higher and models of course such as Red etc. A small entry kit with a limited range of lenses can set you back 50k before you know it.

Just for home and small projects I would suggest to look at the dslr Canons or Sony have good ranges of intro video cameras. Actually the Canon C300 is not a bad camera but will soon be limited in acceptance by the major clients.

Renting might be the cheaper option...
Forum: Pentax Medium Format 11-05-2020, 06:44 AM  
Does anyone shoot medium format video?
Posted By TDvN57
Replies: 9
Views: 532
I tried to use the 645z's video, but it fails miserably in three areas, imho:

autofocus is just about non existent, manual focus is tough to do in bright sunlight, mainly because focus peaking is very poorly implemented;

although the whole of the sensor is apparently read for the image and then processed into 1920x1080 you can't access the full sensor raw data with an external recorder plugged into the hdmi socket, you get the same image as what is recorded;

it appears that the image stabilization uses a 'warp' formula similar to what you find in Premiere Pro, but only poorly executed. And quick movements and the image wabbles badly.

So of they want to go the extra mile to attract the indy video market and competition to Imax, they should bring out a couple of video/film grade lenses and allow a tap into the raw data from the sensor in video. Just the external recorder will cost more than the camera but it will be much more superior than what is available in the market.

Re the film grade lenses they need proper distance gradings marked on the focus ring and get rid of focus breathing. With the quality of lenses available already with these adaptations they will push Pentax way past some of the popular brands in terms of quality.

Just saying....
Forum: Pentax Medium Format 11-02-2020, 05:24 PM  
Landscape lenses for 645z
Posted By TDvN57
Replies: 29
Views: 1,503
I started playing with stitched panoramas about a year ago and struggled with composition, or better said I'm still struggling with composition. This past weekend I did three panos of the same scene, in three different ways, and only one looked acceptable. If you include too much or too little detail the attraction point of the scene is diminished. If you get it right, the picture really 'speaks' to the viewer.

I found Ewan's explanations a bridge across the river that so far had held me back in moving forward with stitched panos.

So thanks again for introducing his work.
Forum: Monthly Photo Contests 11-02-2020, 04:02 AM  
Static
Posted By TDvN57
Replies: 19
Views: 117
I would like to nominate this photo
Forum: Monthly Photo Contests 11-02-2020, 04:01 AM  
Filling Up
Posted By TDvN57
Replies: 15
Views: 123
I would like to nominate this photo
Forum: Monthly Photo Contests 11-02-2020, 04:01 AM  
Dragonfly "Anax imperator", laying eggs in water.
Posted By TDvN57
Replies: 102
Views: 1,078
I would like to nominate this photo
Forum: Pentax Medium Format 11-02-2020, 03:58 AM  
Post your medium format photos!
Posted By TDvN57
Replies: 15,572
Views: 2,580,874
These pictures are really stunning Mike.
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