PH-RBA72 Hood

**StanMac** · 01-15-2021, 11:58 AM

I won a SMC PENTAX-FA 1:3.8-5.6 28-200MM IF&AL lens in an online auction but it didn't have a lens hood for it. I've seen this lens in for sale ads on fleabay with the PH-RBA72 included and it was shown as compatible with this lens in an online search. Consequently, I ordered a black one from Adorama (mine is the all black version of the lens). However, I cannot get the hood to turn into place on the lens. When I set the hood on the lens where it will be in position for turning (the hood flanges are lined up with the lens' slots), it will not turn to the lock position. I don't want to force it and possibly damage the flanges on the hood or lens. Did Pentax change the flange configuration on this hood to work with a later lens? B&H Photo shows this hood as being "For DA 16-85mm F3.5-5.6 ED DC WR Lens." Thanks for any guidance or help you can provide.

Stan

Last edited by StanMac; 01-15-2021 at 12:37 PM. Reason: Correction in referring to Adorama in the online search

**mikesbike** · 01-15-2021, 03:08 PM

I have this lens and its original hood. I keep it on my Pentax PZ-1p 35mm film body, where it saw most of its use, and it rarely sees action over these many years, since I first became fully satisfied with DSLR performance starting with my 3rd model, the K200D. The hood model you give is the correct one. The 72 part has to do with the lens's filter size. But the flanges should match perfectly. Mine has two white marks on the top surface along the edge of the rim to guide mounting. The smaller of the two marks is at the side, while the larger is centered at the top. There is also a similar white mark on the lens's top side at the front edge. So, to install the hood for shooting, you line up the mark on the hood's side with that on the lens, then turn until the mark on top of the hood lines up with that on the lens. I don't get a click on mine- it just stops when the marks are lined up.

For storage, you do the opposite. Reverse the lens, lining up the mark on top of the hood with that of the lens's front edge, then turn until the smaller mark on the hood's left side is lined up with the lens's frontal mark. So it stores with the hood in reversed position with its side upward.

**UncleVanya** · 01-15-2021, 04:29 PM

I'm not 100% certain that Pentax hasn't reused the same part number. The older lens (28-200) was a 3rd party designed lens and the pictures I see of the hood don't look identical to the hood for the DA 16-85 yet they both have the same part number.

@mikesbike do you have a 16-85 to try swapping the hoods with? Maybe you could take some dimensions if you don't - the petal shape of the original 28-200 hood doesn't look the same to me as the 16-85 hood.

**mikesbike** · 01-16-2021, 05:05 AM

I'm afraid I passed on the DA 16-85mm lens. But I cannot imagine the same part number would be reused if it were not the same! I guess stranger things have happened! Yes, the old FA 28-200mm was a rebadged Tamron, with some differences, perhaps in the hood also. Historically, this old lens was the first ever zoom lens going out to 200mm that could focus at the closer distance this one can. What is stranger to me is the APS-C equivalent is off enough to make me question that the hoods should be the same. The most critical would be the wide end of 16mm being like 24mm on FF, not 28mm. My DA 18-135mm is much more like the FA 28-200mm FF model in its angle of view, but does not take a 72mm filter size- it is much smaller and takes a smaller hood.

I just checked a photo of the DA 16-85mm with its hood on, and you are right- it does not look the same. And I see no marks on it for guidance in mounting the hood. My old hood appears to be deeper along the top. I measure exactly 2 inches from the tip along the top to where it fits against the camera body. It also does not have PENTAX printed on it. so perhaps my hood is also a Tamron clone, although I do know the lens coatings are different. Evidently the opening is the same, as the OP says the hood obtained fits onto the lens but the flanges do not engage. Could be a flange design difference. If that is true, having the same part number is indeed a mistake, and why? At least put a -B after the number!

Last edited by mikesbike; 01-16-2021 at 05:41 AM.

**StanMac** · 01-17-2021, 02:06 PM

Thank you all for your responses. Placing the hood on the lens, with the hood's index mark turned 90 degrees CCW (facing the camera) from the lens's index mark, the hood flanges slip into the slots on the lens front ring, as it should (visually verified by looking at the assembly from the front of the lens). Then turning the hood CW the hood flanges jam against the flanges on the lens's front ring. The hood will not mount in the stored position either, even though separate flanges on the hood are used in that position. It appears as if the hood's flanges are too thick to slide into the groove behind the lens's flanges. I measured the hood flanges with my digital caliper and they measured 1.45 - 1.47mm. The inside measuring points on my caliper are too wide to fit into the grooves on the lens, so I couldn't get an inside measurement on the grooves and I don't have any feeler gauges to use to measure the groove, so I don't know what the interference amount would be. I do believe the hood flange thickness is the issue. It would be a time consuming effort to try to thin down the hood's flanges all along their extremely narrow surface and length. So, I'm going to return the hood to Adorama, if they will accept it back. I'll then look for a 72mm screw-in hood. I like the bayonet mounted hoods as they leave the filter ring available for filter mounting without having to unmount the hood. Apparently the specs on this hood did change a hair so that it would fit the front ring on the DA 16-85mm lens.

Thanks for all your input and suggestions, guys.

Stan

**mikesbike** · 01-17-2021, 06:42 PM

Definitely not the same hood. I agree regarding the bayonet hoods being so much more convenient. I have a few older, but very fine-performing Pentax AF lenses that have no hoods so I have to use screw-ins. Feel comforted that the high-class FA 43mm Ltd is designed with its own dedicated...screw-in hood! Actually, I use that hood on my excellent sans-hood FA 28mm f/2.8 when coupled with an APS-C DSLR body, where the FOV will be the same as the 43mm on a film or FF DSLR. Perhaps Adorama will be able to help you in obtaining a screw-in hood of the proper design for this lens. If you are using it on an APS-C body, the hood design will need to be different anyway, as there will be no wide angle aspect to the FOV.

**UncleVanya** · 01-19-2021, 08:18 AM

There are some screw in hood that permit adding a filter while the hood is mounted. Good luck finding one that is the right proportion. I have an FA* 300 with a hood that fits too loosely. So I’m looking at screw in hoods myself.(67mm)

**StanMac** · 01-21-2021, 01:53 PM - **1 Like**

Solution found - I ordered a used PH-RBA72 hood on eBay from Blue Moon Camera that was specified for the 28-200mm lens and it arrived today (from the West Coast to middle Tennessee in 3 days!). It fits perfectly. So it is confirmed that the specs on that model of lens hood did change since it was introduced for the 28-200mm lens. One would think that a change in a product that made it unusable in it's initial use would have had at least a suffix added to the model number so it would be known that it was different.

Stan

**mikesbike** · 01-21-2021, 04:19 PM

Wow! Good for you in discovering such a rare find!

Originally posted by StanMac

One would think that a change in a product that made it unusable in it's initial use would have had at least a suffix added to the model number so it would be known that it was different.

Absolutely!

01-15-2021, 11:58 AM	#1
StanMac Site Supporter Join Date: Nov 2018 Posts: 207	PH-RBA72 Hood I won a SMC PENTAX-FA 1:3.8-5.6 28-200MM IF&AL lens in an online auction but it didn't have a lens hood for it. I've seen this lens in for sale ads on fleabay with the PH-RBA72 included and it was shown as compatible with this lens in an online search. Consequently, I ordered a black one from Adorama (mine is the all black version of the lens). However, I cannot get the hood to turn into place on the lens. When I set the hood on the lens where it will be in position for turning (the hood flanges are lined up with the lens' slots), it will not turn to the lock position. I don't want to force it and possibly damage the flanges on the hood or lens. Did Pentax change the flange configuration on this hood to work with a later lens? B&H Photo shows this hood as being "For DA 16-85mm F3.5-5.6 ED DC WR Lens." Thanks for any guidance or help you can provide. Stan Last edited by StanMac; 01-15-2021 at 12:37 PM. Reason: Correction in referring to Adorama in the online search

01-17-2021, 06:42 PM	#6
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	Definitely not the same hood. I agree regarding the bayonet hoods being so much more convenient. I have a few older, but very fine-performing Pentax AF lenses that have no hoods so I have to use screw-ins. Feel comforted that the high-class FA 43mm Ltd is designed with its own dedicated...screw-in hood! Actually, I use that hood on my excellent sans-hood FA 28mm f/2.8 when coupled with an APS-C DSLR body, where the FOV will be the same as the 43mm on a film or FF DSLR. Perhaps Adorama will be able to help you in obtaining a screw-in hood of the proper design for this lens. If you are using it on an APS-C body, the hood design will need to be different anyway, as there will be no wide angle aspect to the FOV. Last edited by mikesbike; 01-18-2021 at 01:00 PM.

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01-15-2021, 03:08 PM	#2
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	I have this lens and its original hood. I keep it on my Pentax PZ-1p 35mm film body, where it saw most of its use, and it rarely sees action over these many years, since I first became fully satisfied with DSLR performance starting with my 3rd model, the K200D. The hood model you give is the correct one. The 72 part has to do with the lens's filter size. But the flanges should match perfectly. Mine has two white marks on the top surface along the edge of the rim to guide mounting. The smaller of the two marks is at the side, while the larger is centered at the top. There is also a similar white mark on the lens's top side at the front edge. So, to install the hood for shooting, you line up the mark on the hood's side with that on the lens, then turn until the mark on top of the hood lines up with that on the lens. I don't get a click on mine- it just stops when the marks are lined up. For storage, you do the opposite. Reverse the lens, lining up the mark on top of the hood with that of the lens's front edge, then turn until the smaller mark on the hood's left side is lined up with the lens's frontal mark. So it stores with the hood in reversed position with its side upward.

01-15-2021, 04:29 PM	#3
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	I'm not 100% certain that Pentax hasn't reused the same part number. The older lens (28-200) was a 3rd party designed lens and the pictures I see of the hood don't look identical to the hood for the DA 16-85 yet they both have the same part number. @mikesbike do you have a 16-85 to try swapping the hoods with? Maybe you could take some dimensions if you don't - the petal shape of the original 28-200 hood doesn't look the same to me as the 16-85 hood.

01-16-2021, 05:05 AM	#4
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	I'm afraid I passed on the DA 16-85mm lens. But I cannot imagine the same part number would be reused if it were not the same! I guess stranger things have happened! Yes, the old FA 28-200mm was a rebadged Tamron, with some differences, perhaps in the hood also. Historically, this old lens was the first ever zoom lens going out to 200mm that could focus at the closer distance this one can. What is stranger to me is the APS-C equivalent is off enough to make me question that the hoods should be the same. The most critical would be the wide end of 16mm being like 24mm on FF, not 28mm. My DA 18-135mm is much more like the FA 28-200mm FF model in its angle of view, but does not take a 72mm filter size- it is much smaller and takes a smaller hood. I just checked a photo of the DA 16-85mm with its hood on, and you are right- it does not look the same. And I see no marks on it for guidance in mounting the hood. My old hood appears to be deeper along the top. I measure exactly 2 inches from the tip along the top to where it fits against the camera body. It also does not have PENTAX printed on it. so perhaps my hood is also a Tamron clone, although I do know the lens coatings are different. Evidently the opening is the same, as the OP says the hood obtained fits onto the lens but the flanges do not engage. Could be a flange design difference. If that is true, having the same part number is indeed a mistake, and why? At least put a -B after the number! Last edited by mikesbike; 01-16-2021 at 05:41 AM.

01-17-2021, 02:06 PM	#5
StanMac Site Supporter Join Date: Nov 2018 Posts: 207 Original Poster	Thank you all for your responses. Placing the hood on the lens, with the hood's index mark turned 90 degrees CCW (facing the camera) from the lens's index mark, the hood flanges slip into the slots on the lens front ring, as it should (visually verified by looking at the assembly from the front of the lens). Then turning the hood CW the hood flanges jam against the flanges on the lens's front ring. The hood will not mount in the stored position either, even though separate flanges on the hood are used in that position. It appears as if the hood's flanges are too thick to slide into the groove behind the lens's flanges. I measured the hood flanges with my digital caliper and they measured 1.45 - 1.47mm. The inside measuring points on my caliper are too wide to fit into the grooves on the lens, so I couldn't get an inside measurement on the grooves and I don't have any feeler gauges to use to measure the groove, so I don't know what the interference amount would be. I do believe the hood flange thickness is the issue. It would be a time consuming effort to try to thin down the hood's flanges all along their extremely narrow surface and length. So, I'm going to return the hood to Adorama, if they will accept it back. I'll then look for a 72mm screw-in hood. I like the bayonet mounted hoods as they leave the filter ring available for filter mounting without having to unmount the hood. Apparently the specs on this hood did change a hair so that it would fit the front ring on the DA 16-85mm lens. Thanks for all your input and suggestions, guys. Stan

01-19-2021, 08:18 AM	#7
UncleVanya Loyal Site Supporter Join Date: Jul 2014 Photos: Gallery \| Albums Posts: 28,404	There are some screw in hood that permit adding a filter while the hood is mounted. Good luck finding one that is the right proportion. I have an FA* 300 with a hood that fits too loosely. So I’m looking at screw in hoods myself.(67mm)

01-21-2021, 01:53 PM - 1 Like	#8
StanMac Site Supporter Join Date: Nov 2018 Posts: 207 Original Poster	Solution found - I ordered a used PH-RBA72 hood on eBay from Blue Moon Camera that was specified for the 28-200mm lens and it arrived today (from the West Coast to middle Tennessee in 3 days!). It fits perfectly. So it is confirmed that the specs on that model of lens hood did change since it was introduced for the 28-200mm lens. One would think that a change in a product that made it unusable in it's initial use would have had at least a suffix added to the model number so it would be known that it was different. Stan

01-21-2021, 04:19 PM	#9
mikesbike Site Supporter Join Date: Dec 2016 Location: Southeastern Michigan Posts: 4,549	Wow! Good for you in discovering such a rare find! Originally posted by StanMac One would think that a change in a product that made it unusable in it's initial use would have had at least a suffix added to the model number so it would be known that it was different. Absolutely!