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Forum: Pentax Medium Format
09-09-2022, 08:07 PM
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I'm not sure we're talking about the same thing. A curved-field lens is not some defect. Most lenses are flat-field, where if you pinned a map to the wall and photographed it, it would all be in focus even though each point on that map is a different distance from the lens. If focused on the center, a curve-field would only have one of the center in focus. The surface of focus is not a plane but curved, roughly circular. Curved field lenses work really well for landscape photography and allows you to use a smaller f-stop to take the same picture.
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Forum: Pentax Medium Format
09-06-2022, 01:15 PM
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The Pentax 645 33-55mm lens is a curved field lens. But are there others, like the 35mm or the 28-45mm.
Thanks!
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Forum: Pentax Medium Format
12-20-2021, 08:54 PM
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Ryan, as a landscape photographer, myself, note that no GFX lenses can be accurately focused manually. And to me, this is very important for hyperfocal distance focusing.
I know this because I own a GFX100S. I originally purchased their 23mm lens with the camera, but returned it because of the focusing issue. I use the Laowa 17mm, which is extremely sharp.
Fuji GF lenses are focus-by-wire. And if you turn off autofocus and then dial the focus ring to a specific spot, the camera will register different distances depending on how quickly you turn the dial. Yes. It's insane. According to a Fuji engineer in response to my question about how accurate their manual focusing is, "I wouldn't use it to land a plane." There's no way to calibrate the lens with tape and markings. I've done this on other lenses with great success, but it's impossible with this issue. You'd need to be a robot and train yourself to turn the focus ring at a certain rate of speed every time.
However, you could certainly use your Pentax medium format lenses, and they'll probably do quite well. I shoot at 17mm almost all the time with the Laowa. But I also have a Fotodiox adapter to fit my Pentax 645 120mm macro (old version) and 55-110mm lenses, when needed. I've also outfitted my Nikon 14-24mm f/2.8 lens with a Laowa Magic Converter, which expands the image circle to cover the bigger sensor. In preliminary tests, it seems quite sharp, but I hardly use it. I really need to do a serious test.
Also, from my perspective, I find the GFX100S camera clunky and slow to use because, for one, they don't have the "AE-Lock & Hold" feature that makes Aperture Priority a dream. This is huge for me. And they don't have nearly as many dedicated buttons as Nikon and Canon do. I forgot the count, but they have at least 15 fewer dedicated buttons. Their workaround is to offer a bunch of programmable function buttons like F1, F2, etc. They market this programmability as flexible, but it's just a way to keep the price down and makes it that much harder to use the camera. Another weird thing is that it takes forever to delete an image you just took. Instead of just pressing a trash can icon after the picture comes up, you have to make four button presses while answering questions along the way just to delete the image that pops up on the back screen right after you take the picture. Wow! What a pain. I like to delete my images on the fly so that I don't accidentally use a "defective" image later on (and deal with another image to edit). And the in-viewfinder histogram is also quirky and can give the wrong feedback, which can cause clipping if you're not careful. Fuji fanboys blame my complaints on being a beginner with their system. But I have lots of experience in photography, and I blame Fujifilm for making cameras that aren't intuitive and easy to use. Their philosophy seems to be "retro," and cater to people who like "slow" photography.
So why do I own this camera after all my complaints?
I love the 102 megapixels, the unsurpassed dynamic ranged, and the 4:3 aspect ratio. Unless they fix the focusing issue, I never see myself buying a lens from them, which doesn't make this camera a keeper. I'm tired of never being able to see my f-stop after the fact. I'm keeping the camera until a different camera manufacturer comes out with an equivalent, but more efficient and useable camera, especially if dynamic range can be improved even further. I don't see Fuji ever changing their philosophy.
Anyway, you can always sell your Pentax, buy the (relatively affordable) GFX100S, and get a (manual focus) adapter for your Pentax lenses (though the f-stop will not be recorded).
I hope this helps!
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Forum: Pentax Medium Format
01-16-2021, 10:17 AM
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Hi, Gerd,
1. Thank you for the very thoughtful and thorough review. Im considering buying the GFX 100 or upcoming 100s and I own the older Pentax-A 120mm macro lens and the FA 55-110mm from the film days.
2. When the Pentax lenses are stopped down, does the quality difference narrow between Pentax and Fuji. I shoot highly detailed landscapes at high f-stops, like f22 and often f32.
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Forum: Pentax Medium Format
01-15-2021, 06:19 PM
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Thanks! I read that article about the 55-110, but it got fairly bad reviews and wanted some extra opinions. I already own it, so I'm hoping it'll be as good as you say.
---------- Post added 01-15-21 at 07:21 PM ----------
Thanks so much!
---------- Post added 01-15-21 at 07:22 PM ----------
Yes, exactly.
---------- Post added 01-15-21 at 07:25 PM ----------
Thanks for the samples, Sandy! It's nice to see pictures of the lens in action.
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Forum: Pentax Medium Format
01-10-2021, 11:34 PM
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Thanks, Ed! I have the lens and also the 55-110. Do you have any experience with the latter? I sold many of my lenses, and have those two left. I used to shoot 645N and 645NII film cameras for a long time. To be honest, I'm now considering moving into the Fujifilm GFX 100 102MP camera, since Pentax seems not to be supporting meduum format anymore.
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Forum: Pentax Medium Format
01-10-2021, 09:23 PM
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Wondering about the sharpness and resolution of the older Pentax-A 120mm macro lens and the FA 55-110mm on the 645Z.
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Forum: Sold Items
05-13-2014, 11:59 PM
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PentaxForums.com Marketplace Listing
Item for Sale
Pentax 645 SMCP-FA 33-55mm f/4.5 AL Wide Angle Zoom Lens for Landscape Photography
Asking Price
749.00 USD
Item Location
Downers Grove, IL (United States)
Item Description
PENTAX 645 SMCP-FA 33-55mm f/4.5 Zoom Lens
CONDITION: GOOD
Pentax 645 33-55mm f/4.5 Auto Focus Lens in Original Box & User Manual includes:
- Pentax Soft Pouch
- Front & Rear Caps
- Lens Shade (without polarizer cover because they always end up falling off!)
The Pentax 33-55mm Lens may be used with the new Pentax 645D digital camera and these film cameras: 645, 645N, and 645NII.This lens is my favorite. I purchased it new and I've used it for much of my professional landscape photography, which features the prairie and the high quality biodiversity of the immediate Chicago area. (Surprisingly, "Chicago nature" is not an oxymoron.) See examples of my work taken with this lens here Outdoor Photographer Magazine Article - November, 2011 and here Limited EditionPrints. In fact, I wrote the review of this very 33-55mm lens in Outdoor Photographer Magazine when it first came out.
The reason I'm selling this lens is because I moved to digital with another manufacturer.
CONDITION: GOOD
There is visible wear (see photo) on the body, but the glass appears to be great. There is nothing that would detract from the image quality. Over the period of ownership, I've had it professionally cleaned and adjusted a couple of times by Pentax.
IMPORTANT: I am so confident in this product that I am offering a 10-day return policy. See details elsewhere in this listing.
Please see the detailed photos of this lens.
RETURN POLICY:
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but not on cosmetic condition given that this is so subjective. When you get the item, please shoot with it right away so that you have time to evaluate the results.
SHIPPING:
Insured Shipping with Adult Signature Required for $35 to anywhere in the Continental United States (not Alaska or Hawaii). Item must ship to your billing address. I will ship using FedEx Home/Ground or UPS Ground.
Are you the original owner of the item being sold?
Yes
Are you selling or trading this item?
Selling
Item Condition (Key)
Used
Good
Shipping Destinations
United States
Shipping Charge
35
Shipping Services
UPS Ground or FedEx Ground/Home
Accepted Payment Types
Visa, MasterCard, & Discover and will only ship to the address associated with the credit card.
Return Policy & Additional Details
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but no on cosmetic condition given that this is so subjective. Whe you get the item, please shoot with it right away so that you have time to evaluate the results.
Please send me a private message if interested in the item!
Are you the original owner of the item being sold?
Yes
Are you selling or trading this item?
Selling
Item Condition (Key)
Used
Good
Shipping Destinations
Continental U.S. Only
Shipping Charge
35
Shipping Services
UPS Ground or FedEx Ground/Home
Accepted Payment Types
Other (Elaborate)
Return Policy & Additional Details
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but no on cosmetic condition given that this is so subjective. When you get the item, please shoot with it right away so that you have time to evaluate the results.
Please send me a private message if interested in the item!
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Forum: Pentax Medium Format
04-28-2013, 12:11 PM
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That's only true for moving from one film format to another, not film to digital. And that's my entire point. I did the "diagonal conversion" of 1.6 (medium format film of 41.5x56mm to 24x36mm) thinking that would work, but it didn't (as my original post explains). I went from FILM medium format to 35mm DIGITAL. Just factoring in the diagonal (crop factor, you might say) is not the only factor. Pixel pitch matters. How much exactly, I say 3 x pixel pitch, which works for very small apertures. It may be 2 x pixel pitch for the "sharper" apertures like f/5.6 and f/8.
Please do physical tests and find out for yourself. You'll be as surprised as I was. You can test it without a 645D, though.
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Forum: Pentax Medium Format
04-28-2013, 11:55 AM
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It doesn't matter how you view it. Pick 33% or 50% if you'd like The bottom line remains and can easilty be seen: The more you pixels you pack in (the smaller the pixel pitch), the less perceived depth of field, as long as you are using all of the pixels and not downsampling.
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Forum: Pentax Medium Format
04-26-2013, 07:57 PM
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Nope, if anything, it's a lower standard. I had drum scans made of the transparencies at 5400dpi (equivalent to 100 megapixels) and looked at those 100%. So, no, I'm speaking from actual experience and results. Digital changes everything.
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Forum: Pentax Medium Format
04-25-2013, 10:32 PM
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Scott,
I moved from a Pentax 645NII to a full-frame 35mm camera, the Nikon D800E, and it was a wash in depth of field (actually, I lost a little from the switch), in particular as it pertains to hyperfocal distance. That's because film behaves differently than pixels.
I discovered this when using a hyperfocal distance chart that I've been using SUCCESSFULLY for years, based on a standard equation. I photographing a prairie landscape and the closest flower was 18 inches away. To get everything sharp, the chart said f/10 would do it. But, after taking the shot, the closest flowers was completely soft. "Huh? This should be right," I thought. After trying every f-stop and looking at the image at 100%, it only became acceptably sharp at f/18. Then, I ran some tests under controlled conditions and the results matched. The loss was a factor of 1.76 (if a stop is 1.4, then about 1-1/2 stops). According to conventional wisdom, I was supposed to gain by a factor of 1.6 when moving from MF to 35mm FF, but I actually lost 10%. This took me by surprise.
In the past, you may have used a formula like this to calculate the Circle of Confusion: CoC = Film Diagonal / 1730. Nowadays, it's ALSO a function of the distance between pixels (pixel pitch). My tests show that UNDER REAL WORLD CONDITIONS at very small f-stops (like f/22, when diffraction is an issue, but you shouldn't let it bother you): CoC = 3 x Pixel Pitch. Some say it should be 2 x Pixel Pitch. In any case, it's completely different than the film numbers and, most importantly, real world results. If you go by the old film equations, it'll be blurry. My findings show that moving to the 645D from 645 film, you're going to lose about 2-1/3 stops in depth of field. The image diagonal (sensor or film) is a factor, but the pixel pitch is now a variable that must be considered.
My findings also show that a 12-megapixel full-frame or DX sized sensor gives the exact same CoC as the digital calculation. This is why I didn't notice it in the past with my Nikon D300 (and a D700). The results were hidden because they coincidentally equaled that of film.
Now, all of this only matters if we assume, as we should, that you intend to use all 39 megapixels, like maknig really big prints. Otherwise, why waste 8K on a camera that's due for an upgrade and is about ten lenses short.
Good luck with your decision!
Mike
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Forum: Sold Items
02-08-2013, 02:38 PM
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PentaxForums.com Marketplace Listing
Item for Sale
Pentax SMC Pentax-FA 645 150-300mm f/5.6 ED (IF) ZOOM LENS - MINT
Asking Price
1200 USD
Item Location
Downers Grove, IL (United States)
Item Description
SMC PENTAX-FA 645 Zoom 150-300mm f/5.6 ED IF Lens
for 645D, 645NII, 645N, 645 Cameras CONDITION: MINT
Took fewer than 100 shots with this lens!
Lens includes: - Front & Rear Caps
- Lens Shade (without polarizer window because they always end up popping off, anyway! I lost it for you.)
I am the original owner of this lens, but I rarely used it because I almost always shoot landscapes with the 645N and 33-55mm lens (both of which I'm selling on eBay). The 150-300mm lens spent most of its life in my photo vest, just in case I needed it. I don't think I took a hundred shots with it. It's effectively new and was very well cared for.
The reason I'm selling this beautiful lens is because I recently moved to digital with another manufacturer.
Condition: MINT
Functionally, the lens is Like New.
NOTE: I am so confident in this product that I am offering a 10-day return policy. See details elsewhere in this listing.
Cosmetic Appearance: 99% - 100%
Beautiful condition. Glass is perfect. The lens body just shows wear on the flanges where the lens hood attaches (see photos). The lens shade shows some minor wear and polarizer window is gone (where, nobody knows).
Please see the detailed photos.
RETURN POLICY:
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but not on cosmetic condition given that this is so subjective. When you get the item, please shoot with it right away so that you have time to evaluate the results.
SHIPPING:
Insured Shipping for $35 to anywhere in the Continental United States (not Alaska or Hawaii). You must sign for the product and item must ship to your billing address. I usually ship via FedEx Home/Ground or UPS Ground.
PAYMENT:
VISA, MASTERCARD, or DISCOVER. Shipping must be to the address associated with the credit card.
Are you the original owner of the item being sold?
Yes
Are you selling or trading this item?
Selling
Item Condition (Key)
Used
Mint
Shipping Destinations
United States
Shipping Charge
35
Shipping Services
FedEx Home/Ground or UPS Ground
Accepted Payment Types
Other (Elaborate)
Return Policy & Additional Details
PAYMENT: Visa, MC, Discover. Shipping must be to address associated with credit card.
RETURN POLICY:
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but not on cosmetic condition given that this is so subjective. When you get the item, please shoot with it right away so that you have time to evaluate the results.
Please send me a private message if interested in the item!
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Forum: Sold Items
10-30-2012, 11:11 PM
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Forum: Sold Items
09-22-2012, 01:54 PM
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Forum: Sold Items
09-14-2012, 05:42 PM
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PentaxForums.com Marketplace Listing
Item for Sale
Pentax-FA 645 SMC 150-300mm F5.6 ED IF ZOOM LENS - MINT
Asking Price
$1999
Item Location
Downers Grove, IL (United States)
Item Description
SMC PENTAX-FA 645 Zoom 150-300mm f/5.6 ED IF Lens
CONDITION: MINT
Took less than 100 shots with this lens.
Lens includes:
- Front & Rear Caps
- Lens Shade (without polarizer window because they always end up falling off!)
I rarely used this lens because I almost always shoot landscapes with the 645N and 33-55mm lens (both of which I'm selling on this website). The 150-300mm lens most of its life in my photo vest, just in case I needed it. I don't even think I made 100 shots with it. It's effectively new and was very well cared for.
As the original owner, the reason I'm selling this lens is because I recently moved to digital with another manufacturer and no longer need it. Sorry Pentax!
Condition: MINT
Functionally, the lens is Like New;
Price: After scouring the Internet, $1999 is a very fair price for this almost new lens compared to the much higher price of a new one. I accept Visa, MasterCard, and Discover. See payment section below.
NOTE: I am so confident in this product that I am offering a 10-day return policy. See details elsewhere in this listing.
Cosmetic Appearance: 99% - 100%
Beautiful condition. Glass is perfect. The lens body just shows wear on the flanges where the lens hood attaches (see photos). The lens shade shows some minor wear and polarizer window is gone (where, nobody knows).
Please see the detailed photos.
Email me with your questions: subscribe@mikemacdonald.com
Are you the original owner of the item being sold?
Yes
Are you selling or trading this item?
Selling
Item Condition (Key)
Used
Mint
Shipping Destinations
Worldwide
Shipping Charge
$35
Shipping Services
FedEx Home/Ground
Accepted Payment Types
Other (Elaborate)
Return Policy & Additional Details
RETURN POLICY:
10 Days from your receipt of package on Proper Function ONLY (minus shipping), but not on cosmetic condition given that this is so subjective. When you get the item, please shoot with it right away so that you have time to evaluate the results.
SHIPPING:
Insured Shipping for $35 to anywhere in the Continental United States. You must sign for the product and item must ship to your billing address. I usually ship via FedEx Home/Ground.
PAYMENT:
CREDIT CARDS: I accept these credit cards (Visa, MasterCard, and Discover). After all is agreed, I will send you an invoice and we'll make arrangements to get your credit card information. It's that easy!
Please send me a private message if interested in the item!
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Forum: Pentax Medium Format
04-14-2012, 01:07 PM
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Ultra wide angle lenses give a very different look and experience that other lenses cannot and solves some creative problems.
(The 500mm lens is simply an example of the financial savings using older, yet still very good, lenses.)
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Forum: Pentax Medium Format
04-14-2012, 12:57 PM
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From what I've read, the flare mainly occurred in tests when direct sunlight entered the lens from an angle outside the lens' field of view. For instance, on Photozone (http://www.photozone.de/nikon_ff/447-nikkor_afs_1424_28_ff?start=1), the lens tester said that sunlight coming from slightly behind the lens produced flare. Well, in that case, "Just block the light with your body, silly!"
Do you have experience with this lens?
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Forum: Pentax Medium Format
04-13-2012, 02:01 PM
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But, Whats_edoo does landscape photography. In that case, the D800 ($3K) and the revered Nikon 14-24mm f/2.8 lens ($2K) comes to $5K. The Pentax 645D with a the new 25mm Lens is $15,000 and that's just for one focal length. The Nikon user has an extra $10K in his pocket to spend on lenses, vacations, dentures, etc. I'm also certain that a lens like the manual focus Nikkor 500 f/4 P Lens will fair beautifully on the D800. And, you can get it used for $2,500. Plus, medium format lenses, based on their size (much more glass and materials), all cost more than 35mm lenses (focal lengths and maximum apertures being equal).
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Forum: Pentax Medium Format
03-23-2012, 10:32 PM
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No, just so happened this comment applied to both threads. Nonetheless, I was simply reporting on two stories that were recently published by reputable sources.
I've stood by Pentax for the last 12 years or so, buying their products, touting their products, even writing a favorable review of the Pentaxt 645NII, 33-55mm lens, and 55-110mm lens in Outdoor Photographer Magazine. I waited forever for a 645D as they toyed with us by announcing a digital camera, then bailing on the camera, then announcing again years later. And, after promoting the 645D as primarily a landscape photography camera, it took them two years since the announcement of the 645D to come out with a landscape photography lens. Duh! So, I've given Pentax every chance to keep my business and they've now failed. So, I've been participating in the discussions of the Nikon D800/D800E comparisons because I recently pre-ordered one and was hoping for facts to see how they might compare, not to garner snarky remarks.
You say that I'm wasting my time. But, you're the one who has made 395 posts in the last 13 months, averaging 1 post per day. According to my numbers, I average about one post per week.
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Forum: Pentax Medium Format
03-23-2012, 10:09 PM
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Forum: Pentax Medium Format
03-23-2012, 05:12 PM
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If numbers mean anything, which is more scientific than speculating on a forum, then the Nikon 800 sensor just creamed the Pentax 645D by the score of 95 to 82 in DxOMark tests. Though it still needs to be tested with lens, I can't see it not holding up given Nikon's fine glass like the 14-24mm.
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Forum: Pentax Medium Format
03-23-2012, 05:06 PM
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Given today's announcement that the new 25mm lens is only made for the (cropped) 645D says that they've abandoned their plans to go Full Frame with medium format. Glad I pre-ordered the D800E, which has just creamed the 645D in DxOMark testing 95 to 82 and is their highest scoring sensor to date. Of course, it still needs testing with lenses, but it's hard to imagine it will drop much when tested with Nikon's best glass like 14-24mm.
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Forum: Pentax Medium Format
03-15-2012, 10:12 AM
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Nikon D800E vs. D800: Which is more Diffraction Limited? The Technical Guide to the Nikon D800/D800E was just published and I believe it is saying that the D800E (the one with effectively no anti-aliasing filter) is more Diffraction Limited than the D800. Here's the quote, "The D800E offers better resolution at apertures where diffraction is not an issue. The effects of aperture may therefore be more noticeable than with the D800, and care may be required to avoid loss of definition due to diffraction." Does this makes sense from a physics point of view? I mean, shouldn't it be just the opposite of what Nikon is saying because the Nikon D800 is causing the Airy Disk to be a little bit larger due to the increased blurring caused by the anti-aliasing filter? Plus, Nikon uses the word "may" and they show images from the D800, not the D800E. It's confusing.
I have a D800E on pre-order (along with the 14-24mm lens) and I have an opportunity to switch to the D800 without losing my place in line. My application is this: Landscape photographs with the nearest foreground subjects located VERY close to the lens, requiring very small apertures. With my Pentax 645NII medium format film camera, I frequently shoot at f/32 using a 33mm lens (the same as using a 20mm lens at f/20 on 35mm full-frame camera). However, with the D800/D800E, they say it's diffraction limited at f/11. Still, I want to choose the best possible camera for the job.
(Ultimately, I'm simply trying to do as well or better with digital than I am with medium format film. I suppose with the 645 camera at f/32, for all of these years my pictures may be well beyond the diffraction limit anyway and I never really notice it.)
I appreciate help from those who better understand this topic.
Thanks! |
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Forum: Pentax Medium Format
02-26-2012, 04:06 PM
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I was wondering about the flare. I believe I read that it isn't a problem. One report I did read that reported flare was because the front element stuck out in front of the side lens shade (not the top). But, my application is landscape photography using a tripod. If the sun is out of the frame, I would simply block the sunlight hitting the front element with my body, hat, or whatever?
In your experience, when the sun is "in the frame," do you get flare?
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