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Forum: Pentax Medium Format 04-26-2012, 11:01 AM  
tethering software for 645D
Posted By Tim Wilson
Replies: 2
Views: 1,615
I sent an email to someone at Pentax about this a couple weeks ago. No response so far.

-Tim
Forum: Pentax Medium Format 01-28-2011, 07:59 AM  
Rear curtain and slow shutter speed flash sync question for the 645D
Posted By Tim Wilson
Replies: 9
Views: 5,036
It occurs to me that the way Pentax dedicated flash units (as well as units from other manufacturers that implement Pentax protocols) do rear curtain sync may be by inserting a carefully timed delay, which they can do because they know the shutter speed setting and shutter characteristics, avoiding the need for a physical sensor associated with the rear curtain. Which would explain why it's not available at the camera.

Tim Wilson
Chicago
Forum: Pentax Medium Format 01-16-2011, 08:26 AM  
Interesting Accy. for 645D ?
Posted By Tim Wilson
Replies: 9
Views: 1,869
I haven't. I suspect the fix is more RAM, which they have no control over. I need to do more tests--smaller JPGs may work fine.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-15-2011, 08:29 AM  
645D initial exposure workflow
Posted By Tim Wilson
Replies: 1
Views: 1,665
Here's a technique I've discovered for setting initial exposure with the 645D that is probably old hat to long-time Pentaxians, but new to us former Canonites. It's primarily applicable to handheld work.

Have the camera set to M mode, spot meter, with exposure compensation at plus 2 stops. You see some subject matter and look for an area that represents textured highlight. Place that area in the meter spot, press the green button. The 645D does two things: Sets the exposure to what it would use in P, even though you're in M, and does so using the plus 2 compensation for the highlights. Can't do that with a Canon. So let's say the shutter/aperture combo isn't exactly what you want. Press the AE lock button and turn the wheel to adjust the shutter speed and the aperture changes automatically to maintain EV. Can't do that with a Canon either. Fire a shot, check the histogram and hi-lo warnings. Quick adjust to tuck those highlight a little closer to the edge (or pull them back from the brink), and your off to the races.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-15-2011, 07:45 AM  
Interesting Accy. for 645D ?
Posted By Tim Wilson
Replies: 9
Views: 1,869
Shuttershane, I tried the Eye-Fi-to-Shuttersnitch-on-iPad route, but Shuttersnitch apparently can't handle the lo-qual full-size jpegs I was feeding it from the 645D. Frequent crashes. Eye-Fi-to-Lightroom-on-MBP works great, however, as long as you're not in a hurry. I shoot RAW to a big card in slot 1, JPG to an Eye-Fi in slot 2.

The firmware update you mentioned (not available yet) lets the Eye-Fi function as a router. Currently it doesn't and requires a Wi-fi network to do its thing, but you can carry a network with you using a portable router. This article has a lot of information.

Tim Wilson
Chicago

p.s. I'm going to keep looking for a combination that works to the iPad, 'cause that would be a sweet setup.
Forum: Pentax Medium Format 01-12-2011, 08:54 AM  
Why did you purchase a 645D
Posted By Tim Wilson
Replies: 24
Views: 4,133
I did it for these reasons:

1
I'm continually trying to get closer to the quality of "presence" I was able to achieve many years ago working on my MFA thesis, shooting found cultural vignettes on 4x5 color neg film, and making 20x24" C-prints. Only now I want to achieve that working digitally, without always needing a tripod, and targeting prints in the 24x32" range. The 5D2 is capable of that sense, but not at that size.

2
I very much prefer working with 4:3 composition than with 3:2.

3
There's assignment work I get occasionally that would benefit materially from larger files.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-12-2011, 08:18 AM  
645D lens test results
Posted By Tim Wilson
Replies: 20
Views: 7,916
As I mentioned at the top of this thread, my 45-85 had symmetry issues. That was a "new" lens, and therefore presumably under warranty, so I sent it in to Pentax to see if they can fix it. I expect they'll have it a while. In the meantime, I picked up a second one. This one is used, even has a little ding or two, but looks to be a better copy optically, good enough that I've decided to keep it. When the other one comes back, I'll test both, keep the best one and sell the other.

I've also decided to keep the D-FA 55mm, despite its sharpness problem away from center. Because that particular problem seems to plague everyone who's tested one of these, I consider it to be, effectively, a design problem. No point looking for a better copy.

And landscape is not really my thing. I think this lens can work well for a lot of what I might use it for, where edge matter are out-of focus anyway. And having the focal length also available in a zoom that's sharper in the corners, I feel I'm covered.

So I have a nice little set of lenses that, for now, I'm happy with, as a group: FA 75mm/2.8, FA 120mm/4, D-FA 55mm/2.8, FA 45-85mm/4.5, FA 80-160mm/4.5


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-08-2011, 08:26 AM  
Debug Mode and Modset File of the 645D
Posted By Tim Wilson
Replies: 6
Views: 3,323
Got it. Bear with me, I'm new to this.

Doesn't seem to be working. I tried every button while turning the camera on. Tried both card slots.

Anything different I should try?


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-07-2011, 08:28 AM  
645D Performance with Existing Wide Angle Lenses
Posted By Tim Wilson
Replies: 33
Views: 9,009
I recently did a series of 'sharpness' tests of 5 645 lenses on a 645D, in studio, at a 50:1 image ratio (see the thread "645D lens test results"). I did not test the lenses you mention, nor did I test anything wider than 55mm. However, with every lens/focal length combo I did test, there was significant degradation from diffraction by the time you got within 1 stop of minimum aperture. It was very consistent. That would be f/16-22 on the f/2.8 lenses, and f/22-32 on the f/4 and f/4.5 lenses.

(I'm calling these 'sharpness' tests and not 'resolution' tests, because even though I used resolution targets, I didn't quantify anything. Judgements were made on minimally processed images viewed on a computer screen at 100%.)

That's not to say good pictures can't be made at these small apertures, but it seems to me that sharpening protocol and print size considerations would be critical.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-06-2011, 03:38 PM  
645 lens madness
Posted By Tim Wilson
Replies: 120
Views: 18,462
I have 5 FA lenses accumulated since the beginning of December. The 2 that have problems are the 2 I bought "new".

One of those was the new D FA 55, ordered with the camera, which has that same softness-away-from-center that others have seen, likely more than an isolated defect, possibly a design flaw.

The other was a 45-85mm from Samys sold as "new in box" on Ebay. From the literature packed in the box, I'd guess it had been sitting around a while. Shiny and unused as it was, though, there was still misalignment. (Maybe from sitting on one side in the box all those years.) The good news: Since it was sold to me as new, it's under warranty, right? So I sent it in to Pentax. If they say, "umm... this ain't new", then Samys misrepresented, and owes me a refund. Right?

The other 3: All used, all at decent prices, all testing out pretty good so far. Very happy about those.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-06-2011, 08:06 AM  
Debug Mode and Modset File of the 645D
Posted By Tim Wilson
Replies: 6
Views: 3,323
Would love to try, but I don't have any firmware-diving experience so not sure how to answer those questions. The download (OS X version) extracts to a README and a single binary: FWDC207B.BIN, which if opened in an ascii text editor reveals jibberish, of course. Not sure where to go from here.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-06-2011, 07:47 AM  
645 lens madness
Posted By Tim Wilson
Replies: 120
Views: 18,462
You know, Hoya was smart enough after acquiring Pentax to resurrect the 645D project and make it into a great camera that presumably they can make money producing. Now they have a hit on their hands that they must recognized can be a real game changer for their brand. They've gotta know this lens thing is their biggest vulnerability. I'll bet there's a lot of scrambling going on somewhere related to getting a lens series, either new designs or new versions of old designs, into the market ASAP.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-06-2011, 07:34 AM  
645D is TOP's Camera of the Year
Posted By Tim Wilson
Replies: 1
Views: 1,389
Link here.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-05-2011, 07:13 AM  
645 lens madness
Posted By Tim Wilson
Replies: 120
Views: 18,462
Somewhere I got the idea that the FA lenses were still being manufactured for certain markets (Japan, specifically), just not being imported to North America and elsewhere. Does anyone know if that's true or not?


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-02-2011, 03:53 PM  
645D lens test results
Posted By Tim Wilson
Replies: 20
Views: 7,916
My 45-85mm with the asymmetry issue was purchased from Samys, but via eBay, and listed as "new in box". So the issue of what remedy to pursue is complicated. My thinking is that, being "new", it should be covered under Pentax USA warranty, so that's probably where I'll start.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-02-2011, 07:42 AM  
First studio shoot with the 645D
Posted By Tim Wilson
Replies: 43
Views: 10,030
The reduced size JPGs just don't do it justice. Maybe actual pixel crops? or DNGs? or... I know, how about Latasha's phone number?


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-01-2011, 08:12 AM  
645D lens test results
Posted By Tim Wilson
Replies: 20
Views: 7,916
leping,

I looked again at the bidding history, and if you were the 633.33 bid, then it looks like you and I were the two snipers. You got your bid in even later than I did, but, alas, not higher. If it's any consolation, there are currently at least 3 more active listings for FA 80-160s.


Tim Wilson
Chicago
Forum: Pentax Medium Format 01-01-2011, 07:13 AM  
645D lens test results
Posted By Tim Wilson
Replies: 20
Views: 7,916
leping,

Umm... yeah, that was probably me. You may have noticed that I used the bidding technique known as "sniping": one bid only, the maximum you're willing to pay, placed at the very end of the auction. I recommend it to all eBay buyers. It has the effect of keeping prices down.


Tim Wilson
Chicago
Forum: Pentax Medium Format 12-31-2010, 03:44 PM  
Quick Release plate for 645D
Posted By Tim Wilson
Replies: 9
Views: 2,929
Steven, funny you should ask. I did some lens testing today and just posted results in a separate thread.

To answer your questions specifically, this is the order, good to not-so-good:

120mm, 75mm, 80-160mm, 45-85mm (an alignment problem?), 55mm (design or manufacturing issue?)

If the 45-85mm didn't have an alignment problem (or whatever it is), it would probably become my most used lens. I'm going to see about fixing or replacing it. What do I shoot? Good question. It ranges from studio product illustration to "general commercial", as needed, to fine art--but not sappy fine art, more of a conceptualist/formalist blend.


Tim Wilson
Chicago
Forum: Pentax Medium Format 12-31-2010, 03:32 PM  
645D lens test results
Posted By Tim Wilson
Replies: 20
Views: 7,916
I finally found time to do a little lens testing today. I used targets on a studio wall, and a carefully measured and aligned setup. All tests at 50x magnification (subject:sensor). Mainly looking for camera alignment problems and lemon lenses. I tested the new 55/2.8, FA 75/2.8, FA 120/4macro, FA 45-85 and 80-160 zooms. There's good news and there's bad news:

SMC Pentax-FA645 Macro 120mm f4---

GOOD news: Consistent with what others have reported, this is a really sharp lens. Good at f5.6. Really good at f8 or f11, OK at f16, downhill from there. f22 is soft. f32 is mushy. (All of these lenses are mushy at minimum aperture and soft one up from there.) No problems I could see with this individual lens.

SMC Pentax-FA645 75mm f2.8---

GOOD news: Another good sample, it looks like. The center is sharpest at f5.6-8, the corners are sharpest at f8-11. Second sharpest lens in the bunch.

SMC Pentax-D FA645 55mm f2.8---

GOOD news: Tack sharp in the center, at f5.6 or f8.

BAD news: As Lloyd Chambers has reported, really soft in the corners. Worst of all the lenses I tested in that regard. I'm thinking about sending it back.

SMC Pentax-FA645 45-85mm f4.5---

GOOD news: At 55mm, this lens gets sharp really quickly, by f5.6. That's where the center of the new 55mm f2.8 gets sharp, too, except that the zoom gets sharp all over. At longer settings it needs f8. I haven't tested 45mm yet. Most of the time, sharpness is close to what I'm seeing from the 75 f2.8. Looks promising, EXCEPT...

BAD news: at the longer end of the zoom range (75-85mm) the right sides of my test images are noticeably softer than the left sides. Looks like this particular lens is flawed somewhere. Not sure what to do about that yet.

SMC Pentax-FA645 80-160mm f4.5---

GOOD news: Another eBay find, this one just arrived yesterday. Very close in terms of sharpness and optimal apertures to the 45-85, also same layout, feel, filter size... would be a nicely matched pair if the 45-85 wasn't cockeyed. Fortunately, I don't see any asymmetries with this lens.

Overall---

GOOD news: I see no signs of any camera alignment problems. And what limited focussing I did (AF center spot on a centered target) seemed to be accurate in all tests.

I'm really happy with the 120mm, the 75mm, and the 80-160. I think the 45-85 is a good lens in general, but mine has a problem that needs attention--a disappointment. The 55mm? I hate to say it but it's starting to look like Pentax screwed up on these, either with a design problem or with a serious manufacturing issue.


Tim Wilson
Chicago
Forum: Pentax Medium Format 12-31-2010, 08:11 AM  
645D Electronic Level Display issues
Posted By Tim Wilson
Replies: 6
Views: 1,909
iPhones running Tiltmeter Pro (or probably any of the dozens of other utility leveling apps) are more accurate, if only because they have user calibration features.

I suspect the accelerometer in the 645D is fine, but is running against erroneous calibration data. I further suspect that calibration calls are probably buried in the firmware somewhere, and are trivial to implement, though not currently implemented in the user interface.

I sent an email to Pentax "Customer Care", hoping there's an undocumented calibration routine that users can run, but expecting that there isn't, and that they'll suggest I send it in. This is way low priority for me, so if it has to go in, it'll have to wait.


Tim Wilson
Chicago
Forum: Pentax Medium Format 12-31-2010, 07:37 AM  
Quick Release plate for 645D
Posted By Tim Wilson
Replies: 9
Views: 2,929
Steven,

I have the new 55, plus a 75 and the 120 macro, plus 45-85 and 80-160 zooms, all AF.

Tim
Chicago
Forum: Pentax Medium Format 12-30-2010, 05:32 PM  
645D Electronic Level Display issues
Posted By Tim Wilson
Replies: 6
Views: 1,909
Temperature was in the mid-20s (f) and I wasn't out that long, so I don't think temperature should have been a factor. I know 1 doesn't sound like much, but it's enough to render the feature unusable. Here's what 1.2 looks like:



Tim
Chicago
Forum: Pentax Medium Format 12-30-2010, 05:20 PM  
Quick Release plate for 645D
Posted By Tim Wilson
Replies: 9
Views: 2,929
There are holes on the 645D to mate with anti-twist pins. I bought two of the B67 plates from Really Right Stuff. They're perfect.

Tim
Chicago
Forum: Pentax Medium Format 12-29-2010, 01:50 PM  
645D Electronic Level Display issues
Posted By Tim Wilson
Replies: 6
Views: 1,909
The horizon across Lake Michigan has been hard to come by lately, what with all the short days and bad weather. But I got out this morning for a few shots from the snowy beach at the end of our street. 645D, 45-85 zoom, tripod with a 3-axis gear head, calm lake. What better opportunity to try out the 645D's Electronic Level Display?

I quickly discovered that what looked level in the viewfinder did not jive with what the ELD thought was level. When I used the gear head's fine controls to get the ELD carefully squared up, the horizon looked pretty obviously slanty in the viewfinder. When squared by eye there, the ELD consistently showed a 1-2 degree tilt. Either the viewfinder screen is crooked, or my eyes are, or Lake Michigan is, or the ELD sensor is misaligned (or mis-calibrated). So I shot two ways, figuring I'd sort it out later on the computer.

On the computer it's clear: there's something wrong with the ELD. Images that I squared up with the ELD are consistently tilted counterclockwise. A 1.21 degree clockwise rotation (via PS Lens Correction) is required to fix the problem. The ones where I eyeballed it in the viewfinder are all pretty close to square.

Have any other 645D users noticed anything like this?


Tim
Chicago
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