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Forum: Pentax News and Rumors 01-12-2021, 07:42 AM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
I would be cautious in using a simple "eye-meter" to gauge the amount of information contained in a frame. For example, we've all seen those before-after comparisons where someone pulls up the shadows from an under-exposed photo. On the "before" shot, your eye thinks there's basically nothing in the shadows, which is not the case at all. I wouldn't be surprised if a higher magnification shot sharpens up to produce a much nicer result than the crop from a lower magnification shot, even if the unprocessed images initially seem similar to the naked eye. That being said, I won't be the one testing that statement - I prefer to be out shooting...

The other element that people often seem to forget is that diffraction is not the only thing through which you loose information/detail. You lose a lot through having parts of your subject simply out of focus! Over on Flickr and even sometimes on PF, I keep seeing shots proudly posted that were shot at "optimal" apertures and where a critical part of the subject, even often the nearest eye, are completely out of focus. Shooting at a higher aperture means you are more likely to get those critical parts of the subject into acceptable focus. And an image shot at a higher aperture may have a lower *peak* sharpness, but may still contain much more overall detail of the subject through its greater depth of field.

That being said, in my comparison of the Laowa with my D-FA 100mm WR, I did find that although the Laowa is quite a bit sharper at open and mid-apertures, the D-FA resists diffraction better at "criminally high" apertures. Switching to the Laowa for me will require shooting significantly more open to produce better results than what I could achieve with the D-FA/DCR-250 combo. This in turn require much more focus stacking to not lose out on depth of field either. There is the potential for a significant improvement in image quality of my shots from switching, but simply swapping lenses won't achieve it. My technique will need to adjust and improve to manage to exploit the potential offered by the Laowa. It's a challenge I am excited to take on and that I hope will help me grow as a photographer. I won't be selling my D-FA any time soon though...
Forum: Pentax News and Rumors 12-14-2020, 08:24 AM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
I have the Vivitar Series 1 105mm F/2.5, which is a rebranded Lester A Dine, and in testing there simply was no comparison - the Laowa was way superior. That being said, I've had (IMHO) great results with the Vivitar S1, and I wouldn't sell it. But a bit like Thomas Shahan when he tested his older setups in his Laowa 100mm video, I was surprised at the results when I actually tested it. I think people tend to overestimate the real-world differences between macro lenses when looking at 100% crops of shots at optimal apertures with perfect focus done in a controlled environment...

[EDIT:] Also, another point worth mentioning is that the focus throw on the Laowa is short. Very short. Personally, I'd prefer to have more throw, especially between 1:1 and 2:1. Thankfully the focus ring is very well-dampened, but the Lester Dine lenses have the most velvety and pleasant focus action with a super long throw, so there's a major handling difference there...
Forum: Pentax News and Rumors 12-11-2020, 11:34 AM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
Well, it's pretty simple and I just retested it since you had me doubting...! ;) Taking a shot of a ruler at infinity focus, I have about 30mm horizontally on my image. My APS-C sensor is 23.5mm wide, so that's roughly 0.8:1. My DCR-250 is also on a 49-43mm stepdown ring. Now you have me wondering how you bottom out at 1:1, apparently using the exact same lens combo. :o I just dug out my hood BTW, and eyeballing it I am surprised to agree that it might indeed be possible to get decent light even with the hood. This may warrant further testing. Thanks! :cool:
Forum: Pentax News and Rumors 12-11-2020, 08:23 AM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
This is a good point, but remember that I'm not using the DFA by itself. 99.5% of the time, I have a Raynox DCR-250 on the end of it. With this combo, I get a macro range of 0.8:1 with the lens at infinity focus to 2:1 with the lens at MFD. I haven't actually tested this (and maybe I should), but I would expect that when shooting at the "long" end with this combo, if I also had the hood on, it would practically touch the critter and lighting would become difficult/impossible. You might argue that I could "simply" remove the Raynox for those "lower magnification" shots, but that's just a PITA, IMHO. You have to unscrew it, then find the cap for it, then put the cap on and put it in a pocket, then hope that the critter hasn't disappeared in the time it took you to do that. In practice, I mostly don't even bother trying to shoot anything that won't fit in my APS-C frame at 0.8:1. Precisely for this reason, I expect that shooting with the Laowa next summer will mean I will shoot a lot more "near-macro" shots (such as profiles of Odonata, which are useful for species identification) rather than strictly concentrating on high-magnification "portraits". Those portraits will remain my bread and butter though, but I expect I will also have to adjust my technique as the Laowa's optical strengths are very different to those of the DFA 100mm plus Raynox DCR-250 combo...

BTW, if I could have the perfect macro lens for me, I would pick a macro range of 1:3 to 3:1. I don't care about infinity focus, but bottoming out at 1:1 is a bit too tight. And at the other end, shooting above 3:1 in the field is almost mission impossible, so I don't really need the 3:1 to 5:1 range that something like the Canon MP-E offers. But since I can't get something that does 1:3 to 3:1, I'll take infinity to 2:1 (ie the Laowa).

---------- Post added 12-11-20 at 10:50 AM ----------



Thank you!

Yes, me too I guess - time spares no one... But for me it's very much about the "hunt": about getting out there, walking, spotting critters, then managing to get them to accept the camera when they could simply fly/jump away. Corpse photography just really isn't my thing. I think the people who do that are often either techno-geeks who care a lot more about their micro-stepping motors than about the insects themselves, or science geeks that care greatly about the details of obscure anatomical features. I want to shoot critter portraits. Shots that showcase the beauty of living creatures that just happen to be too small for people to generally notice them. If I could no longer do this handheld, I think I would resort to getting up at ungodly hours and learning how to find insects that are still "sleepy" from a cold night and then carefully setting up my tripod and stacking contraption near them...
Forum: Pentax News and Rumors 12-10-2020, 11:17 AM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
Personally, I find the working distance is too great with a very long lens. It requires much more flash power and it's often hard to find an appropriate point to brace on while shooting so far from the critter. My poor man's long macro is a Tamron Adaptall 90mm (52BB) coupled with the well-regarded Adaptall 2X tele-converter, which gives a 1:1 180mm lens. I've gotten good results using this with a Raynox DCR-250 for high-magnification shots (e.g. here), but frankly it no longer sees much use. For me 90-105mm really is a nice sweetspot for in-situ nature macro of critters roughly 5 to 30mm in size.

To come back to the Laowa, they claim it's an internal focus design, but the front element recedes deeply into the lens at infinity and progressively extends as you focus closer and closer. To me this behavior is very similar to a more traditional macro design (like the D-FA 100mm WR), only with a fixed-length external barrel that goes all the way to the maximum extension of the internal barrel (rather than only extending to the infinity focus point as the external barrel on the D-FA 100mm WR does). Not sure if that description is clear...

Nevertheless, what I didn't expect is that having this fixed length external barrel is actually super useful. It makes it much easier to setup a diffusion surface since you know that the barrel will always be there and is a solid point on which to rest a diffusion surface. With the D-FA 100mm, you always have to worry about the lens extension/retraction - both in trying to avoid putting to much pressure on the internal barrel when fully extended, and at the other end not having anything there (to stop your diffusion surface from sagging into the field of view) when the lens is retracted. To me this difference is an unexpected but very welcome improvement in shooting with the Laowa versus D-FA 100mm plus Raynox DCR-250 (in the 1:1 to 2:1 macro range).
Forum: Mini-Challenges, Games, and Photo Stories 12-07-2020, 09:07 AM  
Thematic Show me your insects
Posted By Doundounba
Replies: 6,323
Views: 442,488
Looking through some old SD cards, I found a couple of nice enough shots from 2016, and I don't quite know why I didn't post them at the time... They look pretty good from where I'm standing in 2020, no?


Bee on Flower (Lost and Found) by Pascal Gaudette, on Flickr


Red Dragon (Lost and Found) by Pascal Gaudette, on Flickr
Forum: Mini-Challenges, Games, and Photo Stories 12-07-2020, 09:05 AM  
Thematic Pollinators in action
Posted By Doundounba
Replies: 775
Views: 51,435
I recently found this shot on an old SD card - not sure why I had not posted it in 2016!


Bee on Flower (Lost and Found) by Pascal Gaudette, on Flickr
Forum: Mini-Challenges, Games, and Photo Stories 11-26-2020, 08:46 AM  
Thematic Show me your insects
Posted By Doundounba
Replies: 6,323
Views: 442,488
Thank you!




Hehe, well, I did observe that wasp for probably well over half an hour. :) I'm actually pretty impressed with the lens too. It's incredibly sharp at open and mid apertures (down to about F/10 at 1:1). It's about even with the D-FA 100mm WR more closed down (F/11-F/13) but the D-FA is a bit more resistant to diffraction at "criminally high" apertures (though the shots are still totally usable with some sharpening in post).


The Wasp and the Grapes (#4) by Pascal Gaudette, on Flickr
Forum: Pentax SLR Lens Discussion 11-26-2020, 08:36 AM  
Aperture spring repair/replacement: cost?
Posted By Doundounba
Replies: 4
Views: 468
Wow, that quote from Precision is crazy expensive! BTW, I'm also worried about the delays in getting parts. I wouldn't want to be without the lens for months on end...
Forum: Photographic Technique 11-26-2020, 06:54 AM  
Macro Focusing Rail
Posted By Doundounba
Replies: 35
Views: 2,876
I use Zerene and am very happy with it. There's a bit of a learning curve, but not too much. There are two different stacking algorithms and one of them has a tweakable parameter so you need to develop a feel for what works best for you and also what will work best for any given stack. The retouching interface is excellent IMHO, and makes it often possible to remove stacking artifacts created by a slight movement of the subject - say an antenna or a leg - by manually picking the frame(s) from which that particular part of the final stack will be made.
Forum: Pentax SLR Lens Discussion 11-25-2020, 09:01 AM  
Aperture spring repair/replacement: cost?
Posted By Doundounba
Replies: 4
Views: 468
So my beloved Pentax D-FA 100mm F/2.8 WR Macro lens seems to have developed a lazy aperture spring. The lens will often overexpose single frames, but only the first shot in a burst of shots, and I can feel that the action of the aperture lever is nowhere near as fluid as that of my other lenses.

I have contacted Ricoh's service center in Canada (Sun Camera Service), and am awaiting a response from them before sending the lens in for a repair estimate. But I thought I'd also ask here: has anyone else had a similar repair done? How much did it cost?

Thanks in advance! :)
Forum: Pentax Forums Giveaways 11-24-2020, 03:39 PM  
Pentax K-70 Giveaway - November - Enter here once per day!
Posted By Doundounba
Replies: 2,136
Views: 52,025
Just my second entry...
Forum: Mini-Challenges, Games, and Photo Stories 11-24-2020, 03:38 PM  
Thematic Show me your insects
Posted By Doundounba
Replies: 6,323
Views: 442,488
A few images of a wasp that was feeding on leftover raisins in our vine tree. (Testing out the new Laowa 100mm 2X Macro, these were some of the last shots of a very very sparse season for me...)


Wasp on Vine Tree by Pascal Gaudette, on Flickr


The Wasp and the Grapes (#1) by Pascal Gaudette, on Flickr




The Wasp and the Grapes (#2) by Pascal Gaudette, on Flickr
Forum: Sold Items 11-24-2020, 03:26 PM  
For Sale - Sold: K-Mount Manual Focus Macros for Sale!!! 55/90/100mm
Posted By Doundounba
Replies: 22
Views: 3,033
Those Vivitar 55mm and Soligor 90mm are tempting! Free bump.

BTW, I don't supposed you've tried the Tamron 90mm (72B) with Adaptall tele-converters (either 1.4x or 2x)?
Forum: Photographic Technique 11-24-2020, 03:04 PM  
Macro Focusing Rail
Posted By Doundounba
Replies: 35
Views: 2,876
It should be noted that if you want to try to shoot focus stacks handheld, stacking software is actually pretty good at lining up your shots as long as your movement is reasonably linear and steady. You'll get edge artefacts in your stack from the fames not lining up perfectly, but you can usually either crop that out, or sometimes even manually retouch it using single frames from the stack. I find that for 2-20 frames, it works quite well for me.

That being said, some people really trip out on motorized rails to shoot super deep stacks of non-moving subjects. Not my style, but to each their own...

Here's a single frame at 2:1:



And here's the 22-frame handheld focus stack that the previous shot was pulled from (click through for higher resolution). (Note that the whole point is to not have the subject in the same plane as the sensor.)


Another 1968 by Pascal Gaudette, on Flickr
Forum: Pentax News and Rumors 11-24-2020, 01:44 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
Yeah, shooting greater than lifesize macro without a flash would be quite a challenge...



It's just an old vintage L-braket. Photo of the "doodads" below. :) Note that I'm triggering the flash from a Yongnuo wireless trigger, but it's not wireless triggering! The trigger just happens to have a PC-sync port with screw threads. I tried using the one on the K-3 body directly, but that doesn't have the same size of threads, so I couldn't screw the cable in place, and it kept unplugging itself at inopportune moments. The most important item is the bracket to get the flash horizontal. I got it on Ebay and I think it was meant for video lights, but the nice thing about it is it can't move left to right. Some people use small ballheads to achieve the same thing, but if your flash is heavy (and mine is), this solution is much sturdier. I'm not finding it on Ebay at the moment though...






I agree. Aside from the hood, there's not much to criticize in the build quality. Coming from the D-FA WR, I do find that there's not much area to grab onto that is neither the focus nor the aperture ring. Thankfully, the focus action is very well damped, so you're unlikely to change your shot's magnification inadvertently while approaching the critter.

Oh, and since the actual front element recesses deeply into the outer barrel - which may allow both dust and even inquisitive small critters in - IMHO you should consider the included UV filter as a replaceable front element and always leave it on.
Forum: Pentax Price Watch 11-24-2020, 01:28 PM  
Godox V1/Flashpoint R2 at Adorama $140 off
Posted By Doundounba
Replies: 9
Views: 951
Thanks for this! I just ordered one. :) BTW, B&H accepted a pricematch request. (B&H are better for me because they collect the taxes when shipping to Canada and you avoid a nasty additional carrier brokerage fee.)
Forum: Pentax News and Rumors 11-22-2020, 12:50 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
I'm not sure what you mean, but here is what the setup I used looks like:




Basically the important details are that it's a li-ion powered flash on an L-Bracket camera-left, with a thingamajig that allows me to get the flash horizontal. This flash (Godox AD180) has an external battery (the squiggly cable connects to the battery), but I also use a flash that has an internal battery (Godox V850ii). I use the L-bracket because I like my light to be slightly directional, so I don't want the flash quite centered with respect to the lens. Making the flash horizontal brings the flash head and diffusion surface much closer to the subject and allows me to use lower flash power as well as a smaller diffusion surface for equivalently soft light. Low flash power is useful when shooting bursts for focus stacking at 8.3 fps.

p.s.: That being said, I do think I need to up my diffusion game a bit, especially for lower magnification work.

p.p.s.: If you want I can reshoot this with a cleaner background...
Forum: Pentax News and Rumors 11-15-2020, 06:37 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
Yes, if I understand you correctly, AFAICT, at the "eyeball-the-histogram" level it's very good. Meaning that I can shoot full manual with flash and change (say) the aperture by 2/3 of a stop, bump up the flash by the same amount, and shoot again, then repeat that a few more times, and the histogram stays nearly identical.

Here are a few more samples from the album I linked to previously (but no one follows that type of text-only link, I guess). Click through on each image for higher res.


Wasp on Vine Tree
by Pascal Gaudette, on Flickr


The Wasp and the Grapes (#4)
by Pascal Gaudette, on Flickr

The following is probably my best shot with the lens so far. I was starting to get to know it a bit... It's a two-frame focus stack at 2:1 of a picture-wing fly (Delphinia picta), a species I hadn't seen in a few years! OK, maybe it's not the prettiest creature in the universe, but it is arresting in its own way, IMHO. :) Frame is about 10mm wide here.


Painted-Wing Fly (#1)
by Pascal Gaudette, on Flickr

And here is a slightly more portrait-y shot. I uploaded this one in full resolution over on Flickr...



Russian Doll
by Pascal Gaudette, on Flickr
Forum: Pentax News and Rumors 11-14-2020, 06:56 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
Indeed. For me the solution adopted by Laowa makes sense from a cost perspective, especially since the focal length and max aperture are perfectly standard values here. I don't mind giving the focal length when I turn on the camera, and the max aperture is encoded in the pins. If asked to choose, I'd prefer a locking A position over a chip that tells the camera the focal length...
Forum: Pentax News and Rumors 11-14-2020, 04:55 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
OK, a few thoughts and shots from my upcoming write-up.

- The lens has some handling quirks. For example, there's no pin to lock the A position in place and the aperture ring clicks are very, very low friction. So it's super easy to knock the lens out of the A position while trying to compose and focus a shot in the field. Then the camera doesn't fire at all, which is pretty annoying. But once you know the risk, you can adjust the way you hold the lens.

- The mount aperture control is definitely at the KA level rather than KAF. If you look at this wonderful PF page on the evolution of the K-mount, you'll find the "Digital information contact" which was added with the KAF mount in 1989. AFAIK, this is the contact which a lens uses to communicate its focal length to the body, and it's definitely not present on the Laowa (see image below, or the one posted previously by Mistral75). And as mentioned previously, your K-Mount body will prompt you for a focal length when you turn it on with the Laowa 100mm 2X mounted.

- Optically, after just a few tests, I believe this lens doesn't take many prisoners. I need to retest at 2:1, where it's exceedingly difficult to control for correct focus if you don't have a good focus rail. (For example, when shooting a penny you can find once you review your shots that the bottom of the penny is in focus, but the top of the engraved letters on the penny are not! In the field, if the eyes are not in focus, the shot is just left on the cutting room floor so to speak, but in testing, you need to nail it.) But otherwise, testing against the D-FA 100mm WR and looking both at portrait-type shots shooting very open at around 1m distance, and at 1:1 macro shots shot very closed, I am very impressed.

- I shot about 400 frames in the field over three outings, and have published nine images as a result of those outings. You can have a look at all of them in this Flickr album. Now it definitely will no longer be possible to shoot bugs until the spring...






Forum: Pentax Forums Giveaways 11-13-2020, 04:41 PM  
Pentax K-70 Giveaway - November - Enter here once per day!
Posted By Doundounba
Replies: 2,136
Views: 52,025
Well, count me in at least once... :)
Forum: Pentax News and Rumors 11-13-2020, 04:39 PM  
Laowa 100mm F2.8 2:1 Macro lens for k-mount
Posted By Doundounba
Replies: 439
Views: 45,714
I'm speculating here, but my camera does ask for a focal length when the Laowa is mounted, so I would think it likely that the k-mount version of the 100mm Macro 2X has no chip and is using the A-level pins to communicate its max aperture to the body. I could be wrong, of course, and on the other hand, maybe that new adapter will eventually support auto-aperture with A-level MF glass... Still I do think someone wanting to shoot this lens on Sony would be better served with the EF version (since the smart adapters have been out for a while and are known to work), unless that someone is also a Pentaxian!
Forum: Mini-Challenges, Games, and Photo Stories 11-13-2020, 12:13 PM  
Thematic Spiders
Posted By Doundounba
Replies: 962
Views: 75,242
And another crab spider predation shot!


Crab Spider and Fly Prey by Pascal Gaudette, sur Flickr
Forum: Pentax News and Rumors 11-13-2020, 09:34 AM  
Pentax K-3 Mark III (R03010) - Additional pictures
Posted By Doundounba
Replies: 594
Views: 45,300
Wow, that is one good looking camera, especially in silver...!
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