[JSI]

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I've got a Promaster 5750DX flash that I used with my first digital point-and-shoot Olympus camera. The Olympus is looonnnngggg gone and the folks at Promaster have discontinued support for the 5750DX. However I can still buy the 5050dxr control modules. There isn't much talk on the web regarding this old flash and what I can find is years old.

Has Pentax keep their hot shoe configuration the same, like they've done with the lens mount, and picking up the 5050dxr control module isn't just a waste of money? Or is it time to let the old flash go to its next life at the goodwill?

[nanhi]

You are in Luck Brother. The Promaster 5050DXR Module will just work fine as a PTTL Flash if you can attach it to the old Promaster 5750DX flash, on every Pentax DSLR made till date.
The hot shoe configuration remains the same.
Note: 1) you may have to cut the plastic key off the Promaster 5050DXR module before mounting it to the older Promaster 5750DX flash. So do check this out.
2) Do NOT buy the QDA-PAF module. It is TTL only and will not work on current DSLRs from the K-20D to the K-3 series, or the newer K-S series.
3) The Quantaray QTB-9550U flash is a re-badged Promaster 5750DX. Both are exactly the same.

Here is a Bonus. The plain Quantaray / Promaster Module QDA-P is a marvel and the cheapest at $ 5 to 10 on evil bay. Your old flash will work like an Auto Thyristor, giving you perfectly exposed shot each time. It is even better than the Promaster 5050DXR Module.
It has settings galore on the back of the module - manual, Auto, and Low Power. Auto gives you further 3-color coded setting enhancing your flashes capability.
The module, when set to Auto, communicates with the camera and can read the ISO setting from the camera. It then has the ability to set the aperture as you change the ISO. The sensor on the flash regulates the power output depending on the distance and the amount of light falling on the subject.

Note: Al these earlier Flash Guns and Modules are complementary and work well with each other - Quantaray, Promaster, Vivitar, Tumax, Digital Concepts, Sakar, Bower etc.

Regards.

[mcgregni]

Some great points there nanhi, thanks, very interesting. Sounds like you're saying that module operates the flash as an 'auto-thristor' type ... ? The latest Tumax version with P-TTL and a digital interface looks very tempting at the price ... just seems to be distribution and availability which is a problem (eg I can't get the top model on Amazon UK at present).

[nanhi]

Some great points there nanhi, thanks, very interesting. Sounds like you're saying that module operates the flash as an 'auto-thristor' type ... ? The latest Tumax version with P-TTL and a digital interface looks very tempting at the price ... just seems to be distribution and availability which is a problem (eg I can't get the top model on Amazon UK at present).

Thanks mcgregni Sir. I wrote that post from my personal experience using a Quantaray QB-6550U Flash ($ 12 from Wolf Camera) + Quantaray Manual QDA-P Module ($10 on eBay).
I have the most power little flash like the Auto Thyristors of circa 1980. And OMG, it communicates with the Pentax K-5 IIs:-

"The flash reads the ISO setting from the camera and in Tv mode, it can then set the aperture on the camera appropriately. On the flash module is a slider with three coloured square – blue yellow & green. On the flash is an ISO slider with corresponding f-values and the maximum flash distance - again with the three color codes. For ISO 100, the blue setting calls for f2, yellow f4, and green f5.6.

Since everything communicates, changing the ISO settings changes the aperture. Example, say you have the FA 50mm f1.4 on the camera and have set ISO 100 to start at f4 - yellow. Raising the ISO on the camera to 200 means the flash sets the aperture on the lens to f5.6. Raising the ISO again to 400 mean the flash sets the aperture to f8, and ISO 1000 would get you f11. You could have set the flash to blue - f2. Raising the ISO to 200 would then set the aperture to f4, raising it further to ISO 400 would set the aperture to f5.6, and so on.

The other neat trick to this is that EV comp works in the same fashion. Setting ISO 100 at blue - f2 on the flash, and setting ISO 100 on the camera; to get f1.4 on the FA 50mm 1.4 means adding +1.5 to 2 EV. Bouncing with this flash with a normal 10 foot ceiling and not too wide a lens works really well. The small size and weight is really nice for this".

Note: 1) If I buy the Promaster 5050DXR Module ($40 to 50 on evil bay), I have the smallest most powerful PTTL Flash. But why bother, when Yongnuo sells the best PTTL Flash for $ 60.
Move out Pentax with your $ 400 to 300 flashes.
Sir the Yongnuo is the most popular and far better than the Tumax. Believe me I have an older Tumax version bought in Dubai.
The Quantaray / Promaster / Sakar / Digital Concepts etc. is made by the same one Manufacturer and re-badged.

Regards.

[mcgregni]

Its great to have that functioning on such an old flash and such a new camera !. I have found the 'auto' flash mode on the Pentax AF-540FGZ useful if needing to use older manual focus lenses (when P-TTL doesn't work), and I know many members here have felt that the loss of the 'A' mode on the newest flash models was a backwards step. Certainly it sets us back to using manual flash exposure, when in fact most people report that 'auto' mode working (as you have described) is very reliable.

I was not aware of the Yongnuo P-TTL model you mentioned .... do you have the full model description or a link to it anywhere... ?

[nanhi]

Its great to have that functioning on such an old flash and such a new camera !. I have found the 'auto' flash mode on the Pentax AF-540FGZ useful if needing to use older manual focus lenses (when P-TTL doesn't work), and I know many members here have felt that the loss of the 'A' mode on the newest flash models was a backwards step. Certainly it sets us back to using manual flash exposure, when in fact most people report that 'auto' mode working (as you have described) is very reliable.
I was not aware of the Yongnuo P-TTL model you mentioned .... do you have the full model description or a link to it anywhere... ?

Here are the Links. It as good as the Pentax Flashes sold for $$$. Works great in wireless mode too.

https://www.pentaxforums.com/forums/115-pentax-k-5/216481-yongnuo-yn-560-iii-...uying-not.html

You Tube

You Tube

YONGNUO YN560 III Flash Speedlight for Canon Nikon Pentax Olympus 519890690340 | eBay
Yongnuo Flash for Pentax
Yongnuo Flash for Pentax

Regards,

[mcgregni]

Sorry, I'm not seeing that as a P-TTL capable unit .... is that what you meant? It looks like those Yongnuo units are all Manual, which was what I had presumed.

[JSI]

You are in Luck Brother. The Promaster 5050DXR Module will just work fine as a PTTL Flash if you can attach it to the old Promaster 5750DX flash, on every Pentax DSLR made till date.
The hot shoe configuration remains the same.
Note: 1) you may have to cut the plastic key off the Promaster 5050DXR module before mounting it to the older Promaster 5750DX flash. So do check this out.
2) Do NOT buy the QDA-PAF module. It is TTL only and will not work on current DSLRs from the K-20D to the K-3 series, or the newer K-S series.
3) The Quantaray QTB-9550U flash is a re-badged Promaster 5750DX. Both are exactly the same.

Here is a Bonus. The plain Quantaray / Promaster Module QDA-P is a marvel and the cheapest at $ 5 to 10 on evil bay. Your old flash will work like an Auto Thyristor, giving you perfectly exposed shot each time. It is even better than the Promaster 5050DXR Module.
It has settings galore on the back of the module - manual, Auto, and Low Power. Auto gives you further 3-color coded setting enhancing your flashes capability.
The module, when set to Auto, communicates with the camera and can read the ISO setting from the camera. It then has the ability to set the aperture as you change the ISO. The sensor on the flash regulates the power output depending on the distance and the amount of light falling on the subject.

Note: Al these earlier Flash Guns and Modules are complementary and work well with each other - Quantaray, Promaster, Vivitar, Tumax, Digital Concepts, Sakar, Bower etc.

Regards.

Since I already have an Auto Thyristor flash and I found a deal on a 5050DXR (free) I thought why not. Unfortunately, either I'm doing something wrong or the 505DXR module isn't working. The thyristor flash works everytime, but the promaster flash only flashes once right after you turn the camera on. That picture is horribly over exposed and the flash doesn't flash again until the camera is turn off and on. So I don't know what to think.

[nanhi]

Hi JSI, I am sorry to note that you are unable to get the proper flash output with the 5050DXR Module. You do not mention what Flash Gun you are using with this PTTL module, and also on what camera models. Here are two very important points to note:-

a) PTTL is very badly implemented on all Pentax DSLRs upto the K-5 IIs. Shame on Ricoh-Pentax. So which DSLR are you using?
b) The 5050DXR is actually worthless if not mated with a digital Quantaray or Promaster Flash Gun unit. See these threads:-
https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/107737-q...500a-k20d.html
https://www.pentaxforums.com/forums/125-flashes-lighting-studio/33053-promast...sh-module.html

So the 5050DXR Module will work only with some Quantaray and Promaster Flash Guns (+ some rebadged versions by others)

As you rightly said "either I'm doing something wrong or the 505DXR module isn't working".

Please, please buy the $ 5 to 10 manual QDA-P Module - again check if you are using these Flash Guns:-

ProMaster = Quantaray
-----------------------------------
5750DX = QTB-9550D = QTB-9550U = $ 85 to 55 ]
5550DX = QB-6550D = QB-6550U = $ 50 to 20 ] on evil bay
5250DX = unknown = $ ?? ]

Regards.

[MPrince]

PTTL is very badly implemented on all Pentax DSLRs upto the K-5 IIs. Shame on Ricoh-Pentax

Ricoh purchased the Pentax brand from Hoya in 2011 and had nothing to do whatsoever with the function of Pentax cameras prior to the acquisition. The K-5 was introduced in 2010. The K-5 II and K-5 IIs were introduced in 2012. Not really fair to shame Ricoh. Perhaps you should give Ricoh credit for improving PTTL instead.

[JSI]

Hi JSI, I am sorry to note that you are unable to get the proper flash output with the 5050DXR Module. You do not mention what Flash Gun you are using with this PTTL module, and also on what camera models. Here are two very important points to note:-

a) PTTL is very badly implemented on all Pentax DSLRs upto the K-5 IIs. Shame on Ricoh-Pentax. So which DSLR are you using?

I'm using a K-S2 camera and I've attached photos of the flash unit.

b) The 5050DXR is actually worthless if not mated with a digital Quantaray or Promaster Flash Gun unit. See these threads:-
https://www.pentaxforums.com/forums/58-troubleshooting-beginner-help/107737-q...500a-k20d.html
https://www.pentaxforums.com/forums/125-flashes-lighting-studio/33053-promast...sh-module.html

I've read those threads and it makes me think the 5050DXR module is at fault.

So the 5050DXR Module will work only with some Quantaray and Promaster Flash Guns (+ some rebadged versions by others)

As you rightly said "either I'm doing something wrong or the 5050DXR module isn't working".

The red "OK" light on the 5050DXR module never comes however the green P-TTL light does. Is that the fault of the module or camera? Without a know working camera or module it's pretty much impossible to know.

Please, please buy the $ 5 to 10 manual QDA-P Module - again check if you are using these Flash Guns:-

ProMaster = Quantaray
-----------------------------------
5750DX = QTB-9550D = QTB-9550U = $ 85 to 55 ]
5550DX = QB-6550D = QB-6550U = $ 50 to 20 ] on evil bay
5250DX = unknown = $ ?? ]

Regards.

I'll look into those or maybe sell the Promaster and buy a modern flash. At some point it needs to be about taking pictures rather than fussing with equipment.