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Forum: Pentax Medium Format 03-27-2013, 09:22 AM  
What is the crop factor?!
Posted By Yamanobori
Replies: 19
Views: 3,566
The 90m is a 1.6X lens. Simply take the format diagonal and use it to divide the focal length. It is much easier to work in the format you are using than one you are not. BTW, that is 48mm in APS or 69mm in 35mm.
Forum: Pentax Medium Format 03-27-2013, 08:54 AM  
Best aperture with 55mm/f2.8 ?
Posted By Yamanobori
Replies: 7
Views: 1,158
I guess it would depend on how much DoF is needed. I routinely shoot the 55mm at f/16--I make 4' to 5' prints or 12' panos. I will also shoot at f/22 as well. Set the aperture based on the DoF you need.
Forum: Pentax Medium Format 03-27-2013, 08:51 AM  
645D and Long Exposure
Posted By Yamanobori
Replies: 6
Views: 2,202
I shoot in the 3-5 minute range with the 645D and the files are fine. 10-15 min, I have not tried. The 645D will apply a dark frame, so a 15 min exposure will take 30 minutes.
Forum: Pentax Medium Format 03-27-2013, 08:44 AM  
Opinions on 645D in general use.
Posted By Yamanobori
Replies: 48
Views: 6,947
I use my 645D for all kinds of photography from documentary handheld to astrophotography on a tracking mount. It is really easy to handhold and can work at low shutter speed without a problem. I have also had it in a blizzard with the snow melting and then freezing on the camera. It is like the Energizer Bunny.
Forum: Pentax Medium Format 10-30-2012, 09:30 AM  
My dreams come true
Posted By Yamanobori
Replies: 7
Views: 1,833
No. And you really want the camera to do dark-frame subtraction. You can use the multiple exposure feature to beat the 30 sec limit, but 9 stacked frames at 30 sec each end up with a lot of noise and dark and hot pixels.
Forum: Pentax Medium Format 10-25-2012, 06:00 PM  
Macro 5X
Posted By Yamanobori
Replies: 21
Views: 1,988
If you want to get 5x magnification, you simply need to create an extension 6x the focal length. For a 105mm lens, you simply need 630mm between the lens and the image plane. For a 200mm lens, you need 1200mm between the lens and the image plane.

M = (d ) / where d is the lens to image plane distance.

This is really why microscopes are so popular for imaging.
Forum: Pentax Medium Format 09-29-2012, 11:45 AM  
645D mirror or shutter problem
Posted By Yamanobori
Replies: 4
Views: 1,863
My camera has worked flawlessly for a year and a half. I would send your camera back. I would call Pentax and see what they can do for either fast turn around or a loaner.
Forum: Pentax Medium Format 09-24-2012, 10:09 AM  
Who are the well known or successful Pentax using photographers ?
Posted By Yamanobori
Replies: 15
Views: 4,484
When Pentax released the 645D, it used professional photographers for that. You can see the work here:

PENTAX 645D
Forum: Pentax Medium Format 09-17-2012, 06:14 PM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
Who is being rude?
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 09-17-2012, 06:10 PM  
Phase One announced a new 645DF+ @$6000
Posted By Yamanobori
Replies: 11
Views: 1,421
It would be nice that the folks excited by the demise of the 645D know something about the MFD market. Yes, there are two 645 FF backs for the Phase camera--60MP and 80MP. They are about $20-30k and that is without a camera. The Phase 40mp back has the same size sensor as the 645D, but it is still more expensive.
Forum: Non-Pentax Cameras: Canon, Nikon, etc. 09-17-2012, 09:20 AM  
Phase One announced a new 645DF+ @$6000
Posted By Yamanobori
Replies: 11
Views: 1,421
You also need a lens. And to see what a great deal it is, check out the price for extra batteries.
Forum: Pentax Medium Format 09-12-2012, 09:59 AM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
So you are just trolling this thread? You don't even shoot with a 645 film body and so this release has nothing to do with you. As for overpriced, my 645D paid for itself in the first year of use in film and developing costs alone.

BTW, it would be good that you compare apples to apples. The Hasselblad 80mm f/2.8 is not a macro and was a standard lens design which is produced in greater numbers and has been in production for a very long time.

For someone who believes it is the photographer rather than the equipment, you seem really preoccupied with the gear. But I will let you into another secret, a camera that works for you, does not work for others. What I choose to use has nothing to do with you. What you are willing to pay is irrelevant. Your post is just sour grapes.
Forum: Pentax Medium Format 09-12-2012, 09:47 AM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
Please show proof that a Hasselblad or S2 is better. The dampening on the 645D mirror is excellent.



??? So Leica, which has a really bad reputation for delivering optics for the S2 system, is not an issue, but it is for Pentax? If you look at the release of MF lenses, Pentax is going at a rate at least equal to their competitors.
Forum: Pentax Medium Format 09-12-2012, 09:40 AM  
645D being discontinued - for new model?
Posted By Yamanobori
Replies: 9
Views: 3,125
Falling behind what? How do you determine too far and too far from what?
Forum: Pentax Medium Format 09-10-2012, 09:18 PM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
That's the spirit! ;)
Forum: Pentax Medium Format 09-10-2012, 08:40 PM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
Correct me if I am wrong, but I think this might be the first medium-format lens with image stabilization?
Forum: Pentax Medium Format 09-10-2012, 08:38 PM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
How is the AF, weather sealing, lens coatings, close focus, and image stabilization on that old Planar design? And where can I buy a new Rollei 6000 series cameras? Haven't they all been discontinued?
Forum: Pentax Medium Format 09-09-2012, 09:01 AM  
FA645 MACRO 90mm f/2.8ED
Posted By Yamanobori
Replies: 38
Views: 4,725
Well, the new 90mm is a stop faster than the other lenses which requires an entrance pupil of twice the area. It is rather silly to compare this to a 67 manual focus lens designed in 1998. Also, the FA 120mm is not a new lenses either. Both the 645 and 67 lenses were produced when the customer base was larger. While I think the $5K price tag is over the top, why are you expecting the same price ranges from products made 15 or 20 years ago? A lens that cost $1500 15 years ago and if inflation was just 4%, the same product today would be $2700. This does not take into account changes in production cost, new technology added, nor number of products produced.

As far as the question of why bigger, perhaps Pentax just wants to make a better lens. Not only for the current camera, but for future bodies which presumably will have hight resolutions. BTW, the folks that own a 100mm Macro lens that suits them fine are not actually customers as they are not in the market to buy a lens. This is for customers not having the optics they want and are willing to pay.
Forum: Pentax Medium Format 09-03-2012, 11:34 AM  
Lens Collar for 645 300mm f/4 A lens
Posted By Yamanobori
Replies: 11
Views: 1,997
Ryan, I am sure you know this is situation specific. On a nice sunny day at 1/250s, there is never a problem. At 1/4s in a gale, it might not be so ideal. But collar still might not be enough anyway. But since this lens will not be used often, you might just mount the camera on your nodal slide and then place a piece of rubber between the lens and rail. Personally, my bag is heavy enough and any way I can simplify my gear the better. Yes, my 300mm is lighter, but that can be a double edge sword--the f/4 has more mass and so requires more force to move, inertia counts for something.
Forum: Pentax Medium Format 09-03-2012, 10:12 AM  
Lens Collar for 645 300mm f/4 A lens
Posted By Yamanobori
Replies: 11
Views: 1,997
Are you sure you need a collar? It sounds like you don't have the lens and so how do you know you will have a problem? And even with the collar, how do you know the nodal slide will not be the problem. BTW, why do you need a model slide at all? I do panos with my 300mm f5.6 (no collar) and they stitch nicely.
Forum: Pentax Medium Format 08-31-2012, 06:29 PM  
Pentax 645 FA 45-85 wide open
Posted By Yamanobori
Replies: 6
Views: 1,941
At 45mm, the entrance pupil is 10mm. At 85mm, it is 19mm.
Forum: Pentax Medium Format 08-31-2012, 07:14 AM  
645D Pentax auto focus issue
Posted By Yamanobori
Replies: 2
Views: 812
I am not having a problem with AF. The adjustment can be made by taking an image and then tweaking the fine adjustment. No need for live view. But having the lens go to infinity is not something you can adjust for.
Forum: Pentax Medium Format 08-30-2012, 07:19 PM  
Pentax Officially Drops 645D Price
Posted By Yamanobori
Replies: 16
Views: 3,340
I wonder if there will be interesting news at Photokina?
Forum: Pentax Medium Format 08-29-2012, 05:16 PM  
Kodak dropping film--sad day
Posted By Yamanobori
Replies: 32
Views: 3,124
So how is selling your film production not dropping film production? Whether you decide not to make film by simply closing your business or selling your business, the fact remains the same, you no longer do that business.
Forum: Pentax Medium Format 08-29-2012, 02:32 PM  
Kodak dropping film--sad day
Posted By Yamanobori
Replies: 32
Views: 3,124
You are saying the demise of Kodak is not sad. While they are certainly responsible for their downfall, I do not see this sale as a bright spot for the company. Every time a photographic manufacturer falls, it is a sad day. Just like the loss of Konica, Contax, Minolta, Bronica, and Pannon Camera Company (the maker of the Widelux).

Kodak is going through bankruptcy. Generally speaking you do not sell off your profitable assets if you are planing to stay in business when you come out of chapter 11. Nor do you sell money making ventures to fund other "products."

Who would want to get in the consumer film making business? The market is small and will not see growth. You have the added liability of taking over chemical plant sites which you would then be liable for. I am glad you are optimistic, but this is not going to be an easy sale.
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