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Forum: Troubleshooting and Beginner Help 10-17-2020, 02:04 AM  
Posted By tryphon4
Replies: 16
Views: 879
Mirror lenses lack sharpness, and their bokeh is generally ugly.
I own one 500mm F5.6, seldom use it.

You'd better buy a good zoom, or a vintage A* or FA* 300mm F4.5 and add a 1.4x teleconverter.

My DA* 300mm F4 and Pentax-F 1.7x AF Adapter make a great combo.
Forum: Ricoh GR 10-12-2020, 01:18 PM  
Has anybody tried the old GW-3 wide adapter on the GRIII?
Posted By tryphon4
Replies: 3
Views: 423
It MAY work or it MAY NOT work. If you only look the 49mm mount, you do not see the entire setup.

Do you know that the GRIII lens and the GR/GRII lens are very different?
6 elements in 4 groups for the GRIII, 7 elements in 5 groups for GR and GRII.
The minimum focusing distance is rather different: 6cm for GRIII, 10cm for GR and GRII.

So now, do you see the problem? It is not just a question of mount, it is also a question of distance between the lens and the adapter. Moreover, the old adapter may give bad results on the GRIII because it is optimized for the GR/GRII.

By the way, testing GW-3 on a GRIII could be interesting.
Forum: Ricoh GR 10-11-2020, 01:20 PM  
Has anybody tried the old GW-3 wide adapter on the GRIII?
Posted By tryphon4
Replies: 3
Views: 423
Forum: Photographic Technique 10-10-2020, 02:32 PM  
Macro Some questions regarding dof with different lenses / formats
Posted By tryphon4
Replies: 12
Views: 606
You are right, creamy was not the best word, I should have written "uniform" instead. English is not my main language, I sometimes make some mistakes.
Forum: Photographic Technique 10-09-2020, 02:01 PM  
Macro Some questions regarding dof with different lenses / formats
Posted By tryphon4
Replies: 12
Views: 606
Do not forget bokeh: bokeh is proportional to perspective. Longer length lenses give more creamy bokeh because the perspective is narrower.

Regarding geometric distortion, it is the same story: a photo taken using a 100mm will look more natural than the same one taken using a 35mm at same magnification.
Forum: Pentax SLR Lens Discussion 10-07-2020, 09:27 AM  
Good zoom lens for the K-1
Posted By tryphon4
Replies: 30
Views: 1,604
I own one Tokina 28-70 AT-X (non-PRO).

It is soft wide open but fine from F/4 (looks like spherical aberration).
However, it is a bargain because few people seem interested by this non-PRO lens.

So there are three drawbacks:
The AF sound can be a problem
It has a "vintage" look
It is soft wide open (but I may own a bad copy).

Here is an example @ 70mm F/2.8:

The TAMRON 28-75mm 2,8 XR seems to be a good lens too.
Forum: Flashes, Lighting, and Studio 10-01-2020, 01:17 PM  
Question about vivitar 285 zoom thyristor flash
Posted By tryphon4
Replies: 15
Views: 524
I own one vintage Vivitar 285 and several 283, all are high voltage flashs (about 250V) so a 285 would kill your DSLR.
You can use your 285 in wireless mode but not on the hot shoe and even not wired through a PC sync wire.

These flashs are very interesting because you can modify them in order to replace the removable light cell by a potentiometer, then you get a studio flash that you can calibrate:

IMGP5704 by Hervé Laville, sur Flickr
Forum: Troubleshooting and Beginner Help 09-26-2020, 12:23 AM  
Macro Lenses.
Posted By tryphon4
Replies: 20
Views: 1,164
I still own a K100D super, it was my first DSLR.

I started macro using the standard 18-55mm lens and a magnifying glass. This very basic setup can give good results:
Maya by Harvey LAVIL, sur Flickr

Several months later, I bought my first macro lens, a Cosina 100mm macro F3.5. It can reach 1:2 alone and 1:1 if you use the dedicated close-up.
Then I bought one 1.4x teleconverter and 2 extension ring kits, here is a setup enabling about 5:1:
bagues-allonges by Hervé Laville, sur Flickr

Later, I bought a Tamron 90mm macro (model 52B), my first Tamron. Then I bought (and sold) many other macro lenses.

I currently own 6 macro lenses from 60mm to 180mm, they reach 1:1 to 5:1, I love each one.

I sometimes revert a wide angle lens (35mm e.g.) and maybe add one or two extension rings.
I also can add a close-up to a telelens (the Pentax DA* 300mm F4 performs well if you use it with a Nikon 5T or 6T close-up).

To summarize, the possible setups are endless. You just have to choose a lens according to your needs and you can add

-bellows or extension rings if it is a short focal,
-close-up if it is a long focal.

You also may try microscope lenses or enlarging lenses, it is weird but it works:

objectif de microscope sur reflex by Hervé Laville, sur Flickr
Pentax K7, Zörk MFS, Rodenstock APO-Rodagon 50mm f2.8 by Hervé Laville, sur Flickr

Practically, insects and bugs prefer longer lenses because the working distance is longer. So 100mm to 200mm is a good range.

There are lots of topics about maco lenses over there, you can read them in order to make your choice.
Forum: Troubleshooting and Beginner Help 09-25-2020, 01:54 PM  
Macro Lenses.
Posted By tryphon4
Replies: 20
Views: 1,164
Any macro lens, in K or PK or PKA mount, could be used on a K100D.

The big question is about budget: you can find used or brand new macro lenses between less than 100$ (Cosina 100mm F3.5) and more than 1000$.

Another interesting question is about magnification: most macro lenses go from 0:1 to 1:1.
Do you need higher magnification?
Forum: Ricoh GR 09-05-2020, 02:20 PM  
GRiii compatibility with old GH-3 & GW-3 wide lens kit
Posted By tryphon4
Replies: 4
Views: 528
I own a GR and a GRIII.
I also bought a GH-3 adapter, it cannot be used on a GRIII because the GRIII mount is different from the GR's and GRII's one.

So you need a GA-1 adapter for the GRIII.

A GW-4 will fit on a GA-1 but I guess that a GW-3 will not, to be confirmed.
Forum: Pentax DSLR Discussion 07-24-2020, 06:21 AM  
Why you don’t really want a hybrid viewfinder
Posted By tryphon4
Replies: 36
Views: 4,232
OVF is not always perfect, in some cases EVF is better. If I needed an EVF camera, I would buy a Sony, so I prefer that Sony and other companies invest money in EVF cameras, and Pentax in OVF cameras.
As it has been previously said, an ideal hybrid viewfinder would be very hard to develop, could lead to an expensive camera and may be unprofitable for Pentax.
Forum: General Photography 07-09-2020, 01:20 PM  
How do you store your lenses?
Posted By tryphon4
Replies: 28
Views: 1,536
I use several transparent airtight plastic boxes. Each one contains an hygrometer and some silica gel in a small drilled box :

Of course, I do not travel with these boxes as the lenses are not individually protected agains scratches.
Forum: Pentax Compact Cameras 07-06-2020, 01:16 PM  
ricoh gr ii vs pentax q7
Posted By tryphon4
Replies: 7
Views: 877
I do not own a GR II and a Q7 but I own a GR, a GRIII and a Q.

Q's sensor is a bit smaller than Q7's but it is not relevant, both sensors are very small.
Q's image quality is not amazing at all. Nowadays, I hardly use my Q because bokeh is never smooth and image quality is never excellent.

GR, GRII and GRIII use an aps-c sensor, it is another league, another world compared to Q's family.
Image quality is excellent, bokeh is smooth.
The only problem regarding GR's family is the fixed 28mm (24x36 equivalent) focal length: you cannot zoom in or out, you just can buy a converter in order to shoot at 21mm (24x36 equivalent) or you can crop in order to simulate a longer lens.

In a nutshell: Q is flexible but not so good, GR is excellent but rigid.
Hope it will help.
Forum: Pentax SLR Lens Discussion 07-02-2020, 10:37 AM  
Is the Pentax D FA Macro 100mm WR the best macro option out there for my K1?
Posted By tryphon4
Replies: 22
Views: 1,545
Same for me: I own macro lenses from 28mm to 180mm and choose the one I will use according to the purpose (I will not use the same lens for flowers at 1:10, insects between 1:4 and 1:1 and details between 2:1 and 5:1).

I will prefer my Bresser/Oshiro/no-name 60mm F/2.8 2:1 when a short working distance is acceptable. It is full manual, sharpness is rather good and bokeh is smooth.
I will choose my Mitakon 85mm 1:1-5:1 when I need huge working distance. It is full manual too.
If I need a compact lens, I will use my Tamron 90mm F/2.8 Di, it is close to the Pentax 100mm WR, except that the Tamron is not WR.
If I need AF and a huge working distance, my Sigma 180mm F/3.5 lens will be welcome.
When I want smooth bokeh and vibrant colors, my Irix 150mm F/2.8 will be the one ; it is WR too.
Forum: Pentax SLR Lens Discussion 06-05-2020, 01:32 PM  
APS-C Macro Lens
Posted By tryphon4
Replies: 39
Views: 2,249
I own a Panagor 90mm macro F/2.8, it is a good macro lens and its price is attractive.
Compared to a Tamron 90mm F/2.8 macro Di, the Panagor's working distance is longer, it is a plus in some cases. The largest flaw of the Panagor is CA, I see some chromatic aberration on my photos. The Tamron does not share this flaw.

Of course, a Pentax DFA 100mm macro is slightly better than the Tamron but I could never compare them.

I owned an old "adaptall" Tamron 90mm F/2.5 macro, built like a tank and rather sharp but it only reaches 1:2.

I currently own and use several macro lenses (mainly between 60mm and 180mm), and can say that 100mm is the best compromise in terms of focal length in macro if you aim to shoot living animals. Yet the bokeh is smoother using 100mm and above.

Here are some pics shot using the Panagor 90mm:

Forum: Pentax Camera and Field Accessories 04-11-2020, 12:50 PM  
KENKO 12mm Macro Extension Tube - Aperture not actuating on digital cameras?
Posted By tryphon4
Replies: 10
Views: 650
If you want to keep electrical contacts between lens and body, you should search a KA extension tube, like the one below (the middle one):

It is not very easy to find and it is not cheap.
Forum: General Photography 04-04-2020, 12:33 AM  
CS mount varifocal CCTV lens usage in photography.
Posted By tryphon4
Replies: 5
Views: 453
A C-S lens could be used on a Pentax Q, the problem is to find a "C-S lens to Q" ring adapter.
There are plenty of "C lens to Q" adapters but I never found a "C-S lens to Q" one on €bay.

C mount register is 17.526mm, C-S mount register is 12.526mm, Q register is 9.2mm.
Camera Mounts Sorted by Register

You may want to 3D-print a custom adapter, then there is a useful link : C & CS Lens to PENTAX Q mount adapter by nameless911 - Thingiverse
Forum: Monthly Photo Contests 04-02-2020, 01:14 PM  
Tyrannus under the rain
Posted By tryphon4
Replies: 3
Views: 147
I would like to nominate this photo
Forum: Pentax SLR Lens Discussion 03-29-2020, 10:01 AM  
"Macro" zooms
Posted By tryphon4
Replies: 16
Views: 1,383
Do not trust the name. There is no real macro zoom.
Macro means: able to shoot at 1:1.

Nikon used to produce a "near macro" zoom (70-180mm 1:1.3), decades ago.
Olympus may have produced a macro zoom decades ago, I am not sure.

However, you can find some "proxi" zooms, they reach 1:2 (e.g. 70-300mm from Tamron or Sigma).
Then you can add some stuff (teleconverter, diopter...) to eventually reach 1:1.

In fact, most macro lenses are false zooms (their focal length varies according to the macro ratio) but this information can be confusing for most people.
Forum: Flashes, Lighting, and Studio 01-09-2020, 02:10 PM  
Flash for GR iii
Posted By tryphon4
Replies: 9
Views: 1,964
My old Sigma EF 530 DG Super (Pentax hot shoe) works fine with my brand new GR III, it is great, the drawback is the flash's size which is bigger than the GR's one! :D
Forum: Photographic Technique 12-29-2019, 09:21 AM  
Macro Another Macro option
Posted By tryphon4
Replies: 15
Views: 1,111
Cheap magnifying lenses give crappy results. If you want to get sharp photos, you shall use achromats containing at least 2 elements. There is a useful list here: Index.

I own some excellent achromats (Nikon 5T & 6T, Raynox DCR, Sigma life size converter, Lomo AL-4) and some bad ones (Marumi DHG, Olympus MCON 35).
Forum: Digital Processing, Software, and Printing 12-21-2019, 01:16 AM  
Pixelmator Pro Enlarging
Posted By tryphon4
Replies: 4
Views: 594
This looks interesting but I'd prefer photozoom pro. I look forward to seeing a comparison between Pixelmator and leaders (photozoom, wondershare, onone).
Forum: Photographic Technique 12-18-2019, 11:09 PM  
Macro Another Macro option
Posted By tryphon4
Replies: 15
Views: 1,111
Taking video frames is not silly at all. I've already considered this possibility. It could be achieved, thus the camera movement should be smooth (no vibrations means heavy setup) with stops at intervals (the Stackshot system, by Cognisys, can be an excellent motor-driven setup), in order to have sharp frames.
Forum: Photographic Technique 12-18-2019, 02:49 PM  
Macro Another Macro option
Posted By tryphon4
Replies: 15
Views: 1,111
Indeed! I would love to avoid focus stacking, because this technique is a pain for the shutter. I am looking forward having a global electronic shutter on my DSLR!
Forum: Photographic Technique 12-18-2019, 11:23 AM  
Macro Another Macro option
Posted By tryphon4
Replies: 15
Views: 1,111
It can be useful to remind the basics: We have few means in order to increase magnification:
1. increase focal length thanks to a teleconverter.
2. decrease focal length.
3. increase the "lens to sensor" distance without decreasing focal length.

Solution 1 is practically limited to 2x teleconverters, and if you want to keep full sharpness you should limit to 1.7x (it depends on the lens sharpness and teleconverter sharpness).
Solution 2 is achieved with long focal lenses and diopters (a diopter and a reversed lens are mostly the same thing). This solution may not be a good idea with a short focal length lens because when you decease the focal length, you also decrease the working distance and the latter may tend to zero.
Solution 3 is achieved with bellows, extension rings, helicoid rings, etc. It is easier with short focal length lenses because the needed extension is proportional to the focal length.

You could mix solution 2 and 3: decreasing the global focal length and increasing the "lens to sensor" distance.
Remember one more thing: the focal length of a lens is true when focused to infinity. Most lenses have variable focal length, for example my Tamron 90mm macro, at 1:1, is in fact a 75mm lens. My Irix 150mm, at 1:1, is in fact a 90mm lens.

At the end of the day, you will find that long working distance = long focal length. It is just mathematical.

You can reach 1:1 with a Rodagon 135mm using a 21.75 cm extension ring, the working distance is huge: 26.25 cm (see photo above).
You can reach 1:1 with a Rodagon 105mm using a 16.25 cm extension ring, the working distance is big: 19.25 cm.
You can reach 1:1 with an APO Rodagon 50mm using a 5.75 cm extension ring, the working distance is short: 6.75 cm.
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