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Forum: Pentax Medium Format 07-06-2017, 11:40 AM  
645Z...Strange Issue with Wireless Cable Release & Exposure Time? Help Please
Posted By DandA
Replies: 9
Views: 465
Again I appreciate everyones continued support and responses to this issue I encountered. Let me provide a few facts. In the past I believe I used the Pentax wireless waterproof control for B mode of opening and closing the shutter. In other words press to open shutter snd anout 6 seconds later, let go of the waterproof wireless button and shutter closed instantly upon letting go of the button. No different than if I had used my idex finger on the shutter button to do the same.

This time I had only taken Pentax brand wireless controls (two different small models)...I think one was model F, the other not sure of, and both operated with the same delay when I lwt go of their button in b mode. The shutter would still stay ipen for approx 1-2 seconds before the shutter finally closed.

This happend both during daylight hrs as well as that night in near total darkness.

I cant be certain my waterproof Pentax wireless remote didnt habe this issue of shutter closing delay but from memory it didnt. I have to dig that one out and try. Thats why I didnt takenit that night.

I also have to try what was suggested and put my hand in front of the remote IR and see if that instantly closes the shutter.

Royce, with the remote F I believe you have, can you do the following test? Put 645 Z in B mode and press shutter and hold down for 5 seconds and then let go. Shutter should instantly close. Then do the dame thing with wireless remote F. Press its button, hold down for 5 seconds and then let go. Did the shutter close just as fast? Any detectable delay in closing?

Ahain I appreciate all the suggestions and explanations. I guess since I always previously used the waterproof remote and never noticed this delay, it took me by surprise when I took along two other wireless remotes (both Pentax) but immediately had the 1+ second delay of shutter closing upon release of their button.

Dave (D&A)
Forum: Pentax Medium Format 07-05-2017, 07:31 PM  
645Z...Strange Issue with Wireless Cable Release & Exposure Time? Help Please
Posted By DandA
Replies: 9
Views: 465
Steve, I very much appreciate your reply and explanations. I am familar with the T mode vs. B but unfortunately that was not the cause of the issue I described above. My physically pressing and releasing the shutter buttom in B mode should be emulated by the wireless cable release but with the wireless there was a second or two delay of the closing of the shutter. I dont recall this happening previously and still trying to rectify the situation. Again thanks.

Dave (D&A)
Forum: Pentax Medium Format 07-05-2017, 04:25 PM  
25mm vs 28-45mm comparison on 645Z
Posted By DandA
Replies: 29
Views: 2,422
In my experience testing out multiple samples of each of these two fine lenses, this has been my observations regarding optical performance. Of course I am pixel peeping at 100%.

Most samples of the 28-45 simply outperform the 25mm (both DA and D-FA), especially in the corners up to f9-f11. In the central part of the image, I found the 25mm actually is sharper from the get go and also when stopped down (contrary from what has often been posted), but the differences are not overly dramatic (in central part of the image) The differences though between the two lenses are fairly dramatic in the corners, with the 28-45 having the distinct advantage. This corner performance difference narrows if you shoot the 25mm at f11 and f13, where it becomes much closer.

One of the reasons for this is the 25mm has extreme field curvature, which is small, but increases as it approaches infinity focus. The same thing can be readily seen in the older FA 35mm f3.5 645 lens but not in the newer HF D FA 35mm f3.5 645 lens, which appears to have a redesigned aspherical element.

What I also noticed as has another well known reviewer, is many samples of the 25mm , must be AF fine tuned on the body, otherwise many samples of the 25mm lens doesn't quite reach infinity focus. This can be seen in live view and even on the lens barrel, where it falls short of the infinity mark on the focusing scale...sometimes by a good margin, when focusing at a subject that's definitely at infinity. In other words, the lens fronts focus at infinity. Some samples though don't need much if any AF fine tuning for this. It all depends and this extreme variability in sample to sample performance is another reason why pentax discontinued production.

Still lenses is smaller and lighter than the 28-45 and of course wider, so if used at f11-f13, it may be the preferable choice, especially for hiking or travel. For ultimate performance, especially at something wider than f11-f13, the 28-45 may be the preferable choice.

Dave (D&A)
Forum: Pentax Medium Format 07-05-2017, 04:07 PM  
645Z...Strange Issue with Wireless Cable Release & Exposure Time? Help Please
Posted By DandA
Replies: 9
Views: 465
Hi All,

Noticed something strange right off the bat last night while shooting 5-15 second exposures with the 645Z mounted on a tripod in single frame shutter release with "no"" 3 second delay and "no" mirror lock-up. Camera set in "B" (bulb) mode. Fired shutter with a number of different wireless cable releases. Lens set in manual focus.

If in a test shot, I press the shutter button with my finger, shutter opens as expected and as fast as I can let go of shutter button, it instantly closes. Shutter of course will remain open as long as I hold shutter button down but the moment I let go of shutter button, it instantly closes.

If I use any of the Pentax branded wireless cable releases in same scenario, I press remotes button to open the shutter, but if I let go of button instantly or at any point, there is sort of a 2 second (approx.), delay before shutter closes. Line of sight to IR sensor is perfect. Is it possible with IR, there is a delay in the signal getting to the 645Z in responding to letting go of shutter firing button but not when initially pressing it? That doesn't make sense and why shutter closing time with these wireless remotes should respond differently than pressing the shutter with finger directly and letting go. I don't have a wired remote to try.

I don't recall every experiencing this before and had little time to explore it when shooting last night.

Any thoughts or ideas would be appreciated. Something tells me user error and I'm overlooking something in the settings. Thanks very much!

Dave (D&A)
Forum: Pentax Medium Format 01-04-2017, 03:31 AM  
645z versus X1D
Posted By DandA
Replies: 41
Views: 4,449
Carsten wrote--->>>"Dave, when you visit Germany, we should make a MB bike tour in the Black Forest, great region for MB and landscape"<<<

Carsten sounds great!. I've heard and read so much about the black forest...quite magical.

When you get to the States of course Colorado (Moab) is home to some.of the greatest mountain.biking but here on the east coast where I am, we can ride/hike in the beautiful Blue Ridge Mts in the Shennendoah Valley for those activities and scenic photopgraphy and an hr away is Washingtom D.C. Maybe we'll leave our A*600's at home...LOL.

As for f-stop backpacks, only thr smaller Kenti doesn' use the removeable internal ICU's system and is arranged differently. They hug your body when biking/hiking and thats their advantage. Another brand that also is a good fit for those activitirs is Clik Elite but they are not as well built and often hold less with a so-so internal design. F-stop is the choice of many when engaged in mobile activities combined with photograhy.

As a compact high performance MFD system when biking/hiking/traveling light, its hard not to like the X1D but for most other photographic endeavors, there still are many advantages to the 645Z at the moment.

Dave (D&A)
Forum: Pentax Medium Format 01-03-2017, 03:08 AM  
645z versus X1D
Posted By DandA
Replies: 41
Views: 4,449
Great to hear Ristretto! Thats also the line of backpacks I use...f-stop brand! I use the slightly larger Guru bag with their removeable ICU inserts when biking and one size larger than the Guru when hiking.

Dave (D&A)
Forum: Pentax Medium Format 01-02-2017, 07:05 PM  
645z versus X1D
Posted By DandA
Replies: 41
Views: 4,449
Love it when I hear about another hiker and cyclist taking their kit :). Maybe we need to get together sometime in each others respective location for a ride and shooting. Of course I will let you ride with my Pentax *A 600 f5.6 645 lens....thanks! :). By the way, Mt. Bike or road bike? We have great rides (trails and roads) of each here as well as vistas on hiking trails. I am familar with that Lowepro backpack having owned one but found two other brand backpacks that are even better when cycling with gear and at same time protect the gear even more with rock aolid support on the back but still light weight.

Each camera system has pluses and minuses depending on application and uses and thats why when comparing the X1D to the 645z system, a case can be made for each one.

Dave (D&A)
Forum: Pentax Medium Format 01-02-2017, 11:17 AM  
645z versus X1D
Posted By DandA
Replies: 41
Views: 4,449
Hi Carsten,

Although the *A300 is a good lens, both the FA 300 f4 and FA 300 f5.6 do superceed it in performance. Of course long lens techniques in shooting can have an equally important role in the final aquired image and how sharp it is.

I too encountered issues when trying to adopt lenses via adapters and often times the performance of the lens loses something along the way.

This is what stopped me from moving over to the Leica S system and for not considering the X1D. Simply that I often require really good native long focal length lenses...although Hasselblad has/had some terrifix performing ones for their other lens systems.

Keep up the good work. Thanks.

Dave (D&A)
Forum: Pentax Medium Format 01-02-2017, 09:04 AM  
645z versus X1D
Posted By DandA
Replies: 41
Views: 4,449
Carsten,

The *A300 is an excellent lens as is the FA 300 f4 645 lens. As you probabaly know I tested multiple samples of all Pentax 645 legacy lenses on 645D when that body was first released and posted those results. Subsequesntly tested them on the 645Z but didn't post as of this date.

Upshot is FA 300 f4 and FA 300 f5.6 have similar performance characteristics with of course the f4 being a stop faster. Although the f4 lens is a lot bigger and heavier, that extra stop can be of significant benifit, even as it relates to vibration due to support and shutter speed.

Again thanks for all your thoughts and comparions with the X1D and 645z. Very informative and your objective observations are extremely useful. Look forward to more.

Dave (D&A)
Forum: Welcomes and Introductions 11-06-2016, 12:40 PM  
Hello from Virginia, USA
Posted By DandA
Replies: 7
Views: 348
Another Pentaz shooter from Va. here. Is there enough room for the three of us (so far) in this town or someones got to go..LOL. Welcome!
Forum: Pentax Medium Format 10-27-2016, 10:31 AM  
HELP!! Trying install Latest Firmware in my 645Z
Posted By DandA
Replies: 4
Views: 634
I just sent you an email Dennis about 20 min aho to check to make sure lock on SD card was not in the lock position (slide switch on side of card). If that wasn't it then simply try another card.

Glad though it all worked out.

Dave (D&A)
Forum: Pentax Medium Format 05-31-2013, 03:04 PM  
Pentax 645D focusing screen
Posted By DandA
Replies: 19
Views: 6,266
Hi Light-in-Focus,

Thanks ever so $uch for the info and clarification between the different focusing screens. Too bad the original 645 focusing screens don't work in the 645D since I cam across a few split image ones that might have been idral in aiding in manually focus certain 645 lenses on the 645D body. Again you info is greatly appreciated!

Dave (DandA)
Forum: Pentax Medium Format 05-31-2013, 01:45 PM  
Pentax 645D focusing screen
Posted By DandA
Replies: 19
Views: 6,266
In addition to my questions in my post above regarding use of 645n focusing screens in the 645D, does anyone know if thePentax focusing scfeens for the original 645 body (prior to the 645n) will also work in the 645D? Thanks.

Dave (D&A)
Forum: Pentax Medium Format 05-31-2013, 07:28 AM  
Pentax 645D focusing screen
Posted By DandA
Replies: 19
Views: 6,266
I'm just curious and maybe a bit confused. I've heard conflicting advice. Initially I hear that the focusing sreens for the Pentax 645n do not fit or work correctly in the 645D. Then I heard they do....and finially that some do and some don't (for whatever reason). Does anyone have any difinitive info regarding this? If they do fit and seems to work with regards to manually focusing a lens, do all the 645n screens work accurately with use of autofocus when installed in the 645D? Thanks!

Dave (DandA)
Forum: Pentax Medium Format 05-31-2013, 07:25 AM  
35 A vs FA lens
Posted By DandA
Replies: 8
Views: 1,226
I have tested many sample of the FA version but only a few of the manual focus ones since my posting of comprehensive lens tests of 645 lenses. There is substatial variation in optical performance with the FA lens but if I take the best one I found and compare it to the A* version this is generally what I observed.

1. As noted, field curvature becomes quite great as the camera to subject distance increases with the FA lens. On landscape shots shot at distance, this gives the appearance that the edges/corners aren't as sharp as the central portion of the frame. The edges/corners are but unfortunately (or fortunately depending on subject matter) are focuses in a somewhat differst and closer plane.

2. The FA lens seems to flair less when shooting towards or into bright light...maybe due to better coatings or optical design?

3. Less CA is also evident with the FA lens but it's rarely a issue with the A* lens.

4. I found the Fa lens just a smigen sharper in the central part of the frame but I'd like to revisit this by testing another sample of the A* lens when I can find a sample to test.

Of course the FA has the convience of AF if and when it might be needed. There are some other differences and perculiarities I noted about the FA version in my posted findings.

Both lenses are excellent performers, just having different strengths and weaknesses.

Dave (DandA)
Forum: Pentax Medium Format 05-31-2013, 06:48 AM  
645 600mm A*. Why so many elements?
Posted By DandA
Replies: 33
Views: 3,669
Hi All,

I'm a little late to the party regarding the drop in polarizer for the Pentax 645 A* 600mm f5.6 lens. I had given up looking for one like most here about 9 months ago and then suddenly yesterday I saw one appear for sale, so I quickly grabbed it. I guess it's still pouring rain :). Although I often use polarizers with certain lenses and subjects, I wasn't quite sure how often I'd find myself in circumstances where I'd find the drop in polarizer for this lens necessary or a distinct advnatage without then faing the ussual stability and loss of image sharpness with this lens. Time will tell.

The reason I haven't added a test report to my posted comprehensive list of tested Pentax 645 lenses on the 645D, is simply I wanted to get more of a feel of the lens's performance out in the field with a wide range of subjects and at various distances. What everyone here has already written about this lens has certainly been accurate.

It's been interesting to hear/read that the 67 M* 400mm lens has optical performance that can equal the 600mm f5.6 lens, especially when the 400mm is used with the 1.4x. This certainly gives food for thought, espcially that it provides two different focal lengths out in the field as mentioned.

I haven't participated recently in these forums, simply due to an enormously busy schedule but hopefully that will change somewhat. Always great postings here on Pentax!

Dave (DandA)
Forum: Pentax Medium Format 04-04-2013, 06:57 AM  
Pentax DFA 645 2.8 90mm Macro
Posted By DandA
Replies: 84
Views: 27,364
Ken,

First Congradulations on the purchase of your 645D and lenses. I've been following the other 645D thread but have been extremely busy to post much lately. I have many/most of the lenses you just aquired and great choices!

For portrait work, don't forget the Pentax FA 150 f2.8 645 lens. It's made for portraits. Small, unbeliveably light and a wonderful dawing wide open for portraits that need to be well rounded and foregiving yet when the lens is stopped down, has excellent sharpness. A best buy at prices it can be obtained for. Just out of curiosity, where are you loacted? It nice to know where various 645D hail from. Have fun!

Dave
Forum: Pentax Medium Format 02-14-2013, 07:20 AM  
Pentax DFA 645 2.8 90mm Macro
Posted By DandA
Replies: 84
Views: 27,364
Lovely representitive images from this lens...thank you! I believe it's probably designed more for portrait and general use than for macro. I say this due to a number of factors....the reproduction ration is 1:2 (not 1:1) and that shake reduction thats now often found in macro 35mm lenses, plays a relatively small role in terms of effectiveness at typical macro ranges. Unfortunately the 90mm effective focal length in 35mm terms on the 645D is only 72mm...a focal length thats on the short side for portraits.

In comparison the 150mm f2.8 who's rendition seems to be designed for wider aperture portraits, has a effective focal length thats more idea (on the 645D...namely 120mm!). It's bokeh for portraits and gentle landscapes is very good.

Lastly the Penatx 120 f4 645 macro is an absolutely superb sharp lens and one of the best performing Penatx 645 lenses. At macro distances it's bokeh is not the smoothest but not unattractive either for most subjects.....it's at normal and longer subject distances that it's OOF areas in terms attractiveness is reduced and sometimes simply fairly unattractive. Still all in all, each of these lenses has a lot to offer, with the 150mm f2.8 and 120 f4 lenses being exceptional buys.

Dave (DandA)
Forum: Pentax Medium Format 01-23-2013, 10:30 PM  
Just picked up a Pentax 645D.
Posted By DandA
Replies: 14
Views: 2,139
Hi Peter,

Congradulations on the 645D purchase and from the look fo it, you've made an auspcious start!. As you probably know from the other forum(s) I too am a Leica M shooter and so I find each system lends itself to different types of imagery. You've gotten some great advice here regarding lenses, especially some of the interesting 67 ones. I'll have to go back and find the link to my comprehensive testing of multiple samples of most all Pentax FA Af lenses on the 645D...in case you would like to have some idea of the performance levels of many of these lenses. I enjoyed many of your images and the purple hat portraits. Welcome aboard!

Dave (DandA)
Forum: Pentax Medium Format 11-29-2012, 12:27 PM  
Pentax 645D lenses : which ones to go for ?
Posted By DandA
Replies: 15
Views: 6,203
Very Well Put and excellent thoughts put forth and mirrors much of my experience with both cameras.

Dave (D&A)
Forum: Pentax Medium Format 11-29-2012, 12:24 PM  
fa 150 vs fa 120 macro
Posted By DandA
Replies: 9
Views: 3,769
I use both on the 645D. For portraits and general use, I too much prefer the FA 150mm f2.8, especially with its lower contrast and beautiful bokeh. For macro/clsoe-ups or where I am only concerned with absolute edge to edge sharpness and excellent microcontrast, I'll use the FA 120 f4 macro. The look from each is quite different.

Dave (D&A)
Forum: Pentax Medium Format 11-29-2012, 12:21 PM  
Problem with 645D CCD ?
Posted By DandA
Replies: 11
Views: 2,393
This is a very uneducated guess....but since the readouts of each half of the sensor are on seperate channels, is it possible that it takes the combination of long exposures and cold climate, to effect this phenominon (issue). In other words, very cold temps cause each channel to be read with slightly different timings...therefore they are not in sync" with respect to the other and also the longer the exposure goes for, the more the descrepancy between the respective readout timings (or differences). Very short daylight exposures in cold weather are not long enough to to effectively see theses miniscle timing differences but longer exposures are. Likewise normal ambient temps do not effect these timing diffferences of the channels, hence, no line down the middle of the senor is seen.

This is not an absolute...as I'm sure there are many excepts and other reasons for this sensor issue.

Dave (D&A)
Forum: Pentax Medium Format 09-30-2012, 11:02 PM  
25mm...overpriced or worth the $$?
Posted By DandA
Replies: 37
Views: 4,459
I wish I had known that D FA 25mm was for sale as at that price (or near it), I would have strongly considered it. Still all in all, its a expensive piece of glass.

Dave (D&A)
Forum: Pentax Medium Format 09-09-2012, 06:24 AM  
FA645 MACRO 90mm f/2.8ED
Posted By DandA
Replies: 38
Views: 4,614
Yes, this is perplexing if it's priced at $50000 . The current 120 645 macro ( I use the superlative FA version) , is nothing short of having superb image quality across it's entire docking range and in all the samples I tested, was the only FA 645 lens that required absolutely no AF fine tune adjustment when used on the 645D. This ilies very careful tolerances and adjustment during assembly when new. Tpits good for portraits where it's only drawback may be the too bitingly sharp image it produces may be Too much for certain portrait subjects. That's wherevthe FA 150 f2.8 lens comes in. It's a gem for portraits, especially in the subtle way it draws an image when shot wide open and is another all around light weight superb performer. These two lenses may not have WR, but at their current selling price points, especially used, they are a real bargain when compared to the recent costs of some of the new Pentax 645 lenses now being introduced.

If the new 90mm does have IS (is this confirmed?), then of course this is a factor in it's general use and could certain be of benefit, but that's still a steep price for a lens in a system that was supposed to be a relatively attractive entry way, $$ wise, to medium do at photography.

Dave (D&A)
Forum: Pentax Medium Format 08-18-2012, 12:59 PM  
Pentax 645 25mm DA vs. D FA --any comparisons?
Posted By DandA
Replies: 10
Views: 1,777
Hi Ryan & All,

My post on LL regarding observations a photographer made while having used both versions of the 25mm lens, is from a reliable source and is the only comparison of the two versions I'm aware of. Speaking for myself personally, if I only shot 645 digital, I would opt for the new DA version, in order to gain whatever advantage I could in reducing the occurrence of CA. CA can be dealt with in post processing, but residual amounts often remain and sometimes removal can be moderately destructive in alteration of the image. since I still shoot 645 film too, then it appears I have only one choice and thus will ultimately be looking to purchase the D FA version.

Dave (D&A)
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